Interstellar travel

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and Li. Because fusion yields about 0.3–0.9% of the mass of the nuclear fuel as released energy, it is energetically more favorable than fission, which releases <0.1% of the fuel's mass-energy. The maximum exhaust velocities potentially energetically available are correspondingly higher than for fission, typically 4–10% of the speed of light. However, the most easily achievable fusion reactions release a large fraction of their energy as high-energy neutrons, which are a significant source of energy loss. Thus, although these concepts seem to offer the best (nearest-term) prospects for travel to the nearest stars within a (long) human lifetime, they still involve massive technological and engineering difficulties, which may turn out to be intractable for decades or centuries.

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better propulsion system. This is because a slow spacecraft would probably be passed by another mission sent later with more advanced propulsion (the incessant obsolescence postulate). In 2006, Andrew Kennedy calculated ideal departure dates for a trip to Barnard's Star using a more precise concept of the wait calculation where for a given destination and growth rate in propulsion capacity there is a departure point that overtakes earlier launches and will not be overtaken by later ones and concluded "an interstellar journey of 6 light years can best be made in about 635 years from now if growth continues at about 1.4% per annum", or approximately 2641 AD. It may be the most significant calculation for competing cultures occupying the galaxy.

1115:. In an ion engine, electric power is used to create charged particles of the propellant, usually the gas xenon, and accelerate them to extremely high velocities. The exhaust velocity of conventional rockets is limited to about 5 km/s by the chemical energy stored in the fuel's molecular bonds. They produce a high thrust (about 10 N), but they have a low specific impulse, and that limits their top speed. By contrast, ion engines have low force, but the top speed in principle is limited only by the electrical power available on the spacecraft and on the gas ions being accelerated. The exhaust speed of the charged particles range from 15 km/s to 35 km/s. 2154: 2145:. Although beyond current technological capabilities, a black hole starship offers some advantages compared to other possible methods. Getting the black hole to act as a power source and engine also requires a way to convert the Hawking radiation into energy and thrust. One potential method involves placing the hole at the focal point of a parabolic reflector attached to the ship, creating forward thrust. A slightly easier, but less efficient method would involve simply absorbing all the gamma radiation heading towards the fore of the ship to push it onwards, and let the rest shoot out the back. 486:

the craft. Various shielding methods to mitigate this problem have been proposed. Larger objects (such as macroscopic dust grains) are far less common, but would be much more destructive. The risks of impacting such objects and mitigation methods have been discussed in literature, but many unknowns remain. An additional consideration is that due the non-homogeneous distribution of interstellar matter around the Sun, these risks would vary between different trajectories. Although a high density interstellar medium may cause difficulties for many interstellar travel concepts,

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proposed technologies, travelers will have to spend up to 200 years traveling at 20% the speed of light to reach the best known destinations. Moreover, once the travelers arrive at their destination (by any means), they will not be able to travel down to the surface of the target world and set up a colony unless the atmosphere is non-lethal. The prospect of making such a journey, only to spend the rest of the colony's life inside a sealed habitat and venturing outside in a spacesuit, may eliminate many prospective targets from the list.

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missions. Instead, he envisions interstellar craft with extensive sails, propelled by laser light to about one-tenth the speed of light. It would take such a ship about 43 years to reach Alpha Centauri if it passed through the system without stopping. Slowing down to stop at Alpha Centauri could increase the trip to 100 years, whereas a journey without slowing down raises the issue of making sufficiently accurate and useful observations and measurements during a fly-by.

7377: 7388: 1363: 7768: 2521:, are projected to be realizable within the 21st century. It is alternatively possible to plan for uncrewed slow-cruising missions taking millennia to arrive. These probes would not be for human benefit in the sense that one can not foresee whether there would be anybody around on Earth interested in then back-transmitted science data. An example would be the Genesis mission, which aims to bring unicellular life, in the spirit of 1304: 8081: 1218:

perhaps 3%-5% of the speed of light. A nuclear pulse drive starship powered by fusion-antimatter catalyzed nuclear pulse propulsion units would be similarly in the 10% range and pure matter-antimatter annihilation rockets would be theoretically capable of obtaining a velocity between 50% and 80% of the speed of light. In each case saving fuel for slowing down halves the maximum speed. The concept of using a

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journey, and then decelerates for the second half, so that it arrives at the destination stationary relative to where it began. If this were performed with an acceleration similar to that experienced at the Earth's surface, it would have the added advantage of producing artificial "gravity" for the crew. Supplying the energy required, however, would be prohibitively expensive with current technology.

8069: 8057: 1339:, with a ship initial mass of ~1700 metric tons, and payload fraction above 10%. Although these are still far short of the requirements for interstellar travel on human timescales, the study seems to represent a reasonable benchmark towards what may be approachable within several decades, which is not impossibly beyond the current state-of-the-art. Based on the concept's 2.2% 1631:. With this proposal, this interstellar ship would, theoretically, be able to reach 10 percent the speed of light. It has also been proposed to use beamed-powered propulsion to accelerate a spacecraft, and electromagnetic propulsion to decelerate it; thus, eliminating the problem that the Bussard ramjet has with the drag produced during acceleration. 757:"Slow" interstellar missions (still fast by other standards) based on current and near-future propulsion technologies are associated with trip times starting from about several decades to thousands of years. These missions consist of sending a robotic probe to a nearby star for exploration, similar to interplanetary probes like those used in the 1570:), so the craft could theoretically accelerate to near the speed of light. The limitation is due to the fact that the reaction can only accelerate the propellant to 0.12c. Thus the drag of catching interstellar dust and the thrust of accelerating that same dust to 0.12c would be the same when the speed is 0.12c, preventing further acceleration. 1269:, which includes a prohibition on the detonation of any nuclear devices (even non-weapon based) in outer space. This treaty would, therefore, need to be renegotiated, although a project on the scale of an interstellar mission using currently foreseeable technology would probably require international cooperation on at least the scale of the 984:

capable of continuously generating around 1 g of acceleration (which is comfortable for humans), the ship could reach almost anywhere in the galaxy and return to Earth within 40 years ship-time (see diagram). Upon return, there would be a difference between the time elapsed on the astronaut's ship and the time elapsed on Earth.

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Astrophysicist Sten Odenwald stated that the basic problem is that through intensive studies of thousands of detected exoplanets, most of the closest destinations within 50 light years do not yield Earth-like planets in the star's habitable zones. Given the multitrillion-dollar expense of some of the

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states that a laser-powered interstellar sail ship could possibly be launched within 50 years, using new methods of space travel. "I think that ultimately we're going to do it, it's just a question of when and who," Landis said in an interview. Rockets are too slow to send humans on interstellar

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proposed a means for decelerating an interstellar craft with a light sail of 100 kilometers in the destination star system without requiring a laser array to be present in that system. In this scheme, a secondary sail of 30 kilometers is deployed to the rear of the spacecraft, while the large primary

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reactions, should conceivably be able to reach speeds of the order of 10% of that of light, based on energy considerations alone. In theory, a large number of stages could push a vehicle arbitrarily close to the speed of light. These would "burn" such light element fuels as deuterium, tritium, He, B,

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of 130 years. Later studies indicate that the top cruise velocity that can theoretically be achieved by a Teller-Ulam thermonuclear unit powered Orion starship, assuming no fuel is saved for slowing back down, is about 8% to 10% of the speed of light (0.08-0.1c). An atomic (fission) Orion can achieve

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opposite the engine's acceleration, and the universe ahead will appear to fall in that field, undergoing hyperbolic motion. As part of this, distances between objects in the direction of the ship's motion will gradually contract until the ship begins to decelerate, at which time an onboard observer's

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For example, a spaceship could travel to a star 32 light-years away, initially accelerating at a constant 1.03g (i.e. 10.1 m/s) for 1.32 years (ship time), then stopping its engines and coasting for the next 17.3 years (ship time) at a constant speed, then decelerating again for 1.32 ship-years,

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Proposed in 2019 by NASA scientist Dr. David Burns, the helical engine concept would use a particle accelerator to accelerate particles to near the speed of light. Since particles traveling at such speeds acquire more mass, it is believed that this mass change could create acceleration. According to

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allows a traveler to experience time more slowly, the closer their speed is to the speed of light. This apparent slowing becomes noticeable when velocities above 80% of the speed of light are attained. Clocks aboard an interstellar ship would run slower than Earth clocks, so if a ship's engines were

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We're going to have the Human Connectome Project map the human brain before the end of this century, I think. We're going to put the connectome on a laser beam and shoot it to the moon. In one second, our consciousness is on the moon. In 20 minutes we're on Mars, eight hours we're on Pluto, in four

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The energy requirements make interstellar travel very difficult. It has been reported that at the 2008 Joint Propulsion Conference, multiple experts opined that it was improbable that humans would ever explore beyond the Solar System. Brice N. Cassenti, an associate professor with the Department of

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ship acceleration, approaching 0.3 trillion watts per ton of ship mass), considering the large fraction of the energy that goes into penetrating gamma rays. Even assuming shielding was provided to protect the payload (and passengers on a crewed vehicle), some of the energy would inevitably heat the

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to create high-speed jets of fission fragments, which are ejected at speeds of up to 12,000 km/s (7,500 mi/s). With fission, the energy output is approximately 0.1% of the total mass-energy of the reactor fuel and limits the effective exhaust velocity to about 5% of the velocity of light.

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Nuclear-electric or plasma engines, operating for long periods at low thrust and powered by fission reactors, have the potential to reach speeds much greater than chemically powered vehicles or nuclear-thermal rockets. Such vehicles probably have the potential to power solar system exploration with

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through which the vehicle must pass is essential for the design of any interstellar space mission. A major issue with traveling at extremely high speeds is that due to the requisite high relative speeds and large kinetic energies, collisions with interstellar dust could cause considerable damage to

822:. Kaku also notes that a large number of nanoprobes would need to be sent due to the vulnerability of very small probes to be easily deflected by magnetic fields, micrometeorites and other dangers to ensure the chances that at least one nanoprobe will survive the journey and reach the destination. 2223:, that it is possible to modify spacetime in a way that allows a spaceship to travel with an arbitrarily large speed by a local expansion of spacetime behind the spaceship and an opposite contraction in front of it. Nevertheless, this concept would require the spaceship to incorporate a region of 2075:

Achieving start-stop interstellar trip times of less than a human lifetime require mass-ratios of between 1,000 and 1,000,000, even for the nearer stars. This could be achieved by multi-staged vehicles on a vast scale. Alternatively large linear accelerators could propel fuel to fission propelled

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in which the crew that arrives at the destination is descended from those who started the journey. Generation ships are not currently feasible because of the difficulty of constructing a ship of the enormous required scale and the great biological and sociological problems that life aboard such a

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Regardless of how it is achieved, a propulsion system that could produce acceleration continuously from departure to arrival would be the fastest method of travel. A constant acceleration journey is one where the propulsion system accelerates the ship at a constant rate for the first half of the

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From the viewpoint of the astronaut, onboard clocks seem to be running normally. The star ahead seems to be approaching at a speed of 0.87 light years per ship-year. The universe would appear contracted along the direction of travel to half the size it had when the ship was at rest; the distance

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has argued that an interstellar mission that cannot be completed within 50 years should not be started at all. Instead, assuming that a civilization is still on an increasing curve of propulsion system velocity and not yet having reached the limit, the resources should be invested in designing a

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system orbiting an ultra-cool dwarf star 40 light-years away from the Solar System. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water. The discovery sets a new record for greatest number of

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Moving at a speed close to the speed of light and encountering even a tiny stationary object like a grain of sand will have fatal consequences. For example, a gram of matter moving at 90% of the speed of light contains a kinetic energy corresponding to a small nuclear bomb (around 30kt TNT).

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reported observing a small apparent thrust from one such test, a result not since replicated. One of the designs is called EMDrive. In December 2002, Satellite Propulsion Research Ltd described a working prototype with an alleged total thrust of about 0.02 newtons powered by an 850 W

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has looked into various feasibility issues of crewed interstellar travel. Notable results of the project include an assessment of world ship system architectures and adequate population size. Its members continue to publish on crewed interstellar travel in collaboration with the

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and coming to a stop at the destination. After a short visit, the astronaut could return to Earth the same way. After the full round-trip, the clocks on board the ship show that 40 years have passed, but according to those on Earth, the ship comes back 76 years after launch.

761:. By taking along no crew, the cost and complexity of the mission is significantly reduced, as is the mass that needs to be accelerated, although technology lifetime is still a significant issue next to obtaining a reasonable speed of travel. Proposed concepts include 2617:

habitable-zone planets found around a single star outside the Solar System. All of these seven planets could have liquid water – the key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

3285: 999:(30,000 light years from Earth) and back in 40 years ship-time. But the speed according to Earth clocks will always be less than 1 light year per Earth year, so, when back home, the astronaut will find that more than 60 thousand years will have passed on Earth. 2246:. It is not known whether wormholes are possible in practice. Although there are solutions to the Einstein equation of general relativity that allow for wormholes, all of the currently known solutions involve some assumption, for example the existence of 837:

In crewed missions, the duration of a slow interstellar journey presents a major obstacle and existing concepts deal with this problem in different ways. They can be distinguished by the "state" in which humans are transported on-board of the spacecraft.

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to decelerate the spacecraft as it approaches its destination has been discussed as an alternative to using propellant, this would allow the ship to travel near the maximum theoretical velocity. Alternative designs utilizing similar principles include

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in the quantities required and store it safely, it would be theoretically possible to reach speeds of several tens of percent that of light. Whether antimatter propulsion could lead to the higher speeds (>90% that of light) at which relativistic

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A few organisations dedicated to interstellar propulsion research and advocacy for the case exist worldwide. These are still in their infancy, but are already backed up by a membership of a wide variety of scientists, students and professionals.

1562:, and expel it out of the back. Later calculations with more accurate estimates suggest that the thrust generated would be less than the drag caused by any conceivable scoop design. Yet the idea is attractive because the fuel would be collected 2340:

has been researching interstellar travel since its formation, translating important foreign language papers and conducting early studies on applying fusion propulsion, in the 1960s, and laser propulsion, in the 1970s, to interstellar travel.

1331:, completed in 1988. Another fairly detailed vehicle system, "Discovery II", designed and optimized for crewed Solar System exploration, based on the DHe reaction but using hydrogen as reaction mass, has been described by a team from NASA's 2377:(100YSS) study was the name of a one-year project to assess the attributes of and lay the groundwork for an organization that can carry forward the 100 Year Starship vision. 100YSS-related symposia were organized between 2011 and 2015. 472:

2008 was 143,851 terawatt-hours), without factoring in efficiency of the propulsion mechanism. This energy has to be generated onboard from stored fuel, harvested from the interstellar medium, or projected over immense distances.

1235:. The principle of external nuclear pulse propulsion to maximize survivable power has remained common among serious concepts for interstellar flight without external power beaming and for very high-performance interplanetary flight. 1638:

could also decelerate at its destination without depending on carried fuel or a driving beam in the destination system, by interacting with the plasma found in the solar wind of the destination star and the interstellar medium.

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One of the major stumbling blocks is having enough Onboard Spares & Repairs facilities for such a lengthy time journey assuming all other considerations are solved, without access to all the resources available on Earth.

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sail is detached from the craft to keep moving forward on its own. Light is reflected from the large primary sail to the secondary sail, which is used to decelerate the secondary sail and the spacecraft payload. In 2002,

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from NASA's Johnson Space Center is a member of Icarus Interstellar, the nonprofit foundation whose mission is to realize interstellar flight before the year 2100. At the 2012 meeting of 100YSS, he reported using a

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Speculating that production and storage of antimatter should become feasible, two further issues need to be considered. First, in the annihilation of antimatter, much of the energy is lost as high-energy

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would become more noticeable, thus making time pass at a slower rate for the travelers as perceived by an outside observer, is doubtful owing to the large quantity of antimatter that would be required.

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From the perspective of a planetary observer, the ship will appear to accelerate steadily at first, but then more gradually as it approaches the speed of light (which it cannot exceed). It will undergo

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A system which boasts seven Earth-like planets, some of which may have liquid water. The discovery is a major advancement in finding a habitable planet and in finding a planet that could support life.

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In 1994, NASA and JPL cosponsored a "Workshop on Advanced Quantum/Relativity Theory Propulsion" to "establish and use new frames of reference for thinking about the faster-than-light (FTL) question".

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would actually be available if the antimatter were simply allowed to annihilate into radiations thermally. Even so, the energy available for propulsion would be substantially higher than the ~1% of

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When the ship reaches its destination, if it were to exchange a message with its origin planet, it would find that less time had elapsed on board than had elapsed for the planetary observer, due to

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Thus, for interstellar rocket concepts of all technologies, a key engineering problem (seldom explicitly discussed) is limiting the heat transfer from the exhaust stream back into the vehicle.

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Engineering and Science at Rensselaer Polytechnic Institute, stated that at least 100 times the total energy output of the entire world would be required to send a probe to the nearest star.

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proposed that a matter-antimatter GeV gamma ray laser photon rocket is possible by a relativistic proton-antiproton pinch discharge, where the recoil from the laser beam is transmitted by the

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Landis, Geoffrey A. (2003). "The Ultimate Exploration: A Review of Propulsion Concepts for Interstellar Flight". In Yoji Kondo; Frederick Bruhweiler; John H. Moore, Charles Sheffield (eds.).

2354:(terminated in FY 2003 after a 6-year, $ 1.2-million study, because "No breakthroughs appear imminent.") identified some breakthroughs that are needed for interstellar travel to be possible. 1094:, the ratio of thrust to total vehicle mass, is required to reach interstellar targets within sub-century time-frames. Some heat transfer is inevitable, resulting in an extreme thermal load. 1157:

For maximum velocity, the reaction mass should optimally consist of fission products, the "ash" of the primary energy source, so no extra reaction mass need be bookkept in the mass ratio.

6299: 4953: 121:, they are not "interstellar craft" because they are not purposefully designed to explore other star systems. Thus, as of the 2020s, interstellar spaceflight remains a popular trope in 4462: 3081:

Kennedy, A., "The Wait Calculation: The Broader Consequences of the minimum time from now to interstellar destinations and its significance to the space economy". JBIS, 66:96-109, 2013

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Scientists and authors have postulated a number of ways by which it might be possible to surpass the speed of light, but even the most serious-minded of these are highly speculative.

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term in the kinetic energy formula, millions of times as much energy is required. Accelerating one ton to one-tenth of the speed of light requires at least 450 petajoules or 4.50

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The velocity for a crewed round trip of a few decades to even the nearest star is several thousand times greater than those of present space vehicles. This means that due to the

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or particle accelerator in the home star system could potentially reach even greater speeds than rocket- or pulse propulsion methods, because it would not need to carry its own

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A system of at least two planets, with a super-Earth lying in the zone around the star where liquid water could exist, making it a possible candidate for the presence of life.

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Near-lightspeed nano spacecraft might be possible within the near future built on existing microchip technology with a newly developed nanoscale thruster. Researchers at the

321:, has covered 1/390 of a light-year in 46 years and is currently moving at 1/17,600 the speed of light. At this rate, a journey to Proxima Centauri would take 75,000 years. 1419:

would have a far higher energy density and specific impulse than any other proposed class of rocket. If energy resources and efficient production methods are found to make

949:. There may be ways to take advantage of these resources for a good part of an interstellar trip, slowly hopping from body to body or setting up waystations along the way. 6121: 3157: 1504:

A problem with all traditional rocket propulsion methods is that the spacecraft would need to carry its fuel with it, thus making it very massive, in accordance with the

1533:. The device could operate for only a few dozen seconds before the magnetron failed, due to overheating. The latest test on the EMDrive concluded that it does not work. 660:

similar to the Sun. High probability of possessing a Solar-System-type planetary system: current evidence shows four planets with potentially two in the habitable zone.

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A significant factor contributing to the difficulty is the energy that must be supplied to obtain a reasonable travel time. A lower bound for the required energy is the

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John G. Cramer; Robert L. Forward; Michael S. Morris; Matt Visser; Gregory Benford; Geoffrey A. Landis (15 March 1995). "Natural Wormholes as Gravitational Lenses".

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Distances between the planets in the Solar System are often measured in astronomical units (AU), defined as the average distance between the Sun and Earth, some 1.5

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powered by the energy beamed to it from a base station laser. Lenard and Andrews proposed using a base station laser to accelerate nuclear fuel pellets towards a

3257: 1480:, could replace their internal energy source with an energy collector, potentially reducing the mass of the ship greatly and allowing much higher travel speeds. 4562: 2141:

A theoretical idea for enabling interstellar travel is to propel a starship by creating an artificial black hole and using a parabolic reflector to reflect its

1627:'s Glen Research center also proposed a laser-powered, propulsion, sail ship that would host a diamond sail (of a few nanometers thick) powered with the use of 398: 4031: 7093: 4531: 3271: 78:

and gas at such speeds can be catastrophic for the spacecraft. There are ways for crewed travel much slower, and thus circumvent human lifespan, by making a

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Smith, Cameron M (2014). "Estimation of a genetically viable population for multigenerational interstellar voyaging: Review and data for project Hyperion".

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is 1.6 times the size of Earth; it may have rocky terrain. It also sits within the 'Goldilocks' zone where it might be possible for liquid water to exist.

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If a spaceship could average 10 percent of light speed (and decelerate at the destination, for human crewed missions), this would be enough to reach

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C. R. Williams et al., 'Realizing "2001: A Space Odyssey": Piloted Spherical Torus Nuclear Fusion Propulsion', 2001, 52 pages, NASA Glenn Research Center

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on arrival is desired and cannot be achieved by any means other than the engines of the ship, then the lower bound for the required energy is doubled to

118: 2933: 1281: 1034:. The ship will be close to the speed of light after about a year of accelerating and remain at that speed until it brakes for the end of the journey. 6321: 3707: 1129:

reasonable trip times within the current century. Because of their low-thrust propulsion, they would be limited to off-planet, deep-space operation.

5043: 2681: 5200: 74:, requiring enormous energy. Communication with such interstellar craft will experience years of delay due to the speed of light. Collisions with 7424: 2879:

Crawford, I. A. (2011). "Project Icarus: A review of local interstellar medium properties of relevance for space missions to the nearest stars".

6289: 4943: 7555: 2860: 4470: 3798: 2348: 2337: 5001: 3614: 158:, the farthest human-made object from Earth, is 163 AU away, exiting the Solar System at a speed of 17 km/s (0.006% of the speed of light). 70:

To reach stars within reasonable amount of time (decades or centuries), an interstellar spacecraft must reach a significant fraction of the

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Existing astronomical technology is capable of finding planetary systems around these objects, increasing their potential for exploration.

6384:"Evaluation of Technological-Social and Political Projections for the Next 100-300 Years and the Implications for an Interstellar Mission" 5312: 4234: 547:

within 40 light years of the Sun, containing 81 visible stars. The following could be considered prime targets for interstellar missions:

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As a near-term solution, small, laser-propelled interstellar probes, based on current CubeSat technology were proposed in the context of

6047: 4260: 4213: 1130: 4860: 818:, a theoretical physicist, has suggested that clouds of "smart dust" be sent to the stars, which may become possible with advances in 4002:

Project Daedalus: The Propulsion System Part 1; Theoretical considerations and calculations. 2. REVIEW OF ADVANCED PROPULSION SYSTEMS

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Terrestrial and Extraterrestrial Space Dangers: Outer Space Perils, Rocket Risks and the Health Consequences of the Space Environment

2385: 1015:(10 m/s or about 1.0 ly/y) "felt" or proper-acceleration can go far, except for the problem of accelerating on-board propellant. 4619: 2686: 2602: 1209:

fraction. He computed an exhaust velocity of 15,000 km/s and a 100,000-tonne space vehicle able to achieve a 20,000 km/s

1020: 299:, hence the name). Light in a vacuum travels around 300,000 kilometres (186,000 mi) per second, so 1 light-year is about 9.461 110: 17: 5650: 639:

Single K2 star slightly smaller and colder than the Sun. It has two asteroid belts. It is also believed to host a gas giant (

7953: 7071: 6661: 5833: 5421:"Estimation of a genetically viable population for multigenerational interstellar voyaging: Review and data for project Hyperion" 4000: 2644: 2351: 1452:

Second, heat transfer from the exhaust to the vehicle seems likely to transfer enormous wasted energy into the ship (e.g. for 0.1

809: 490:, and some proposed concepts for decelerating interstellar spacecraft, would actually benefit from a denser interstellar medium. 6545: 6111: 3147: 2242:

are conjectural distortions in spacetime that theorists postulate could connect two arbitrary points in the universe, across an

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Yagasaki, Kazuyuki (2008). "Invariant Manifolds And Control Of Hyperbolic Trajectories On Infinite- Or Finite-Time Intervals".

2123:(potentially along with AI or uploaded humans), or an alien civilization (which might also be in a different galaxy, perhaps a 1558:, a fusion rocket in which a huge scoop would collect the diffuse hydrogen in interstellar space, "burn" it on the fly using a 1521: 303:

10 kilometers (5.879 trillion miles) or 63,241 AU. Hence, Proxima Centauri is approximately 4.243 light-years from Earth.

4365: 6651: 6586: 6508: 6485: 6466: 6447: 6424: 5292: 4747: 4450: 4168: 3864: 3841: 3782: 2995: 1246:, in this case producing fusion explosions via compressing fusion fuel pellets with high-powered electron beams. Since then, 4500: 3676: 3344: 3239: 2454:, crewed spacecraft that would combine beamed-powered propulsion, electromagnetic propulsion, and nuclear propulsion (2020). 1380: 1073:, which sets the characteristic velocity available as a function of exhaust velocity and mass ratio, the ratio of initial ( 5904: 5857: 4200: 3929: 961:

in forty years. Several propulsion concepts have been proposed that might be eventually developed to accomplish this (see

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The crew of an interstellar ship would face several significant hazards, including the psychological effects of long-term

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concerns: travel faster than light may, under certain conditions, permit travel backwards in time within the context of

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Another way of understanding the vastness of interstellar distances is by scaling: One of the closest stars to the Sun,

6671: 2397: 2314: 1194: 2317:, based on the ideas of Robert Duncan-Enzmann. The spacecraft itself as proposed used a 12,000,000 ton ball of frozen 6691: 4822:

Roger X. Lenard; Ronald J. Lipinski (2000). "Interstellar rendezvous missions employing fission propulsion systems".

4554: 4296: 3434: 2836: 2788:"Simulating the Compton-Getting Effect for Hydrogen Flux Measurements: Implications for IBEX-Hi and -Lo Observations" 1402: 5519: 4302: 7911: 7799: 4024: 3124: 3096: 1559: 6202:

Gros, Claudius (5 September 2016). "Developing ecospheres on transiently habitable planets: the genesis project".

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engines, i.e. driven by a series of nuclear explosions. This propulsion system contains the prospect of very high

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to one meter (3.28 ft). On this scale, the distance to Alpha Centauri A would be 276 kilometers (171 miles).

6846: 5627: 3375: 2697: 2525:, to habitable but otherwise barren planets. Comparatively slow cruising Genesis probes, with a typical speed of 2439: 2309: 2281: 2276: 826: 770: 5808: 5680: 5485: 7410: 7221: 7083: 6666: 6322:"Release 17-015: NASA Telescope Reveals Largest Batch of Earth-Size, Habitable-Zone Planets Around Single Star" 6256: 5711: 3541: 2650: 1384: 1316: 1031: 6530: 5339: 4706: 3477: 2967: 1179:

Based on work in the late 1950s to the early 1960s, it has been technically possible to build spaceships with

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Interstellar space is not completely empty; it contains trillions of icy bodies ranging from small asteroids (

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Crawford, Ian A. (1995). "Some thoughts on the implications of faster-than-light interstellar space travel".

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At higher speeds, the time on board will run even slower, so the astronaut could travel to the center of the

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The following table lists some example concepts using beamed laser propulsion as proposed by the physicist

5035: 4327:

Winterberg, F. (21 August 2012). "Matter–antimatter gigaelectron volt gamma ray laser rocket propulsion".

2119:. This requires a receiver at the destination which would first have to be set up e.g. by humans, probes, 7906: 7792: 7199: 7035: 6782: 6629: 2556: 2153: 1270: 1243: 310:(a Sun-like star that is one of two companions of Proxima Centauri), can be pictured by scaling down the 122: 8035: 7829: 7743: 7679: 7271: 7040: 6713: 5196: 4824: 3923:

VISTA – A Vehicle for Interplanetary Space Transport Application Powered by Inertial Confinement Fusion

2665: 2635: 1012: 812:. These devices act like small particle accelerators shooting conductive nanoparticles out into space. 5640:

Malik, Tariq, "Sex and Society Aboard the First Starships." Science Tuesday, Space.com March 19, 2002.

5420: 7726: 7686: 7194: 7076: 6814: 6579: 4555:"NASA Engineer Claims 'Helical Engine' Concept Could Reach 99% The Speed of Light Without Propellant" 3410: 3185: 2243: 2120: 1258:

and hyper-kinetic projectiles have been suggested to produce nuclear pulses for propulsion purposes.

904: 657: 5165: 2483:

Tennessee Valley Interstellar Workshop (TVIW), business name Interstellar Research Group (IRG) (USA)

7943: 7588: 7545: 7540: 7448: 7309: 6809: 6797: 6769: 6478:

Making Starships and Stargates: The Science of Interstellar Transport and Absurdly Benign Wormholes

5969: 2451: 1180: 1166: 469: 83: 4370:. Conference on Practical Robotic Interstellar Flight. NY University, New York, NY. Archived from 3805: 7916: 7691: 7664: 7525: 7507: 7313: 7249: 7028: 6930: 6841: 6745: 6718: 6619: 5681:"Icarus Interstellar – A nonprofit foundation dedicated to achieving interstellar flight by 2100" 2627: 2609: 2182: 2181:

It is also debatable whether faster-than-light travel is physically possible, in part because of

1373: 1266: 1149: 284: 87: 6021: 2756: 1853: 965:

below), but none of them are ready for near-term (few decades) developments at acceptable cost.

510:

to the muscles, joints, bones, immune system, and eyes. There also exists the risk of impact by

8012: 7844: 7701: 7696: 7669: 7470: 7361: 7323: 6757: 6676: 6614: 5308: 5160: 4226: 3833: 801: 6358: 5943: 5587: 8022: 7981: 7948: 7921: 7875: 7627: 7517: 7433: 7211: 7018: 6656: 4257:"ALPHA Stores Antimatter Atoms Over a Quarter of an Hour – and Still Counting - Berkeley Lab" 3563:

Bond, A.; Martin, A.R. (1984). "World Ships – An Assessment of the Engineering Feasibility".

3042: 2691: 2518: 2445: 2361: 2322: 1517: 1461: 1457:

vehicle, and may thereby prove a limiting factor if useful accelerations are to be achieved.

1335:. It achieves characteristic velocities of >300 km/s with an acceleration of ~1.7•10 1332: 1255: 1188: 1091: 778: 6225: 4256: 2985: 992:

between that star and the Sun would seem to be 16 light years as measured by the astronaut.

407: 7976: 7926: 7839: 7674: 7637: 7617: 7380: 7281: 7264: 6901: 6836: 6829: 6686: 6572: 6395: 6370: 6221: 6166: 5792: 5750: 5432: 5370: 5241: 5221: 5152: 5104: 5077: 4915: 4833: 4786: 4593: 4401: 4387:"Use of Mini-Mag Orion and superconducting coils for near-term interstellar transportation" 4338: 4118: 4104:"Use of Mini-Mag Orion and superconducting coils for near-term interstellar transportation" 4067: 3749: 3668: 3572: 3469: 3204: 3057: 3023: 2898: 2799: 2639: 2528: 1171: 1137:, producing only small accelerations, would take centuries to reach for example 15% of the 440: 5133:

Alcubierre, Miguel (1994). "The warp drive: hyper-fast travel within general relativity".

4765:"Optimized trajectories to the nearest stars using lightweight high-velocity photon sails" 2124: 1201:

proposed in 1968 an interstellar spacecraft using nuclear pulse propulsion that used pure

643:), possibly another smaller planet, and may possess a Solar-System-type planetary system. 318: 8: 8085: 7885: 7731: 7706: 7485: 7254: 7189: 6908: 6752: 6116: 2671: 2631: 2522: 2474: 2136: 1038: 880: 527: 482: 6399: 6374: 6170: 5796: 5754: 5436: 5396:

Hein, Andreas M.; Pak, Mikhail; Pütz, Daniel; Bühler, Christian; Reiss, Philipp (2012).

5374: 5245: 5156: 5108: 5081: 4919: 4837: 4790: 4597: 4405: 4342: 4122: 4071: 3753: 3672: 3576: 3473: 3208: 3061: 3027: 2902: 2803: 2325:

is tall and assembled in-orbit, the spacecraft was part of a larger project preceded by

1465: 165:, is approximately 268,332 AU away, or over 9,000 times farther away than Neptune. 8073: 7880: 7849: 7815: 7748: 7391: 7174: 7100: 6955: 6851: 6703: 6536: 6436: 6237: 6211: 6184: 6156: 5658: 5265: 5231: 5178: 5142: 4980: 4905: 4804: 4776: 3903: 3824: 3533: 3515: 3220: 3194: 2914: 2888: 2854: 2702: 2594: 2357: 2326: 2254:

argue that such wormholes might have been created in the early universe, stabilized by

2216: 2186: 2092: 1620: 1485: 1481: 1050: 926: 918: 808:

as propellant. Their technology is called "nanoparticle field extraction thruster", or

790: 752: 581: 503: 383: 114: 4006: 3216: 2812: 2787: 2388:

by 1 part in 10 million with the aim of helping to make interstellar travel possible.

1343:

fraction it could achieve a pure fusion product exhaust velocity of ~3,000 km/s.

129:. A civilization that mastered interstellar travel is called an interstellar species. 7387: 7346: 6986: 6881: 6856: 6802: 6792: 6609: 6542: 6504: 6497: 6481: 6462: 6443: 6420: 5397: 5288: 5257: 5174: 4808: 4743: 4584:

Forward, R.L. (1984). "Roundtrip Interstellar Travel Using Laser-Pushed Lightsails".

4446: 4329: 4292: 4164: 3956: 3907: 3837: 3778: 3537: 3265: 3244: 3224: 3180: 2991: 2961:

There and Back Again: A Layman's Guide to Ultra-Reliability for Interstellar Missions

2842: 2832: 2659: 2418: 2374: 2190: 2173: 2166: 2142: 1643: 1615: 1583: 1551: 1416: 1352: 1138: 1107: 922: 597: 531: 311: 99: 32: 6188: 5444: 5382: 5269: 4892:

Larrouturou, Mathias N.; Higgns, Andrew J.; Greason, Jeffrey K. (28 November 2022).

4413: 4350: 4130: 2910: 2053:

Successive assists at α Cen A and B could allow travel times to 75 yr to both stars.

1516:

A radio frequency (RF) resonant cavity thruster is a device that is claimed to be a

8049: 7960: 7854: 7716: 7632: 7535: 7259: 7088: 7045: 7011: 6976: 6913: 6866: 6708: 6412: 6241: 6229: 6174: 5800: 5758: 5550: 5542: 5440: 5378: 5249: 5182: 5170: 5112: 4923: 4841: 4794: 4601: 4409: 4371: 4346: 4126: 4075: 4020: 3895: 3525: 3249: 3212: 3119: 2906: 2807: 2598: 2424: 2412: 2403: 2298: 2212: 2206: 2162: 1530: 1328: 1320: 1312: 1239: 1228: 1224: 1202: 1184: 979:

Physicists generally believe faster-than-light travel is impossible. Relativistic

958: 861: 774: 762: 665: 589: 307: 292: 264: 162: 5825: 5543:"Report on the NASA/JPL Workshop on advanced quantum/relativity theory propulsion" 3858: 3091: 2918: 2197:

and, it is not known if it could be produced in sufficient quantities, if at all.

7936: 7304: 7204: 7157: 7055: 6996: 6981: 6935: 6918: 6824: 6819: 6549: 5861: 3657:"Embryo Space Colonisation to Overcome the Interstellar Time Distance Bottleneck" 3656: 2088: 2077: 1505: 1434: 1153: 1134: 1070: 853: 847: 758: 631: 126: 79: 5741:

Forward, R. L. (May–June 1985). "Starwisp – An ultra-light interstellar probe".

4188: 3922: 1280:

imparted to a rapidly accelerated spacecraft, cargo, and passengers inside (see

502:, the physiological effects of extreme acceleration, the effects of exposure to 7890: 7721: 7495: 7490: 7351: 7338: 7231: 7162: 7152: 7137: 7115: 7105: 7001: 6991: 6940: 6861: 6179: 6144: 6052: 5854: 4979:

Crane, Louis; Westmoreland, Shawn (2009). "Are Black Hole Starships Possible".

4928: 4893: 4799: 4764: 4025:"Nuclear Pulse Vehicle Study Condensed Summary Report (General Dynamics Corp.)" 3768: 2729: 2514: 2304: 2116: 2108: 1555: 1493: 1296: 1232: 1214: 819: 640: 585: 564: 544: 511: 507: 487: 330: 71: 37: 6416: 6233: 5874: 4680: 3899: 3183:(October 2014). "Disentangling Planets and Stellar Activity for Gliese 667C". 3043:"Interstellar Travel: The Wait Calculation and the Incentive Trap of Progress" 2846: 8095: 7753: 7465: 7299: 7216: 7147: 7110: 6950: 6871: 6735: 6730: 6294: 5253: 5116: 4492: 4058: 3975:

Dawn Of A New Era: The Revolutionary Ion Engine That Took Spacecraft To Ceres

2582: 2255: 2247: 2228: 2224: 2194: 1854:

Interstellar travel catalog to use photogravitational assists for a full stop

1635: 1607: 1599: 1425: 1292: 1219: 1198: 1046: 980: 974: 154:, the farthest planet from the Sun, is 29.8 AU away. As of January 20, 2023, 91: 3314:"Project Dragonfly: The case for small, laser-propelled, distributed probes" 8061: 8002: 7859: 7657: 7530: 7500: 7480: 7457: 7356: 7291: 6960: 6945: 6646: 6641: 6261: 5261: 4865: 3607:"Project Hyperion: The Hollow Asteroid Starship – Dissemination of an Idea" 3592:

Limits of Interstellar Flight Technology in Frontiers of Propulsion Science

3529: 1628: 1578: 1489: 946: 892: 874: 805: 573: 515: 401: 56: 4861:"'Dynamic Soaring' Trick Could Speed Spacecraft Across Interstellar Space" 3699: 3426: 3313: 3253: 2321:

to power 12–24 thermonuclear pulse propulsion units. Twice as long as the

1141:, thus unsuitable for interstellar flight during a single human lifetime. 7652: 7647: 7475: 7184: 7050: 6740: 6723: 6595: 6524: 5511: 4283: 3740:

Crawford, I. A. (1990). "Interstellar Travel: A Review for Astronomers".

3405: 3152: 1238:

In the 1970s the Nuclear Pulse Propulsion concept further was refined by

891:. Although neither is currently practical, they offer the possibility of 884: 815: 698: 690: 623: 75: 52: 7402: 5554: 4635:"The Radical Spacecraft That Could Send Humans to a Habitable Exoplanet" 4524:"The Latest Test on The 'Impossible' EM Drive Concludes It Doesn't Work" 2193:

travel within the theory of general relativity require the existence of

1542:

Burns, the spacecraft could theoretically reach 99% the speed of light.

105:

The benefit of interstellar travel includes detail surveys of habitable

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How to build a starship – and why we should start thinking about it now

3821: 2613: 1595: 1587: 1420: 1387: in this section. Unsourced material may be challenged and removed. 1112: 942: 895:

in which the passengers lie inert for the long duration of the voyage.

724: 280: 95: 64: 48: 5804: 5147: 4845: 4079: 4030:. U.S. Department of Commerce National Technical Information Service. 3148:"Astronomers Have Discovered The Closest Potentially Habitable Planet" 913:

interstellar mission carrying some number of frozen early stage human

7784: 7642: 7328: 7179: 6896: 6777: 6698: 6681: 5622: 3383: 2935:

Active Radiation Shielding Utilizing High Temperature Superconductors

2318: 2258:. The general theory of wormholes is discussed by Visser in the book 1858:

The following table is based on work by Heller, Hippke and Kervella.

996: 682: 606: 577: 296: 251: 238: 155: 150:, the closest planet to Earth is (at closest approach) 0.28 AU away. 106: 5762: 5688: 5197:"Ideas Based On What We'd Like To Achieve: Worm Hole transportation" 3503: 2653: – Cancer causing exposure to ionizing radiation in spaceflight 2448:, fleet of uncrewed interstellar probes, announced on 12 April 2016. 1362: 719:

A very young system possibly in the process of planetary formation.

40:, one of many possible methods that could serve to propel spacecraft 6383: 6216: 6161: 5778:"Near-Term Beamed Sail Propulsion Missions: Cosmos-1 and Sun-Diver" 5335: 5236: 5095:

Feinberg, G. (1967). "Possibility of faster-than-light particles".

4948: 4910: 4781: 4605: 3520: 3457: 3290:. Louisiana State University: ERIC Clearing House. 1977. p. 12 2829:

Outer Solar System : prospective energy and material resources

2734: 2585:. Uncrewed missions not for human benefit would hence be feasible. 2239: 2220: 1438: 1251: 930: 888: 674: 648: 499: 6290:"Should we seed life through the cosmos using laser-driven ships?" 5991: 5618:"Sailing to the Stars: Sex and Society Aboard the First Starships" 4985: 3199: 2893: 1037:

From the perspective of an onboard observer, the crew will feel a

279:

Because of this, distances between stars are usually expressed in

6558: 4821: 2601:, 4.2 light-years away, was announced. This is the nearest known 1277: 1210: 1007: 910: 518:. These risks represent challenges that have yet to be overcome. 224: 151: 5791:. Department of Physics, University of California, Irvine: 358. 5541:

Bennett, Gary; Forward, Robert; Frisbee, Robert (10 July 1995).

4463:"NASA Team Claims 'Impossible' Space Engine Works—Get the Facts" 4384: 4101: 3501: 1303: 576:(a G2 star). On August 24, 2016, the discovery of an Earth-size 8017: 7142: 7006: 6525:

Leonard David – Reaching for interstellar flight (2003) – MSNBC

5460:"How Many People Does It Take to Colonize Another Star System?" 1340: 1206: 914: 614: 288: 6564: 5775: 5712:"Warp Drive May Be More Feasible Than Thought, Scientists Say" 2508: 1476:

Rockets deriving their power from external sources, such as a

879:

Scientists and writers have postulated various techniques for

6112:"Interstellar Travel as Delusional Fantasy [Excerpt]" 4182: 4180: 1603: 1477: 1247: 283:(defined as the distance that light travels in vacuum in one 210: 147: 936: 8007: 6326: 4894:"Dynamic soaring as a means to exceed the solar wind speed" 4161:

The Release of Thermonuclear Energy by Inertial Confinement

4056:

Freeman J. Dyson (October 1968). "Interstellar Transport".

3766: 2705: – Hypothetical process of digitally emulating a brain 1624: 1525: 1324: 711: 572:

Closest system. Three stars (G2, K1, M5). Component A

184: 60: 8056: 4620:"Alpha Centauri: Our First Target for Interstellar Probes" 4493:"Roger SHAWYER -- EM Space Drive -- Articles & Patent" 4177: 7023: 1880: 1471: 1056:

The result is an impressively fast journey for the crew.

933:

and educational robots that would replace human parents.

197: 6143:

Kulkarni, Neeraj; Lubin, Philip; Zhang, Qicheng (2017).

5965: 4891: 4763:

Heller, René; Hippke, Michael; Kervella, Pierre (2017).

3458:"World Ships: Architectures & Feasibility Revisited" 2115:

could be transmitted with laser or radio signals at the

1610:

and therefore would only need to accelerate the craft's

1508:. Several concepts attempt to escape from this problem: 1449:

yield of nuclear fusion, the next-best rival candidate.

1042:

experience of the gravitational field will be reversed.

538: 6409:

Deep Space Propulsion: A Roadmap to Interstellar Flight

5935: 5398:"World ships—architectures & feasibility revisited" 5336:

World Ships – Architectures & Feasibility Revisited

4944:"Michio Kaku foretells humanity's extraordinary future" 3654: 3240:"ScienceShot: Older Vega Mature Enough to Nurture Life" 2707:

Pages displaying short descriptions of redirect targets

2655:

Pages displaying short descriptions of redirect targets

2442:, small laser-propelled interstellar probe (2013–2015). 2112: 82:. Hypothetical interstellar propulsion systems include 6145:"Relativistic Spacecraft Propelled by Directed Energy" 5966:"Pioneering Interstellar Flight - Tau Zero Foundation" 5549:. American Institute of Aeronautics and Astronautics. 5486:"Want to Colonize an Alien Planet? Send 40,000 People" 4186: 4019: 3777:. American Institute of Aeronautics and Astronautics. 3307: 3305: 2565: 346: 27:

Hypothetical travel between stars or planetary systems

8033: 6017: 5540: 4967:

years our consciousness has reached the nearest star.

3502:

Hein, A.M.; Smith, C.; Marin, F.; Staats, K. (2020).

2559: 2531: 2060:) of 8.6×10 gram m for a nominal graphene-class sail. 443: 410: 386: 338: 4762: 4740:

Interstellar Travel and Multi-Generation Space Ships

921:

requires, among other things, the development of an

6499:

Entering Space: Creating a Spacefaring Civilization

6363:

Quarterly Journal of the Royal Astronomical Society

6048:"Interstellar travel may remain in science fiction" 5577:

project at NASA Glenn Research Center, Nov 19, 2008

5070:

Quarterly Journal of the Royal Astronomical Society

5002:"Dark power: Grand designs for interstellar travel" 4737: 4363: 3742:

Quarterly Journal of the Royal Astronomical Society

3497: 3495: 3302: 2677:

List of artificial objects leaving the Solar System

2329:and telescopic observation of target star systems. 2103: 1781:51 years (including 5 years exploring star system) 917:is another theoretical possibility. This method of 119:

five uncrewed spacecraft have left our Solar System

63:, interstellar travel is not possible with current 6496: 6435: 6142: 5128: 5126: 3955: 3928:(Report). Lawrence Livermore National Laboratory. 3857:Crowell, Benjamin (2010). "4 (Force and motion)". 3823: 3822:Taylor, Edwin F.; Wheeler, John Archibald (1966). 3178: 3009: 3007: 2647: – Medical issues associated with spaceflight 2588: 2573: 2545: 1105:A type of electric propulsion, spacecraft such as 456: 426: 392: 372: 5395: 5036:"A Black Hole Engine That Could Power Spaceships" 4978: 4705:Zubrin, Robert; Martin, Andrew (11 August 1999). 3953: 3345:"The myths and reality about interstellar travel" 3270:: CS1 maint: DOI inactive as of September 2024 ( 2215:is based on an argument, within the framework of 8093: 5709: 5651:"Dr. Harold "Sonny" White – Icarus Interstellar" 4385:Lenard, Roger X.; Andrews, Dana G. (June 2007). 4102:Lenard, Roger X.; Andrews, Dana G. (June 2007). 4055: 3562: 3492: 3376:"Near-lightspeed nano spacecraft might be close" 2931: 2682:List of nearest terrestrial exoplanet candidates 2076:space-vehicles, avoiding the limitations of the 2056:Lightsail has a nominal mass-to-surface ratio (σ 929:, and advances in the field of fully autonomous 6461:. CreateSpace Independent Publishing Platform. 6359:"Interstellar Travel: A Review for Astronomers" 6257:"How to Jumpstart Life Elsewhere in Our Galaxy" 6041: 6039: 5905:"Solar One – a concept for interstellar travel" 5123: 3767:Parkinson, Bradford W.; Spilker, James J. Jr.; 3004: 2668: – Communication between planetary systems 2421:, fleet of uncrewed interstellar probes (1996). 317:The fastest outward-bound spacecraft yet sent, 5285:Lorentzian Wormholes: from Einstein to Hawking 2958: 2827:Badescu, Viorel; Zacny, Kris (28 April 2018). 1511: 291:(one parsec is 3.26 ly, the distance at which 7800: 7418: 6580: 6388:Journal of the British Interplanetary Society 5402:Journal of the British Interplanetary Society 5333: 5199:. NASA Glenn Research Center. 11 March 2015. 4673:Journal of the British Interplanetary Society 4663: 4583: 3661:Journal of the British Interplanetary Society 3638:Journal of the British Interplanetary Society 3565:Journal of the British Interplanetary Society 3462:Journal of the British Interplanetary Society 3237: 3050:Journal of the British Interplanetary Society 3016:Journal of the British Interplanetary Society 2763:. NASA Glenn Research Center. 11 March 2015. 2662: – Spaceflight with a crew or passengers 2612:had revealed seven Earth-size planets in the 2409:Starwisp, uncrewed interstellar probe (1985). 2400:, human crewed interstellar ship (1958–1968). 1496:spacecraft that ignites them for propulsion. 1276:Another issue to be considered, would be the 6531:NASA Breakthrough Propulsion Physics Program 6036: 5547:31st Joint Propulsion Conference and Exhibit 4704: 4664:Andrews, Dana G.; Zubrin, Robert M. (1990). 2826: 2694: – Method used to accelerate spacecraft 1265:nuclear-explosion-powered spacecraft is the 6045: 5334:Hein, Andreas; et al. (January 2012). 3920: 3594:. Progress in Astronautics and Aeronautics. 2509:Interstellar missions not for human benefit 2458: 2250:, which may be unphysical. However, Cramer 2148: 2063:Area of the Lightsail, about 10 m = (316 m) 1586:'s scheme for slowing down an interstellar 1261:A current impediment to the development of 7807: 7793: 7767: 7425: 7411: 6587: 6573: 6543:DARPA seeks help for interstellar starship 6459:Interstellar Travel: An Astronomer's Guide 6381: 6081:"Interstellar travel: Where should we go?" 5282: 5132: 5063: 5061: 4326: 4158: 3735: 3733: 3731: 3729: 3727: 3725: 2859:: CS1 maint: location missing publisher ( 2608:In February 2017, NASA announced that its 2433:, uncrewed interstellar probe (2009–2014). 2415:, uncrewed interstellar probe (1987–1988). 2406:, uncrewed interstellar probe (1973–1978). 2368: 1133:powered by a portable power-source, say a 1131:Electrically powered spacecraft propulsion 1118: 7432: 6215: 6178: 6160: 5776:Benford, James; Benford, Gregory (2003). 5235: 5164: 5146: 5033: 4984: 4927: 4909: 4798: 4780: 3519: 3198: 2990:. Bentham Science Publishers. p. 1. 2892: 2811: 2785: 2724: 2722: 2593:On August 24, 2016, Earth-size exoplanet 2563: 2066:Velocity up to 37,300 km s (12.5% c) 1403:Learn how and when to remove this message 1287: 937:Island hopping through interstellar space 137: 6475: 6456: 6356: 6254: 6078: 5309:"Icarus Interstellar – Project Hyperion" 5094: 5067: 4666:"Magnetic Sails and Interstellar Travel" 3885: 3832:. W.H. Freeman, San Francisco. pp. 3739: 3655:Crowl, A.; Hunt, J.; Hein, A.M. (2012). 3504:"World Ships: Feasibility and Rationale" 3014:Forward, Robert L. (1996). "Ad Astra!". 2878: 2687:List of potentially habitable exoplanets 2427:, human crewed interstellar ship (2009). 2152: 2130: 1577: 1302: 1175:Modern Pulsed Fission Propulsion Concept 1170: 1021:Space travel under constant acceleration 1006: 1002: 952: 832: 784: 746: 111:search for extraterrestrial intelligence 55:. Due to the vast distances between the 31: 7072:Effect of spaceflight on the human body 6433: 5933: 5740: 5509: 5058: 4632: 3856: 3722: 3697: 3589: 3342: 3311: 3040: 3013: 2645:Effect of spaceflight on the human body 2436:Sun-diver, uncrewed interstellar probe. 2352:Breakthrough Propulsion Physics Program 2159:Wormhole Induction Propelled Spacecraft 2098: 2070: 1545: 1069:All rocket concepts are limited by the 622:Large, very bright A1 star with a 373:{\displaystyle K={\tfrac {1}{2}}mv^{2}} 146:10 kilometers (93 million miles). 14: 8094: 7814: 7623:Differential technological development 7094:Psychological and sociological effects 6494: 6287: 5710:Moskowitz, Clara (17 September 2012). 5203:from the original on 24 September 2013 4503:from the original on 14 September 2019 4364:Landis, Geoffrey A. (29 August 1994). 4308:from the original on 10 September 2021 4281: 3867:from the original on 26 September 2022 3373: 2983: 2719: 2265: 1522:Advanced Propulsion Physics Laboratory 1499: 1472:Rockets with an external energy source 868: 476: 7788: 7406: 6568: 6302:from the original on 14 November 2017 6109: 6091:from the original on 22 February 2017 5998:from the original on 7 September 2022 5936:"Initiative For Interstellar Studies" 5457: 5418: 5360: 5342:from the original on 16 December 2021 5046:from the original on 22 November 2015 4999: 4956:from the original on 20 December 2021 4858: 4645:from the original on 11 December 2020 4633:Delbert, Caroline (9 December 2020). 4565:from the original on 30 November 2019 4552: 4534:from the original on 12 November 2019 4521: 4263:from the original on 6 September 2015 4203:from the original on 4 December 2017. 3935:from the original on 21 December 2016 3710:from the original on 18 November 2021 3480:from the original on 16 December 2021 3260:from the original on 4 December 2012. 3160:from the original on 14 February 2021 2874: 2872: 2870: 2303:The Enzmann starship, as detailed by 2157:Artist's depiction of a hypothetical 1346: 925:, the prior detection of a habitable 539:Prime targets for interstellar travel 481:A knowledge of the properties of the 6406: 6201: 6124:from the original on 18 January 2021 6060:from the original on 26 January 2009 5483: 4873:from the original on 6 December 2022 4189:"Feasibility of Interstellar Travel" 3455: 3437:from the original on 20 January 2013 3424: 3404: 1573: 1385:adding citations to reliable sources 1356: 1011:This plot shows a ship capable of 1- 7712:Future-oriented technology analysis 6537:Bibliography of Interstellar Flight 5915:from the original on 7 January 2023 5722:from the original on 17 August 2013 4553:Starr, Michelle (15 October 2019). 4237:from the original on 28 August 2015 3636:"Various articles on hibernation". 3427:"How Will Humans Fly to the Stars?" 2574:{\displaystyle 1000\,{\mbox{km/s}}} 2513:Explorative high-speed missions to 2469:Initiative for Interstellar Studies 2292: 2287:Initiative for Interstellar Studies 2270: 2200: 1144: 1123: 841: 741: 521: 506:, and the physiological effects of 24: 6803:Weather and environment monitoring 6350: 6288:Romero, James (13 November 2017). 6024:from the original on 23 April 2023 5972:from the original on 19 April 2018 5885:from the original on 28 April 2017 5836:from the original on 12 April 2016 5315:from the original on 20 April 2013 5034:Barribeau, Tim (4 November 2009). 5012:from the original on 26 April 2015 5000:Chown, Marcus (25 November 2009). 4469:. 21 November 2016. Archived from 4443:Non Rocket Space Launch and Flight 4285:Interstellar travel and antimatter 3982:from the original on 13 March 2015 3698:Gilster, Paul (12 February 2012). 3343:Nogrady, Bianca (4 October 2016). 3312:Gilster, Paul (5 September 2014). 2932:Westover, Shayne (27 March 2012). 2867: 2597:orbiting in the habitable zone of 2083: 1566:(commensurate with the concept of 1205:detonations with a very high fuel- 1064: 804:are developing thrusters that use 673:M3 red dwarf with the super-Earth 609:. Second closest to Solar System. 324: 25: 8118: 6518: 6334:from the original on 5 March 2017 6269:from the original on 18 June 2022 6255:Andersen, Ross (25 August 2016). 5743:Journal of Spacecraft and Rockets 5575:"Breakthrough Propulsion Physics" 5522:from the original on 30 June 2011 4707:"NIAC Study of the Magnetic Sail" 4187:D.F. Spencer; L.D. Jaffe (1963). 3679:from the original on 31 July 2020 3456:Hein, A. M.; et al. (2012). 3374:Wilson, Daniel H. (8 July 2009). 3355:from the original on 12 July 2017 3238:Croswell, Ken (3 December 2012). 2227:, or the hypothetical concept of 1536: 1323:, a student project sponsored by 898: 468:10 joules or 125 terawatt-hours ( 109:and distant stars, comprehensive 8079: 8067: 8055: 8043: 7766: 7386: 7376: 7375: 6314: 6281: 6248: 6195: 6136: 6103: 6072: 6010: 5984: 5958: 5946:from the original on 1 June 2015 5598:from the original on 7 July 2008 5512:"A Note on the Enzmann Starship" 4719:from the original on 24 May 2015 4367:Laser-powered Interstellar Probe 4037:from the original on 11 May 2010 3604: 3544:from the original on 16 May 2021 3324:from the original on 2 July 2018 3125:Extrasolar Planets Encyclopaedia 3097:Extrasolar Planets Encyclopaedia 2941:. NIAC Symposium. Archived from 2767:from the original on 8 July 2013 2519:Breakthrough Starshot initiative 2391: 2332: 2219:and without the introduction of 2104:Transmission of minds with light 1361: 1160: 968: 677:orbiting in the habitable zone. 6847:Space launch market competition 6594: 6079:Odenwald, Sten (2 April 2015). 6046:O'Neill, Ian (19 August 2008). 5927: 5897: 5867: 5848: 5818: 5769: 5734: 5703: 5673: 5643: 5610: 5580: 5568: 5534: 5503: 5477: 5451: 5445:10.1016/j.actaastro.2013.12.013 5412: 5389: 5383:10.1016/j.actaastro.2013.12.013 5354: 5327: 5301: 5276: 5215: 5189: 5088: 5027: 4993: 4972: 4936: 4898:Frontiers in Space Technologies 4885: 4859:Mcrae, Mike (6 December 2022). 4852: 4815: 4756: 4731: 4698: 4657: 4626: 4612: 4577: 4546: 4515: 4485: 4455: 4435: 4414:10.1016/j.actaastro.2007.01.052 4378: 4357: 4351:10.1016/j.actaastro.2012.07.001 4320: 4275: 4249: 4219: 4207: 4159:Winterberg, Friedwardt (2010). 4152: 4131:10.1016/j.actaastro.2007.01.052 4095: 4086: 4049: 4013: 3993: 3966: 3947: 3914: 3879: 3850: 3791: 3760: 3700:"'Island-Hopping' to the Stars" 3691: 3648: 3629: 3598: 3583: 3556: 3449: 3425:Hein, Andreas (17 April 2012). 3418: 3398: 3367: 3336: 3278: 3231: 3172: 3140: 3112: 3084: 3075: 3034: 2959:Garrett, Henry (30 July 2012). 2911:10.1016/j.actaastro.2010.10.016 2698:Space travel in science fiction 2603:potentially-habitable exoplanet 2589:Discovery of Earth-like planets 2480:Limitless Space Institute (USA) 2277:Project Hyperion (interstellar) 2125:Kardashev type III civilization 1590:at the star system destination. 1372:needs additional citations for 1242:by use of externally triggered 962: 7084:Health threat from cosmic rays 6442:. John Wiley & Sons, Inc. 6204:Astrophysics and Space Science 5592:NASA Breakthrough Technologies 5510:Gilster, Paul (1 April 2007). 3256:(inactive 11 September 2024). 2977: 2952: 2925: 2820: 2779: 2749: 2651:Health threat from cosmic rays 2487: 2386:laser to try to warp spacetime 1317:British Interplanetary Society 605:Small, low-luminosity M5 47:is the hypothetical travel of 13: 1: 7739:Technology in science fiction 6382:Hein, A.M. (September 2012). 6018:"Interstellar Research Group" 5458:Fecht, Sarah (2 April 2014). 5135:Classical and Quantum Gravity 4622:– via go.galegroup.com. 3041:Kennedy, Andrew (July 2006). 2712: 2581:, can be decelerated using a 2307:in the October 1973 issue of 1100: 1059: 795: 267:(nearest star and exoplanet) 132: 7584:Laser communication in space 6110:Regis, Ed (3 October 2015). 4742:. Apogee Books. p. 52. 2313:, was a design for a future 2234: 2161:, based loosely on the 1994 1708:Rendezvous – Alpha Centauri 1560:proton–proton chain reaction 1441:, so that only about 40% of 1267:1963 Partial Test Ban Treaty 1080:, including fuel) to final ( 7: 7200:Self-replicating spacecraft 7036:International Space Station 5992:"Limitless Space Institute" 5879:breakthroughinitiatives.org 5484:Wall, Mike (28 July 2014). 4522:McRae, Mike (24 May 2018). 4227:"Storing antimatter - CERN" 3921:Orth, C. D. (16 May 2003). 3217:10.1088/2041-8205/793/2/L24 2813:10.1088/0004-637x/778/2/112 2620: 1512:RF resonant cavity thruster 1307:Daedalus interstellar probe 1271:International Space Station 1244:inertial confinement fusion 10: 8123: 7830:Interplanetary spaceflight 7744:Technology readiness level 7680:Technological unemployment 6714:Space Liability Convention 5875:"Breakthrough Initiatives" 5419:Smith, Cameron M. (2014). 5287:. AIP Press, Woodbury NY. 5175:10.1088/0264-9381/11/5/001 4929:10.3389/frspt.2022.1017442 4825:AIP Conference Proceedings 3954:Clarke, Arthur C. (1951). 2730:"Voyager - Mission Status" 2666:Interstellar communication 2605:outside our Solar System. 2296: 2274: 2204: 2189:. Proposed mechanisms for 2171: 2134: 2091:as a way to travel across 1350: 1213:allowing a flight-time to 1164: 1018: 972: 902: 872: 845: 788: 750: 493: 123:speculative future studies 7995: 7969: 7899: 7868: 7822: 7762: 7727:Technological singularity 7687:Technological convergence 7605: 7571: 7516: 7456: 7447: 7440: 7370: 7337: 7290: 7242: 7128: 7077:Space adaptation syndrome 7064: 6969: 6889: 6880: 6768: 6602: 6417:10.1007/978-1-4614-0607-5 6357:Crawford, Ian A. (1990). 6234:10.1007/s10509-016-2911-0 4679:: 265–272. Archived from 3900:10.1080/14689360802263571 3411:Physics of the Impossible 3186:The Astrophysical Journal 2553:, corresponding to about 2121:self replicating machines 1780: 1758:Crewed – Epsilon Eridani 1757: 1730: 1707: 1672:(% of the speed of light) 1582:This diagram illustrates 1437:, and especially also as 905:Embryo space colonization 483:interstellar gas and dust 7589:Orbital propellant depot 7546:Plasma propulsion engine 7541:Nuclear pulse propulsion 6810:Communications satellite 6476:Woodward, James (2013). 6434:Mallove, Eugene (1989). 6180:10.3847/1538-3881/aaafd2 6149:The Astronomical Journal 5860:3 September 2016 at the 5830:Breakthrough Initiatives 5785:Beamed Energy Propulsion 5254:10.1103/PhysRevD.51.3117 5117:10.1103/physrev.159.1089 4800:10.3847/1538-3881/aa813f 4769:The Astronomical Journal 4467:National Geographic News 4282:Rouaud, Mathieu (2020). 3958:The Exploration of Space 2984:Gibson, Dirk C. (2015). 2966:(Report). Archived from 2517:, as planned for by the 2459:Non-profit organizations 2149:Faster-than-light travel 1181:nuclear pulse propulsion 1167:Nuclear pulse propulsion 1150:Fission-fragment rockets 470:world energy consumption 161:The closest known star, 84:nuclear pulse propulsion 18:Interstellar spaceflight 7954:Trans-Neptunian objects 7692:Technological evolution 7665:Exploratory engineering 7526:Beam-powered propulsion 7508:Reusable launch vehicle 7314:reusable launch systems 6931:Extravehicular activity 6842:Commercial use of space 6746:Militarisation of space 6719:Registration Convention 6635:Accidents and incidents 6495:Zubrin, Robert (1999). 6457:Odenwald, Sten (2015). 6438:The Starflight Handbook 6226:2016Ap&SS.361..324G 5909:Innovation News Network 5826:"Breakthrough Starshot" 5023:(subscription required) 3825:"Chapter 1 Exercise 51" 2786:Zirnstein, E.J (2013). 2757:"A Look at the Scaling" 2626:Levels of spaceflight: 2610:Spitzer Space Telescope 2369:100 Year Starship study 1680:Flyby – Alpha Centauri 1119:Nuclear fission powered 1087:, fuel depleted) mass. 88:fission-fragment rocket 8013:National Space Society 7845:Planetary habitability 7702:Technology forecasting 7697:Technological paradigm 7670:Proactionary principle 7471:Non-rocket spacelaunch 7362:Mission control center 7324:Non-rocket spacelaunch 6758:Billionaire space race 5685:icarusinterstellar.org 5655:icarusinterstellar.org 4023:Corp. (January 1964). 3590:Frisbee, R.H. (2009). 3530:10.5281/zenodo.3747333 3120:"Planet eps Eridani c" 3092:"Planet eps Eridani b" 2575: 2547: 2381:Harold ("Sonny") White 2169: 1591: 1311:Early studies include 1308: 1295:starships, powered by 1288:Nuclear fusion rockets 1256:neutral particle beams 1176: 1016: 883:. These include human 802:University of Michigan 458: 428: 427:{\displaystyle mv^{2}} 400:is the final mass. If 394: 374: 138:Interstellar distances 41: 8023:The Planetary Society 7628:Disruptive innovation 7434:Emerging technologies 7212:Spacecraft propulsion 6662:European Space Agency 6407:Long, Kelvin (2012). 3774:18.2.2.1Time Dilation 3254:10.1126/article.26684 2831:. Cham, Switzerland. 2792:Astrophysical Journal 2692:Spacecraft propulsion 2576: 2548: 2546:{\displaystyle c/300} 2446:Breakthrough Starshot 2362:Glenn Research Center 2323:Empire State Building 2244:Einstein–Rosen Bridge 2156: 2131:Artificial black hole 1602:powered by a massive 1581: 1462:Friedwardt Winterberg 1333:Glenn Research Center 1306: 1174: 1010: 1003:Constant acceleration 953:Fast, crewed missions 833:Slow, crewed missions 785:Fast, uncrewed probes 779:Breakthrough Starshot 747:Slow, uncrewed probes 574:is similar to the Sun 530:writer and physicist 459: 457:{\displaystyle v^{2}} 429: 395: 375: 35: 8107:Spaceflight concepts 7970:Terraforming targets 7900:Colonization targets 7840:Intergalactic travel 7675:Technological change 7618:Collingridge dilemma 6837:Satellite navigation 6503:. Tarcher / Putnam. 6330:. 22 February 2017. 6085:Huffington Post Blog 4441:A. Bolonkin (2005). 4163:. World Scientific. 4092:Cosmos by Carl Sagan 3863:. Benjamin Crowell. 3771:; Enge, Per (2014). 3156:. 18 December 2015. 2948:on 11 February 2014. 2557: 2529: 2260:Lorentzian Wormholes 2109:Uploaded human minds 2099:Theoretical concepts 2071:Pre-accelerated fuel 1546:Interstellar ramjets 1381:improve this article 889:cryonic preservation 777:, and more recently 488:interstellar ramjets 441: 408: 384: 336: 8102:Interstellar travel 7835:Interstellar travel 7732:Technology scouting 7707:Accelerating change 7579:Interstellar travel 7222:Electric propulsion 6909:Life-support system 6793:Imagery and mapping 6753:Private spaceflight 6400:2012JBIS...65..330H 6375:1990QJRAS..31..377C 6171:2018AJ....155..155K 6117:Scientific American 5814:on 24 October 2014. 5797:2003AIPC..664..358B 5755:1985JSpRo..22..345F 5594:. 26 January 2009. 5588:"Warp Drive, When?" 5555:10.2514/6.1995-2599 5437:2014AcAau..97...16S 5375:2014AcAau..97...16S 5283:Visser, M. (1995). 5246:1995PhRvD..51.3117C 5230:(3117): 3117–3120. 5157:1994CQGra..11L..73A 5109:1967PhRv..159.1089F 5082:1995QJRAS..36..205C 4920:2022FrST....317442L 4838:2000AIPC..504.1544L 4791:2017AJ....154..115H 4598:1984JSpRo..21..187F 4473:on 12 November 2019 4406:2007AcAau..61..450L 4343:2012AcAau..81...34W 4123:2007AcAau..61..450L 4072:1968PhT....21j..41D 3962:. New York: Harper. 3799:"Clock paradox III" 3754:1990QJRAS..31..377C 3673:2012JBIS...65..283C 3611:Icarus Interstellar 3577:1984JBIS...37..254B 3474:2012JBIS...65..119H 3209:2014ApJ...793L..24R 3062:2006JBIS...59..239K 3028:1996JBIS...49...23F 2903:2011AcAau..68..691C 2804:2013ApJ...778..112Z 2672:Interstellar object 2638:, interstellar and 2523:directed panspermia 2475:Tau Zero Foundation 2327:interstellar probes 2266:Designs and studies 2137:Black hole starship 2095:has been proposed. 1518:spacecraft thruster 1500:Non-rocket concepts 1468:to the spacecraft. 1315:, performed by the 1039:gravitational field 881:suspended animation 869:Suspended animation 565:Alpha Centauri 543:There are 59 known 528:speculative fiction 477:Interstellar medium 45:Interstellar travel 7881:McKendree cylinder 7850:Space and survival 7816:Space colonization 7749:Technology roadmap 7175:Robotic spacecraft 7101:Space and survival 6956:Space colonization 6852:Space architecture 6704:Outer Space Treaty 6548:2014-03-04 at the 5855:Starshot – Concept 5691:on 2 December 2013 4686:on 12 October 2014 4374:on 2 October 2013. 4291:. Mathieu Rouaud. 3181:Mahadevan, Suvrath 3128:. 16 December 1995 3100:. 16 December 1995 2703:Uploaded astronaut 2595:Proxima Centauri b 2571: 2569: 2543: 2358:Geoffrey A. Landis 2217:general relativity 2187:special relativity 2170: 2093:interstellar space 1831:deceleration stage 1787:deceleration stage 1737:deceleration stage 1621:Geoffrey A. Landis 1592: 1486:interstellar probe 1482:Geoffrey A. Landis 1347:Antimatter rockets 1319:in 1973–1978, and 1309: 1177: 1051:length contraction 1017: 927:terrestrial planet 919:space colonization 791:Interstellar probe 753:Interstellar probe 584:) orbiting in the 582:Proxima Centauri b 504:ionising radiation 454: 424: 390: 370: 355: 312:Earth–Sun distance 227:(farthest planet) 115:space colonization 42: 8031: 8030: 7782: 7781: 7601: 7600: 7597: 7596: 7400: 7399: 7347:Flight controller 7124: 7123: 6882:Human spaceflight 6857:Space exploration 6783:Earth observation 6510:978-1-58542-036-0 6487:978-1-4614-5622-3 6468:978-1-5120-5627-3 6449:978-0-471-61912-3 6426:978-1-4614-0606-8 6394:(9/10): 330–340. 5832:. 12 April 2016. 5805:10.1063/1.1582124 5464:Popular Mechanics 5425:Acta Astronautica 5363:Acta Astronautica 5294:978-1-56396-394-0 5224:Physical Review D 4846:10.1063/1.1290979 4749:978-1-896522-99-9 4639:Popular Mechanics 4451:978-0-08-044731-5 4394:Acta Astronautica 4330:Acta Astronautica 4193:Astronautica Acta 4170:978-981-4295-91-8 4111:Acta Astronautica 4080:10.1063/1.3034534 3978:, 10 March 2015, 3888:Dynamical Systems 3843:978-0-7167-0336-5 3830:Spacetime Physics 3784:978-1-56347-106-3 3605:Hein, Andreas M. 3179:Robertson, Paul; 2997:978-1-60805-991-1 2881:Acta Astronautica 2660:Human spaceflight 2568: 2440:Project Dragonfly 2419:Starseed/launcher 2375:100 Year Starship 2191:faster-than-light 2174:Faster-than-light 2167:Miguel Alcubierre 2143:Hawking radiation 2050: 2049: 1851: 1850: 1670:Maximum Velocity 1644:Robert L. Forward 1616:Robert L. Forward 1584:Robert L. Forward 1574:Beamed propulsion 1568:energy harvesting 1552:Robert W. Bussard 1417:antimatter rocket 1413: 1412: 1405: 1353:Antimatter rocket 1139:velocity of light 1032:hyperbolic motion 923:artificial uterus 827:Project Dragonfly 771:Project Dragonfly 736: 735: 532:Robert L. Forward 393:{\displaystyle m} 354: 277: 276: 213:(nearest planet) 100:antimatter rocket 16:(Redirected from 8114: 8084: 8083: 8082: 8072: 8071: 8070: 8060: 8059: 8048: 8047: 8046: 8039: 7886:O'Neill cylinder 7855:Space settlement 7809: 7802: 7795: 7786: 7785: 7770: 7769: 7717:Horizon scanning 7633:Ephemeralization 7551:Helicon thruster 7536:Laser propulsion 7454: 7453: 7445: 7444: 7427: 7420: 7413: 7404: 7403: 7390: 7379: 7378: 7089:Space psychology 6914:Animals in space 6887: 6886: 6867:Space technology 6709:Rescue Agreement 6589: 6582: 6575: 6566: 6565: 6559:The Conversation 6514: 6502: 6491: 6472: 6453: 6441: 6430: 6403: 6378: 6344: 6343: 6341: 6339: 6318: 6312: 6311: 6309: 6307: 6285: 6279: 6278: 6276: 6274: 6252: 6246: 6245: 6219: 6199: 6193: 6192: 6182: 6164: 6140: 6134: 6133: 6131: 6129: 6107: 6101: 6100: 6098: 6096: 6076: 6070: 6069: 6067: 6065: 6043: 6034: 6033: 6031: 6029: 6014: 6008: 6007: 6005: 6003: 5988: 5982: 5981: 5979: 5977: 5962: 5956: 5955: 5953: 5951: 5931: 5925: 5924: 5922: 5920: 5901: 5895: 5894: 5892: 5890: 5871: 5865: 5852: 5846: 5845: 5843: 5841: 5822: 5816: 5815: 5813: 5807:. Archived from 5782: 5773: 5767: 5766: 5738: 5732: 5731: 5729: 5727: 5707: 5701: 5700: 5698: 5696: 5687:. Archived from 5677: 5671: 5670: 5668: 5666: 5657:. Archived from 5647: 5641: 5639: 5637: 5635: 5630:on 27 March 2009 5626:. Archived from 5614: 5608: 5607: 5605: 5603: 5584: 5578: 5572: 5566: 5565: 5563: 5561: 5538: 5532: 5531: 5529: 5527: 5507: 5501: 5500: 5498: 5496: 5481: 5475: 5474: 5472: 5470: 5455: 5449: 5448: 5416: 5410: 5409: 5393: 5387: 5386: 5358: 5352: 5351: 5349: 5347: 5331: 5325: 5324: 5322: 5320: 5305: 5299: 5298: 5280: 5274: 5273: 5239: 5219: 5213: 5212: 5210: 5208: 5193: 5187: 5186: 5168: 5150: 5130: 5121: 5120: 5103:(5): 1089–1105. 5092: 5086: 5085: 5065: 5056: 5055: 5053: 5051: 5031: 5025: 5024: 5021: 5019: 5017: 4997: 4991: 4990: 4988: 4976: 4970: 4969: 4963: 4961: 4952:. 2 March 2018. 4940: 4934: 4933: 4931: 4913: 4889: 4883: 4882: 4880: 4878: 4856: 4850: 4849: 4819: 4813: 4812: 4802: 4784: 4760: 4754: 4753: 4735: 4729: 4728: 4726: 4724: 4718: 4711: 4702: 4696: 4695: 4693: 4691: 4685: 4670: 4661: 4655: 4654: 4652: 4650: 4630: 4624: 4623: 4616: 4610: 4609: 4581: 4575: 4574: 4572: 4570: 4550: 4544: 4543: 4541: 4539: 4519: 4513: 4512: 4510: 4508: 4489: 4483: 4482: 4480: 4478: 4459: 4453: 4439: 4433: 4432: 4430: 4428: 4422: 4416:. Archived from 4400:(1–6): 450–458. 4391: 4382: 4376: 4375: 4361: 4355: 4354: 4324: 4318: 4317: 4315: 4313: 4307: 4290: 4279: 4273: 4272: 4270: 4268: 4253: 4247: 4246: 4244: 4242: 4231:home.web.cern.ch 4223: 4217: 4211: 4205: 4204: 4184: 4175: 4174: 4156: 4150: 4149: 4147: 4145: 4139: 4133:. Archived from 4117:(1–6): 450–458. 4108: 4099: 4093: 4090: 4084: 4083: 4053: 4047: 4046: 4044: 4042: 4036: 4029: 4021:General Dynamics 4017: 4011: 4010: 4005:, archived from 3997: 3991: 3990: 3989: 3987: 3970: 3964: 3963: 3961: 3951: 3945: 3944: 3942: 3940: 3934: 3927: 3918: 3912: 3911: 3883: 3877: 3876: 3874: 3872: 3860:Light and Matter 3854: 3848: 3847: 3827: 3820: 3818: 3816: 3810: 3804:. Archived from 3803: 3795: 3789: 3788: 3764: 3758: 3757: 3737: 3720: 3719: 3717: 3715: 3695: 3689: 3688: 3686: 3684: 3652: 3646: 3645: 3633: 3627: 3626: 3624: 3622: 3617:on 10 April 2013 3613:. Archived from 3602: 3596: 3595: 3587: 3581: 3580: 3560: 3554: 3553: 3551: 3549: 3523: 3499: 3490: 3489: 3487: 3485: 3453: 3447: 3446: 3444: 3442: 3422: 3416: 3415: 3402: 3396: 3395: 3393: 3391: 3386:on 15 April 2016 3382:. Archived from 3371: 3365: 3364: 3362: 3360: 3340: 3334: 3333: 3331: 3329: 3309: 3300: 3299: 3297: 3295: 3282: 3276: 3275: 3269: 3261: 3235: 3229: 3228: 3202: 3176: 3170: 3169: 3167: 3165: 3144: 3138: 3137: 3135: 3133: 3116: 3110: 3109: 3107: 3105: 3088: 3082: 3079: 3073: 3072: 3070: 3068: 3047: 3038: 3032: 3031: 3011: 3002: 3001: 2981: 2975: 2974: 2972: 2965: 2956: 2950: 2949: 2947: 2940: 2929: 2923: 2922: 2896: 2887:(7–8): 691–699. 2876: 2865: 2864: 2858: 2850: 2824: 2818: 2817: 2815: 2783: 2777: 2776: 2774: 2772: 2753: 2747: 2746: 2744: 2742: 2726: 2708: 2656: 2599:Proxima Centauri 2580: 2578: 2577: 2572: 2570: 2566: 2552: 2550: 2549: 2544: 2539: 2425:Project Valkyrie 2413:Project Longshot 2404:Project Daedalus 2299:Enzmann starship 2293:Enzmann starship 2282:Project Hyperion 2271:Project Hyperion 2213:Alcubierre drive 2211:In physics, the 2207:Alcubierre drive 2201:Alcubierre drive 1861: 1860: 1649: 1648: 1531:cavity magnetron 1488:propelled by an 1466:Mössbauer effect 1408: 1401: 1397: 1394: 1388: 1365: 1357: 1329:US Naval Academy 1321:Project Longshot 1313:Project Daedalus 1282:Inertia negation 1240:Project Daedalus 1229:Project Daedalus 1225:Project Longshot 1203:deuterium fusion 1185:specific impulse 1145:Fission-fragment 1124:Fission-electric 959:Proxima Centauri 862:interstellar ark 842:Generation ships 775:Project Longshot 763:Project Daedalus 742:Proposed methods 590:Proxima Centauri 550: 549: 522:Wait calculation 467: 463: 461: 460: 455: 453: 452: 433: 431: 430: 425: 423: 422: 399: 397: 396: 391: 379: 377: 376: 371: 369: 368: 356: 347: 308:Alpha Centauri A 302: 293:stellar parallax 265:Proxima Centauri 168: 167: 163:Proxima Centauri 145: 21: 8122: 8121: 8117: 8116: 8115: 8113: 8112: 8111: 8092: 8091: 8090: 8080: 8078: 8068: 8066: 8054: 8044: 8042: 8034: 8032: 8027: 7991: 7965: 7907:Lagrange points 7895: 7864: 7818: 7813: 7783: 7778: 7758: 7593: 7567: 7512: 7436: 7431: 7401: 7396: 7366: 7333: 7305:Escape velocity 7286: 7238: 7205:Space telescope 7158:Reentry capsule 7120: 7060: 6965: 6936:Overview effect 6919:Bioastronautics 6876: 6764: 6598: 6593: 6550:Wayback Machine 6527:(MSNBC Webpage) 6521: 6511: 6488: 6469: 6450: 6427: 6353: 6351:Further reading 6348: 6347: 6337: 6335: 6320: 6319: 6315: 6305: 6303: 6286: 6282: 6272: 6270: 6253: 6249: 6200: 6196: 6141: 6137: 6127: 6125: 6108: 6104: 6094: 6092: 6077: 6073: 6063: 6061: 6044: 6037: 6027: 6025: 6016: 6015: 6011: 6001: 5999: 5990: 5989: 5985: 5975: 5973: 5964: 5963: 5959: 5949: 5947: 5932: 5928: 5918: 5916: 5911:. 22 May 2020. 5903: 5902: 5898: 5888: 5886: 5873: 5872: 5868: 5862:Wayback Machine 5853: 5849: 5839: 5837: 5824: 5823: 5819: 5811: 5780: 5774: 5770: 5763:10.2514/3.25754 5739: 5735: 5725: 5723: 5708: 5704: 5694: 5692: 5679: 5678: 5674: 5664: 5662: 5649: 5648: 5644: 5633: 5631: 5616: 5615: 5611: 5601: 5599: 5586: 5585: 5581: 5573: 5569: 5559: 5557: 5539: 5535: 5525: 5523: 5516:Centauri Dreams 5508: 5504: 5494: 5492: 5482: 5478: 5468: 5466: 5456: 5452: 5417: 5413: 5394: 5390: 5359: 5355: 5345: 5343: 5332: 5328: 5318: 5316: 5307: 5306: 5302: 5295: 5281: 5277: 5220: 5216: 5206: 5204: 5195: 5194: 5190: 5166:10.1.1.338.8690 5131: 5124: 5097:Physical Review 5093: 5089: 5066: 5059: 5049: 5047: 5032: 5028: 5022: 5015: 5013: 4998: 4994: 4977: 4973: 4959: 4957: 4942: 4941: 4937: 4890: 4886: 4876: 4874: 4857: 4853: 4820: 4816: 4761: 4757: 4750: 4736: 4732: 4722: 4720: 4716: 4709: 4703: 4699: 4689: 4687: 4683: 4668: 4662: 4658: 4648: 4646: 4631: 4627: 4618: 4617: 4613: 4582: 4578: 4568: 4566: 4551: 4547: 4537: 4535: 4520: 4516: 4506: 4504: 4497:rexresearch.com 4491: 4490: 4486: 4476: 4474: 4461: 4460: 4456: 4440: 4436: 4426: 4424: 4423:on 17 June 2014 4420: 4389: 4383: 4379: 4362: 4358: 4325: 4321: 4311: 4309: 4305: 4299: 4288: 4280: 4276: 4266: 4264: 4259:. 5 June 2011. 4255: 4254: 4250: 4240: 4238: 4225: 4224: 4220: 4212: 4208: 4185: 4178: 4171: 4157: 4153: 4143: 4141: 4140:on 17 June 2014 4137: 4106: 4100: 4096: 4091: 4087: 4054: 4050: 4040: 4038: 4034: 4027: 4018: 4014: 4009:on 28 June 2013 3999: 3998: 3994: 3985: 3983: 3972: 3971: 3967: 3952: 3948: 3938: 3936: 3932: 3925: 3919: 3915: 3884: 3880: 3870: 3868: 3855: 3851: 3844: 3814: 3812: 3811:on 21 July 2017 3808: 3801: 3797: 3796: 3792: 3785: 3769:Axelrad, Penina 3765: 3761: 3738: 3723: 3713: 3711: 3704:Centauri Dreams 3696: 3692: 3682: 3680: 3653: 3649: 3644:: 81–144. 2006. 3635: 3634: 3630: 3620: 3618: 3603: 3599: 3588: 3584: 3561: 3557: 3547: 3545: 3500: 3493: 3483: 3481: 3454: 3450: 3440: 3438: 3431:Centauri Dreams 3423: 3419: 3414:. Anchor Books. 3403: 3399: 3389: 3387: 3372: 3368: 3358: 3356: 3341: 3337: 3327: 3325: 3318:Centauri Dreams 3310: 3303: 3293: 3291: 3284: 3283: 3279: 3263: 3262: 3236: 3232: 3177: 3173: 3163: 3161: 3146: 3145: 3141: 3131: 3129: 3118: 3117: 3113: 3103: 3101: 3090: 3089: 3085: 3080: 3076: 3066: 3064: 3045: 3039: 3035: 3012: 3005: 2998: 2982: 2978: 2970: 2963: 2957: 2953: 2945: 2938: 2930: 2926: 2877: 2868: 2852: 2851: 2839: 2825: 2821: 2784: 2780: 2770: 2768: 2755: 2754: 2750: 2740: 2738: 2728: 2727: 2720: 2715: 2706: 2654: 2623: 2591: 2564: 2558: 2555: 2554: 2535: 2530: 2527: 2526: 2511: 2490: 2461: 2394: 2371: 2335: 2301: 2295: 2279: 2273: 2268: 2237: 2209: 2203: 2176: 2151: 2139: 2133: 2106: 2101: 2089:Dynamic soaring 2086: 2084:Dynamic soaring 2078:Rocket equation 2073: 2059: 2036:Epsilon Eridani 1884: 1878: 1873: 1868: 1856: 1675:Total duration 1671: 1576: 1548: 1539: 1520:. In 2016, the 1514: 1506:rocket equation 1502: 1474: 1460:More recently, 1435:gamma radiation 1409: 1398: 1392: 1389: 1378: 1366: 1355: 1349: 1290: 1169: 1163: 1154:nuclear fission 1147: 1135:nuclear reactor 1126: 1121: 1103: 1086: 1079: 1071:rocket equation 1067: 1065:Rocket concepts 1062: 1023: 1005: 977: 971: 955: 939: 907: 901: 877: 871: 860:) is a type of 854:generation ship 850: 848:Generation ship 844: 835: 798: 793: 787: 759:Voyager program 755: 749: 744: 632:Epsilon Eridani 592:was announced. 545:stellar systems 541: 524: 512:micrometeoroids 496: 479: 465: 448: 444: 442: 439: 438: 418: 414: 409: 406: 405: 385: 382: 381: 364: 360: 345: 337: 334: 333: 327: 325:Required energy 300: 295:is exactly one 175: 143: 140: 135: 127:science fiction 80:generation ship 28: 23: 22: 15: 12: 11: 5: 8120: 8110: 8109: 8104: 8089: 8088: 8076: 8064: 8052: 8029: 8028: 8026: 8025: 8020: 8015: 8010: 8005: 7999: 7997: 7993: 7992: 7990: 7989: 7984: 7979: 7973: 7971: 7967: 7966: 7964: 7963: 7958: 7957: 7956: 7951: 7946: 7941: 7940: 7939: 7929: 7924: 7919: 7909: 7903: 7901: 7897: 7896: 7894: 7893: 7891:Stanford torus 7888: 7883: 7878: 7872: 7870: 7869:Space habitats 7866: 7865: 7863: 7862: 7857: 7852: 7847: 7842: 7837: 7832: 7826: 7824: 7820: 7819: 7812: 7811: 7804: 7797: 7789: 7780: 7779: 7777: 7776: 7763: 7760: 7759: 7757: 7756: 7751: 7746: 7741: 7736: 7735: 7734: 7729: 7724: 7719: 7714: 7709: 7699: 7694: 7689: 7684: 7683: 7682: 7672: 7667: 7662: 7661: 7660: 7655: 7650: 7645: 7635: 7630: 7625: 7620: 7615: 7609: 7607: 7603: 7602: 7599: 7598: 7595: 7594: 7592: 7591: 7586: 7581: 7575: 7573: 7569: 7568: 7566: 7565: 7560: 7559: 7558: 7553: 7543: 7538: 7533: 7528: 7522: 7520: 7514: 7513: 7511: 7510: 7505: 7504: 7503: 7498: 7496:Space fountain 7493: 7491:Space elevator 7488: 7483: 7478: 7468: 7462: 7460: 7451: 7442: 7438: 7437: 7430: 7429: 7422: 7415: 7407: 7398: 7397: 7395: 7394: 7383: 7371: 7368: 7367: 7365: 7364: 7359: 7354: 7352:Ground station 7349: 7343: 7341: 7339:Ground segment 7335: 7334: 7332: 7331: 7326: 7321: 7316: 7307: 7302: 7296: 7294: 7288: 7287: 7285: 7284: 7279: 7274: 7272:Interplanetary 7269: 7268: 7267: 7265:Geosynchronous 7262: 7252: 7246: 7244: 7240: 7239: 7237: 7236: 7235: 7234: 7232:Gravity assist 7229: 7224: 7219: 7209: 7208: 7207: 7202: 7197: 7192: 7187: 7182: 7172: 7167: 7166: 7165: 7163:Service module 7160: 7155: 7153:Orbital module 7145: 7140: 7138:Launch vehicle 7134: 7132: 7126: 7125: 7122: 7121: 7119: 7118: 7116:Space sexology 7113: 7108: 7106:Space medicine 7103: 7098: 7097: 7096: 7086: 7081: 7080: 7079: 7068: 7066: 7062: 7061: 7059: 7058: 7053: 7048: 7043: 7038: 7033: 7032: 7031: 7021: 7016: 7015: 7014: 7009: 6999: 6994: 6989: 6984: 6979: 6973: 6971: 6967: 6966: 6964: 6963: 6958: 6953: 6948: 6943: 6941:Weightlessness 6938: 6933: 6928: 6927: 6926: 6921: 6916: 6906: 6905: 6904: 6893: 6891: 6884: 6878: 6877: 6875: 6874: 6869: 6864: 6862:Space research 6859: 6854: 6849: 6844: 6839: 6834: 6833: 6832: 6827: 6822: 6817: 6807: 6806: 6805: 6800: 6798:Reconnaissance 6795: 6790: 6780: 6774: 6772: 6766: 6765: 6763: 6762: 6761: 6760: 6750: 6749: 6748: 6743: 6738: 6728: 6727: 6726: 6721: 6716: 6711: 6706: 6696: 6695: 6694: 6689: 6684: 6679: 6674: 6669: 6667:European Union 6664: 6659: 6654: 6644: 6639: 6638: 6637: 6632: 6627: 6622: 6612: 6606: 6604: 6600: 6599: 6592: 6591: 6584: 6577: 6569: 6563: 6562: 6557:(Article from 6552: 6540: 6534: 6533:(NASA Webpage) 6528: 6520: 6519:External links 6517: 6516: 6515: 6509: 6492: 6486: 6473: 6467: 6454: 6448: 6431: 6425: 6404: 6379: 6352: 6349: 6346: 6345: 6313: 6280: 6247: 6194: 6135: 6102: 6071: 6053:Universe Today 6035: 6009: 5983: 5957: 5926: 5896: 5866: 5847: 5817: 5768: 5749:(3): 345–350. 5733: 5702: 5672: 5661:on 1 June 2015 5642: 5609: 5579: 5567: 5533: 5502: 5476: 5450: 5411: 5388: 5353: 5326: 5300: 5293: 5275: 5214: 5188: 5141:(5): L73–L77. 5122: 5087: 5057: 5026: 4992: 4971: 4935: 4884: 4851: 4814: 4755: 4748: 4730: 4697: 4656: 4625: 4611: 4606:10.2514/3.8632 4592:(2): 187–195. 4576: 4545: 4514: 4484: 4454: 4434: 4377: 4356: 4319: 4297: 4274: 4248: 4218: 4206: 4176: 4169: 4151: 4094: 4085: 4048: 4012: 3992: 3965: 3946: 3913: 3894:(3): 309–331. 3878: 3849: 3842: 3790: 3783: 3759: 3721: 3690: 3647: 3628: 3597: 3582: 3555: 3491: 3448: 3417: 3397: 3366: 3335: 3301: 3277: 3230: 3171: 3139: 3111: 3083: 3074: 3056:(7): 239–246. 3033: 3003: 2996: 2976: 2973:on 8 May 2014. 2951: 2924: 2866: 2837: 2819: 2798:(2): 112–127. 2778: 2748: 2717: 2716: 2714: 2711: 2710: 2709: 2700: 2695: 2689: 2684: 2679: 2674: 2669: 2663: 2657: 2648: 2642: 2636:interplanetary 2622: 2619: 2590: 2587: 2562: 2542: 2538: 2534: 2515:Alpha Centauri 2510: 2507: 2489: 2486: 2485: 2484: 2481: 2478: 2472: 2460: 2457: 2456: 2455: 2449: 2443: 2437: 2434: 2431:Project Icarus 2428: 2422: 2416: 2410: 2407: 2401: 2393: 2390: 2370: 2367: 2334: 2331: 2305:G. Harry Stine 2297:Main article: 2294: 2291: 2275:Main article: 2272: 2269: 2267: 2264: 2256:cosmic strings 2236: 2233: 2205:Main article: 2202: 2199: 2172:Main article: 2150: 2147: 2135:Main article: 2132: 2129: 2117:speed of light 2105: 2102: 2100: 2097: 2085: 2082: 2072: 2069: 2068: 2067: 2064: 2061: 2057: 2054: 2048: 2047: 2044: 2041: 2038: 2032: 2031: 2028: 2025: 2022: 2016: 2015: 2012: 2009: 2006: 2000: 1999: 1996: 1993: 1990: 1984: 1983: 1980: 1977: 1974: 1968: 1967: 1964: 1961: 1958: 1952: 1951: 1948: 1945: 1942: 1936: 1935: 1932: 1929: 1926: 1920: 1919: 1916: 1913: 1910: 1904: 1903: 1900: 1897: 1894: 1888: 1887: 1882: 1875: 1870: 1865: 1855: 1852: 1849: 1848: 1845: 1842: 1839: 1836: 1833: 1827: 1826: 1825:50% @ 10.4 ly 1823: 1820: 1817: 1814: 1811: 1805: 1804: 1803:50% @ 10.4 ly 1801: 1798: 1795: 1792: 1789: 1783: 1782: 1779: 1776: 1773: 1770: 1767: 1764: 1762:outbound stage 1759: 1755: 1754: 1753:21% @ 4.29 ly 1751: 1748: 1745: 1742: 1739: 1733: 1732: 1729: 1728:21% @ 4.29 ly 1726: 1723: 1720: 1717: 1714: 1712:outbound stage 1709: 1705: 1704: 1701: 1700:11% @ 0.17 ly 1698: 1695: 1692: 1689: 1686: 1684:outbound stage 1681: 1677: 1676: 1673: 1668: 1665: 1662: 1659: 1656: 1653: 1575: 1572: 1556:Bussard ramjet 1547: 1544: 1538: 1537:Helical engine 1535: 1513: 1510: 1501: 1498: 1494:Mini-Mag Orion 1473: 1470: 1411: 1410: 1369: 1367: 1360: 1351:Main article: 1348: 1345: 1297:nuclear fusion 1289: 1286: 1233:Mini-Mag Orion 1215:Alpha Centauri 1189:specific power 1165:Main article: 1162: 1159: 1146: 1143: 1125: 1122: 1120: 1117: 1102: 1099: 1092:specific power 1084: 1077: 1066: 1063: 1061: 1058: 1004: 1001: 973:Main article: 970: 967: 954: 951: 945:) to possible 938: 935: 903:Main article: 900: 899:Frozen embryos 897: 873:Main article: 870: 867: 846:Main article: 843: 840: 834: 831: 820:nanotechnology 797: 794: 789:Main article: 786: 783: 767:Project Icarus 751:Main article: 748: 745: 743: 740: 734: 733: 730: 727: 721: 720: 717: 714: 708: 707: 704: 701: 695: 694: 688: 685: 679: 678: 671: 668: 662: 661: 654: 651: 645: 644: 637: 634: 628: 627: 620: 617: 611: 610: 603: 600: 598:Barnard's Star 594: 593: 586:habitable zone 570: 567: 561: 560: 557: 554: 540: 537: 523: 520: 508:weightlessness 495: 492: 478: 475: 451: 447: 421: 417: 413: 389: 367: 363: 359: 353: 350: 344: 341: 331:kinetic energy 326: 323: 275: 274: 271: 268: 261: 260: 257: 254: 248: 247: 244: 241: 235: 234: 231: 228: 221: 220: 217: 214: 207: 206: 203: 200: 194: 193: 190: 187: 181: 180: 177: 172: 139: 136: 134: 131: 117:. Even though 72:speed of light 67:technologies. 38:Bussard ramjet 26: 9: 6: 4: 3: 2: 8119: 8108: 8105: 8103: 8100: 8099: 8097: 8087: 8077: 8075: 8065: 8063: 8058: 8053: 8051: 8041: 8040: 8037: 8024: 8021: 8019: 8016: 8014: 8011: 8009: 8006: 8004: 8001: 8000: 7998: 7996:Organizations 7994: 7988: 7985: 7983: 7980: 7978: 7975: 7974: 7972: 7968: 7962: 7959: 7955: 7952: 7950: 7947: 7945: 7942: 7938: 7935: 7934: 7933: 7930: 7928: 7925: 7923: 7920: 7918: 7915: 7914: 7913: 7910: 7908: 7905: 7904: 7902: 7898: 7892: 7889: 7887: 7884: 7882: 7879: 7877: 7874: 7873: 7871: 7867: 7861: 7858: 7856: 7853: 7851: 7848: 7846: 7843: 7841: 7838: 7836: 7833: 7831: 7828: 7827: 7825: 7823:Core concepts 7821: 7817: 7810: 7805: 7803: 7798: 7796: 7791: 7790: 7787: 7775: 7774: 7765: 7764: 7761: 7755: 7754:Transhumanism 7752: 7750: 7747: 7745: 7742: 7740: 7737: 7733: 7730: 7728: 7725: 7723: 7720: 7718: 7715: 7713: 7710: 7708: 7705: 7704: 7703: 7700: 7698: 7695: 7693: 7690: 7688: 7685: 7681: 7678: 7677: 7676: 7673: 7671: 7668: 7666: 7663: 7659: 7656: 7654: 7651: 7649: 7646: 7644: 7641: 7640: 7639: 7636: 7634: 7631: 7629: 7626: 7624: 7621: 7619: 7616: 7614: 7611: 7610: 7608: 7604: 7590: 7587: 7585: 7582: 7580: 7577: 7576: 7574: 7570: 7564: 7561: 7557: 7554: 7552: 7549: 7548: 7547: 7544: 7542: 7539: 7537: 7534: 7532: 7529: 7527: 7524: 7523: 7521: 7519: 7515: 7509: 7506: 7502: 7499: 7497: 7494: 7492: 7489: 7487: 7484: 7482: 7479: 7477: 7474: 7473: 7472: 7469: 7467: 7466:Fusion rocket 7464: 7463: 7461: 7459: 7455: 7452: 7450: 7449:Space science 7446: 7443: 7439: 7435: 7428: 7423: 7421: 7416: 7414: 7409: 7408: 7405: 7393: 7389: 7384: 7382: 7373: 7372: 7369: 7363: 7360: 7358: 7355: 7353: 7350: 7348: 7345: 7344: 7342: 7340: 7336: 7330: 7327: 7325: 7322: 7320: 7317: 7315: 7311: 7308: 7306: 7303: 7301: 7300:Direct ascent 7298: 7297: 7295: 7293: 7289: 7283: 7282:Intergalactic 7280: 7278: 7275: 7273: 7270: 7266: 7263: 7261: 7258: 7257: 7256: 7253: 7251: 7248: 7247: 7245: 7241: 7233: 7230: 7228: 7225: 7223: 7220: 7218: 7217:Rocket engine 7215: 7214: 7213: 7210: 7206: 7203: 7201: 7198: 7196: 7193: 7191: 7188: 7186: 7183: 7181: 7178: 7177: 7176: 7173: 7171: 7168: 7164: 7161: 7159: 7156: 7154: 7151: 7150: 7149: 7148:Space capsule 7146: 7144: 7141: 7139: 7136: 7135: 7133: 7131: 7127: 7117: 7114: 7112: 7111:Space nursing 7109: 7107: 7104: 7102: 7099: 7095: 7092: 7091: 7090: 7087: 7085: 7082: 7078: 7075: 7074: 7073: 7070: 7069: 7067: 7065:Health issues 7063: 7057: 7054: 7052: 7049: 7047: 7044: 7042: 7039: 7037: 7034: 7030: 7027: 7026: 7025: 7022: 7020: 7019:Space Shuttle 7017: 7013: 7010: 7008: 7005: 7004: 7003: 7000: 6998: 6995: 6993: 6990: 6988: 6985: 6983: 6980: 6978: 6975: 6974: 6972: 6968: 6962: 6959: 6957: 6954: 6952: 6951:Space tourism 6949: 6947: 6944: 6942: 6939: 6937: 6934: 6932: 6929: 6925: 6922: 6920: 6917: 6915: 6912: 6911: 6910: 6907: 6903: 6900: 6899: 6898: 6895: 6894: 6892: 6888: 6885: 6883: 6879: 6873: 6872:Space weather 6870: 6868: 6865: 6863: 6860: 6858: 6855: 6853: 6850: 6848: 6845: 6843: 6840: 6838: 6835: 6831: 6828: 6826: 6823: 6821: 6818: 6816: 6813: 6812: 6811: 6808: 6804: 6801: 6799: 6796: 6794: 6791: 6789: 6786: 6785: 6784: 6781: 6779: 6776: 6775: 6773: 6771: 6767: 6759: 6756: 6755: 6754: 6751: 6747: 6744: 6742: 6739: 6737: 6736:Space command 6734: 6733: 6732: 6731:Space warfare 6729: 6725: 6722: 6720: 6717: 6715: 6712: 6710: 6707: 6705: 6702: 6701: 6700: 6697: 6693: 6692:United States 6690: 6688: 6685: 6683: 6680: 6678: 6675: 6673: 6670: 6668: 6665: 6663: 6660: 6658: 6655: 6653: 6650: 6649: 6648: 6645: 6643: 6640: 6636: 6633: 6631: 6628: 6626: 6623: 6621: 6618: 6617: 6616: 6613: 6611: 6610:Astrodynamics 6608: 6607: 6605: 6601: 6597: 6590: 6585: 6583: 6578: 6576: 6571: 6570: 6567: 6560: 6556: 6553: 6551: 6547: 6544: 6541: 6539:(source list) 6538: 6535: 6532: 6529: 6526: 6523: 6522: 6512: 6506: 6501: 6500: 6493: 6489: 6483: 6479: 6474: 6470: 6464: 6460: 6455: 6451: 6445: 6440: 6439: 6432: 6428: 6422: 6418: 6414: 6410: 6405: 6401: 6397: 6393: 6389: 6385: 6380: 6376: 6372: 6368: 6364: 6360: 6355: 6354: 6333: 6329: 6328: 6323: 6317: 6301: 6297: 6296: 6295:New Scientist 6291: 6284: 6268: 6264: 6263: 6258: 6251: 6243: 6239: 6235: 6231: 6227: 6223: 6218: 6213: 6209: 6205: 6198: 6190: 6186: 6181: 6176: 6172: 6168: 6163: 6158: 6154: 6150: 6146: 6139: 6123: 6119: 6118: 6113: 6106: 6090: 6086: 6082: 6075: 6059: 6055: 6054: 6049: 6042: 6040: 6023: 6019: 6013: 5997: 5993: 5987: 5971: 5967: 5961: 5945: 5941: 5937: 5930: 5914: 5910: 5906: 5900: 5884: 5880: 5876: 5870: 5863: 5859: 5856: 5851: 5835: 5831: 5827: 5821: 5810: 5806: 5802: 5798: 5794: 5790: 5786: 5779: 5772: 5764: 5760: 5756: 5752: 5748: 5744: 5737: 5721: 5717: 5713: 5706: 5690: 5686: 5682: 5676: 5660: 5656: 5652: 5646: 5629: 5625: 5624: 5619: 5613: 5597: 5593: 5589: 5583: 5576: 5571: 5556: 5552: 5548: 5544: 5537: 5521: 5517: 5513: 5506: 5491: 5487: 5480: 5465: 5461: 5454: 5446: 5442: 5438: 5434: 5430: 5426: 5422: 5415: 5407: 5403: 5399: 5392: 5384: 5380: 5376: 5372: 5368: 5364: 5357: 5341: 5337: 5330: 5314: 5310: 5304: 5296: 5290: 5286: 5279: 5271: 5267: 5263: 5259: 5255: 5251: 5247: 5243: 5238: 5233: 5229: 5225: 5218: 5202: 5198: 5192: 5184: 5180: 5176: 5172: 5167: 5162: 5158: 5154: 5149: 5148:gr-qc/0009013 5144: 5140: 5136: 5129: 5127: 5118: 5114: 5110: 5106: 5102: 5098: 5091: 5083: 5079: 5075: 5071: 5064: 5062: 5045: 5041: 5037: 5030: 5011: 5007: 5006:New Scientist 5003: 4996: 4987: 4982: 4975: 4968: 4955: 4951: 4950: 4945: 4939: 4930: 4925: 4921: 4917: 4912: 4907: 4903: 4899: 4895: 4888: 4872: 4868: 4867: 4862: 4855: 4847: 4843: 4839: 4835: 4832:: 1544–1555. 4831: 4827: 4826: 4818: 4810: 4806: 4801: 4796: 4792: 4788: 4783: 4778: 4774: 4770: 4766: 4759: 4751: 4745: 4741: 4734: 4715: 4708: 4701: 4682: 4678: 4674: 4667: 4660: 4644: 4640: 4636: 4629: 4621: 4615: 4607: 4603: 4599: 4595: 4591: 4587: 4580: 4564: 4560: 4556: 4549: 4533: 4529: 4525: 4518: 4502: 4498: 4494: 4488: 4472: 4468: 4464: 4458: 4452: 4448: 4444: 4438: 4419: 4415: 4411: 4407: 4403: 4399: 4395: 4388: 4381: 4373: 4369: 4368: 4360: 4352: 4348: 4344: 4340: 4336: 4332: 4331: 4323: 4304: 4300: 4298:9782954930930 4294: 4287: 4286: 4278: 4262: 4258: 4252: 4236: 4232: 4228: 4222: 4215: 4210: 4202: 4198: 4194: 4190: 4183: 4181: 4172: 4166: 4162: 4155: 4136: 4132: 4128: 4124: 4120: 4116: 4112: 4105: 4098: 4089: 4081: 4077: 4073: 4069: 4065: 4061: 4060: 4059:Physics Today 4052: 4033: 4026: 4022: 4016: 4008: 4004: 4003: 3996: 3981: 3977: 3976: 3969: 3960: 3959: 3950: 3931: 3924: 3917: 3909: 3905: 3901: 3897: 3893: 3889: 3882: 3866: 3862: 3861: 3853: 3845: 3839: 3835: 3831: 3826: 3807: 3800: 3794: 3786: 3780: 3776: 3775: 3770: 3763: 3755: 3751: 3747: 3743: 3736: 3734: 3732: 3730: 3728: 3726: 3709: 3705: 3701: 3694: 3678: 3674: 3670: 3666: 3662: 3658: 3651: 3643: 3639: 3632: 3616: 3612: 3608: 3601: 3593: 3586: 3578: 3574: 3570: 3566: 3559: 3543: 3539: 3535: 3531: 3527: 3522: 3517: 3513: 3509: 3505: 3498: 3496: 3479: 3475: 3471: 3467: 3463: 3459: 3452: 3436: 3432: 3428: 3421: 3413: 3412: 3407: 3401: 3385: 3381: 3377: 3370: 3354: 3350: 3346: 3339: 3323: 3319: 3315: 3308: 3306: 3289: 3288: 3281: 3273: 3267: 3259: 3255: 3251: 3247: 3246: 3241: 3234: 3226: 3222: 3218: 3214: 3210: 3206: 3201: 3196: 3192: 3188: 3187: 3182: 3175: 3159: 3155: 3154: 3149: 3143: 3127: 3126: 3121: 3115: 3099: 3098: 3093: 3087: 3078: 3063: 3059: 3055: 3051: 3044: 3037: 3029: 3025: 3021: 3017: 3010: 3008: 2999: 2993: 2989: 2988: 2980: 2969: 2962: 2955: 2944: 2937: 2936: 2928: 2920: 2916: 2912: 2908: 2904: 2900: 2895: 2890: 2886: 2882: 2875: 2873: 2871: 2862: 2856: 2848: 2844: 2840: 2838:9783319738451 2834: 2830: 2823: 2814: 2809: 2805: 2801: 2797: 2793: 2789: 2782: 2766: 2762: 2758: 2752: 2737: 2736: 2731: 2725: 2723: 2718: 2704: 2701: 2699: 2696: 2693: 2690: 2688: 2685: 2683: 2680: 2678: 2675: 2673: 2670: 2667: 2664: 2661: 2658: 2652: 2649: 2646: 2643: 2641: 2637: 2633: 2629: 2625: 2624: 2618: 2615: 2611: 2606: 2604: 2600: 2596: 2586: 2584: 2583:magnetic sail 2560: 2540: 2536: 2532: 2524: 2520: 2516: 2506: 2502: 2498: 2494: 2482: 2479: 2476: 2473: 2470: 2467: 2466: 2465: 2453: 2450: 2447: 2444: 2441: 2438: 2435: 2432: 2429: 2426: 2423: 2420: 2417: 2414: 2411: 2408: 2405: 2402: 2399: 2398:Project Orion 2396: 2395: 2392:Other designs 2389: 2387: 2382: 2378: 2376: 2366: 2363: 2359: 2355: 2353: 2350: 2345: 2342: 2339: 2333:NASA research 2330: 2328: 2324: 2320: 2316: 2312: 2311: 2306: 2300: 2290: 2288: 2283: 2278: 2263: 2261: 2257: 2253: 2249: 2248:negative mass 2245: 2241: 2232: 2230: 2229:negative mass 2226: 2225:exotic matter 2222: 2218: 2214: 2208: 2198: 2196: 2195:exotic matter 2192: 2188: 2184: 2179: 2175: 2168: 2164: 2160: 2155: 2146: 2144: 2138: 2128: 2126: 2122: 2118: 2114: 2110: 2096: 2094: 2090: 2081: 2079: 2065: 2062: 2055: 2052: 2051: 2045: 2042: 2039: 2037: 2034: 2033: 2029: 2026: 2023: 2021: 2018: 2017: 2013: 2010: 2007: 2005: 2002: 2001: 1997: 1994: 1991: 1989: 1986: 1985: 1981: 1978: 1975: 1973: 1970: 1969: 1965: 1962: 1959: 1957: 1954: 1953: 1949: 1946: 1943: 1941: 1938: 1937: 1933: 1930: 1927: 1925: 1922: 1921: 1917: 1914: 1911: 1909: 1906: 1905: 1901: 1898: 1895: 1893: 1890: 1889: 1885: 1876: 1871: 1866: 1863: 1862: 1859: 1847:50% @ 0.4 ly 1846: 1843: 1840: 1837: 1834: 1832: 1829: 1828: 1824: 1821: 1818: 1815: 1812: 1810: 1807: 1806: 1802: 1799: 1796: 1793: 1791:21,500,000 GW 1790: 1788: 1785: 1784: 1778:50% @ 0.4 ly 1777: 1774: 1771: 1768: 1766:75,000,000 GW 1765: 1763: 1760: 1756: 1752: 1749: 1746: 1743: 1740: 1738: 1735: 1734: 1727: 1724: 1721: 1718: 1715: 1713: 1710: 1706: 1702: 1699: 1696: 1693: 1690: 1687: 1685: 1682: 1679: 1678: 1674: 1669: 1667:Sail Diameter 1666: 1663: 1660: 1657: 1654: 1651: 1650: 1647: 1645: 1640: 1637: 1636:magnetic sail 1632: 1630: 1626: 1622: 1617: 1613: 1609: 1608:reaction mass 1605: 1601: 1600:magnetic sail 1597: 1589: 1585: 1580: 1571: 1569: 1565: 1561: 1557: 1554:proposed the 1553: 1543: 1534: 1532: 1527: 1523: 1519: 1509: 1507: 1497: 1495: 1491: 1487: 1483: 1479: 1469: 1467: 1463: 1458: 1455: 1450: 1448: 1444: 1440: 1436: 1430: 1427: 1426:time dilation 1422: 1418: 1407: 1404: 1396: 1386: 1382: 1376: 1375: 1370:This section 1368: 1364: 1359: 1358: 1354: 1344: 1342: 1338: 1334: 1330: 1326: 1322: 1318: 1314: 1305: 1301: 1298: 1294: 1293:Fusion rocket 1285: 1283: 1279: 1274: 1272: 1268: 1264: 1259: 1257: 1253: 1249: 1245: 1241: 1236: 1234: 1230: 1226: 1221: 1220:magnetic sail 1216: 1212: 1208: 1204: 1200: 1199:Freeman Dyson 1196: 1195:Project Orion 1192: 1190: 1186: 1182: 1173: 1168: 1161:Nuclear pulse 1158: 1155: 1151: 1142: 1140: 1136: 1132: 1116: 1114: 1110: 1109: 1098: 1095: 1093: 1088: 1083: 1076: 1072: 1057: 1054: 1052: 1048: 1047:time dilation 1043: 1040: 1035: 1033: 1027: 1022: 1014: 1009: 1000: 998: 993: 989: 985: 982: 981:time dilation 976: 975:Time dilation 969:Time dilation 966: 964: 960: 950: 948: 947:rogue planets 944: 934: 932: 931:mobile robots 928: 924: 920: 916: 912: 906: 896: 894: 893:sleeper ships 890: 886: 882: 876: 866: 865:ship raises. 863: 859: 855: 849: 839: 830: 828: 823: 821: 817: 813: 811: 807: 806:nanoparticles 803: 792: 782: 780: 776: 772: 768: 764: 760: 754: 739: 731: 728: 726: 723: 722: 718: 715: 713: 710: 709: 705: 702: 700: 697: 696: 692: 689: 686: 684: 681: 680: 676: 672: 669: 667: 666:Luyten's Star 664: 663: 659: 655: 652: 650: 647: 646: 642: 638: 635: 633: 630: 629: 625: 621: 618: 616: 613: 612: 608: 604: 601: 599: 596: 595: 591: 587: 583: 579: 575: 571: 568: 566: 563: 562: 558: 556:Distance (ly) 555: 552: 551: 548: 546: 536: 533: 529: 519: 517: 513: 509: 505: 501: 491: 489: 484: 474: 471: 449: 445: 435: 419: 415: 411: 403: 387: 365: 361: 357: 351: 348: 342: 339: 332: 322: 320: 315: 313: 309: 304: 298: 294: 290: 286: 282: 272: 269: 266: 263: 262: 258: 255: 253: 250: 249: 245: 242: 240: 237: 236: 232: 229: 226: 223: 222: 218: 215: 212: 209: 208: 204: 201: 199: 196: 195: 191: 188: 186: 183: 182: 178: 173: 170: 169: 166: 164: 159: 157: 153: 149: 130: 128: 124: 120: 116: 112: 108: 103: 101: 97: 93: 92:fusion rocket 89: 85: 81: 77: 73: 68: 66: 62: 58: 54: 50: 46: 39: 34: 30: 19: 8086:Solar System 8003:Mars Society 7912:Solar System 7860:Terraforming 7834: 7771: 7658:Robot ethics 7578: 7531:Ion thruster 7501:Space tether 7481:Orbital ring 7292:Space launch 7277:Interstellar 7276: 7243:Destinations 7012:Apollo–Soyuz 6961:Space diving 6946:Space toilet 6770:Applications 6687:Soviet Union 6647:Space policy 6642:Space launch 6498: 6480:. Springer. 6477: 6458: 6437: 6411:. Springer. 6408: 6391: 6387: 6366: 6362: 6336:. Retrieved 6325: 6316: 6304:. Retrieved 6293: 6283: 6271:. Retrieved 6262:The Atlantic 6260: 6250: 6207: 6203: 6197: 6152: 6148: 6138: 6126:. Retrieved 6115: 6105: 6093:. Retrieved 6084: 6074: 6062:. Retrieved 6051: 6026:. Retrieved 6012: 6000:. Retrieved 5986: 5974:. Retrieved 5960: 5948:. Retrieved 5939: 5934:Webpole Bt. 5929: 5917:. Retrieved 5908: 5899: 5887:. Retrieved 5878: 5869: 5850: 5838:. Retrieved 5829: 5820: 5809:the original 5788: 5784: 5771: 5746: 5742: 5736: 5724:. Retrieved 5715: 5705: 5693:. Retrieved 5689:the original 5684: 5675: 5663:. Retrieved 5659:the original 5654: 5645: 5632:. Retrieved 5628:the original 5621: 5612: 5600:. Retrieved 5591: 5582: 5570: 5558:. Retrieved 5546: 5536: 5524:. Retrieved 5515: 5505: 5493:. Retrieved 5489: 5479: 5467:. Retrieved 5463: 5453: 5428: 5424: 5414: 5405: 5401: 5391: 5366: 5362: 5356: 5344:. Retrieved 5329: 5317:. Retrieved 5303: 5284: 5278: 5227: 5223: 5217: 5205:. Retrieved 5191: 5138: 5134: 5100: 5096: 5090: 5073: 5069: 5048:. Retrieved 5039: 5029: 5014:. Retrieved 5005: 4995: 4974: 4965: 4958:. Retrieved 4947: 4938: 4901: 4897: 4887: 4875:. Retrieved 4866:ScienceAlert 4864: 4854: 4829: 4823: 4817: 4772: 4768: 4758: 4739: 4733: 4721:. Retrieved 4700: 4688:. Retrieved 4681:the original 4676: 4672: 4659: 4647:. Retrieved 4638: 4628: 4614: 4589: 4586:J Spacecraft 4585: 4579: 4567:. Retrieved 4559:ScienceAlert 4558: 4548: 4536:. Retrieved 4528:ScienceAlert 4527: 4517: 4505:. Retrieved 4496: 4487: 4475:. Retrieved 4471:the original 4466: 4457: 4445:. Elsevier. 4442: 4437: 4425:. Retrieved 4418:the original 4397: 4393: 4380: 4372:the original 4366: 4359: 4337:(1): 34–39. 4334: 4328: 4322: 4312:10 September 4310:. Retrieved 4284: 4277: 4265:. Retrieved 4251: 4239:. Retrieved 4230: 4221: 4209: 4196: 4192: 4160: 4154: 4142:. Retrieved 4135:the original 4114: 4110: 4097: 4088: 4063: 4057: 4051: 4039:. Retrieved 4015: 4007:the original 4001: 3995: 3984:, retrieved 3974: 3968: 3957: 3949: 3937:. Retrieved 3916: 3891: 3887: 3881: 3869:. Retrieved 3859: 3852: 3829: 3813:. Retrieved 3806:the original 3793: 3773: 3762: 3745: 3741: 3712:. Retrieved 3703: 3693: 3681:. Retrieved 3664: 3660: 3650: 3641: 3637: 3631: 3619:. Retrieved 3615:the original 3610: 3600: 3591: 3585: 3568: 3564: 3558: 3546:. Retrieved 3511: 3507: 3482:. Retrieved 3465: 3461: 3451: 3439:. Retrieved 3430: 3420: 3409: 3406:Kaku, Michio 3400: 3388:. Retrieved 3384:the original 3379: 3369: 3357:. Retrieved 3348: 3338: 3326:. Retrieved 3317: 3292:. Retrieved 3286: 3280: 3243: 3233: 3190: 3184: 3174: 3162:. Retrieved 3151: 3142: 3130:. Retrieved 3123: 3114: 3102:. Retrieved 3095: 3086: 3077: 3065:. Retrieved 3053: 3049: 3036: 3022:(1): 23–32. 3019: 3015: 2986: 2979: 2968:the original 2954: 2943:the original 2934: 2927: 2884: 2880: 2828: 2822: 2795: 2791: 2781: 2769:. Retrieved 2760: 2751: 2739:. Retrieved 2733: 2640:intergalatic 2607: 2592: 2512: 2503: 2499: 2495: 2491: 2462: 2379: 2372: 2356: 2346: 2343: 2336: 2308: 2302: 2280: 2259: 2251: 2238: 2210: 2180: 2177: 2163:"warp drive" 2158: 2140: 2107: 2087: 2074: 2035: 2019: 2003: 1987: 1971: 1955: 1939: 1924:α Centauri B 1923: 1908:α Centauri A 1907: 1891: 1857: 1830: 1809:return stage 1808: 1786: 1775:1000 km 1761: 1736: 1711: 1683: 1664:Acceleration 1661:Vehicle Mass 1641: 1633: 1629:solar energy 1593: 1567: 1563: 1549: 1540: 1515: 1503: 1490:ion thruster 1484:proposed an 1475: 1459: 1453: 1451: 1446: 1442: 1431: 1414: 1399: 1390: 1379:Please help 1374:verification 1371: 1336: 1310: 1291: 1275: 1262: 1260: 1237: 1197:team member 1193: 1178: 1148: 1127: 1106: 1104: 1096: 1089: 1081: 1074: 1068: 1055: 1044: 1036: 1028: 1024: 994: 990: 986: 978: 963:§ Propulsion 956: 940: 908: 878: 875:Sleeper ship 857: 851: 836: 824: 814: 799: 756: 737: 542: 525: 516:space debris 497: 480: 436: 402:deceleration 328: 316: 305: 278: 219:2.4 minutes 192:1.3 seconds 160: 141: 104: 69: 57:Solar System 53:star systems 44: 43: 29: 8074:Outer space 7876:Bishop Ring 7722:Moore's law 7653:Neuroethics 7648:Cyberethics 7476:Mass driver 7250:Sub-orbital 7185:Space probe 7051:New Shepard 7029:Shuttle–Mir 6788:Archaeology 6741:Space force 6724:Moon Treaty 6596:Spaceflight 6369:: 377–400. 6338:25 February 6306:16 November 6210:(10): 324. 6095:20 February 6002:7 September 5726:29 December 5560:8 September 5526:18 November 5495:24 February 5469:24 February 5207:4 September 5076:: 205–218. 5016:1 September 4960:20 December 4649:12 December 4569:12 November 4538:12 November 4507:12 November 4477:12 November 4427:24 November 4144:24 November 3748:: 377–400. 3667:: 283–285. 3571:: 254–266. 3508:Acta Futura 3468:: 119–133. 3390:13 November 3153:Yahoo! News 2488:Feasibility 1988:Fomalhaut A 1867:Travel time 1844:100 km 1822:100 km 1800:320 km 1725:100 km 1697:3.6 km 1658:Laser Power 1393:August 2015 885:hibernation 816:Michio Kaku 699:Gliese 667C 691:Wolf 1061 c 626:companion. 624:white dwarf 285:Julian year 281:light-years 273:4.24 years 259:22.6 hours 246:18.9 hours 179:Light time 76:cosmic dust 59:and nearby 8096:Categories 7961:Free space 7613:Automation 7563:Solar sail 7518:Propulsion 7319:Launch pad 7310:Expendable 7260:Geocentric 7227:Solar sail 7170:Spaceplane 7130:Spacecraft 6924:Space suit 6902:commercial 6830:Television 6625:Space Race 6273:29 January 6217:1608.06087 6162:1710.10732 6155:(4): 155. 6128:24 January 5919:7 December 5346:7 February 5338:(Report). 5237:ph/9409051 4911:2211.14643 4877:6 December 4782:1704.03871 4775:(3): 115. 4066:(10): 41. 3521:2005.04100 3514:: 75–104. 3484:1 November 3349:BBC Future 3294:26 October 3193:(2): L24. 2847:1033673323 2713:References 2628:Suborbital 2614:TRAPPIST-1 2360:of NASA's 1877:Luminosity 1813:710,000 GW 1750:30 km 1596:light sail 1588:light-sail 1421:antimatter 1113:ion engine 1101:Ion engine 1090:Very high 1060:Propulsion 1019:See also: 943:Oort cloud 858:world ship 796:Nanoprobes 725:TRAPPIST-1 514:and other 233:4.1 hours 205:8 minutes 133:Challenges 107:exoplanets 96:solar sail 65:propulsion 49:spacecraft 8050:Astronomy 7932:Asteroids 7643:Bioethics 7329:Spaceport 7180:Satellite 6897:Astronaut 6825:Telephone 6778:Astronomy 6699:Space law 6652:Australia 6064:25 August 5716:space.com 5623:Space.com 5490:Space.com 5431:: 16–29. 5408:(4): 119. 5369:: 16–29. 5161:CiteSeerX 5050:11 August 4986:0908.1803 4809:119070263 4723:8 October 4690:8 October 4199:: 49–58. 3908:123409581 3815:31 August 3538:218571111 3225:118404871 3200:1409.0021 2894:1010.4823 2855:cite book 2452:Solar One 2319:deuterium 2240:Wormholes 2235:Wormholes 2221:wormholes 2183:causality 2165:paper of 1940:Procyon A 1835:60,000 GW 1741:26,000 GW 1731:41 years 1703:40 years 1550:In 1960, 1439:neutrinos 1252:ion beams 1187:and high 997:Milky Way 683:Wolf 1061 607:red dwarf 578:exoplanet 500:isolation 319:Voyager 1 297:arcsecond 252:Voyager 1 239:Voyager 2 156:Voyager 1 94:, beamed 7381:Category 7046:Tiangong 7041:Shenzhou 6970:Programs 6815:Internet 6620:Timeline 6546:Archived 6332:Archived 6300:Archived 6267:Archived 6189:62839612 6122:Archived 6089:Archived 6058:Archived 6028:22 April 6022:Archived 5996:Archived 5976:18 April 5970:Archived 5944:Archived 5940:i4is.org 5913:Archived 5889:14 April 5883:Archived 5858:Archived 5840:12 April 5834:Archived 5720:Archived 5596:Archived 5520:Archived 5340:Archived 5319:13 April 5313:Archived 5270:42837620 5262:10018782 5201:Archived 5044:Archived 5010:Archived 5008:(2736). 4954:Archived 4949:NBC News 4871:Archived 4714:Archived 4643:Archived 4563:Archived 4532:Archived 4501:Archived 4303:Archived 4267:5 August 4261:Archived 4241:5 August 4235:Archived 4201:Archived 4032:Archived 3986:13 March 3980:archived 3930:Archived 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