284:
of the orbiting vehicle above an equatorial base would facilitate tracking and communications. Most important, an equatorial launch site would avoid the costly dogleg technique, a prerequisite for placing rockets into equatorial orbit from sites such as Cape
Canaveral, Florida (28 degrees north latitude). The necessary correction in the space vehicle's trajectory could be very expensive - engineers estimated that doglegging a Saturn vehicle into a low-altitude equatorial orbit from Cape Canaveral used enough extra propellant to reduce the payload by as much as 80%. In higher orbits, the penalty was less severe but still involved at least a 20% loss of payload.
1108:
283:
Equatorial launch sites offered certain advantages over facilities within the continental United States. A launching due east from a site on the
Equator could take advantage of the earth's maximum rotational velocity (460 meters per second) to achieve orbital speed. The more frequent overhead passage
86:, only launches eastward take advantage of this boost of speed. Westward launches, in fact, are especially difficult from the Equator because of the need to counteract the extra rotational speed.
89:
Equatorial orbits offer other advantages, such as to communication: a spaceship in an equatorial orbit passes directly over an equatorial spaceport on every rotation, in contrast to the varying
96:
Furthermore, launches directly into equatorial orbit eliminate the need for costly adjustments to a spacecraft's launch trajectory. The maneuver to reach the 5° inclination of the
266:
46:
Equatorial orbits can be advantageous for several reasons. For launches of human technology to space, sites near the
Equator, such as the
43:. A satellite in a geostationary orbit appears stationary, always at the same point in the sky, to observers on the surface of the Earth.
985:
164:
However, a non-inclined orbit need not be referenced only to an equatorial reference plane. If the plane of reference is the
195:. In these cases, alternative orbital elements or different definitions must be used to ensure an orbit is fully described.
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305:
269:. NASA Special Publication-4204 in the NASA History Series. p. Chapter 1.2: A Saturn Launch Site. Archived from
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35:, the great circle of the imaginary celestial sphere on the same plane as the equator of Earth. A
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example of an equatorial orbit, non-inclined orbit that is coplanar with the equator of
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131:
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893:
823:
578:
532:
450:
301:
230:
143:
97:
32:
161:, and the non-inclined orbit is merely a special case of the near-equatorial orbit.
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300:(1st ed.). New York, New York: Oxford University Press. p. 49.
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reduces the fuel needed to launch spacecraft to orbit. Since Earth
78:
of the Earth, 460 m/s, to the spacecraft at launch. The added
925:
79:
24:
267:"Moonport: A History of Apollo Launch Facilities and Operations"
104:
was originally estimated to reduce the payload capacity of the
51:
730:
349:
207:
124:
139:
39:
is a particular type of equatorial orbit, one which is
265:William Barnaby Faherty; Charles D. Benson (1978).
1124:
183:is undefined, as well as its related classical
295:
333:
296:Prussing, John E.; Conway, Bruce A. (1993).
27:of the object orbited. Such an orbit has an
1107:
340:
326:
260:
258:
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31:near 0°. On Earth, such orbits lie on the
16:Type of orbit around an astronomical body
347:
253:
149:If the plane of reference is a massive
1125:
986:Transposition, docking, and extraction
321:
114:
62:in Brazil, can be good locations for
23:is an orbit that lies close to the
13:
14:
1149:
1046:Kepler's laws of planetary motion
1106:
1041:Interplanetary Transport Network
921:Collision avoidance (spacecraft)
66:as they provide some additional
1006:Astronomical coordinate systems
760:Longitude of the ascending node
189:longitude of the ascending node
138:is 0° for prograde orbits, and
1079:Retrograde and prograde motion
289:
1:
246:
1026:Equatorial coordinate system
175:As non-inclined orbits lack
7:
213:
100:from the 28° N latitude of
10:
1154:
778:Longitude of the periapsis
168:plane, they are called an
157:, these orbits are called
111:rocket by as much as 80%.
1102:
1089:Specific angular momentum
994:
906:
850:
786:
739:
679:
670:
566:
476:
365:
356:
1084:Specific orbital energy
60:Alcantara Launch Centre
496:Geostationary transfer
93:of an inclined orbit.
1069:Orbital state vectors
1011:Characteristic energy
981:Trans-lunar injection
769:Argument of periapsis
446:Prograde / Retrograde
407:Hyperbolic trajectory
193:argument of periapsis
21:near-equatorial orbit
916:Bi-elliptic transfer
436:Parabolic trajectory
956:Low-energy transfer
236:Orbital inclination
225:Geostationary orbit
200:geostationary orbit
136:orbital inclination
48:Guiana Space Centre
37:geostationary orbit
951:Inclination change
599:Distant retrograde
132:plane of reference
121:non-inclined orbit
115:Non-inclined orbit
1120:
1119:
1094:Two-line elements
902:
901:
824:Eccentric anomaly
666:
665:
533:Orbit of the Moon
392:Highly elliptical
298:Orbital Mechanics
231:Celestial equator
74:by imparting the
33:celestial equator
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1110:
1109:
1051:Lagrangian point
946:Hohmann transfer
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646:Heliosynchronous
595:Lagrange points
548:Transatmospheric
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312:
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293:
287:
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185:orbital elements
155:equatorial plane
106:Apollo Program's
84:rotates eastward
76:rotational speed
25:equatorial plane
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1152:
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1016:Escape velocity
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971:Rocket equation
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718:Semi-minor axis
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709:Semi-major axis
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689:
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584:Areosynchronous
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543:Sun-synchronous
528:Near-equatorial
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1112:List of orbits
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1064:Orbit equation
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931:Delta-v budget
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862:Orbital period
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842:True longitude
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833:Mean longitude
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589:Areostationary
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558:Very low Earth
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468:Transfer orbit
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348:Gravitational
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241:Inclined orbit
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220:List of orbits
215:
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204:geosynchronous
181:ascending node
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102:Cape Canaveral
72:launch vehicle
41:geosynchronous
15:
9:
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1133:Astrodynamics
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1059:-body problem
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961:Oberth effect
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880:Orbital speed
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634:Earth's orbit
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491:Geostationary
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307:0-19-507834-9
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273:on 2018-09-15
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68:orbital speed
65:
61:
57:
56:French Guiana
53:
49:
44:
42:
38:
34:
30:
26:
22:
1074:Perturbation
1056:
1031:Ground track
941:Gravity turn
892:
885:
878:
869:
860:
840:
831:
822:
815:True anomaly
813:
798:Mean anomaly
796:
776:
767:
758:
749:
729:
716:
707:
700:Eccentricity
698:
656:Lunar cycler
629:Heliocentric
569:other points
527:
518:Medium Earth
416:Non-inclined
297:
291:
282:
275:. Retrieved
271:the original
197:
174:
169:
163:
158:
148:
120:
118:
98:Moon's orbit
95:
91:ground track
88:
45:
20:
18:
1036:Hill sphere
871:Mean motion
751:Inclination
740:Orientation
641:Mars cycler
579:Areocentric
451:Synchronous
142:(180°) for
29:inclination
1127:Categories
976:Rendezvous
672:Parameters
508:High Earth
478:Geocentric
431:Osculating
388:Elliptical
247:References
159:equatorial
144:retrograde
64:spaceports
1021:Ephemeris
998:mechanics
908:Maneuvers
851:Variation
614:Libration
609:Lissajous
513:Low Earth
503:Graveyard
402:Horseshoe
787:Position
412:Inclined
383:Circular
214:See also
191:and the
170:ecliptic
166:ecliptic
151:spheroid
128:coplanar
109:Saturn V
80:velocity
996:Orbital
966:Phasing
926:Delta-v
731:Apsides
725:,
523:Molniya
441:Parking
378:Capture
366:General
172:orbit.
153:body's
134:. The
130:with a
70:to the
1138:Orbits
652:Other
553:Tundra
421:Kepler
397:Escape
350:orbits
304:
187:, the
179:, the
146:ones.
123:is an
52:Kourou
894:Epoch
683:Shape
621:Lunar
575:Mars
567:About
538:Polar
358:Types
277:8 May
227:(GEO)
208:Earth
202:is a
177:nodes
125:orbit
58:, or
686:Size
625:Sun
604:Halo
456:semi
302:ISBN
279:2019
461:sub
373:Box
50:in
1129::
809:,
805:,
414:/
390:/
281:.
255:^
210:.
198:A
119:A
54:,
19:A
1057:n
889:0
886:t
876:v
867:n
858:T
838:l
829:L
820:E
811:f
807:θ
803:ν
794:M
774:ϖ
765:ω
756:Ω
747:i
727:q
723:Q
714:b
705:a
696:e
341:e
334:t
327:v
310:.
140:π
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