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suffered a spin lock while attempting to jostle the communications payload: the spun and despun sections locked together. Remembering this second failure of F4, and with F1 beginning to wear out at the spin bearing, it was decided to "flip" F1 every six months to keep the payload in the sun. Thus F1 went on to operate smoothly for its remaining life and never encountered a locked despun section.
153:, Don Williams, and Thomas Hudspeth. All three satellites were cylindrical in shape, with a diameter of about 71 centimetres (28 in) and a height of about 39 centimetres (15 in). Pre-launch fueled masses were 68 kilograms (150 lb), and orbital masses were 39 kilograms (86 lb) with a 25-kilogram (55 lb)
318:(DOD) along with telemetry, command stations, and range and rangefinding equipment. DOD had, in fact, provided the communications ground stations used to relay transmissions via the two Syncoms since their launch. DOD agreed to provide telemetry and ranging data of continuing scientific and engineering interest.
393:
oceans, spaced about 90 degrees apart. Five satellites were ordered, with one as a replacement. Also part of the contract were the associated control systems and ground stations. The lease contracts were typically for five-year terms, with the lessee having the opportunity to extend the lease or to
365:
propellant for station keeping and spin stabilization. The communications systems offers a wideband UHF channel (500 kHz bandwidth), six relay 25 kHz channels, and five narrowband 5 kHz channels. This is in addition to the fleet broadcast frequency, which is in the military's X-band.
262:
Syncom 2 also relayed a number of test television transmissions from Fort Dix, New Jersey to a ground station in
Andover, Maine, beginning on September 29, 1963. Although it was low-quality video with no audio, it was the first successful television transmission through a geosynchronous satellite.
487:
Leasat F4 was subsequently powered down and moved to a graveyard orbit with a large amount of station keeping fuel in reserve. This was fortuitous; when another satellite suffered a loss of its fuel ten years later, Hughes engineers pioneered the use of alternative propellants with Leasat F4. Long
483:
The stricken F4 did not remain a complete failure. Data from F4's failure permitted the saving of F1 from a premature failure. Since all of the
Leasats are spin-stabilized, they have a bearing that connects the non-rotating and rotating parts of the spacecraft. After F4's communication failure, it
440:
However, with another satellite planned to be launched, it was determined that a space walk by a subsequent
Shuttle crew might be able to "wake" the craft. The best guess was that a switch had failed to turn on the satellite. A "bypass box" was hastily constructed, NASA was excited to offer
1073:
The spacecraft next carried out a series of attitude and velocity maneuvers to align itself with the equator at an inclination of 0.1 degrees and to slow its speed so it drifted west to the planned location at 180 degrees longitude where its speed at altitude was synchronized with the
344:
The five satellites of the 1980s Leasat (Leased
Satellite) program (Leasat F1 through Leasat F5) were alternatively named Syncom IV-1 to Syncom IV-5 and called HS 381 by the manufacturer. These satellites were considerably larger than Syncoms 1 to 3, weighing 1.3
507:
on
January 9, 1990. The last active Leasat, it was officially decommissioned on September 24, 2015, at 18:25:13 UTC. F5 was one of the longest-serving and most successful commercial satellites. Towards the end of its 25-year life, F5 had been leased by the
488:
after its primary mission had failed, F4 was powered back on to test whether a satellite could be kept on station using nonvolatile propellants. F4 was used to perform numerous tests, including maneuvers with oxidizer for propulsion once the hydrazine ran out.
235:
During the first year of Syncom 2 operations, NASA conducted voice, teletype, and facsimile tests, as well as 110 public demonstrations to show the capabilities of this satellite and invite feedback. In August 1963, President
431:. Attempts by Shuttle astronauts to activate F3 with a makeshift "flyswatter" were unsuccessful. The satellite was left in low Earth orbit, and the Space Shuttle returned to Earth. This failure made front-page news in
1319:
For example, no transistor amplifiers existed, and transistors then didn't work well at frequencies above 70 MHz. We had to get up to 10 GHz. So we used a chain of diode frequency multipliers, or
200:
kick motor for circularizing the orbit was fired, the spacecraft fell silent. Later telescopic observations verified the satellite was in an orbit with a period of almost 24 hours at a 33° inclination.
466:, van Hoften manually spun the satellite up. Once released, the F3 successfully powered up, fired its perigee motor and obtained a geostationary orbit. (This scenario would play out again in 1992 with
1280:
366:
The system was used by military customers in the US and later in
Australia. Most of the satellites were retired in the 1990s, but one would remain operational until 2015. During the
437:. Hughes had an insurance policy on the satellite, and so claimed a total loss for the spacecraft of about $ 200 million, an amount underwritten by numerous parties.
381:
Hughes was contracted to provide a worldwide communications system based on four satellites, one over the continental United States (CONUS), and one each over the
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995:
417:. F2 was largely successful, but its wideband receiver was out of commission after only four months. F1 was launched successfully on November 8, 1984 aboard
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1284:
314:
By the end of 1964, Syncoms 2 and 3 had completed NASA's R&D experiments. On
January 1, 1965, NASA transferred operation of the satellites to the
1367:
1086:
851:
109:). Syncom 2, launched in 1963, was the world's first geosynchronous communications satellite. Syncom 3, launched in 1964, was the world's first
960:
806:
378:, but was more typically used by "mobile air, surface, subsurface, and fixed earth stations of the Navy, Marine Corps, Air Force, and Army."
116:
In the 1980s, the series was continued as Syncom IV with some much larger satellites, also manufactured by Hughes. They were leased to the
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227:
Prime
Minister Balewa (2nd from right) talks to President John F. Kennedy on the first live broadcast via the SYNCOM satellite from USNS
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349:
each (over 7 tonnes with launch fuel). At 4.26 metres (14.0 ft), the satellites were the first to be designed for launch from the
425:. F3's launch was declared a failure when the satellite failed to start its maneuver to geostationary orbit once released from
737:
1134:
480:.) While F3 was now operational, Leasat F4 soon failed and was itself declared a loss after only 40 hours of RF communications.
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assistance, the customer was supportive, and the insurance underwriters agreed to fund the first ever attempt at space salvage.
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with a despun communications and antenna section. They were made with a solid rocket motor for initial perigee burn and
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Leasat F1's launch was canceled just prior to lift-off, and F2 became the first into orbit on August 30, 1984 aboard
68:
46:
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connections. As of 25 June 2009, all three satellites are still in orbit, although no longer functioning.
39:
984:
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216:#20 launch vehicle from Cape Canaveral. The satellite successfully kept station at the altitude calculated by
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154:
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1311:"Boeing. Satellite Development Center. Syncom. The world's first geosynchronous communications satellite"
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708:
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652:
624:
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836:
837:"Television Tests with the Syncom II Synchronous Communications Satellite (NASA technical note D-2911)"
165:. Thus, Syncom satellites were only capable of carrying a single two-way telephone conversation, or 16
223:
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358:
524:
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196:, but was lost on the way to geosynchronous orbit due to an electronics failure. Seconds after the
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satellite first broadcast television from the United States to Japan on
November 22, 1963.
287:
181:
101:, all of which were developed and manufactured by the Space and Communications division of
8:
491:
The fifth and last Leasat (F5), which was built as a spare, was successfully launched by
298:. Although Syncom 3 is sometimes credited with the first television program to cross the
275:
433:
1110:"The Men Who Staff HCI's LEASAT Earth Stations Are Accustomed to Working on Their Own"
217:
1142:
935:
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375:
286:, had the addition of a wideband channel for television and was used to telecast the
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455:
1053:"Detailed information about SYNCOM 3 satellite, 1964-047A, TLE data for Norad 858"
745: – Early geostationary communications and weather satellite, launched in 1966
321:
In 1965, Syncom 3 was implemented to support the DOD's communications in
Vietnam.
462:
spun down the F3 satellite. After the bypass box was installed by van Hoften and
255:
Harbor—the first live two-way call between heads of government by satellite. The
237:
382:
245:
193:
95:
771:"Harold Rosen, Who Ushered in the Era of Communication Satellites, Dies at 90"
370:, Leasat would be used for personal communications between Secretary of State
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985:"Significant Achievements in Space Communications and Navigation, 1958-1964"
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282:#25 launch vehicle from Cape Canaveral. The satellite, in orbit near the
184:
communications satellite. It was launched on February 14, 1963, with the
371:
166:
141:
The three early Syncom satellites were experimental spacecraft built by
328:
as of 2024. In 50 years it has drifted east, to longitude 123 W.
362:
1281:"Another Intelsat Satellite Serves Customers for More Than 25 Years"
1258:"The LEASAT Program That Launched HCI Completes 13 Years Of Service"
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was again used to launch Leasat F4, and during the same mission (
395:
354:
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876:
Uhlig, Thomas; Sellmaier, Florian; Schmidhuber, Michael (2014).
751: – United States Department of Defense official (1920–2015)
336:
128:
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197:
16:
1960s and 80s NASA program to develop communications satellites
278:
communication satellite, launched on August 19, 1964 with the
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in Washington, D.C., telephoned Nigerian Prime Minister
421:. This was followed on April 12, 1985 by Leasat F3 on
454:) captured the 15,000 lb stricken F3. Astronaut
1264:. Hughes Communications. Winter 1993. Archived from
1116:. Hughes Communications. Summer 1994. Archived from
835:
Henry, Varice F.; McDonald, Michael E. (July 1965).
1179:"First Satellite Designed for Space Shuttle Launch"
1158:"Leasat Beginnings and Significance–Boris Subbotin"
1141:. Federation of American Scientists. Archived from
1359:
1173:
1171:
1337:NASA Goddard Space Flight center descriptions:
924:. London: Institution of Electrical Engineers.
259:acted as a control station and uplink station.
212:was launched by NASA on July 26, 1963 with the
157:. They were capable of emitting signals on two
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1250:
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340:Syncom IV, Hughes-owned US military Leasat
1278:
1237:"The Leasat Rescue Mission—Steve Dorfman"
1230:
1228:
977:
310:Transfer to Department of Defense control
69:Learn how and when to remove this message
1368:1961 establishments in the United States
830:
828:
826:
335:
324:Turned off in 1969, Syncom 3 remains in
222:
127:
32:This article includes a list of general
1215:"LEASAT F5, The Final Chapter-Andy Ott"
1087:"Track SYNCOM 3 Satellite in Real Time"
768:
738:List of communications satellite firsts
1360:
1279:Nerenberg, Sharyn (January 24, 2015).
1234:
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1212:
1208:
1206:
1204:
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1200:
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921:Spacecraft Technology: the early years
353:payload bay, and were deployed like a
1013:
823:
394:purchase the equipment outright. The
331:
1033:from the original on October 9, 2022
1021:"Aeronautics and Astronautics, 1965"
1001:from the original on October 9, 2022
857:from the original on October 9, 2022
123:
18:
1193:
1124:
316:United States Department of Defense
107:Boeing Satellite Development Center
88:synchronous communication satellite
13:
1398:Satellites in geosynchronous orbit
1303:
1063:from the original on March 4, 2016
969:. October 16, 1964. Archived from
769:Wichter, Zach (February 2, 2017).
136:
38:it lacks sufficient corresponding
14:
1409:
1326:
1213:Fisher, Jack (November 2, 2015).
357:. The satellites are 30 rpm
132:First generation Syncom satellite
1156:Fisher, Jack (January 3, 2013).
23:
1272:
1235:Fisher, Jack (April 23, 2013).
1079:
1045:
961:"For Gold, Silver & Bronze"
1333:Syncom 2 satellite description
994:. NASA. 1966. pp. 30–32.
953:
911:
869:
815:. May 14, 1965. Archived from
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781:
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1:
1383:History of telecommunications
1183:Defense, Space & Security
789:"U.S. Space Objects Registry"
755:
180:was intended to be the first
1241:Our Space Heritage 1960–2000
1219:Our Space Heritage 1960-2000
1162:Our Space Heritage 1960–2000
7:
731:
266:
204:
172:
10:
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1283:. Intelsat. Archived from
120:under the Leasat program.
1378:Communications satellites
918:Williamson, Mark (2006).
398:was the original lessee.
1185:. Boeing. Archived from
510:Australian Defence Force
444:On August 27, 1985
218:Herman PotoÄŤnik Noordung
99:communication satellites
1139:Military Space Programs
284:International Date Line
147:Culver City, California
143:Hughes Aircraft Company
111:geostationary satellite
103:Hughes Aircraft Company
53:more precise citations.
1317:on November 11, 2010.
882:. New York: Springer.
341:
242:Abubakar Tafawa Balewa
232:
133:
118:United States military
1287:on September 26, 2015
1189:on December 30, 2009.
879:Spacecraft Operations
807:"The Room-Size World"
339:
226:
131:
90:") started as a 1961
1099:Requires Javascript.
326:geosynchronous orbit
288:1964 Summer Olympics
1373:1963 in spaceflight
795:on October 6, 2013.
413:on shuttle mission
149:, by a team led by
94:program for active
1091:Infosatellites.com
1057:Infosatellites.com
973:on April 21, 2008.
775:The New York Times
458:grappled and then
434:The New York Times
342:
332:Syncom IV (Leasat)
233:
231:in Lagos, Nigeria.
134:
1145:on June 23, 2012.
1097:on March 4, 2016.
729:
728:
512:for UHF service.
376:George H. W. Bush
124:Syncom 1, 2 and 3
79:
78:
71:
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1393:Satellite series
1322:
1313:. Archived from
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791:. Archived from
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456:James van Hoften
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718:
690:
662:
634:
606:
582:Thor Delta D
564:Thor Delta B
546:Thor Delta B
499:
490:
486:
482:
476:
468:Intelsat 603
446:
443:
439:
432:
427:
409:
400:
380:
343:
323:
320:
313:
271:
270:
261:
256:
247:
234:
228:
209:
208:
177:
176:
159:transponders
151:Harold Rosen
140:
115:
87:
83:
82:
80:
65:
56:
37:
1005:October 31,
861:December 7,
702:1990-01-09
674:1985-08-29
646:1985-04-12
618:1984-08-31
588:1984-11-10
570:1964-08-19
552:1963-07-26
534:1963-02-14
464:Bill Fisher
372:James Baker
51:introducing
1362:Categories
1037:January 2,
992:NASA-SP-93
940:2008530215
898:2014945749
756:References
705:Leasat F5
677:Leasat F4
649:Leasat F3
621:Leasat F2
591:Leasat F1
251:docked in
246:USNS
34:references
1320:doublers.
709:1990-002B
691:Discovery
681:1985-076D
663:Discovery
653:1985-028C
635:Discovery
625:1984-113C
607:Discovery
595:1984-093C
577:1964-047A
573:Syncom 3
559:1963-031A
555:Syncom 2
541:1963-004A
537:Syncom 1
477:Endeavour
447:Discovery
428:Discovery
410:Discovery
363:hydrazine
257:Kingsport
248:Kingsport
229:Kingsport
105:(now the
59:July 2011
1351:Syncom 3
1346:Syncom 2
1341:Syncom 1
1135:"LEASAT"
1067:July 14,
1061:Archived
1028:Archived
996:Archived
945:June 13,
903:June 13,
852:Archived
732:See also
719:Columbia
696:STS-51-I
668:STS-51-D
640:STS-41-D
612:STS-51-A
503:mission
500:Columbia
460:manually
452:STS-51-I
423:STS-51-D
419:STS-51-A
415:STS-41-D
383:Atlantic
272:Syncom 3
267:Syncom 3
210:Syncom 2
205:Syncom 2
178:Syncom 1
173:Syncom 1
167:Teletype
396:US Navy
387:Pacific
355:Frisbee
304:Relay 1
294:to the
280:Delta D
244:aboard
214:Delta B
186:Delta B
155:payload
47:improve
1262:Uplink
1114:Uplink
1074:Earth.
938:
928:
896:
886:
724:STS-32
505:STS-32
391:Indian
389:, and
347:tonnes
302:, the
198:apogee
86:(for "
84:Syncom
36:, but
1031:(PDF)
1024:(PDF)
999:(PDF)
988:(PDF)
855:(PDF)
840:(PDF)
743:ATS-1
716:
688:
660:
632:
604:
521:Name
518:Date
497:
474:
407:
292:Tokyo
253:Lagos
192:from
1293:2015
1069:2024
1039:2019
1007:2009
966:TIME
947:2020
936:LCCN
926:ISBN
905:2020
894:LCCN
884:ISBN
863:2014
848:NASA
812:TIME
470:and
188:#16
92:NASA
290:in
1364::
1260:.
1249:^
1239:.
1227:^
1217:.
1195:^
1181:.
1170:^
1160:.
1137:.
1126:^
1112:.
1089:.
1071:.
1059:.
1055:.
990:.
963:.
934:.
892:.
850:.
846:.
842:.
825:^
809:.
773:.
722:,
694:,
666:,
638:,
610:,
525:ID
385:,
113:.
1295:.
1243:.
1221:.
1164:.
1041:.
1009:.
949:.
907:.
865:.
777:.
163:W
72:)
66:(
61:)
57:(
43:.
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