29:
252:
satellites are punctured by orbiting space debris—calculated to be 8 percent over any 50-year period—and release their remaining NaK coolant into space. The coolant self-forms into frozen droplets of solid sodium-potassium of up to around several centimeters in size, and these solid objects then
160:. The satellite failed to boost into a nuclear-safe storage orbit as planned. Nuclear materials re-entered the Earth's atmosphere on 24 January 1978 and left a trail of radioactive pollution over an estimated 124,000 square kilometres of
174:. Failed to boost into storage orbit in late 1982. The reactor core was separated from the remainder of the spacecraft and was the last piece of the satellite to return to Earth, landing in the South Atlantic Ocean on 7 February 1983.
242:
of 269 years. There is no risk of surface contamination, as the droplets will burn up completely in the upper atmosphere on re-entry and the argon, a chemically inert gas, will dissipate. The major risk is impact with operational
85:
Because a return signal from an ordinary target illuminated by a radar transmitter diminishes as the inverse of the fourth power of the distance, for the surveillance radar to work effectively, US-A satellites had to be placed in
105:. Normally the nuclear reactor cores were ejected into high orbit (a so-called "disposal orbit") at the end of the mission, but there were several failure incidents, some of which resulted in radioactive material re-entering the
136:(RTGs) do not generate significant gamma radiation as compared with unshielded satellite fission reactors, and all of the BES-5-containing spacecraft orbited too low to cause positron pollution in the magnetosphere.
128:) which were each capable of operating for six months. The higher-orbiting TOPAZ-containing satellites were the major source of orbital contamination for satellites that sensed
230:
reactors. The smaller droplets have already decayed/reentered, but larger droplets (up to 5.5 cm in diameter) are still in orbit. Since the metal coolant was exposed to
180:. The primary system failed to eject the reactor core into storage orbit, but the backup managed to push it into an orbit 80 km (50 mi) below its intended altitude.
1291:
94:
due to drag through the upper atmosphere. Further, the satellite would have been useless in the shadow of Earth. Hence the majority of the satellites carried type
1382:
1243:
Wiedemann, C.; Oswald, M.; Stabroth, S.; Klinkrad, H.; Vörsmann, P. (2005). "Size distribution of NaK droplets released during RORSAT reactor core ejection".
148:
Launch failure, 25 April 1973. Launch failed and the reactor fell into the
Pacific Ocean north of Japan. Radiation was detected by US air sampling airplanes.
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177:
1217:
1116:
Wiedemann, C.; Oswald, M.; Stabroth, S.; Klinkrad, H.; Vörsmann, P. (2005). "Modeling of RORSAT NaK droplets for the MASTER 2005 upgrade".
151:
249:
116:
types with a capacity of providing about two kilowatts of power for the radar unit. In addition, in 1987 the
Soviets launched two larger
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133:
248:
An additional mechanism is through the impact of space debris hitting intact contained coolant loops. A number of these
1332:
189:
Although most nuclear cores were successfully ejected into higher orbits, their orbits will still eventually decay.
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67:
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106:
1292:"Effects of the RORSAT NaK Drops on the Long Term Evolution of the Space Debris Population"
1252:
1125:
262:
There were 38 Rorsat satellite launches from
Baikonur, all with reported mass of 3,800 kg.
112:
The US-A programme was responsible for orbiting a total of 33 nuclear reactors, 31 of them
17:
154:(04564 / 1970-079A), 3 October 1970, failed 110 hours after launch, moved to higher orbit.
8:
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1345:"Havoc in the Heavens: Soviet-Era Satellite's Leaky Reactor's Lethal Legacy"
193:
90:. Had they used large solar panels for power, the orbit would have rapidly
64:
1094:, an experimental nuclear reactor launched into orbit by the United States
1277:
C. Wiedemann et al, "Size distribution of NaK droplets for MASTER-2009",
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1218:"Spy Satellite Reactor Now in a Safe Orbit, Its Trackers Report"
226:, respectively) escaped from the primary coolant systems of the
1333:
Encyclopedia
Astronautica article on the US-A RORSAT programme.
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219:
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During 16 reactor core ejections, approximately 128 kg of
161:
235:
227:
113:
95:
75:
71:
1279:
Proceedings of the 5th
European Conference on Space Debris
1191:
David. S.F. Portree; Joseph P. Loftus Jr. (January 1999).
205:
253:
become a significant source of space debris themselves.
139:
The last US-A satellite was launched 14 March 1988.
1281:, 30 March-2 April 2009, (ESA SP-672, July 2009).
1374:
1338:The US-A program and radio observations thereof
1362:"Old Nuclear-Powered Soviet Satellite Acts Up"
1157:"Summary of space-based nuclear power systems"
1383:Reconnaissance satellites of the Soviet Union
1359:
1342:
23:Soviet nuclear-powered surveillance satellite
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1236:
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70:. Launched between 1967 and 1988 to monitor
132:for astronomical and security purposes, as
257:
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234:radiation, it contains some radioactive
27:
192:US-A satellites were a major source of
1398:Nuclear technology in the Soviet Union
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134:radioisotope thermoelectric generators
120:(six kilowatts) in Kosmos satellites (
47:for Controlled Active Satellite), or
53:Radar Ocean Reconnaissance Satellite
13:
200:. The debris is created two ways:
14:
1409:
1360:Leonard David (15 January 2009).
1326:
184:
78:, the satellites were powered by
1155:Regina Hagen (8 November 1998).
1343:Leonard David (29 March 2004).
1138:10.1016/j.actaastro.2005.03.014
1297:
1210:
1170:
1148:
1:
1177:positron pollution from TOPAZ
1108:
1193:Orbital Debris: A Chronology
142:
63:17F16K), was a series of 33
51:, also known in the west as
45:Управляемый Спутник Активный
37:Upravlyaemy Sputnik Aktivnyy
7:
1294:, University of Pisa, 1997.
1085:
74:and merchant vessels using
10:
1414:
1245:Advances in Space Research
266:Rorsat satellite launches
15:
1265:10.1016/j.asr.2005.05.056
1103:List of Kosmos satellites
68:reconnaissance satellites
44:
258:List of US-A satellites
1393:Nuclear power in space
118:TOPAZ nuclear reactors
33:
166:Northwest Territories
31:
18:USA (disambiguation)
16:For other uses, see
1257:2005AdSpR..35.1290W
1130:2005AcAau..57..478W
267:
1222:The New York Times
666:1977 September 18
643:1977 September 16
286:Inclination (deg)
265:
107:Earth's atmosphere
34:
1118:Acta Astronautica
1098:Space-based radar
1083:
1082:
1015:1987 December 12
574:1975 December 12
459:1973 December 27
390:1971 December 25
1405:
1369:
1356:
1355:on 5 April 2004.
1351:. Archived from
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1301:
1295:
1290:A. Rossi et al,
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1251:(7): 1290–1295.
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1124:(2–8): 478–489.
900:1984 October 31
620:1976 October 21
597:1976 October 17
322:US-A Mass Model
319:1969 January 25
268:
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99:nuclear reactors
80:nuclear reactors
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413:1972 August 21
342:1970 October 3
277:Launch Vehicle
274:Satellite Name
260:
215:of 22% and 78%
198:low Earth orbit
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88:low Earth orbit
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1198:(Report). NASA
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289:Period (min)
288:
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280:Perigee (km)
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210:fusible alloy
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1388:Space radars
1365:
1353:the original
1348:
1312:. Retrieved
1308:
1299:
1286:
1278:
1273:
1248:
1244:
1238:
1226:. Retrieved
1221:
1212:
1200:. Retrieved
1172:
1160:. Retrieved
1150:
1121:
1117:
1064:Cosmos 1932
1041:Cosmos 1860
1018:Cosmos 1900
995:Cosmos 1736
972:Cosmos 1771
949:Cosmos 1677
926:Cosmos 1670
903:Cosmos 1607
880:Cosmos 1579
857:Cosmos 1412
834:Cosmos 1365
831:1982 May 14
811:Cosmos 1372
808:1982 June 1
763:Cosmos 1249
740:Cosmos 1299
717:Cosmos 1266
694:Cosmos 1176
505:1974 May 17
482:1974 May 15
283:Apogee (km)
271:Launch Date
261:
238:-39, with a
194:space debris
191:
188:
138:
111:
84:
56:
52:
48:
36:
35:
25:
787:Cosmos 1402
646:Cosmos 952
623:Cosmos 861
600:Cosmos 860
577:Cosmos 785
554:Cosmos 724
531:Cosmos 723
508:Cosmos 654
485:Cosmos 651
462:Cosmos 626
416:Cosmos 516
393:Cosmos 469
370:Cosmos 402
345:Cosmos 367
297:Cosmos 209
243:satellites.
178:Kosmos 1900
172:Kosmos 1402
126:Kosmos 1867
122:Kosmos 1818
103:uranium-235
101:fuelled by
1377:Categories
1314:31 October
1109:References
1067:Tsyklon 2
1044:Tsyklon 2
1021:Tsyklon 2
998:Tsyklon 2
975:Tsyklon 2
952:Tsyklon 2
929:Tsyklon 2
906:Tsyklon 2
883:Tsyklon 2
860:Tsyklon 2
837:Tsyklon 2
814:Tsyklon 2
791:Tsyklon 2
766:Tsyklon 2
743:Tsyklon 2
720:Tsyklon 2
697:Tsyklon 2
674:Tsyklon 2
670:Cosmos 954
649:Tsyklon 2
626:Tsyklon 2
603:Tsyklon 2
580:Tsyklon 2
557:Tsyklon 2
534:Tsyklon 2
511:Tsyklon 2
488:Tsyklon 2
465:Tsyklon 2
442:Tsyklon 2
419:Tsyklon 2
396:Tsyklon 2
373:Tsyklon 2
158:Kosmos 954
152:Kosmos 367
130:gamma-rays
61:GRAU index
1366:Space.com
1349:Space.com
349:Tsyklon 2
240:half-life
224:potassium
143:Incidents
1228:19 March
1202:19 March
1162:19 March
1092:SNAP-10A
1086:See also
439:failure
325:Tsyklon
213:eutectic
1253:Bibcode
1126:Bibcode
1079:104.40
1056:104.00
1010:104.40
987:104.20
964:103.90
941:104.10
918:104.10
895:103.90
872:103.90
849:103.60
826:103.90
778:103.90
755:103.90
732:103.60
709:103.40
661:104.10
638:104.20
615:104.30
592:104.20
569:102.90
546:103.60
523:104.40
500:103.40
477:103.90
431:104.50
408:104.60
385:104.90
362:104.50
314:103.00
301:Tsyklon
232:neutron
208:-78 (a
92:decayed
41:Russian
1305:"US-A"
1076:65.10
1073:1,008
1053:65.00
1033:99.10
1030:66.10
1007:65.00
984:65.00
981:1,000
961:64.70
958:1,001
938:64.90
935:1,007
915:65.00
892:65.10
869:64.80
846:65.10
823:64.90
803:89.60
800:65.00
775:65.00
752:65.10
729:64.80
706:64.80
686:89.70
683:65.00
658:64.90
635:64.90
612:64.70
589:65.10
586:1,004
566:65.60
543:64.70
520:64.90
517:1,006
497:65.00
474:65.40
428:64.80
425:1,038
405:64.50
402:1,006
382:65.00
379:1,011
359:65.30
356:1,022
311:65.30
220:sodium
162:Canada
65:Soviet
57:RORSAT
32:RORSAT
1196:(PDF)
236:argon
228:BES-5
114:BES-5
96:BES-5
76:radar
1316:2023
1230:2023
1204:2023
1164:2023
1070:920
1050:992
1047:900
1027:735
1024:696
1004:995
1001:936
978:909
955:880
932:893
912:994
909:908
889:970
886:914
866:998
863:886
843:979
840:881
820:966
817:919
797:266
794:250
772:976
769:904
749:962
746:926
726:941
723:911
703:962
700:873
680:265
677:251
655:990
652:911
632:987
629:928
609:995
606:923
583:907
563:943
560:852
540:961
537:899
514:924
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