40:
263:
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
171:. 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
185:. 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.
253:
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
96:
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
116:. 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
147:(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.
1393:
139:) 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
241:
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
191:. 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.
1302:
1408:
105:
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
1254:
Wiedemann, C.; Oswald, M.; Stabroth, S.; Klinkrad, H.; Vörsmann, P. (2005). "Size distribution of NaK droplets released during RORSAT reactor core ejection".
159:
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.
260:
144:
1228:
1127:
Wiedemann, C.; Oswald, M.; Stabroth, S.; Klinkrad, H.; Vörsmann, P. (2005). "Modeling of RORSAT NaK droplets for the MASTER 2005 upgrade".
127:
types with a capacity of providing about two kilowatts of power for the radar unit. In addition, in 1987 the
Soviets launched two larger
1355:
1403:
259:
An additional mechanism is through the impact of space debris hitting intact contained coolant loops. A number of these
1343:
200:
Although most nuclear cores were successfully ejected into higher orbits, their orbits will still eventually decay.
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51:
1303:"Effects of the RORSAT NaK Drops on the Long Term Evolution of the Space Debris Population"
273:
There were 38 Rorsat satellite launches from
Baikonur, all with reported mass of 3,800 kg.
123:
The US-A programme was responsible for orbiting a total of 33 nuclear reactors, 31 of them
208:
165:(04564 / 1970-079A), 3 October 1970, failed 110 hours after launch, moved to higher orbit.
109:
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1356:"Havoc in the Heavens: Soviet-Era Satellite's Leaky Reactor's Lethal Legacy"
359:
250:
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101:. Had they used large solar panels for power, the orbit would have rapidly
1105:, an experimental nuclear reactor launched into orbit by the United States
1288:
C. Wiedemann et al, "Size distribution of NaK droplets for MASTER-2009",
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17:
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124:
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38:
1229:"Spy Satellite Reactor Now in a Safe Orbit, Its Trackers Report"
237:, respectively) escaped from the primary coolant systems of the
82:
1344:
Encyclopedia
Astronautica article on the US-A RORSAT programme.
215:
During 16 reactor core ejections, approximately 128 kg of
216:
1290:
Proceedings of the 5th
European Conference on Space Debris
1202:
David. S.F. Portree; Joseph P. Loftus Jr. (January 1999).
264:
become a significant source of space debris themselves.
150:
The last US-A satellite was launched 14 March 1988.
1292:, 30 March-2 April 2009, (ESA SP-672, July 2009).
1349:The US-A program and radio observations thereof
1373:"Old Nuclear-Powered Soviet Satellite Acts Up"
1168:"Summary of space-based nuclear power systems"
1394:Reconnaissance satellites of the Soviet Union
34:Soviet nuclear-powered surveillance satellite
8:
81:. Launched between 1967 and 1988 to monitor
143:for astronomical and security purposes, as
275:
1197:
1195:
245:radiation, it contains some radioactive
1158:
203:US-A satellites were a major source of
1409:Nuclear technology in the Soviet Union
145:radioisotope thermoelectric generators
131:(six kilowatts) in Kosmos satellites (
58:for Controlled Active Satellite), or
7:
64:Radar Ocean Reconnaissance Satellite
211:. The debris is created two ways:
25:
1371:Leonard David (15 January 2009).
89:, the satellites were powered by
1166:Regina Hagen (8 November 1998).
1354:Leonard David (29 March 2004).
1149:10.1016/j.actaastro.2005.03.014
1:
1188:positron pollution from TOPAZ
1204:Orbital Debris: A Chronology
74:17F16K), was a series of 33
62:, also known in the west as
56:Управляемый Спутник Активный
48:Upravlyaemy Sputnik Aktivnyy
1305:, University of Pisa, 1997.
85:and merchant vessels using
1425:
1256:Advances in Space Research
277:Rorsat satellite launches
26:
1276:10.1016/j.asr.2005.05.056
1114:List of Kosmos satellites
79:reconnaissance satellites
55:
269:List of US-A satellites
1404:Nuclear power in space
129:TOPAZ nuclear reactors
44:
177:Northwest Territories
42:
29:USA (disambiguation)
27:For other uses, see
1268:2005AdSpR..35.1290W
1141:2005AcAau..57..478W
278:
1233:The New York Times
677:1977 September 18
654:1977 September 16
297:Inclination (deg)
276:
118:Earth's atmosphere
45:
1129:Acta Astronautica
1109:Space-based radar
1094:
1093:
1026:1987 December 12
585:1975 December 12
470:1973 December 27
401:1971 December 25
16:(Redirected from
1416:
1380:
1367:
1366:on 5 April 2004.
1362:. Archived from
1331:
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1312:
1306:
1301:A. Rossi et al,
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1262:(7): 1290–1295.
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1135:(2–8): 478–489.
911:1984 October 31
631:1976 October 21
608:1976 October 17
333:US-A Mass Model
330:1969 January 25
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110:nuclear reactors
91:nuclear reactors
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424:1972 August 21
353:1970 October 3
288:Launch Vehicle
285:Satellite Name
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226:of 22% and 78%
209:low Earth orbit
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99:low Earth orbit
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1338:External links
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300:Period (min)
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291:Perigee (km)
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221:fusible alloy
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1399:Space radars
1376:
1364:the original
1359:
1323:. Retrieved
1319:
1310:
1297:
1289:
1284:
1259:
1255:
1249:
1237:. Retrieved
1232:
1223:
1211:. Retrieved
1183:
1171:. Retrieved
1161:
1132:
1128:
1075:Cosmos 1932
1052:Cosmos 1860
1029:Cosmos 1900
1006:Cosmos 1736
983:Cosmos 1771
960:Cosmos 1677
937:Cosmos 1670
914:Cosmos 1607
891:Cosmos 1579
868:Cosmos 1412
845:Cosmos 1365
842:1982 May 14
822:Cosmos 1372
819:1982 June 1
774:Cosmos 1249
751:Cosmos 1299
728:Cosmos 1266
705:Cosmos 1176
516:1974 May 17
493:1974 May 15
294:Apogee (km)
282:Launch Date
272:
249:-39, with a
205:space debris
202:
199:
149:
122:
95:
67:
63:
59:
47:
46:
36:
798:Cosmos 1402
657:Cosmos 952
634:Cosmos 861
611:Cosmos 860
588:Cosmos 785
565:Cosmos 724
542:Cosmos 723
519:Cosmos 654
496:Cosmos 651
473:Cosmos 626
427:Cosmos 516
404:Cosmos 469
381:Cosmos 402
356:Cosmos 367
308:Cosmos 209
254:satellites.
189:Kosmos 1900
183:Kosmos 1402
137:Kosmos 1867
133:Kosmos 1818
114:uranium-235
112:fuelled by
1388:Categories
1325:31 October
1120:References
1078:Tsyklon 2
1055:Tsyklon 2
1032:Tsyklon 2
1009:Tsyklon 2
986:Tsyklon 2
963:Tsyklon 2
940:Tsyklon 2
917:Tsyklon 2
894:Tsyklon 2
871:Tsyklon 2
848:Tsyklon 2
825:Tsyklon 2
802:Tsyklon 2
777:Tsyklon 2
754:Tsyklon 2
731:Tsyklon 2
708:Tsyklon 2
685:Tsyklon 2
681:Cosmos 954
660:Tsyklon 2
637:Tsyklon 2
614:Tsyklon 2
591:Tsyklon 2
568:Tsyklon 2
545:Tsyklon 2
522:Tsyklon 2
499:Tsyklon 2
476:Tsyklon 2
453:Tsyklon 2
430:Tsyklon 2
407:Tsyklon 2
384:Tsyklon 2
169:Kosmos 954
163:Kosmos 367
141:gamma-rays
72:GRAU index
1377:Space.com
1360:Space.com
360:Tsyklon 2
251:half-life
235:potassium
154:Incidents
1239:19 March
1213:19 March
1173:19 March
1103:SNAP-10A
1097:See also
450:failure
336:Tsyklon
224:eutectic
1264:Bibcode
1137:Bibcode
1090:104.40
1067:104.00
1021:104.40
998:104.20
975:103.90
952:104.10
929:104.10
906:103.90
883:103.90
860:103.60
837:103.90
789:103.90
766:103.90
743:103.60
720:103.40
672:104.10
649:104.20
626:104.30
603:104.20
580:102.90
557:103.60
534:104.40
511:103.40
488:103.90
442:104.50
419:104.60
396:104.90
373:104.50
325:103.00
312:Tsyklon
243:neutron
219:-78 (a
103:decayed
52:Russian
1316:"US-A"
1087:65.10
1084:1,008
1064:65.00
1044:99.10
1041:66.10
1018:65.00
995:65.00
992:1,000
972:64.70
969:1,001
949:64.90
946:1,007
926:65.00
903:65.10
880:64.80
857:65.10
834:64.90
814:89.60
811:65.00
786:65.00
763:65.10
740:64.80
717:64.80
697:89.70
694:65.00
669:64.90
646:64.90
623:64.70
600:65.10
597:1,004
577:65.60
554:64.70
531:64.90
528:1,006
508:65.00
485:65.40
439:64.80
436:1,038
416:64.50
413:1,006
393:65.00
390:1,011
370:65.30
367:1,022
322:65.30
231:sodium
173:Canada
76:Soviet
68:RORSAT
43:RORSAT
18:RORSAT
1207:(PDF)
247:argon
239:BES-5
125:BES-5
107:BES-5
87:radar
1327:2023
1241:2023
1215:2023
1175:2023
1081:920
1061:992
1058:900
1038:735
1035:696
1015:995
1012:936
989:909
966:880
943:893
923:994
920:908
900:970
897:914
877:998
874:886
854:979
851:881
831:966
828:919
808:266
805:250
783:976
780:904
760:962
757:926
737:941
734:911
714:962
711:873
691:265
688:251
666:990
663:911
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