List of nuclear power systems in space

This list of nuclear power systems in space includes 83 nuclear power systems that were flown to space, or at least launched in an attempt to reach space. Such used nuclear power systems include:

• radioisotope heater units (RHU) (usually produce heat by spontaneous decay of ²³⁸
  Pu)
• radioisotope thermoelectric generators (RTG) (usually produce heat by spontaneous decay of ²³⁸
  Pu and convert it to electricity using a thermoelectric generator)
• miniaturized fission reactors (usually produce heat by controlled fission of highly enriched ²³⁵
  U and convert it to electricity using a thermionic converter)

Systems never launched are not included here, see Nuclear power in space.

Initial total power is provided as either electrical power (We) or thermal power (Wt), depending on the intended application.

Nation	Mission	Launched	Status	Location	Notes	Type	System name	Nuclear fuel	Power (nominal)	Ref
USA	Transit-4A	1961	Intact	Earth orbit		RTG	SNAP-3B	238 Pu	2.7 We	[1]
USA	Transit-4B	1961	Intact	Earth orbit		RTG	SNAP-3B	238 Pu	2.7 We	[1]
USA	Transit 5BN-1	1963	Intact	Earth orbit		RTG	SNAP-9A	238 Pu	25.2 We	[1]
USA	Transit 5BN-2	1963	Intact	Earth orbit		RTG	SNAP-9A	238 Pu	26.8 We	[1]
USA	Transit 5BN-3	1964	Destroyed	-	Failed to reach orbit, burned up in atmosphere.	RTG	SNAP-9A	238 Pu	25 We	[2]
USA	SNAPSHOT	1965	Intact	Earth orbit	Low graveyard orbit in 1300 km height	Fission reactor	SNAP-10A	235 U (uranium-zirconium hydride)	500 We	[1]
USA	Nimbus B (Nimbus-B1)	1968-05-18	Destroyed	-	Crashed at launch, radioactive material from RTG recovered from ocean and reused	RTG	SNAP-19B (2)	238 Pu	56 We	[1][3]
USA	Nimbus 3 (Nimbus-B2)	1969-04-14	Destroyed	-	Earth re-entry 1972	RTG	SNAP-19B (2)	238 Pu	56 We	[1]
USA	Nimbus IV	1970	Intact	Earth orbit		RTG	SNAP-19			[4]
USA	Nimbus V	1972	Intact	Earth orbit		RTG	SNAP-19			[4]
USA	Nimbus VI	1975	Damaged	Earth orbit		RTG	SNAP-19			[4]
USA	Nimbus VII	1978	Damaged	Earth orbit		RTG	SNAP-19			[4]
USA	Apollo 11	1969	Intact	Lunar surface	Sea of Tranquility	RHU	RHU (2)		30 Wt	[1]
USA	Apollo 12 ALSEP	1969	Intact	Lunar surface	Ocean of Storms[5]	RTG	SNAP-27	238 Pu	73.6 We	[1]
USA	Apollo 13 ALSEP	1970	Intact	Earth ocean	Survived reentry, remains at 7000+ ft depth, Tonga Trench, Pacific Ocean	RTG	SNAP-27	238 Pu	73 We	[1]
USA	Apollo 14 ALSEP	1971	Intact	Lunar surface	Fra Mauro	RTG	SNAP-27	238 Pu	72.5 We	[1]
USA	Apollo 15 ALSEP	1971	Intact	Lunar surface	Hadley–Apennine	RTG	SNAP-27	238 Pu	74.7 We	[1]
USA	Pioneer 10	1972	Intact	Solar escape trajectory		RTG	SNAP-19 (4) + RHU (12)	238 Pu	162.8 We + 12 Wt	[1]
USA	Apollo 16 ALSEP	1972	Intact	Lunar surface	Descartes Highlands	RTG	SNAP-27	238 Pu	70.9 We	[1]
USA	TRAID-01-1X	1972	Intact	Earth orbit		RTG	SNAP-19	238 Pu	35.6 We	[1]
USA	Apollo 17 ALSEP	1972	Intact	Lunar surface	Taurus–Littrow	RTG	SNAP-27	238 Pu	75.4 We	[1]
USA	Pioneer 11	1973	Intact	Solar escape trajectory		RTG	RTG SNAP-19 (4) + RHU (12)	238 Pu	159.6 We + 12 Wt	[1]
USA	Viking 1	1976	Intact	Mars surface	Chryse Planitia	RTG	lander modified SNAP-19 (2)	238 Pu	84.6 We	[1]
USA	Viking 2	1976	Intact	Mars surface	Utopia Planitia	RTG	lander modified SNAP-19 (2)	238 Pu	86.2 We	[1]
USA	LES-8	1976	Intact	Earth orbit	Near geostationary orbit	RTG	MHW-RTG (2)	238 Pu	307.4 We	[1]
USA	LES-9	1976	Intact	Earth orbit	Near geostationary orbit	RTG	MHW-RTG (2)	238 Pu	308.4 We	[1]
USA	Voyager 1	1977	In use	Solar escape trajectory		RTG	MHW-RTG (3) + RHU(9)	238 Pu	477.6 We + 9 Wt	[1]
USA	Voyager 2	1977	In use	Solar escape trajectory		RTG	MHW-RTG (3) + RHU(9)	238 Pu	470.1 We + 9 Wt	[1]
USA	Mars 2020/Perseverance	2020	In use	Mars surface		RTG	MMRTG	238 Pu	110 We	[6]
USA	Galileo	1989	Destroyed	-	Jupiter atmospheric entry	RTG	GPHS-RTG (2)		576.8 We	[1]
USA	Ulysses	1990	Intact	Heliocentric orbit		RTG	GPHS-RTG		283 We	[1]
USA	Cassini	1997	Destroyed	-	Burned-up in Saturn's atmosphere	RTG	GPHS-RTG (3)	238 Pu	887 We
USA	New Horizons	2006	In use	Solar escape trajectory		RTG	GPHS-RTG (1)	238 Pu	249.6 We
USA	MSL/Curiosity rover	2011	In use	Mars surface		RTG	MMRTG	238 Pu	113 We
Soviet Union	Kosmos 84	1965	Intact	Earth orbit		RTG	Orion-1 RTG	210 Po		[4][7]
Soviet Union	Kosmos 90	1965	Intact	Earth orbit		RTG	Orion-1 RTG	210 Po		[4][7]
Soviet Union	Kosmos 198 (RORSAT)	1967-12-27	Intact	Earth orbit		Fission reactor	BES-5 ??	235 U		[4][8]
Soviet Union	Kosmos 209 (RORSAT)	1968-03-22	Intact	Earth orbit		Fission reactor	BES-5 ??	235 U		[4][8]
Soviet Union	Kosmos 300 (Moon)	1969-09-23	Destroyed	-	Failed to achieve escape trajectory, burned up 4 days after launch	RTG		210 Po		[9]
Soviet Union	Kosmos 305 (Moon)	1969-10-22	Destroyed	-	Failed to achieve escape trajectory, burned up 2 days after launch	RTG		210 Po		[4][10][11][12][9]
Soviet Union	Kosmos 367 (RORSAT)	1970-10-03	Intact	Earth orbit, 579 mile altitude		Fission reactor	BES-5 ??	235 U	2 kWe	[4][8][13]
Soviet Union	Kosmos 402 (RORSAT)	1971	Intact	Earth orbit		Fission reactor	BES-5 ??	235 U	2 kWe	[4][8]
Soviet Union	Kosmos 469 (RORSAT)	1971	Intact	High orbit		Fission reactor	BES-5 (officially confirmed)	235 U	2 kWe	[14]
Soviet Union	Kosmos 516	1972	Intact	High orbited 1972		Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	RORSAT	1973	Destroyed	-	Launch failure over Pacific Ocean, near Japan	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 626	1973	Intact	Earth orbit		Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 651	1974				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 654	1974				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 723	1975				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 724	1975				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 785	1975	Destroyed	-	Failed after reaching orbit	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 860	1976				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 861	1976				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 952	1977				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 954	1977	Destroyed	-	Exploded on re-entry 1978 (over Canada)	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1176	1980	Intact	Earth orbit	11788/11971 Earth orbit 870–970 km	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1249	1981				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1266	1981				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1299	1981				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1402	1982	Destroyed	-	Earth re-entry 1983 (South Atlantic)	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1372	1982				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1365	1982				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1412	1982				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1461	1983	Destroyed	-	Earth orbit, exploded	Fission reactor	BES-5	235 U	2 kWe	[4]
Soviet Union	Kosmos 1597	1984				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1607	1984	Intact	Earth orbit	High orbited 1985	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1670	1985	Intact	Earth orbit	High orbited 1985	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1677	1985	Intact	Earth orbit	High orbited 1985	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1736	1986	Intact	Earth orbit	High orbited 1986	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1771	1986	Intact	Earth orbit	High orbited 1986	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1900	1987	Intact	Earth orbit	Earth orbit, 454 mile altitude	Fission reactor	BES-5	235 U	2 kWe	[14][13]
Soviet Union	Kosmos 1860	1987				Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1932	1988	Intact	Earth orbit	800–900 km	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1682	1985	Intact	Earth orbit	High orbited 1986	Fission reactor	BES-5	235 U	2 kWe	[14]
Soviet Union	Kosmos 1818 (RORSAT)	1987	Destroyed	-	Destroyed in high Earth orbit	Fission reactor	Topaz-I	235 U	5 kWe	[15]
Soviet Union	Kosmos 1867 (RORSAT)	1987	Intact	Earth	Parked in high Earth orbit	Fission reactor	Topaz-I	235 U	5 kWe	[16]
Soviet Union	Lunokhod 201	1969-02-19	Destroyed	-	Rocket exploded at launch, radioactive material from RHU spread over Russia	RHU		210 Po		[17]
Soviet Union	Lunokhod 1	1970	Intact	Lunar surface		RHU		210 Po		[17]
Soviet Union	Lunokhod 2	1973	Intact	Lunar surface		RHU		210 Po		[17]
Russia	Mars 96	1996	Destroyed	-	Launch failure, entered Pacific Ocean	RHU	RHU (4)	238 Pu		[17]
China	Chang'e 3 lander	2013	In use	Lunar surface		RHU	In combination with solar panels allows continued use of the Lunar-based ultraviolet telescope	238 Pu		[18] [19]
China	Yutu rover	2013	Intact	Lunar surface		RHU	Communication lost in 2015
India	Chandrayaan-3 propulsion module	2023	In use	Earth orbit		RHU	BARC RHU, transferred back from lunar orbit after lander mission completion	241Am	2 Wt	[20]

See also

• Outer Space Treaty
• List of high-altitude nuclear explosions
• Nuclear power in space
• List of artificial radiation belts
• Category:Nuclear-powered robots