Encyclopedia Astronautica
Nuclear/LH2



rd0410.jpg
RD-0410 NTP Engine
RD-0410 Nuclear Thermal Engine
Credit: © Dietrich Haeseler
Nuclear thermal engines use the heat of a nuclear reactor to heat a propellant. Although early Russian designs used ammonia or alcohol as propellant, the ideal working fluid for space applications is the liquid form of the lightest element, hydrogen. Nuclear engines would have twice the performance of conventional chemical rocket engines. Although successfully ground-tested in both Russia and America, they have never been flown due primarily to environmental and safety concerns. Liquid hydrogen was identified by all the leading rocket visionaries as the theoretically ideal rocket fuel. It had big drawbacks, however - it was highly cryogenic, and it had a very low density, making for large tanks. The United States mastered hydrogen technology for the highly classified Lockheed CL-400 Suntan reconnaissance aircraft in the mid-1950's. The technology was transferred to the Centaur rocket stage program, and by the mid-1960's the United States was flying the Centaur and Saturn upper stages using the fuel. It was adopted for the core of the space shuttle, and Centaur stages still fly today.

In Russia hydrogen fuelled upper stages were designed and developed by the mid-1970's, but the Russians never seem to have found the extra performance to be worth the extra cost. Europe and China developed liquid oxygen/liquid hydrogen engines for upper stages of the Ariane and Long March launch vehicles.

The equilibrium composition of liquid hydrogen is 99.79 per cent parahydrogen and 0.21 per cent orthohydrogen. The boiling point of this composition is -253 deg C. Liquid hydrogen is transparent and without a characteristic odour. Gaseous hydrogen is colourless. Hydrogen is not toxic but is an extremely flammable material. The flammable limits of gaseous hydrogen in air are 4.0 to 75 volume percent.

Hydrogen is produced from by-product hydrogen from petroleum refining and the partial oxidation of fuel oil. The gaseous hydrogen is purified to 99.999+ per cent, and then liquefied in the presence of paramagnetic metallic oxides. The metallic oxides catalyse the ortho-para transformation of freshly liquefied hydrogen. Freshly liquefied hydrogen which has not been catalysed consists of a 3:1 ortho-para mixture and cannot be stored for any length of time because of the exothermic heat of conversion. The delivered cost of liquid hydrogen in 1960 was approximately $ 2.60 per kg. Large-scale production was expected to reduce the cost to $ 1.00 per kg. In the 1980's NASA was actually paying $ 3.60 per kg.

Oxidizer: Nuclear. Fuel: LH2. Fuel Density: 0.071 g/cc. Fuel Freezing Point: -259 deg C. Fuel Boiling Point: -253 deg C.

More... - Chronology...


Associated Spacecraft
  • Mars Expedition NASA Lewis 1960 American manned Mars expedition. Study 1960. The first NASA study of a manned Mars expedition outlined an opposition-class, nuclear thermal rocket powered spacecraft that would take seven astronauts to the planet's surface for 40 days. More...
  • Saturn S-N C-3BN American space tug. Study 1961. Upper stage / space tug - Study 1961. Launched by Saturn C-5N-3. Nuclear upper stage considered in lieu of S-IVB in final Saturn C-3B study in November 1961. More...
  • Saturn S-N C-5N American space tug. Study 1961. Upper stage / space tug - Study 1961. Launched by Saturn C-5N-3. Nuclear upper stage considered in lieu of S-IVB in final Saturn C-5 study in November 1961. More...
  • EMPIRE Aeronutronic American manned Mars flyby. Study 1962. Aeronutronic's Mars flyby spacecraft design of 1962 had a total mass of 170 metric tons and would be launched into low earth orbit with a single launch of a Nova booster. More...
  • EMPIRE Lockheed American manned Mars flyby. Study 1962. Lockheed's manned Mars flyby spacecraft design of 1962 had a total mass of 100 metric tons. More...
  • EMPIRE General Dynamics American manned Mars flyby. Study 1962. General Dynamics' manned Mars orbiter spacecraft design of 1962 had a total mass of 900 metric tons and would be launched into low earth orbit with a two launches of a Nova booster or eight launches of a Saturn V. More...
  • UMPIRE Douglas American manned Mars expedition. Study 1964. Unfavorable Manned Planetary - Interplanetary Roundtrip Expedition profiles were studied under NASA Huntsville contracts to General Dynamics and Douglas in June 1963. More...
  • IMIS 1968 American manned Mars expedition. Study 1968. In January 1968 Boeing issued a report that was the result of a 14 month study on manned Mars missions. More...
  • Von Braun Mars Expedition - 1969 American manned Mars expedition. Study 1969. Von Braun's final vision for a manned expedition to Mars was a robust plan that eliminated much of the risk of other scenarios. Two ships would fly in convoy from earth orbit to Mars and back. More...
  • FLEM American manned Mars expedition. Study 1966. More...
  • PPM American space tug. Study 1968. The Primary Propulsion Module was the definitive 1960's design for a nuclear thermal rocket stage suitable for interplanetary operations. More...
  • Saturn S-N V-25(S)U American space tug. Study 1968. Upper stage / space tug - study 1969. Launched by Saturn V-25(S)U. Version of Nerva studied by Boeing for manned Mars expedition. More...
  • MK-700 Russian manned Mars flyby. Study 1972. Chelomei was the only Chief Designer to complete an Aelita draft project and present it to the Soviet government. More...
  • Nerva American space tug. Study 1980. Upper stage / space tug - Development 1971. More...
  • Nerva 2/NTR American space tug. Study 2005. Upper stage / space tug - study completed 1991. Late 1980's update of 1960's Nerva design. More...
  • Mars 1994 Russian manned Mars expedition. Study 1994. Soviet / Russian design for a Mars expedition powered by RD-0410 bi-modal nuclear thermal engines. A crew of five would complete the trip to Mars and back in 460 days. More...

Associated Engines
  • NERVA 1mlbf Notional nuclear/lh2 rocket engine. 8963 kN. DAC Helios, DAC Helios ISI studies 1963. Isp=850s. More...
  • Nerva NTR DoE nuclear/lh2 rocket engine. 333.4 kN. Study 1991. Late 1980's update of 1960's Nerva design. Isp=925s. More...
  • Nerva Gamma DoE nuclear/lh2 rocket engine. 81 kN. Study 1972. Isp=975s. The final Nerva Gamma flight engine was an improved version of the Alpha, a small engine that could be launched together with its stage and a payload in a single space shuttle launch. More...
  • Nerva 12 GW Notional nuclear/lh2 rocket engine. Study 1959. Used on Hyperion launch vehicle. More...
  • Nerva DoE nuclear/lh2 rocket engine. 266 kN. Study 1968. Early version of Nerva engine proposed for use in Saturn and RIFT configurations in 1961. Isp=800s. More...
  • Nerva Alpha DoE nuclear/lh2 rocket engine. 71.7 kN. Study 1972. The final Nerva Alpha flight engine reference configuration as documented at the end of its development. Isp=860s. More...
  • Nerva 2 DoE nuclear/lh2 rocket engine. 867.4 kN. Developed 1950-74. Isp=825s. More...
  • NPS-2 Rocketdyne nuclear/lh2 rocket engine. Nuclear Deep Space. Nuclear. Liquid hydrogen turbopumps, feed systems, and nozzles developed for KIWI-A, KIWI-B, Nerva, Pheobus IA, MFS-1, MFS-2, MFS-3, and Rover nuclear development systems. More...
  • Nuclear 12 Gw Notional nuclear/lh2 rocket engine. 2892 kN. Helios A, Helios C study 1960. Nuclear second stage. Isp=830s. More...
  • Nuclear 14 Gw Notional nuclear/lh2 rocket engine. 3334 kN. Study 1960. Nuclear second stage Isp=830s. Used on Helios B launch vehicle. More...
  • RD-0410 Kosberg nuclear/lh2 rocket engine. 35.3 kN. Experimental nuclear engine, propellant LH2. Developed 1965-94. Isp=910s. Tested at Semipalatinsk test range in 1980s and was "the only operational nuclear engine in the USSR". First flight 1985. More...
  • RD-0411 Kosberg nuclear/lh2 rocket engine. 392 kN. Full-size nuclear thermal engine. Design concept 1965-94. Planned full-size nuclear thermal engine for Mars expeditions. Never progressed beyond study stage. Isp=900s. More...
  • RD-410 Glushko nuclear/lh2 rocket engine. 68 kN. UR-700M concept. Developed 1960s. More...
  • RD-600 Glushko nuclear/lh2 rocket engine. 1960 kN. Isp=2000s. Gas core nuclear engine worked developed 1962-1970 for use in second stage of two-stage interplanetary rockets. More...
  • RN-6 Rocketdyne nuclear/lh2 rocket engine. Nuclear Deep Space. Nuclear. More...
  • RO-31 Kosberg nuclear/lh2 rocket engine. 392 kN. UR-700 Third Stage. Study 1967. Engine proposed for UR-700 third stage to achieve 250 tonne payload to low earth orbit. Probably closely related to RD-0411. More...
  • Timberwind 250 DoE nuclear/lh2 rocket engine. 2451.6 kN. Development ended 1992. Isp=1000s. Used on Timberwind launch vehicle. More...
  • Timberwind 45 DoE nuclear/lh2 rocket engine. 441.3 kN. Development ended 1992. Isp=1000s. Used on Timberwind Centaur launch vehicle. More...
  • Timberwind 75 DoE nuclear/lh2 rocket engine. 735.5 kN. Development ended 1992. Isp=1000s. Used on Timberwind Titan launch vehicle. More...
  • YaRD Type V-B Korolev nuclear/lh2 rocket engine. 392 kN. Study 1963. Isp=900s. Design considered in N1 nuclear upper stage studies. This version had 7,000 kg bioshield for manned missions. Used liquid hydrogen as propellant. More...
  • YaRD Type A Korolev nuclear/lh2 rocket engine. 177 kN. Study 1963. Design considered in N1 nuclear upper stage studies. Outgrowth of work done by Bondaryuk and Glushko on YaRD engines for nuclear ICBM's, but using liquid hydrogen as propellant. Isp=900s. More...
  • YaRD Type AF Korolev nuclear/lh2 rocket engine. 196 kN. Study 1963. Design considered in N1 nuclear upper stage studies. Outgrowth of work done by Bondaryuk and Glushko on YaRD engines for nuclear ICBM's, but using liquid hydrogen as propellant. Isp=950s. More...
  • YaRD Type V Korolev nuclear/lh2 rocket engine. 392 kN. Study 1963. Design considered in N1 nuclear upper stage studies. Outgrowth of work done by Bondaryuk and Glushko on YaRD engines for nuclear ICBM's, but using liquid hydrogen as propellant. Isp=900s. More...

Associated Stages
  • DAC Helios-2 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 1,070,000/214,000 kg. Thrust 17,926.00 kN. Vacuum specific impulse 850 seconds. More...
  • DAC Helios ISI-2 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 1,070,000/214,000 kg. Thrust 17,926.00 kN. Vacuum specific impulse 850 seconds. More...
  • Helios A-2 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 153,000/26,000 kg. Thrust 2,892.00 kN. Vacuum specific impulse 830 seconds. Nuclear second stage More...
  • Helios B-2 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 177,000/29,000 kg. Thrust 3,330.00 kN. Vacuum specific impulse 830 seconds. Nuclear second stage More...
  • Helios C-2 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 309,000/54,000 kg. Thrust 5,780.00 kN. Vacuum specific impulse 830 seconds. Nuclear second stage More...
  • Hyperion Sustainer Nuclear/LH2 propellant rocket stage. Loaded/empty mass 453,592/110,000 kg. Thrust 5,782.68 kN. Vacuum specific impulse 800 seconds. More...
  • N1 Nuclear V-Bioshield Nuclear/LH2 propellant rocket stage. Loaded/empty mass 2,000,000/650,000 kg. Thrust 19,600.00 kN. Vacuum specific impulse 900 seconds. N1 nuclear upper stage study, 1963. Figures calculated based on given total stage thrust, specific impulse, engine mass. More...
  • N1 Nuclear A Nuclear/LH2 propellant rocket stage. Loaded/empty mass 700,000/250,000 kg. Thrust 6,860.00 kN. Vacuum specific impulse 900 seconds. N1 nuclear upper stage study, 1963. Figures calculated based on given total stage thrust, specific impulse, engine mass. More...
  • N1 Nuclear AF Nuclear/LH2 propellant rocket stage. Loaded/empty mass 800,000/150,000 kg. Thrust 7,840.00 kN. Vacuum specific impulse 810 seconds. N1 nuclear upper stage study, 1963. Figures calculated based on given total stage thrust, specific impulse, engine mass. More...
  • N1 Nuclear V Nuclear/LH2 propellant rocket stage. Loaded/empty mass 1,500,000/500,000 kg. Thrust 14,700.00 kN. Vacuum specific impulse 900 seconds. N1 nuclear upper stage study, 1963. Figures calculated based on given total stage thrust, specific impulse, engine mass. More...
  • Nerva Gamma Nuclear/LH2 propellant rocket stage. Loaded/empty mass 18,643/5,829 kg. Thrust 81.00 kN. Vacuum specific impulse 975 seconds. Improved version of the Alpha nuclear stage designed to fit into the space shuttle payload bay. Additional propellant modules could be added in orbit. Such propellant modules would have a mass of 23,181 kg, including 21,265 kg of usable propellant. Given an Alpha engine development program, it would have been flight tested by 1984. In addition to propulsion, it would provide 10 to 25 MWe power for missions of two to five years duration. More...
  • Nerva Alpha Nuclear/LH2 propellant rocket stage. Loaded/empty mass 17,783/4,969 kg. Thrust 71.70 kN. Vacuum specific impulse 860 seconds. Nuclear stage designed to fit into the space shuttle payload bay. Additional propellant modules could be added in orbit. Such propellant modules would have a mass of 23,181 kg, including 21,265 kg of usable propellant. Given goahead in 1972, it would have been flight tested by 1982. More...
  • Nerva Nuclear/LH2 propellant rocket stage. Loaded/empty mass 178,321/34,019 kg. Thrust 867.41 kN. Vacuum specific impulse 825 seconds. More...
  • Nerva 2/NTR Nuclear/LH2 propellant rocket stage. Loaded/empty mass 158,400/27,000 kg. Thrust 333.00 kN. Vacuum specific impulse 925 seconds. Design as revised in detail in 2005. More...
  • Nova C-3 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 61,000/9,000 kg. Thrust 264.00 kN. Vacuum specific impulse 830 seconds. More...
  • Nova D-3 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 96,000/12,000 kg. Thrust 264.00 kN. Vacuum specific impulse 830 seconds. More...
  • RITA C Nuclear/LH2 propellant rocket stage. Loaded/empty mass 4,399,000/880,000 kg. Thrust 96,507.00 kN. Vacuum specific impulse 810 seconds. Same engine chamber used to burn liquid oxygen and hydrogen for boost phase, switching to pure nuclear thermal engine for high-performance final acceleration. More...
  • Saturn S-N C-3BN Nuclear/LH2 propellant rocket stage. Loaded/empty mass 32,470/7,708 kg. Thrust 266.80 kN. Vacuum specific impulse 800 seconds. Nuclear upper stage considered in lieu of S-IVB in final Saturn C-3B study in November 1961. More...
  • Saturn S-N C-5N Nuclear/LH2 propellant rocket stage. Loaded/empty mass 53,694/10,429 kg. Thrust 266.80 kN. Vacuum specific impulse 800 seconds. Nuclear upper stage considered in lieu of S-IVB in final Saturn C-5 study in November 1961. More...
  • Saturn S-N V-25(S)U Nuclear/LH2 propellant rocket stage. Loaded/empty mass 245,760/71,190 kg. Thrust 889.33 kN. Vacuum specific impulse 825 seconds. Version of Nerva studied by Boeing for manned Mars expedition. More...
  • Timberwind 250 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 170,000/45,000 kg. Thrust 2,450.00 kN. Vacuum specific impulse 1000 seconds. More...
  • Timberwind 45 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 28,000/7,500 kg. Thrust 441.00 kN. Vacuum specific impulse 1000 seconds. More...
  • Timberwind 75 Nuclear/LH2 propellant rocket stage. Loaded/empty mass 110,000/28,500 kg. Thrust 2,206.00 kN. Vacuum specific impulse 1000 seconds. More...

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