NERVA: Difference between revisions
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*[https://history.nasa.gov/SP-4533/Plum%20Brook%20Complete.pdf NASA's Nuclear Frontier] ''The Plum Brook Reactor Facility'' - 188 page monograph |
*[https://history.nasa.gov/SP-4533/Plum%20Brook%20Complete.pdf NASA's Nuclear Frontier] ''The Plum Brook Reactor Facility'' - 188 page monograph |
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*[http://www.daviddarling.info/encyclopedia/N/NERVA.html NERVA] in [[David Darling (astronomer)|David Darling]]'s Internet Encyclopedia of Science |
*[http://www.daviddarling.info/encyclopedia/N/NERVA.html NERVA] in [[David Darling (astronomer)|David Darling]]'s Internet Encyclopedia of Science |
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*[http://www.astronautix.com/engines/nerva.htm Nerva] entry at [[Encyclopedia Astronautica]] |
*[https://web.archive.org/web/20040904233822/http://www.astronautix.com/engines/nerva.htm Nerva] entry at [[Encyclopedia Astronautica]] |
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*[http://www.bisbos.com/rocketscience/spacecraft/nerva/reactor.html Spacecraft: Project Nerva] |
*[https://web.archive.org/web/20080329081838/http://www.bisbos.com/rocketscience/spacecraft/nerva/reactor.html Spacecraft: Project Nerva] |
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{{Nuclear propulsion}} |
{{Nuclear propulsion}} |
Revision as of 07:25, 11 November 2017
The Nuclear Engine for Rocket Vehicle Application (NERVA) was a U.S. nuclear thermal rocket engine development program that ran for roughly two decades. NERVA was a joint effort of the U.S. Atomic Energy Commission (AEC) and NASA, managed by the Space Nuclear Propulsion Office (SNPO) until both the program and the office ended at the end of 1972.
NERVA demonstrated that nuclear thermal
NERVA was considered by the AEC, SNPO and NASA to be a highly successful program; it met or exceeded its program goals. Its principal objective was to "establish a technology base for nuclear rocket engine systems to be utilized in the design and development of propulsion systems for space mission application".[1] Virtually all space mission plans that use nuclear thermal rockets use derivative designs from the NERVA NRX or Pewee.
History
Project Rover
NERVA engine development
Finger then immediately selected
Almost all of the NERVA research, design and fabrication was done at
- Demonstrate the feasibility of starting and restarting the engine without an external power source.
- Evaluate the control system characteristics (stability and control mode) during startup, shutdown, cooldown and restart for a variety of initial conditions.
- Investigate the system stability over a broad operating range.
- Investigate the endurance capability of the engine components, especially the reactor, during transient and steady state operation with multiple restarts.
All test objectives were successfully accomplished, and the first NERVA NRX operated for nearly 2 hours, including 28 minutes at full power. It exceeded the operating time of previous KIWI reactors by nearly a factor of two.[1]
NERVA XE
The second NERVA engine, the NERVA XE, was designed to come as close as possible to a complete flight system, even to the point of using a flight-design turbopump. Components that would not affect system performance were allowed to be selected from what was available at
The NERVA NRX/EST engine test objectives now included:
- Demonstrating engine system operational feasibility
- Showing that no enabling technology issues remained as a barrier to flight engine development.
- Demonstrating completely automatic engine startup.
The objectives also included testing the use of the new facility at Jackass Flats for flight engine qualification and acceptance.[3] Total run time was 115 minutes, including 28 starts. NASA and SNPO felt that the test "confirmed that a nuclear rocket engine was suitable for space flight application and was able to operate at a specific impulse twice that of chemical rocket system [sic]."[1] The engine was deemed adequate for Mars missions being planned by NASA. The facility was also deemed adequate for flight qualification and acceptance of rocket engines from the two contractors.
Loss of political support and cancellation
The Rover/NERVA program accumulated 17 hours of operating time with 6 hours above 2000 K. Although the engine, turbine and liquid hydrogen tank were never physically assembled together, the NERVA was deemed ready to design into a working vehicle by NASA, creating a small political crisis in Congress because of the danger a Mars exploration program presented to the national budget.
The most serious injury during testing was a hydrogen explosion in which two employees sustained foot and ear drum injuries. At one point in 1965, during a test at Los Alamos Scientific Laboratory, the liquid hydrogen storage at Test Cell #2 was intentionally allowed to run dry; the core overheated and was ejected on to the floor of the Nevada desert. Test Site personnel waited 3 weeks and then walked out and collected the pieces without mishap. The nuclear waste from the damaged core was spread across the desert and was collected by an Army group as a decontamination exercise.
An engine of this type is on outdoor display on the grounds of the NASA Marshall Space Flight Center in Huntsville Alabama.
In the space program
NASA plans for NERVA included a visit to Mars by 1978 and a permanent
NERVA rockets had progressed rapidly to the point where they could run for hours, limited in run time by the size of the liquid hydrogen propellant tanks at the Jackass Flats test site. They also climbed in power density. The larger NERVA I rocket gradually gave way to the smaller NERVA II rocket in mission plans as efficiency increased and thrust-to-weight ratios grew, and the KIWI gradually gave way at Los Alamos to the smaller Pewee and Pewee 2 as funding was cut to lower and lower levels by Congress.
The RIFT vehicle consisted of a Saturn S-IC first stage, an SII stage and an S-N (Saturn-Nuclear) third stage. The Space Nuclear Propulsion Office planned to build ten RIFT vehicles, six for ground tests and four for flight tests, but RIFT was delayed after 1966 as NERVA became a political proxy in the debate over a Mars mission. The nuclear
The Mars mission became NERVA's downfall.[7] Members of Congress in both political parties judged that a manned mission to Mars would be a tacit commitment for the United States to decades more of the expensive Space Race. Manned Mars missions were enabled by nuclear rockets; therefore, if NERVA could be discontinued the Space Race might wind down and the budget would be saved. Each year the RIFT was delayed and the goals for NERVA were set higher. Ultimately, RIFT was never authorized, and although NERVA had many successful tests and powerful Congressional backing, it never left the ground.
Succession
For the
NERVA rocket stage specifications
- Diameter: 10.55 meters (34.6 ft)
- Length: 43.69 meters (143.3 ft)
- Mass empty: 34,019 kilograms (74,999 lb)
- Mass full: 178,321 kilograms (393,131 lb)
- Thrust (vacuum): 333.6 kN (75,000 lbf)
- ISP (vacuum): 850 seconds (8.3 km/s)
- ISP (sea level): 380 seconds (3.7 km/s)
- Burn Time: 1,200 s
- Propellants: LH2
- Engines: 1 Nerva-2
See also
- Nuclear thermal rocket
- Project Orion (nuclear propulsion) nuclear pulse drive system.
- Project Pluto, nuclear powered ramjet engines for use in US cruise missiles
- Project Rover to develop a nuclear thermal rocket engine
- UHTREX (a Rover spin-off using unclad fuel)
- RD-0410, the Soviet nuclear thermal rocket engine
- Project Prometheus (NASA nuclear generation of electric power 2003-2005)
- SNAP-10A, an experimental nuclear reactor launched into space in 1965
References
- ^ a b c Robbins, W.H. and Finger, H.B., "An Historical Perspective of the NERVA Nuclear Rocket Engine Technology Program", NASA Contractor Report 187154/AIAA-91-3451, NASA Lewis Research Center, NASA, July 1991.
- ^ "Moon Rocket Flight 'In Decade'". The Canberra Times. Vol. 35, , no. 9, 934. Australian Capital Territory, Australia. 9 June 1961. p. 11. Retrieved 12 August 2017 – via National Library of Australia.
{{cite news}}
: CS1 maint: extra punctuation (link) - ^ "NERVA rocket". The Canberra Times. Vol. 43, , no. 12, 306. Australian Capital Territory, Australia. 8 May 1969. p. 23. Retrieved 12 August 2017 – via National Library of Australia.
{{cite news}}
: CS1 maint: extra punctuation (link) - ^ "$24,000m for trip to Mars". The Canberra Times. Vol. 43, , no. 12, 381. Australian Capital Territory, Australia. 4 August 1969. p. 4. Retrieved 12 August 2017 – via National Library of Australia.
{{cite news}}
: CS1 maint: extra punctuation (link), ..."In our opinion", he said, "the nuclear-powered Mars spaceship would be a 3,000-ton vehicle the size of a navy destroyer with the equivalent of 300,000 horsepower in its fuel pumps alone. It would be capable of travelling at 28,000 miles an hour". The Nerva nuclear rocket that would power such a spaceship would be tested in flight in 1976 or 1977, and would have the power output of Boulder Dam... - ^ "Nuclear power will make it possible in due course to colonise the moon and the planets'". The Canberra Times. Vol. 42, , no. 11, 862. Australian Capital Territory, Australia. 4 December 1967. p. 2. Retrieved 12 August 2017 – via National Library of Australia.
{{cite news}}
: CS1 maint: extra punctuation (link) - ^ "Nuclear Rockets: To Mars and Beyond". National Security Science Magazine. Los Alamos National Laboratory. This article incorporates text from this source, which is in the public domain.
- ISBN 978-1-894959-68-1.
- ^ "NASA Researchers Studying Advanced Nuclear Rocket Technologies".
- ^ "NUCLEAR ROCKETS: To Mars and Beyond Nuclear Rockets: Then and Now. LANL".
- ^ "How long would a trip to Mars take?".
- ^ "How Fast Could (Should) We Go to Mars? Comparing Nuclear Electric Propulsion (NEP) with the Nuclear Thermal Rocket (NTR) and Chemical Rocket for Sustainable 1-year human Mars round-trip mission".
- ^ a b "A One-year Round Trip Crewed Mission to Mars using Bimodal Nuclear Thermal and Electric Propulsion (BNTEP) (doi: 10.2514/6.2013-4076)".
- ^ Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W. (April 9, 2012). "Nuclear Thermal Propulsion (NTP): A Proven Growth Technology for Human NEO / Mars Exploration Missions" (PDF). NASA.
- ^ Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W. (August 16, 2012). "Nuclear Thermal Rocket/Vehicle Characteristics And Sensitivity Trades For NASA's Mars Design Reference Architecture (DRA) 5.0 Study" (PDF). NASA.
- ^ "Nuclear Thermal Propulsion (NTP): A Proven Growth Technology for Human NEO / Mars Exploration Missions" (PDF). 2012.
- ^ Chris Bergin (24 January 2012). "SLS Exploration Roadmap evaluations provide clues for human Mars missions". NASASpaceflight.com. Retrieved 26 January 2012.
- ^ "NASA Researchers Studying Advanced Nuclear Rocket Technologies by Rick Smith for Marshall Space Flight Center, Huntsville AL (SPX) Jan 10, 2013".
External links
- Nuclear Space Propulsion: NASA 1968 on YouTube
- NASA's Nuclear Frontier The Plum Brook Reactor Facility - 188 page monograph
- NERVA in David Darling's Internet Encyclopedia of Science
- Nerva entry at Encyclopedia Astronautica
- Spacecraft: Project Nerva