Prometheus project

from Wikipedia, the free encyclopedia
The space probe Jupiter Icy Moons Orbiter , equipped with an ion drive and a nuclear reactor, was to be realized as part of the project. However, it was deleted.

The Prometheus project was a NASA program on the use of nuclear energy for interplanetary space travel , which was carried out in 2002 and carried out until September 2005 . The aim of this project was the further development of existing radioisotope generators (RTG) as well as the development of a nuclear reactor for use in interplanetary space probes . Associated with this was research into improved technologies for energy conversion. The use of nuclear energy in electric drives was the third area of ​​this program. NASA cooperated with the US Department of Energy on the nuclear parts of the program , especially with the Office of Naval Reactors .

financing

In the 2005 budget year (beginning October 1 of the previous year), the Prometheus project had a budget of $ 270.3 million. For the 2006 fiscal year, the budget was cut to $ 75.7 million. The reason for this were relocations to other programs, above all to the development of the Orion spacecraft . From 2007 to 2011, annual amounts between $ 9.5 million and $ 9.9 million are planned. In 2006, NASA's nuclear research program is to be reviewed to determine how and when new programs or projects could be initiated.

aims

As part of the program, more efficient radionuclide batteries (RTG) with an output of approx. 120 W electrical energy that can be better adapted to different mission requirements are to be developed. The components for thermoelectric energy conversion are to be improved and new technologies such as thermovoltaic or dynamic ( Stirling ) energy conversions are to be developed. At the start of the project in 2003, the US Department of Energy planned to purchase up to 30 kg of plutonium-238 from Russia, which was also supposed to examine the possibility of producing plutonium-238 within the USA. According to these plans, these new RTGs should be ready by 2008. The Mars Science Laboratory , Mars Scout 2 or New Frontiers Missions could be considered as first missions .

The specifications for the planned nuclear reactor ranged from a few tens of kW to a few hundred kW of electrical power. Brayton converters, Rankine converters and thermoelectric processes should be developed as energy conversion technologies. Another part of the Prometheus project is the development of electric drives that should have an output of 20–50 kW and up to 250 kW. The first nuclear reactor, which was intended for the JIMO mission (Prometheus 1), which was canceled in autumn 2005 , was to be developed by the Bettis Atomic Power Laboratory .

In mid-2005 it became known that the Bush administration was planning to restart the production of plutonium 238. "The real reason we're starting production is for national security," Timothy A. Frazier of the US Department of Energy was quoted as saying. Plutonium 238 is used as fuel in batteries for space systems ( see space weapon ).

Initial preparations for the production of plutonium-238 began in 2013 at the Oak Ridge National Laboratory (ORNL). In 2015, the ORNL reported the successful production of 50 grams of plutonium-238. This sample was used to demonstrate and test the manufacturing process. After analyzing this sample at Los Alamos National Laboratory , the material was released for space missions. Initially, 300 to 400 grams of plutonium-238 could be produced per year. With expansion and automation processes, production could be increased to 1.5 kg per year.

review

The US satellite Snapshot (SNAP-10A), launched in 1965, was equipped with an experimental nuclear reactor, as were the Soviet RORSAT military satellites of the 1970s and 80s. At the end of the 1980s two Russian satellites (Kosmos 1818 and 1867) were equipped with reactors of the TOPAZ type, which, with a mass of 320 kg, delivered 5-10 kW of electrical power and contained 12 kg of uranium-235 . The American reactor of the type SP-100 (Space Power 100) could have achieved an electrical output of up to 100 kW with a weight of 5422 kg with adequate shielding (for comparison: the three RTGs of the Cassini space probe achieved 888 W at 168 kg, the launch weight of the probe was 5712 kg, a Delta IV Heavy can carry up to 8 t payload on an interplanetary mission).

Since the 1960s there have been repeated projects dealing with nuclear energy in space and nuclear-thermal engines . In the USA, for example, these were the NERVA project, which was canceled in 1972, the Clinch River Reactor (project discontinued in 1982), the multi-megawatt program initiated as part of SDI in 1985 with the resulting Timberwind project and plans within the Space Exploration Initiative Early 1990s. In the USSR, nuclear reactors such as BOUK or TOPAZ as well as nuclear-thermal drives have been developed since the 1950s.

( see also: gas nuclear reactor )

outlook

Despite the low budget of the Prometheus project until 2011, the development of nuclear systems for future NASA space missions remains part of the strategic planning:

Nuclear thermal propulsion systems offer a promising technological approach for providing a high-thrust, high-efficiency departure stage to transport astronauts to future destinations while reducing spacecraft mass.

"Thermonuclear propulsion systems offer a promising technological approach to providing a highly accelerating, highly effective launch stage for transporting astronauts to future destinations while reducing spacecraft mass."

Nuclear systems likely will play an important role in power systems capabilities beyond 2016. Deployment and utilization of nuclear systems on the Moon could directly enable scientific and human exploration of the Moon and operational understanding of the requirements of these systems for eventual exploration on Mars.

Regarding the future of the Prometheus program, NASA Director Griffin wrote in November 2005: (...) surface nuclear power systems to support potential long-duration stays on the Moon will not be required until after 2018. Nuclear propulsion will not be required until planning for Mars missions begins in earnest. (...) NASA will continue a low level of funding for key, high-priority, nuclear system R&T issues, with longer-term plans to increase funding in the future, as the need for long duration lunar and Mars applications approaches .

From the 2007 budget year, the Prometheus Nuclear Systems & Technology project will be part of the Exploration Systems Research and Technology program of the Exploration Systems Mission Directorate (ESMD) .

See also

literature

  • NASA Final Report : Randall Taylor: PROMETHEUS PROJECT - Final Report . Ed .: NASA - Jet Propulsion Laboratory California Institute of Technology. Pasadena, California October 1, 2005 ( everyspec.com [PDF] English: PROMETHEUS PROJECT - Final Report .).

Web links

Individual evidence

  1. ^ Randall Taylor: PROMETHEUS PROJECT - Final Report . Ed .: NASA - Jet Propulsion Laboratory California Institute of Technology. Pasadena, California October 1, 2005 ( everyspec.com [PDF] English: PROMETHEUS PROJECT - Final Report .).
  2. ^ A b Newhouse, Alan: Project Prometheus, The Nuclear Systems Program. Revolutionizing Solar System Exploration. Presentation to Structure and Evolution of the Universe & Origins Subcommittees October 24, 2003. Aug. 21, 2006.
  3. ^ National Aeronautics and Space Administration: President's FY 2007 Budget Request. Exploration Systems Research & Technology, SAE ESMD 3-4 (p. 236). (PDF; 5.3 MB) Aug. 22, 2006.
  4. ↑ US plans to resume plutonium production (NYT, June 27, 2005) .
  5. ^ US Once Again Producing Fuel for Deep-Space Missions . In: Space.com . ( space.com [accessed June 21, 2017]).
  6. ↑ ORNL achieves milestone with plutonium-238 sample | ORNL. Retrieved June 21, 2017 (English).
  7. ↑ djysrv: NASA Re-starts PU-238 Production at Two Sites. In: Neutron Bytes. March 5, 2017. Retrieved June 21, 2017 .
  8. ↑ ORNL achieves milestone with plutonium-238 sample | ORNL. Retrieved June 21, 2017 (English).
  9. ↑ Bernd Leitenberger: The radioisotope elements on board space probes. Aug 21, 2006.
  10. ↑ Butler, Amy: DOD'S 'FLIRTATION' WITH NUCLEAR-POWERED SATELLITES ENDS, ANALYST SAYS. 23 Aug 2006.
  11. ^ Pike, John: Strategic Defense Initiative. Aug 26, 2006.
  12. ^ Institute of Physics and Power Engineering (IPPE): High-Temperature Nuclear Reactors for Space Applications. ( Memento from August 30, 2006 in the Internet Archive ) Aug. 27, 2006.
  13. ↑ National Aeronautics and Space Administration: 2006 NASA Strategic Plan, p. 38 (PDF; 1.5 MB) Aug. 25, 2006.
  14. ^ Griffin, Michael D .: Statement of Michael D. Griffin, Administrator National Aeronautics and Space Administration, before the Committee on Science House of Representatives. (P. 4) ( Memento of September 30, 2006 in the Internet Archive ) Aug 26, 2006.