Project Prometheus (also known as Project Promethian) was established in 2003 by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

to develop

nuclear-powered Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced b ...

systems for long-duration space missions. This was NASA's first serious foray into nuclear spacecraft propulsion since the cancellation of the

SNTP The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable- latency data networks. In operation since before 1985, NTP is one of the oldest Internet protocols in c ...

project in 1995. The project was planned to design, develop, and fly multiple deep space missions to the outer planets. The project was cancelled in 2005, due to other demands on NASA's budget. Its budget shrank from $252.6 million in 2005 to only $100 million in 2006, $90 million of which was for closeout costs on cancelled contracts.

Namesake

Originally named the "Nuclear Systems Initiative", Project Prometheus was named for the wisest of the Titans in

Greek mythology A major branch of classical mythology, Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the origin and nature of the world, the lives and activities o ...

who gave the gift of fire to humanity. NASA said the name ''Prometheus'' indicates its hopes of establishing a new tool for understanding nature and expanding capabilities for the exploration of the Solar System.

Motivations

Due to their distance from the Sun, spacecraft exploring the outer planets are severely limited in that they cannot use

solar power Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovolta ...

as a source of electrical energy for onboard instrumentation or for

ion propulsion An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity. An ion thruster ionizes a neutral gas by extracting some electrons out of ...

systems. Previous missions to the outer planets such as

Voyager Voyager may refer to: Computing and communications * LG Voyager, a mobile phone model manufactured by LG Electronics * NCR Voyager, a computer platform produced by NCR Corporation * Voyager (computer worm), a computer worm affecting Oracle ...

and

Galileo probe ''Galileo'' was an American robotic space probe that studied the planet Jupiter and its moons, as well as the asteroids Gaspra and Ida. Named after the Italian astronomer Galileo Galilei, it consisted of an orbiter and an entry probe. It ...

have relied on

radioisotope thermoelectric generator A radioisotope thermoelectric generator (RTG, RITEG), sometimes referred to as a radioisotope power system (RPS), is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioa ...

s (RTGs) as their primary power source. Unlike RTGs which rely on heat produced by the natural decay of radioactive isotopes, Project Prometheus called for the use of a small

nuclear reactor A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat fr ...

as the primary power source. The primary advantages of this would have been: *Increased power generation compared to RTGs, allowing scientists and engineers more flexibility in both mission design and operations. *Increased spacecraft longevity. *Increased range and propulsion power. *Extra power for high speed data transmission.

Missions

Missions planned to involve Prometheus Nuclear Systems and Technology included: *

Jupiter Icy Moons Orbiter The ''Jupiter Icy Moons Orbiter'' (JIMO) was a proposed NASA spacecraft designed to explore the icy moons of Jupiter. The main target was Europa, where an ocean of liquid water may harbor alien life. Ganymede and Callisto, which are now th ...

*Exploration of the Jovian moons

Europa Europa may refer to: Places * Europe * Europa (Roman province), a province within the Diocese of Thrace * Europa (Seville Metro), Seville, Spain; a station on the Seville Metro * Europa City, Paris, France; a planned development * Europa Clif ...

, Ganymede, and Callisto. Originally planned to be the first mission of Project Prometheus, it was deemed too complex and expensive, and its funding was cut in the 2006 budget. NASA instead considered a demonstration mission to a target closer to Earth to test out the reactor and heat rejection systems, possibly with a spacecraft scaled down from its original size.

Technology

Project Prometheus was focused on Nuclear electric propulsion: Abstract, and link to pdf, of 227 page final report. Development of spacecraft powered by

nuclear reactors A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from ...

to generate electricity.

Brayton cycle The Brayton cycle is a thermodynamic cycle that describes the operation of certain heat engines that have air or some other gas as their working fluid. The original Brayton engines used a piston compressor and piston expander, but modern gas tu ...

turboalternators were selected for power generation. This electricity would then be used to run

ion engines An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity. An ion thruster ionizes a neutral gas by extracting some electrons out of a ...

. It did not study nor pursue

nuclear thermal propulsion A nuclear thermal rocket (NTR) is a type of thermal rocket where the heat from a nuclear reaction, often nuclear fission, replaces the chemical energy of the propellants in a chemical rocket. In an NTR, a working fluid, usually liquid hydro ...

(e.g.

NERVA Nerva (; originally Marcus Cocceius Nerva; 8 November 30 – 27 January 98) was Roman emperor from 96 to 98. Nerva became emperor when aged almost 66, after a lifetime of imperial service under Nero and the succeeding rulers of the Flavian dy ...

). NASA's Prometheus reactor was to be built by the U.S. Department of Energy's Office of

Naval Reactors Naval Reactors (NR), also known as the Naval Nuclear Propulsion Program, is an umbrella term for the U.S. government office that has comprehensive responsibility for the safe and reliable operation of the United States Navy's nuclear propulsion p ...

in Washington, D.C., per an agreement signed in August 2004. The reactor would have generated 200,000 watts of power for the propulsion and instruments of a spacecraft.

Collaboration

The project was managed by

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a Federally funded research and development centers, federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, La Cañada Flintridge, California ...

(JPL). Spacecraft design contracts were awarded to Boeing, Lockheed-Martin, and Northrop Grumman. Project Prometheus would have had substantial involvement of the U.S. Department of Energy (DOE).

, which oversees the nuclear reactor program of the

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...

, was to participate in the design and construction of the reactors for the

(JIMO). In addition to

Knolls Atomic Power Laboratory Knolls Atomic Power Laboratory (KAPL) is an American research and development facility based in Niskayuna, New York and dedicated to the support of the US Naval Nuclear Propulsion Program. KAPL was instituted in 1946 under a contract between Gen ...

Schenectady Schenectady () is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2020 census, the city's population of 67,047 made it the state's ninth-largest city by population. The city is in eastern New Y ...

, New York,

Bettis Laboratory Bettis Atomic Power Laboratory is a U.S. Government-owned research and development facility in the Pittsburgh suburb of West Mifflin, Pennsylvania, that works exclusively on the design and development of nuclear power for the U.S. Navy. It was one ...

Pittsburgh Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...

, Pennsylvania, and other supporting Department of Energy national laboratories participated in the Prometheus cooperation. In September 2004, JPL chose Northrop Grumman Space Technology to co-design the projected Prometheus spacecraft. The awarded contract was worth around $400 million.

Notes

External links

NASA space propulsion and mission analysis officeBBC audio programme about Project Prometheus982-R120461, PROMETHEUS PROJECT FINAL REPORT
Abstract, and link to pdf, of 227 page final report. Retrieved 2010-02-14
Project Prometheus-related items in the Naval Reactors History Database
{{NASA navbox

Prometheus In Greek mythology, Prometheus (; , , possibly meaning " forethought")Smith"Prometheus". is a Titan god of fire. Prometheus is best known for defying the gods by stealing fire from them and giving it to humanity in the form of technology, kn ...

Nuclear spacecraft propulsion