View source for Project Prometheus

{{short description|NASA nuclear electric propulsion project 2003-2006}}
{{More citations needed|date=February 2010}}
[[Image:Ion Engine Test Firing - GPN-2000-000482.jpg|thumb|right|Nuclear reactors could be used to power [[ion engine]]s such as this one used on [[Deep Space 1]].]]
'''Project Prometheus ('''also known as '''Project Promethian)''' was established in 2003 by [[NASA]] to develop [[Nuclear power|nuclear-powered]] systems for long-duration space missions.<ref name=":0">{{Cite web |last=Brown |first=David W. |title=NASA's "Nuclear Option" May Be Crucial for Getting Humans to Mars |url=https://www.scientificamerican.com/article/nasas-nuclear-option-may-be-crucial-for-getting-humans-to-mars/ |access-date=2023-01-04 |website=Scientific American |language=en}}</ref> This was NASA's first serious foray into [[Nuclear propulsion|nuclear spacecraft propulsion]] since the cancellation of the [[Project Timberwind#Space Nuclear Thermal Propulsion Program|SNTP]] 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.<ref>
{{Cite book | last = The National Academy of Sciences
| title = Launching Science: Science Opportunities Provided by NASA's Constellation System
| publisher = The National Academies Press | year = 2009 | location = Washington, DC
| page = 18
| url = https://books.google.com/books?id=wOTXYbC-c14C&pg=PA18
| isbn = 978-0-309-11644-2}}</ref><ref name=":0" /> Its budget shrank from $252.6 million in 2005<ref>{{Cite report | title=Prometheus Project Final Report | publisher = NASA/JPL| date = October 1, 2005 | page = 191}}</ref> to only $100 million in 2006, $90 million of which was for closeout costs on cancelled contracts. With the onset of the second Donald Trump administration, and given its opposition to nuclear thermal and electric propulsion per the FY2026 NASA budget, it is possible that there will be a looming ban on nuclear thermal and electric propulsion which could be retroactive, meaning that all documentation and artifacts pertaining to Project Prometheus are to be destroyed.

==Namesake==
Originally named the "Nuclear Systems Initiative", Project Prometheus was named for the [[Prometheus|wisest of the Titans]] in [[Greek mythology]] 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]] as a source of electrical energy for onboard instrumentation or for [[ion propulsion]] systems. Previous missions to the outer planets such as [[Voyager program|Voyager]] and [[Galileo probe]] have relied on [[radioisotope thermoelectric generator]]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]] 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==
[[Image:Prometheus1.jpg|thumb|300px|right|Prometheus I (Jupiter Icy Moons Orbiter)]]
Missions planned to involve Prometheus Nuclear Systems and Technology included:
*[[Jupiter Icy Moons Orbiter]]
*Exploration of the [[Jupiter|Jovian]] moons [[Europa (moon)|Europa]], [[Ganymede (moon)|Ganymede]], and [[Callisto (moon)|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 rocket|Nuclear electric propulsion]]:<ref name=PFR>{{cite web |url=http://www.everyspec.com/NASA/NASA-JPL/JPL_Prometheus_Final_Report_3673/ |title=982-R120461, PROMETHEUS PROJECT FINAL REPORT |date=Oct 2005 }} Abstract, and link to pdf, of 227 page final report.</ref>{{rp|1}}

Development of spacecraft powered by [[Nuclear electric rocket|nuclear reactors]] to generate electricity. [[Brayton cycle]] turboalternators were selected for power generation.<ref name="PFR" />{{rp|118}} This electricity would then be used to run [[Ion thruster|ion engines]]. It did not study nor pursue [[nuclear thermal propulsion]] (e.g. [[NERVA]]).

NASA's Prometheus reactor was to be built by the U.S. Department of Energy's Office of [[Naval Reactors]] in Washington, D.C., per an agreement signed in August 2004.<ref name=":1">{{Cite web |last=David |first=Leonard |date=2005-04-06 |title=NASA's Prometheus: Fire, Smoke And Mirrors |url=https://www.space.com/929-nasas-prometheus-fire-smoke-mirrors.html |access-date=2023-01-04 |website=Space.com |language=en}}</ref> The reactor would have generated 200,000 watts of power for the propulsion and instruments of a spacecraft.<ref name=":0" /> 

==Collaboration==
The project was managed by [[Jet Propulsion Laboratory]] (JPL).<ref name=":1" /> Spacecraft design contracts were awarded to Boeing, Lockheed-Martin, and Northrop Grumman.<ref name=PFR/>{{rp|25}}

Project Prometheus would have had substantial involvement of the [[U.S. Department of Energy]] (DOE). 

[[Naval Reactors]], which oversees the nuclear reactor program of the [[U.S. Navy]], was to participate in the design and construction of the reactors for the [[Jupiter Icy Moons Orbiter]] (JIMO).

In addition to [[Knolls Atomic Power Laboratory]] in [[Schenectady, New York|Schenectady]], New York, [[Bettis Laboratory]] in [[Pittsburgh]], Pennsylvania, and other supporting Department of Energy national laboratories participated in the Prometheus cooperation.<ref name=":1" />

In September 2004, JPL chose [[Northrop Grumman|Northrop Grumman Space Technology]] to co-design the projected Prometheus spacecraft. The awarded contract was worth around $400 million.<ref name=":1" />

==See also==
*[[Knolls Atomic Power Laboratory]]
*{{annotated link|Bettis Atomic Power Laboratory}}
*{{annotated link|Demonstration Rocket for Agile Cislunar Operations (DRACO)}}
*[[Gerald Feinberg]], author of ''The Prometheus Project'' (1969)
*{{annotated link|Magnetoplasmadynamic thruster}}
*{{annotated link|NERVA}}
*[[Nuclear fission]]
*{{annotated link|Project Orion (nuclear propulsion)}}
*{{annotated link|Project Rover}}

==Notes==
{{reflist}}

==External links==
*[https://web.archive.org/web/20110412093255/http://trajectory.grc.nasa.gov/projects/ntp/index.shtml NASA space propulsion and mission analysis office]
*[http://www.bbc.co.uk/radio4/science/projectprometheus.shtml BBC audio programme about Project Prometheus]
*[http://www.everyspec.com/NASA/NASA-JPL/JPL_Prometheus_Final_Report_3673/ 982-R120461, PROMETHEUS PROJECT FINAL REPORT] Abstract, and link to pdf, of 227 page final report.  Retrieved 2010-02-14
*[http://navalreactorshistorydb.info:8080/xtf/search?f1-subject=Project%20Prometheus Project Prometheus-related items in the Naval Reactors History Database] {{Webarchive|url=https://web.archive.org/web/20160422025120/http://navalreactorshistorydb.info:8080/xtf/search?f1-subject=Project%20Prometheus |date=2016-04-22 }}

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[[Category:NASA programs|Prometheus]]
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