Project Prometheus

Nuclear reactors may be used to power ion engines such as this one used on Deep Space 1

Project Prometheus was established in 2003 by NASA to develop nuclear-powered systems for long-duration space missions. This is NASA's first serious foray into nuclear spacecraft propulsion since the cancellation of the NERVA project in 1972. However, as of 2005, the Project faces an uncertain future and is likely to be reduced to a low-level research effort. Its budget shrank from $430 million in 2005 to only $100 million in 2006, $90 million of which was allocated to pay closeout costs on cancelled contracts.

[edit] Namesake

Originally named the "Nuclear Systems Initiative", Project Prometheus is named after the wisest of the Titans in Greek mythology who gave the gift of fire to humanity. NASA says the name Prometheus indicates its hopes of establishing a new tool for understanding nature and expanding capabilities for the exploration of the Solar System.

[edit] 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 and Galileo probe have relied on radioisotope thermoelectric generators (RTG's) as their primary power source. Unlike RTG's 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 be:

• Increased power generation compared to RTG's, allowing scientists and engineers more flexibility in both mission design and operations.
• Increased spacecraft longevity.
• Increased range and propulsion power.

[edit] Missions

Prometheus I (Jupiter Icy Moons Orbiter)

Missions involving Prometheus Nuclear Systems and Technology currently include:

• Jupiter Icy Moons Orbiter
  • Exploration of the Jovian moons Europa, Ganymede, and Callisto. Originally planned to be the first mission of Project Prometheus, it has been deemed too complex and expensive and its funding was cut in the 2006 budget. NASA is instead considering a demonstration mission to a target closer to Earth to test out the reactor and heat rejection systems. The spacecraft would possibly be scaled down from its original size as well.
• Prometheus follow on missions:
  • Possible lunar orbiter style mission to fit FY2006 budget proposal.

[edit] Technology

Project Prometheus is focused on two types of spacecraft power systems:

• Nuclear Thermal Propulsion (NTP)

Studies of Nuclear thermal rocket engines along similar lines as NERVA.

• Nuclear Electric Propulsion (NEP)

Development of RTG type technology,

The use of a nuclear reactor to run ion engines.

[edit] Collaboration

Project Prometheus will have 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.

[edit] See also

• NERVA
• Nuclear fission
• Bettis Atomic Power Laboratory
• Magnetoplasmadynamic thruster

[edit] External links

• NASA JPL Project Prometheus website
• Northrop Grumman website for Prometheus I
• NASA space propulsion and mission analysis office
• Rundown of Prometheus goals, technology, and stats
• BBC audio programme about Project Prometheus