In the future, NASA's fleet of robotic spacecraft might cruise among the planets like sailboats in space, or perhaps they will be propelled from planet to planet by advanced ion engines.

NASA's Office of Space Science in Washington announced that those technologies and other advanced propulsion ideas have been selected for development as part of a suite of in-space propulsion technologies. Development of these technologies will provide giant steps in capability for NASA to conduct future planetary missions, especially to the outer planets of Jupiter and beyond.

"NASA has invested in the development of a set of multiple technology paths for future propulsion systems that will enable new, exciting classes of planetary exploration missions," said Paul Wercinski, In-Space Propulsion (ISP) Program Executive in the Office of Space Science, NASA Headquarters, Washington. The awards, part of the ISP Program, cover four propulsion technology areas: Aerocapture, High-Power Electric Propulsion for Nuclear Systems, Power Conversion Technologies for Nuclear Electric Propulsion, and Solar Sails.

For Aerocapture, the following Principal Investigators (PIs) have been selected:

• Timothy Collins (NASA Langley Research Center (LaRC), Hampton Va.) -- 'High temperature composite structures';
• William Congdon (ARA Inc., Englewood, Colo.) -- 'Light-weight Thermal Protection System ablators';
• Bernard Laub (NASA Ames Research Center (ARC), Moffett Field, Calif.) --'Characterization of Advanced Thermal Protection Systems';
• Kevin Miller (Ball Aerospace, Boulder, Colo.) -- 'Ballute analysis and development';
• KR Sridhar (ELORET Corp., Sunnyvale, Calif.) -- 'Advanced TP Instrumentation';
• William Willcockson (Lockheed Martin Astronautics, Denver) -- 'Aeroshell System Development and Integration.'

For Electric Propulsion, the following PIs have been selected:

• Mark Cappelli (Stanford University, Stanford, Calif.) -- 'Development of a Two-Stage Bismuth Hall thruster';
• James Polk (NASA Jet Propulsion Lab (JPL), Pasadena, Calif.) -- 'Development of a 65 cm, 20 kW, Xenon ion thruster';
• Vincent Rawlin (NASA Glenn Research Center (GRC), Cleveland) -- 'Development of a 50 cm, 25 kW Xenon ion thruster.'

For Power Conversion, the following PIs have been selected:

• Jack Mondt (JPL) --'Segmented thermoelectric multicouple Space Reactor Power System';
• Richard Rovang (Boeing Rocketdyne, Canoga Park, Calif.) -- 'Brayton Power Conversion System';
• Graydon Yoder (Oak Ridge National Lab, Oak Ridge, Tenn.) -- 'Potassium Rankine cycle Power Conversion System.'

For Solar Sails, the following PIs have been selected:

• David Lichodziejewski (L'Garde Inc., Tustin, Calif.) -- 'Development of a Striped-Net sail and Inflatable boom model';
• David Murphy (Able Engineering, Goleta, Calif.) -- 'Development of a CP1 sail and Coilable boom model';
• Bobby Williams (JPL) -- 'Development of an integrated set of solar sail simulation tools.'

Beginning in fiscal year 2003, the propulsion technologies unique to nuclear power systems will be managed under NASA's Nuclear Systems Initiative (NSI), including the High-Power Electric Propulsion (EP) and Power Conversion (PC) technologies.

The total anticipated budget for High-Power EP and PC in fiscal 2002 is $1 million, $16 million in fiscal 2003, and $16 million in fiscal 2004, contingent on budget approval. Total anticipated budget for proposed work in the Aerocapture and Solar Sail areas under the ISP program in fiscal 2002 is $2 million, $17 million in fiscal 2003, and $18 million in fiscal 2004, contingent on budget approval.

Aerocapture uses a planet's atmosphere rather than an onboard propulsion system to slow a spacecraft to capture into orbit about a planet. Using the analogy of a high performance racecar, the ability to slow down or stop is just as critical as going fast, which is what aerocapture provides. The subsequent reduction in fuel load for this braking maneuver enables long-term orbital missions, rather than traditional planetary fly-bys.

Nuclear electric propulsion -- or the use of nuclear reactors to generate heat, which is converted into electrical power for high- performance electric thrusters -- has the potential to greatly improve the capability, sophistication and reach of future science missions. The development of high power thrusters and power conversion systems are critical components to enable future nuclear-electric propulsion systems.

Solar sails, consisting of thin, lightweight membranes, could be propelled through space by sunlight, much as wind pushes sailboats here on Earth. This lightweight, propellantless alternative to heavy, onboard propulsion systems allows spacecraft to travel to distant locations at reduced costs.

The ISP Program is managed by the Office of Space Science, NASA Headquarters, Washington, and is implemented by the Marshall Space Flight Center, Huntsville, Ala. The NSI is managed by the Office of Space Science at NASA Headquarters, and the power conversion and electric propulsion awards of NSI will be implemented by NASA's GRC. The ISP Program is supported by NASA's ARC; GRC; JPL; Johnson Space Center, Houston; and LaRC. NASA's partners in meeting the ambitious in-space propulsion goals include industry, the nation's academic institutions and other government agencies.