(U) This Subthrust develops all propulsion technology that could be applied to satellites. It addresses all technologies that could be used in satellite orbit raising maneuvers, on orbit station keeping and satellite repositioning. The efforts in this subthrust address the need for low cost, long life satellite propulsion, including solar thermal propulsions, solar electric propulsion and chemical propulsion.
(U) Solar thermal propulsion is the means of transmitting the solar energy directly into a working fluid for use as a propulsion agent. Application of material technology to solar thermal concentrators and reflectors is incorporated into this subthrust.
(U) Solar electric propulsion is the method of converting the solar energy into useable electric energy then into a propulsive force. This can be accomplished using electrostatic (arcjets and resistojets), electromagnetic (Hall Effects thrusters) or ion propulsion. Current efforts are focused on improving the performance of the thrusters and reducing the weight of the power processing units. Developing smaller, lighter weight, and longer life components involves application of new materials as well as new designs.
(U) Chemical propulsion converts the chemical potential in fuels into propulsive force. Efforts in this area include environmentally cleaner propellants as well as reduced weight components.
(U) Several projects, on-going in FY98, work toward overcoming the major hurdles in these areas. The Solar Thermal Components Development program will address the material deficiencies in the concentrator as well as the absorber. Elements developed in this and other previous solar efforts will be demonstrated at high altitude in the Solar Thermal Balloon Experiment. Development of solar thermal propulsion components for use in the Solar Thermal Orbit Transfer Vehichle is underway. Continuing support of the 30 kW Arcjet ATD Electric Space Experiment (ESEX) will be provided through the launch of the satellite in FY98. Improvements in the Hall Thruster and the Pulsed Plasma Thruster (PPT) will continue. Efforts in Hall Effects Thruster improvements began in FY97 with High Performance Hall Thruster Ground Demo. Improvements in the PPT will applied in MightySat Flight Experiment. The Air Force has no plans to develop liquid fueled thrusters designed specifically for spacecraft application, but will take advantage of any breakthroughs created by NASA in this field.
|Propulsion Technology||Spacecraft and Tactical Propulsion Technology|
|TECHNOLOGY- RDT&E||SPACE TECHNOLOGY|
(U) National Security Space Road Map Team, NSSA, Open Phone: (703) 808-6040, DSN 898-6040.
(U) 15 July 1997
(U) Road Map Production Date: 23 June 2001