Technology for Small Spacecraft (1994) / Chapter Skim
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3 Spacecraft Propulsion Technology
3 Spacecraft Propulsion Technology
Pages 23-30
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From page 23... ...
The very low-thrust electric propulsion devices can be employed for payload placement in orbit or on interplanetary trajectories within reasonable time frames and can possibly reduce the size of the launch vehicle required.
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From page 24... ...
For monopropellant systems using hydrazine, research has been focused on increasing the pulse duty-cycle life by reducing catalyst bed degradation, and on increasing the specific impulse by use of electric energy for raising the decomposition products temperature before expansion through the nozzle. NASA Chemical Propulsion Programs The Lewis Research Center (LeRC)
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From page 25... ...
One system has tentatively been baselined on an advanced commercial communication spacecraft. Specific goals of the project include attaining specific impulses greater than 350 seconds, a factor of three or greater reduction in rocket sizes anti masses, and the ability to operate radiation-cooled rockets at arbitrary propellant mixture ratios with all on-board propellant options (Bennett, 19941.
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From page 26... ...
utilize the solar electric propulsion for continuous thrusting out to perhaps three astronomical units before solar flux diminishes beyond a useful intensity. For surveillance or remote sensing missions that require frequent maneuvering or repositioning, the comparatively high efficiency of electric thrusters can substantially increase spacecraft lifetime or enhance versatility.
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From page 27... ...
In addition, Boeing is currently exploring a solar electric propulsion option for the Pluto Fast Flyby mission with internal funds. While a variety of technical issues still need to be resolved, studies on the Pluto Fast Flyby mission inclicate that a solar electric propulsion unit that utilizes three high voltage, 5-kilowatt-electric xenon ion thrusters may enable a Delta-ciass or AtIas-cIass launch vehicle to be used instead of a Titan IV.
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From page 28... ...
Solar Thermal Propulsion Solar thermal propulsion offers promise of a higher thrust capability than electric propulsion at Tower specific impulse. Research indicates that these devices for propulsion may be able to deliver a specific impulse of about 850 seconds with higher thrust levels than solar electric thrusters (less than one newton)
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From page 29... ...
FINDINGS AND PRIORITIZED RECOMMENDATIONS The Panel on Small Spacecraft Technology believes that advanced propulsion technology can provide dramatic reductions in the cost of placing the payload in orbit. Specifically, electric propulsion can be an enabling technology for small spacecraft in that its use for orbit-raising functions can effect a reduction in launch vehicle size with an attendant reduction in launch costs.
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From page 30... ...
I An aggressive program should be established to demonstrate, in ground tests, the life of xenon ion propulsion systems that operate at power levels in the range from about 0.5 kilowatt to about 2.5 kilowatts for lifetimes of up to 8,000 hours.
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