SpaceDev & DARPA: Solar Thermal Propulsion

[docm]

Not a huge contract, but quite interesting.<br /><br />Solar Thermal Propulsion @ Wikipedia....<br /><br />http://www.spacedev.com/press_more_info.php?id=189<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p><b>SpaceDev Selected as Contractor for DARPA Propulsion Program<br /><br /><i>$3.75M Prime Contract to Develop New Space Propulsion Technology for Small Satellites</i></b><br /><br />POWAY, CA – October 2, 2007 - SpaceDev (OTCBB: SPDV) has been awarded a contract from the United States Defense Advanced Research Projects Agency (DARPA). The first phase contract value is $3.75 million for the initial development of solar thermal propulsion (STP) and bus design for the High Delta-V Satellite Program. SpaceDev has assembled a team, including General Atomics and BAE Systems, to bring strong and proven capabilities to address the program technical challenges. The key program goals are to develop a space qualified, low-cost, high delta-V, modular STP system combined into a complete satellite, capable of performing the required missions.<br /><br />“By using a combination of flight proven materials and subsystems in conjunction with the unique challenges within the HiDVE program, we see an opportunity to help transform how propulsion is accomplished on orbit,†said Mark N. Sirangelo, SpaceDev’s Chairman and CEO. “We view this initial phase as an opportunity to close the design solution and thus lead to fabricating ground test hardware and ultimately culminate in a full flight demonstration. This is an excellent and exciting opportunity to be part of a major shift in space propulsion and satellite technology.â€<p><hr /></p></p></blockquote> <div class="Discussion_UserSignature"> </div>

 

[gunsandrockets]

The USAF has done a lot of work with Solar Thermal Propulsion. It's too bad the DARPA contract is only for microsatellites since STP has a lot more potential, even potential for manned missions. <br /><br />SOTV

 

[h2ouniverse]

Why not.<br />Btw, can't it be adapted to a power supplied by RTGs?

 

[gunsandrockets]

<Btw, can't it be adapted to a power supplied by RTGs?><br /><br />No.<br /><br />I think you might misunderstand the nature of Solar Thermal Propulsion (STP). Unlike Solar Electric Propulsion (SEP), STP does not use electric energy but uses thermal energy to accelerate rocket propellant. One design of STP uses a large inflatable mirror to direct sunlight unto a carbon heat-sink. Once the heat-sink is hot enough liquid-hydrogen propellent is fed into the heat-sink which heats the hydrogen to temperatures approaching 2,000 degrees Celsius. The heated hydrogen is expelled from a convergent-divergent nozzle providing rocket propulsion with an efficiency approaching 800 seconds ISP, nearly double the efficiency of the best chemical rocket engines.<br /><br />As far as RTG energy goes, there is an interesting variant of nuclear propulsion which has been refered to as a 'poodle thruster' that might interest you. But a poodle thruster is a thermal rocket engine too and not an electric rocket engine.