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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 217 records · Page 12

Construction of Power Receiving Rectenna Using Mars- In-Situ Materials; A Low Energy Materials Processing Approach

It is highly desirable to have a non-nuclear power rich option for the human exploration of Mars. Utilizing a Solar Electric Propulsion, SEP, / Power Beaming architecture for a non-nuclear power option for a human Mars base potentially avoids the weather and dust sensitivities of the surface photovoltaic option. Further from Mars areosynchronous orbit near year round power can be provided. Mission analysis, however, concludes that ultra high (245 GHz) frequencies or laser transmission technologies are required for Mars landed mass competitiveness with the surface photovoltaic option if the receiving rectifying antenna "rectenna" is transported from Earth. It is suggested in this paper that producing rectenna in situ on Mars surface might make a more conventional 5.8 GHz system competitive with surface PV. The premium of a competitive, robust, continuous base power might make the development of a 10 plus MWe class SEP for human Mars mission a more attractive non-nuclear option.

Curreri, Peter A.↗

Cr.sup.4+-doped mixed alloy laser materials and lasers and methods using the materials

A laser medium includes a single crystal of Cr.sup.4+:Mg.sub.2-xM.sub.xSi.sub.1-yA.sub.yO.sub.4, where, where M is a bivalent ion having an ionic radius larger than Mg.sup.2+, and A is a tetravalent ion having an ionic radius larger than Si.sup.4+. In addition, either a) 0.ltoreq.x<2 and 0<y<1 or b) 0<x<2 and y is 0 or 1 with the proviso that if M is Ca.sup.2+ and x=1 then y is not 0. The laser medium can be used in a laser device, such as a tunable near infrared (NIR) laser.

Alfano, Robert R.↗