Linear alternators for space applications

Thermo-Acoustic Stirling Heat Engine alternatorsReliable power supplies are needed for long duration space missions, such as the proposed "Jupiter Icy Moons Orbiter", to investigate the outer planets where solar power is not available and batteries or radioisotope thermoelectric generators (RTGs), such as those aboard the Cassini-Huygens spacecraft, are insufficient. Thermo-acoustic devices, using radioactive heat sources, can be used to power linear alternators. Problems associated with matching the alternator to the thermo-acoustic engine are being investigated. Novel manufacturing and assembly methods are being developed to give the precision necessary for high efficiency and extreme reliability in difficult environments.

A prototype device designed to generate around 100 Watts, constructed by Oxford and Honeywell Hymatic, was delivered to Northrop Grumman Space Technology in 2004. Theoretical studies have begun to investigate much larger alternators which would be might be used to generate the power needed for ion propulsion systems.

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