General Purpose Heat Source

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Exploded view of a stack of General Purpose Heat Source modules.

The General Purpose Heat Source is a radioactive heat source designed for Radioisotope Thermoelectric Generators (RTG) or Stirling radioisotope generators (SRG). It is meant for space applications and is packaged as a stackable module.

Characteristics[edit]

GPHSs are fueled with plutonium-238. Each module has a temperature of over 600 degrees Celsius[citation needed] and delivers 250 watts at the time of manufacture. They measure 9.948 cm wide x 9.32 cm deep x 5.82 cm high and weigh no more than 1.44 kg each.

Safety[edit]

GPHSs are designed with safety in mind and employ iridium-clad plutonium-238 pellets. The generated alpha particles are blocked by the cladding, thus no further radiation shielding is necessary. The pellets are encased within nested layers of carbon-based material and placed within an aeroshell housing to comprise the complete module.

The modules can withstand extreme conditions including a launch-pad explosion or a high-speed reentry.

Uses[edit]

GPHSs of this, or very similar, design were used in the GPHS-RTGs of Cassini-Huygens, New Horizons, the Galileo probe, and the Ulysses probe.

They are used in the Multi-Mission Radioisotope Thermoelectric Generator, as used by Mars Science Laboratory.

They are also used in the Advanced Stirling Radioisotope Generator.

Stages of assembly[edit]

References[edit]

  • [1] Department of Energy (DOE) Office of Nuclear Energy GPHS article
  • [2] "Radioisotope Thermoelectric Generators (RTGs)" NASA Galileo Information

External links[edit]