CHIPSat (Cosmic Hot Interstellar Plasma Spectrometer Satellite) was a UnEX (University-class Explorer) mission, funded by NASA and designed to carry out an all-sky spectroscopic survey of the extreme ultraviolet background at wavelengths of 9-26 nm (nanometers) with a peak resolution of about 0.5 eV. CHIPS data helped scientists determine the electron temperature, ionization conditions, and cooling mechanisms of the million-degree plasma believed to fill the local interstellar bubble. The majority of the luminosity from diffuse million-degree plasma is expected to emerge in the poorly-explored CHIPSat band, making the mission's data relevant in a wide variety of galactic and extragalactic astrophysical environments. CHIPSat was launched together with another NASA science satellite, ICESat. Satellite operations were terminated in April 2008.