IBSS (Infrared Background Signature Survey)

IBSS (Infrared Background Signature Survey) was a test of infrared sensor technology for SDIO (Strategic Defense Initiative Organization). The IBSS sensors were mounted on a SPAS-II pallet and used to observe the Space Shuttle's engines firing from a distance away. They also observed a variety of common rocket propellants, including nitrogen tetroxide, MMH, and UDMH, released by three Chemical Release Observation subsatellites launched from Get-Away Special canisters on the Shuttle.


Shuttle deployment sate May 1, 1991
Shuttle mission STS-39
orbit 245 × 255 km × 57.0°
mass 1,901 kg