Spacelab Instrument Pointing System

ESA's Instrument Pointing System (IPS) provided high-precision pointing for astronomical telescopes on Spacelab missions. It has flown three times: Spacelab-2/STS-51F in July-August 1985; Astro-1/STS-35 in December 1990; Astro-2/STS-67 in March 1995. Shown is Spacelab-2, when the drum-like IPS carried a package of four solar telescopes.