Two camera/photometers were included as part of the Induced Environment Contamination Monitor on STS-2, -3, -4, and -9 orbital missions to record photographically Shuttle-induced particulate and background contamination. The cameras collected stereoscopic data continuously during the on-orbit phases of these missions making exposures every 150 s. The results recorded throughout a 32° field-of-view indicate high particle concentrations during early mission operations. These decay to a quiescent rate of 500 particles of >10-μm radius observed per orbit. Preliminary size and velocity distributions of measured particles are presented as are measurements of background brightness due to unresolved particles in the visible spectral region.
K. Stuart Clifton and Jerry K. Owens, "Optical contamination measurements on early Shuttle missions," Appl. Opt. 27, 603-609 (1988)