Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. Data is acquired using ground-based radars and optical telescopes, space-based telescopes, and analysis of spacecraft surfaces returned from space. Some important data sources have been the U.S. Space Surveillance Network, the Haystack X-Band Radar, and returned surfaces from the Solar Max, the Long Duration Exposure Facility (LDEF), the Hubble Space Telescope (HST) and the Space Shuttle spacecraft. The data provide validation for the environment models and identify the presence of new sources.

Long Duration Exposure Facility (LDEF) was left in low Earth orbit (LEO) for 5.7 years before being retrieved by space shuttle Columbia in January, 1990.