COBE
Professor Rainer Weiss’ group was housed in Building 20 from the 1970s until the building was torn down. Balloon-lifted packages to measure the cosmic microwave background, and the Cosmic Background Explorer (COBE) satellite’s FIRAS instrument and its analysis all had homes there. The LIGO gravitational-wave antenna project was also germinated in Building 20, with prototypes of various detectors built, as well as the writing of the Blue Book which was the first thorough study to build a gravitational-wave antenna. Many of the leaders of the gravitational-wave field did their early work in the F Wing of the building.