A series of spacecraft that over a three-year period investigated the extent of the micrometeroid threat to the manned Apollo missions. Each was launched with a boilerplate Apollo capsule and, when in orbit, extended two large “wings,” each measuring 4.3 by 14.6 m, mounted with detector panels. The fewer-than-expected number of impacting particles enabled about 450 kg of shielding to be trimmed from the operational Apollo vehicles.
All the Pegasus spacecraft were launched by Saturn I's from Cape Canaveral and had a total mass, with boilerplate capsules, of about 10,500 kg.