近地轨道
Pegasus 2 or Pegasus II, known before launch as Pegasus B was an American satellite which was launched in 1965 to study micrometeoroid impacts in Low Earth orbit. It was the second of three Pegasus satellites to be launched, following the launch of Pegasus 1 three months earlier. The Pegasus spacecraft were manufactured by Fairchild Hiller, and operated by NASA.