The last of NASA's three High Energy Astronomy Observatories, HEAO 3 was launched 20 September 1979 on an Atlas-Centaur launch vehicle, into a nearly circular, 43.6 degree inclination low-Earth orbit with an initial perigeum of 486.4 km.
Yang ketiga terakhir NASA High Energy Astronomy Observatories, HEAO 3 diluncurkan 20 September 1979 pada peluncur kendaraan Atlas-Centaur, hampir bundar, 43,6 derajat kemiringan orbit Bumi rendah dengan perigee awal 486,4 km.