Vela 4A (also known Vela 7 and OPS 6638) was an American reconnaissance satellite to detect explosions and nuclear tests on land and in space. It was released together with Vela 4B, ERS 18, OV5 1 and OV5 3.
The ship remains in orbit around Earth.
Instruments 2 optical bhangmeters observing Earth 12 external X-ray detectors 18 internal neutron and gamma-ray detectors
See also Vela (satellite)
References