Vela 4B (also known Vela 8 and OPS 6679) was an American reconnaissance satellite to detect explosions and nuclear tests on land and in space. It was released together with Vela 4A, ERS 18, OV5 1 and OV5 3.
Instruments 2 optical bhangmeters observing Earth 12 external X-ray detectors 18 internal neutron and gamma-ray detectors
See also Vela (satellite)
References