Vela 1B was one of two spin-stabilized 134 kilograms (295 lb) satellites comprising the first launch in a series of 6 Vela launches. Their objectives were to monitor nuclear weapons explosions in space and to study X-rays, gamma-rays, neutrons, and charged particles as the satellites passed through interplanetary space, the bow shock, the magnetosheath, and the magnetotail. The satellite operated in either a real-time mode (one data frame/sec) or a memory store mode (one data frame every 256 seconds). The spacecraft was operated in the real-time mode about 40% of the time and in the store mode for the rest of the time until the next Vela launch. At this time, tracking priority was given to the new spacecraft, and the older spacecraft was operated in the store mode only. There had been less and less data coverage of these satellites with each succeeding launch.[3]
Payloads are separated by bullets ( · ), launches by pipes ( | ). Crewed flights are indicated in underline. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in (brackets).
