| Vela 4B | |
| Operator: | USAF |
| Cospar Id: | 1967-040B[1] |
| Satcat: | 2766[2] |
| Manufacturer: | TRW |
| Launch Mass: | 225kg (496lb) |
| Power: | 120 W |
| Launch Date: | UTC |
| Launch Rocket: | Titan 3C-10 |
| Launch Site: | Cape Canaveral LC-41 |
| Orbit Epoch: | 1 May 1967 |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Highly Elliptical |
| Orbit Periapsis: | 107337km (66,696miles) |
| Orbit Apoapsis: | 114612km (71,217miles) |
| Orbit Inclination: | 33.06° |
| Orbit Period: | 6671.8minutes |
| Apsis: | gee |
| Programme: | Vela |
| Previous Mission: | Vela 4A |
| Next Mission: | Vela 5A |
Vela 4B (also known Vela 8 and OPS 6679[3]) 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.[4]