| ESSA-8 | |
| Mission Type: | Weather satellite |
| Operator: | ESSA/NASA[1] |
| Cospar Id: | 1968-114A |
| Satcat: | 3615 |
| Manufacturer: | RCA Astro |
| Launch Mass: | [2] |
| Launch Date: | UTC[3] |
| Launch Rocket: | Delta N |
| Launch Site: | Vandenberg SLC-2E |
| Disposal Type: | Decommissioned |
| Orbit Epoch: | December 7, 2013, 13:01:30 UTC[4] |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Low Earth |
| Orbit Periapsis: | 1421km (883miles) |
| Orbit Apoapsis: | 1470km (910miles) |
| Orbit Inclination: | 101.31 degrees |
| Orbit Semimajor: | 7816.7km (4,857.1miles) |
| Orbit Eccentricity: | 0.0031481 |
| Orbit Period: | 114.63 minutes |
| Apsis: | gee |
| Programme: | TOS |
| Previous Mission: | ESSA-7 |
| Next Mission: | ESSA-9 |
ESSA-8 was a weather satellite launched by the National Aeronautics and Space Administration (NASA) on December 15, 1968, from Vandenberg Air Force Base, California. Its name was derived from that of its oversight agency, the Environmental Science Services Administration (ESSA).
ESSA-8 was an 18-sided polygon. It measured 42inches in diameter by 22inches in height, with a mass of 290lb. It was made of aluminum alloy and stainless steel covered with 10,020 solar cells. The cells charged 63 nickel–cadmium batteries, which served as a power source. The satellite could take 8 to 10 pictures every 24 hours. Each photo covered a 2000sqmi area at a resolution of 2miles per pixel.ESSA-8's mission was to replace ESSA-6, and provide detailed cloud pattern photography to ground stations worldwide. Partners in the project included NASA, ESSA, RCA, the National Weather Service, and the National Centers for Environmental Prediction (NMC).
ESSA-8 operated for 2,644 days until it was deactivated on March 12, 1976.