Operator NOAA SATCAT no. 11819 Manufacturer RCA Astro Electronics Period 1.7 hours Launch date 29 May 1980 Decay date 3 May 1981 | COSPAR ID 1980-043A Bus TIROS-N Inclination 92.3° Launch mass 1,405 kg Mission type Weather satellite | |
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Mission duration Planned: 2 years
Launch failure Similar NOAA‑7, ESSA‑8, ESSA‑9, NOAA‑4, Oceansat‑1 | ||
NOAA-B was a spacecraft in the TIROS-N series launched by NASA on 29 May 1980. Intended for a sun-synchronous orbit, the spacecraft entered a lower, elliptical orbit due to a launch vehicle malfunction resulting in a failed mission. Had the launch been successful it would have been designated NOAA-7.
Contents
Science Objectives
Launch Failure
Following launch a fuel leak between the turbopump and gearbox caused the main engine to lose 20–25% of its thrust. This caused the guidance system of the Atlas launch vehicle to increase the length of the first stage burn to compensate.
Due to requirements specific to TIROS missions, there was no interface between the satellite and the launch vehicle guidance systems. This resulted in the satellite attempting to separate from the launch vehicle at approximately 370 seconds after launch. The separation failed due to recontact between the Atlas - which was still under thrust - and the satellite, which only separated when the solid-fuel rocket motor intended to place NOAA-B into a circular 830 km (450 nmi) sun-synchronous orbit fired.
Because the satellite had been unable to perform the pitch-down maneuver necessary to reach its intended orbit the spacecraft ended up in a highly elliptical orbit that was unsuitable for the intended mission. Following unsuccessful attempts to correct the orbit using the satellite's attitude control thrusters, NASA pronounced the mission a failure.
Unlike the earlier Nimbus 1, which was also launched into an unplanned elliptical orbit following a launch vehicle malfunction, no attempt appears to have been made to operate the spacecraft instrumentation during its remaining lifetime in orbit.