The Meteorological Operational satellite program (MetOp) launched its first polar orbiting satellite (MetOp-A) on October 19, 2006. On 17 September 2012, the follow-on MetOp-B was successfully launched into polar orbit, which is now in a co-planar orbit and nearly half an orbit out of phase with MetOp-A.
MetOp is the first in a series of European satellites dedicated to near-real-time operational meteorology observations. The MetOp mission is primarily a joint collaboration between ESA and EUMETSAT with additional assistance from CNES and NOAA. MetOp is in a sun-synchronous orbit, carrying a payload of 10 scientific instruments including NOAA’s well established Advanced Very High Resolution Radiometer (AVHRR) to measure sea surface temperature (SST) and the new European Advanced Scatterometer (ASCAT) to measure ocean surface wind vectors.
MetOp has a repeat period of 29 days/412 orbits and the local equator crossing time at the ascending node is 21 hours 30 minutes; a repeat orbit is almost reached every 5 days/71 orbits. The orbit period is approximately 101 minutes. Metop flies at a mean altitude of 817 km and has an orbit inclination of 98.7 degrees. The operational mission duration is expected to be 4.5 years.