N° 46–1993: Meteosat-6 successfully launched

The initial configuration and checkout operations have been successful. Further information on the scheduled activities during the first months of Meteosat-6 in orbit can be found in the attached note.

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The first months of Meteosat-6 in orbit

Following the launch of Meteosat-6 on Ariane flight V61 from the Guyana Space Center in Kourou at 01h17 GMT on 20 November 1993, ESA will place the satellite at its final position in geostationary orbit, test it thoroughly and then operate it on behalf of EUMETSAT.

Control of the satellite was taken over by ESA's Operations Centre, ESOC, in Darmstadt, Germany, immediately after its separation from the launcher, 26 minutes after lift-off. For this purpose, a global network of 4 ground stations operated from ESOC's main mission control centre, had been set up.

ESOC commenced configuration and check-out of the main electrical systems during the first hours in orbit, whith Meteosat-6 still in the elliptical geostationary transfer orbit. On arrival at the 4th apogee, approximately 37 hours after launch, the apogee boost motor will be ignited to circularise the orbit and put Meteosat-6 into a 24-hour near- geostationary orbit.

The spacecraft's longitude at this time will be approximately 19+W and it will be slowly drifting eastwards. The plan is for it to drift past 10+W on 17 December. A further small adjustment may then be made to the drift rate, taking it to the final 0+ longitude by the end of January 1994. There, the drift motion will be stopped by a small orbit change obtained by firing the satellite's thrusters. The actual commissioning of Meteosat-6 is to be performed while it is drifting towards its final position, so that ownership of the satellite can be transferred to EUMETSAT as from early February 1994.

An important event in the commissioning phase is the transmission of the first image from Meteosat-6, scheduled for the end of November. The infrared detectors on board have first to be cooled down, and the first infrared images are expected two days later. However, many more images will be generated and their quality assessed before the satellite is declared operational.

EUMETSAT currently intends to make Meteosat-6 the operational satellite replacing Meteosat-4, which will become the in-orbit back-up satellite. Meteosat-5, which has served as back-up so far, will then be moved westwards over the Americas. There it will take over from Meteosat-3, which has been on loan to the US weather Service, NOAA, since 1991, until NASA's next-generation geostationary satellites are launched and become operational. After 5 years of service, Meteosat-3 has little propellant left for orbital manoeuvres, and needs to be replaced within a couple of months from now. During the 1994 hurricane season, Meteosat-5 is expected to play an important role in the detection and real-time tracking of these dangerous events.

Meteosat-6 and Meteosat-7, to be launched at the end of 1995, will ensure continuity of vital weather data until the turn of the century. As from the end of 1995, EUMETSAT will take over operations of all Meteosat satellites from ESA.