MetOp-A set for launch

MetOp-A, the first member of a new family of European satellites designed to monitor the Earth’s atmosphere from low Earth orbit, is to be launched from

, on 17 July.

It will complement Europe’s Meteosat satellites in geostationary orbit and form part of an integrated system to be run with the USA to provide better weather and climate information.

The MetOp satellite series is a joint programme by the European Space Agency (ESA) and the European Meteorological Satellite Organisation (EUMETSAT), with the latter to operate the spacecraft once in orbit. These new satellites will form the space segment of the EUMETSAT Polar System (EPS) and probe the atmosphere with from a sun-synchronous orbit.

They will circle the globe from pole to pole at an altitude of about 817 km, collecting high- resolution data to complement the hemispheric survey of the atmosphere conducted from geostationary orbit by the Meteosat system.

These new European satellites will be operated in partnership with the US National Oceanic and Atmospheric Administration (NOAA) polar weather satellite system, providing data that will be used to monitor the planet’s climate and improve weather forecasting. NOAA satellites will operate the 'afternoon shift' (crossing the equator in the afternoon, local time), with Europe’s MetOp taking over the 'morning orbit' service.

The MetOp spacecraft have been developed and built by an industrial team led by EADS Astrium in Toulouse, France. Three flight models have been ordered and essentially completed, and will be launched sequentially in order to ensure continuous data delivery up to 2020. Each satellite is 6.5m high and weighs about 4 tonnes at launch. MetOp-A, the first spacecraft in the series, is carrying 11 instruments.

IASI will measure the infrared radiation emitted by the Earth. This payload includes a new generation of European instruments – provided by ESA, Eumetsat, and the French Space Agency (CNES) – to deliver improved remote-sensing capabilities to both meteorologists and climatologists.

The IASI spectrometer will provide highly accurate temperature and humidity profile measurements, the Gome-2 spectrometer will probe the atmosphere for ozone and trace gas concentrations, the Ascat scatterometer will measure wind speed and direction on the ocean surface, and the Gras payload will provide atmospheric profiles using the occultation of radio signals from GPS satellites.

The MHS instrument, replacing the AMSU-B instrument carried on previous US satellites, will give microwave measurements of humidity.

In addition, the satellite incorporates a set of 'heritage' instruments provided by the USA: the AVHRR radiometer for global imagery, the AMSU-A microwave sounder, the HIRS infrared sounder, an advanced Argos data collection system, a Search & Rescue package and the SEM-2 spectrometer to monitor charged particle flux in space, or so-called 'space weather'.