ESA Science & Technology - Fact Sheet

Venus Express was ESA's first mission to Earth's nearest planetary neighbour. The spacecraft was based on the Mars Express platform, with some modifications primarily due to the different thermal environment at Venus.

Many of the instruments on Venus Express were upgraded versions of those used on the Mars Express and Rosetta missions.

Mission Objectives

Venus Express's science objectives were to study the atmosphere, the plasma environment, and the surface of Venus in great detail.

Spacecraft

The main body of the spacecraft, the spacecraft bus, was comprised of a honeycomb aluminium box 1.7m × 1.7m and 1.4m high, onto which all the payload instruments were integrated. The solar arrays with a collecting area of 5.7 m² provided 1100 W of power, when the spacecraft was in orbit around Venus.

Instruments

Orbit

Venus Express was launched from the Baikonur Cosmodrome in Kazakhstan on 9 November 2005. A Soyuz-Fregat rocket carried it into space and placed the spacecraft in its transfer orbit to Venus. After an interplanetary cruise that lasted 5 months, Venus Express arrived at Venus on 11 April 2006. A 50-minute engine burn slowed the spacecraft and allowed it to enter orbit around the planet. The first capture orbit was an eccentric polar orbit and lasted 9 days. Several manoeuvres between 15 April and 6 May then lowered the spacecraft into its operational orbit: a 24-hour elliptical, quasi-polar orbit.

At its closest, Venus Express reached an altitude of 250 kilometres and at its furthest, it was 66 000 kilometres away from the planet. Over two years later, between 13 July and 4 August 2008 a series of manoeuvres further lowered the pericentre of the orbit to 185-300 km, with the apocentre still at about 66 000 km.

After the conclusion of its main scientific mission in May 2014, the spacecraft's altitude at closest approach to Venus was lowered further, from 190 km to 130 km, eventually reaching a minimum of 129.2 km on 11 July 2014. At this altitude the atmospheric drag on the spacecraft significantly altered its orbit, reducing it from 24 hours to 22 hours 20 minutes.

In the second half of July 2014, a series of manoeuvres raised the orbit, placing the spacecraft in a new orbit with a pericentre altitude of 460 km and an apocentre altitude of 63 000 km. A final series of raising manoeuvres were planned to take place between 23-30 November 2014, to compensate for the natural steady decrease of the pericentre altitude. However, full contact with Venus Express was lost half-way through the manoeuvres, on 28 November 2014. The spacecraft had exhausted its propellant, leaving its orbit to naturally decay, and the spacecraft eventually plummeted into the atmosphere.

The Venus Express mission officially ended in December 2014.

Mission Operations Centre

The Venus Express Mission Operations Centre (VMOC) was located at the European Space Operations Centre (ESOC) in Darmstadt, Germany. Communications with the spacecraft were done using the ESA deep space ground station located in Cebreros, near Madrid, Spain. For observations to be carried out with the Venus Radio science experiment (VeRa) additional support came from the New Norcia ground station.

During critical periods support was also provided by the NASA Deep Space Network of stations. This support enabled increased accuracy of spacecraft tracking during events such as Venus Orbit Insertion, as well as extra downlink during data-intensive observation campaigns.

Science Operations Centre

The Venus Express Science Operations Centre (VSOC) was located at the European Space Astronomy Centre (ESAC) near Madrid, Spain. Data from the Venus Express mission are available from the ESA Planetary Science Archive.