Venus Express patterned after the Mars Express mission, is the first Venus exploration mission of the European Space Agency. Launched on November 9, 2005, it has reached its final operational orbit last May 7, 2006.

The initial orbit – or ‘capture orbit’ – was an ellipse ranging from 330 000 kilometres at its furthest point from Venus surface (apocentre) to less than 400 kilometres at its closest (pericentre).

Venus Express' thrusters were ignited five times during the course of the 9-day capture orbit to gradually reduce the apocentre and the pericentre, meaning the orbiter is getting closer to the planet's surface.

"Firing at apocentre allows the spacecraft to control the altitude of the next pericentre, while firing at the pericentre controls the altitude of the following apocentre," says Andrea Accomazzo, Spacecraft Operations Manager at ESOC.

As of May 7, the orbit now ranges from between 66,000 and 250 kilometers as its apocentre and pericentre respectively.

"This is the orbit designed to perform the best possible observations of Venus, given the scientific objectives of the mission. These include global observations of the Venusian atmosphere, of the surface characteristics and of the interaction of the planetary environment with the solar wind," says Han Svedhem, Venus Express Project Scientist.

Venus Express’ nominal science phase begins on June 4, 2006.