Venus flyer to trap planetary data

Europe's first space mission to Venus was successfully launched last Wednesday to begin its five-month journey to study Earth’s closest neighbour. ESA’s Venus Express spacecraft took off from Baikonur Cosmodrome in Kazakhstan on a Russian Soyuz rocket.

Mission control based in Darmstadt, Germany had to wait two hours before it received the first signals from the spacecraft to show that it was operating as planned.

Venus Express will orbit Venus for around 500 days, with the option of a further 500 days if all goes to plan, and will take scientific readings designed to find out more about the planet’s strange atmosphere.

Based on the design of the Mars Express probe which began orbiting the red planet last Christmas, the new spacecraft was built for ESA by a European industrial team led by EADS Astrium with 25 main contractors spread across 14 countries.

However, environmental conditions around Venus are very different from those around Mars. Solar flux is four times higher so Venus Express had to be adapted to cope with this hotter environment, which involved a new thermal insulation design.

Whereas Mars Express sought to retain heat to enable its electronics to function properly, Venus Express will be aiming for maximum heat dissipation to stay cool.

The solar arrays on Venus Express were redesigned so they are interspersed with aluminium strips to help reject some solar flux and protect the craft from temperatures of over 250ºC. The back of the solar arrays, which normally stay in shadow, also needed to be protected from solar radiation reflected by Venus’s atmosphere.

Venus Express has seven instruments on-board. Among these a high-resolution spectrometer will measure atmospheric temperature and search for signs of volcanic activity on the surface, while an infrared and ultraviolet spectrometer will look for molecules of water, oxygen and sulphuric compounds thought to be present in the atmosphere. To do this Venus Express will fly as low as 250km from the surface.

Scientists hope that studying Venus’s atmosphere will help them understand Earth’s own climate better and the effects of global warming.