Venus Express Clean-Up Goes Well, European Space Agency Says

Engineers mate the Venus Express spacecraft to its Soyuz-Fregat launch vehicle. Traces of contamination from booster insulation delayed the mission's Oct. 26 launch shortly after this photograph was taken. CREDIT: ESA/Starsem-S. Corvaja.

European scientists are reasonably confident their Venus Express spacecraft will launch to Earth's nearest neighbor before the tight window of opportunity when the planets are aligned slams shut in a few weeks.

The mission was supposed to blast off Wednesday from Baikonur Cosmodrome in Kazakhstan. But contamination found on the satellite forced launch preparations to stop, putting Venus Express into an unplanned holding pattern.

The spacecraft was already mated to its Soyuz rocket inside an assembly building in advance of being rolled to the launch pad. Then came the discovery of some insulation material that had come off the Fregat upper stage and was floating free inside the rocket's nose cone where Venus Express sat encapsulated for launch.

Over the weekend, the Fregat and spacecraft still tucked inside the nose cone were detached from the Soyuz for train transport to another facility 25 miles (40 kilometers) away. The shroud was opened Monday, enabling inspections of Venus Express by technicians to determine if any damage had occurred by the insulation.

European Space Agency (ESA) officials said Tuesday that the spacecraft appeared to be in good health.

"The scenario is so far very encouraging, as only fairly large particles, pieces of the insulating material initially covering the launcher's Fregat upper stage, have been found on the body of the spacecraft," ESA said in a press statement.

"These have been easy to identify by naked eye or with UV lamps, and are being carefully removed with tweezers, vacuum-cleaners or nitrogen gas airbrushes, according to size."

The cleaning will continue for the next few days, followed by re-installation of the nose cone and transfer back to the Soyuz rocket's assembly building.

Although a new launch date has not been set, liftoff is expected to be targeted for sometime between November 6 and 9. Venus Express must launch by November 24 to catch the necessary trajectory from Earth to its destination. 

"The ESA Project team is confident that Venus Express will be launched well within the launch window," the press statement said.

The probe should reach Venus five months after launch. It will fire the onboard main engine to enter orbit around the planet for the most comprehensive examination of the mysterious Venusian atmosphere and new observations of its surface.

The mission, Europe's first exploration of Venus, will last two Venusian days or 486 Earth days.

"There are so many interesting questions about Venus. For example, why is the atmosphere rotating so fast around the planet while the planet itself is rotating so slowly? We believe that long ago the temperature was much less than now and that water was flowing on Venus, but how and when did it disappear?" said H?kan Svedhem, the Venus Express project scientist.

"The whole surface of Venus has not long ago (in geological terms) been completely changed by material from the interior streaming out through volcanoes and cracks in the crust. Is this process still active somewhere on the planet?

"Perhaps the most fascinating question about Venus is that Venus was once quite similar to Earth, but now the two planets are very different. Why are they so different now and when did this change start?"

Venus Express will fly in a highly elliptical orbit looping from 155 miles (249 kilometers) at its closest point to 41,000 miles (65,983 kilometers) at the most distant. The EADS Astrium-built craft carries seven instruments mostly derived from Europe's Mars Express and the Rosetta comet mission.

• A Cloudy Target: Europe's Venus Express Probe to Explore Shrouded Planet
• Venus and Earth: Worlds Apart
• Image Gallery: Beneath the Clouds of Venus