A European space probe orbiting Venus since 2006 is approaching the end of its mission and will go out with a bang -- or at least in a ball of fire as it plummets into the planet's corrosive atmosphere, controllers say.
After 8 years in orbit, earlier this year the European Space Agency's Venus Express was commanded to perform an aerobraking maneuver to take it closer to Venus to study previously uncharted regions of the atmosphere.
Normally in such a procedure that spacecraft would also conduct a series of thruster burns to keep it from going too far into the atmosphere, and after the orbit reached it lowest level -- around 80 miles above the planet -- such burns were initiated to lift the orbit up to around 285 miles.
Then contact with the Venus Express was lost Nov. 28.
Some limited contact has been reestablished, but only fragmentary information on the space probe's status has been received, mission officials are reporting.
"The available information provides evidence of the spacecraft losing attitude control most likely due to thrust problems during the raising manoeuvres," says Patrick Martin, ESA's Venus Express mission manager.
"It seems likely, therefore, that Venus Express exhausted its remaining propellant about half way through the planned maneuvers last month."
Without propellant for any further thruster burns, the orbit of the Venus Express will continue to degrade over the coming weeks, the ESA says, and it will finally sink into the planet's corrosive, sulphuric acid-laden atmosphere and burn up.
"After over eight years in orbit around Venus, we knew that our spacecraft was running on fumes," says Adam Williams, ESA's acting Venus Express spacecraft operations manager.
Mission scientist have expressed great satisfaction with the way Venus Express has performed and the science data is has gathered since its launch in 2005.
While the surface of Venus is extremely inhospitable -- temperatures on the planet are as high as 800 degrees Fahrenheit -- the Venus Express probe found levels of hydrogen and deuterium in the atmosphere suggesting the planet once had considerable amounts of water in its atmosphere, and may even have once possessed water oceans like those on Earth.
The data gathered by Venus Express will give scientists lots to analyze for a long time, says Håkan Svedhem, ESA's Venus Express project scientist.
"While the science collection phase of the mission is now complete, the data will keep the scientific community busy for many years to come," he says.
