The European Space Agency’s Venus Express Orbiter is on the rise again after a month-long aero braking phase that took the 1,500-lb. spacecraft to within 130 km (80 mi.) of the planet’s surface.
Flight control teams intend to raise the low point of the probe’s elliptical polar orbit to 460 km by July 26, if there is enough fuel aboard the eight-year-old spacecraft.
On May 15, normal science operations gave way to an aero braking challenge – one meant to provide engineers with data that could save mass and fuel in the design of future planetary missions.
Artists image of ESA's Venus Express. ESA
“We have explored uncharted territory, diving deeper into the atmosphere than ever before,” Håkan Svedhem, ESA’s Venus Express project scientist, noted in a statement preceding the retreat to higher altitude.
“We’ve measured the effects of atmospheric drag on the spacecraft, which will teach us how the density of the atmosphere varies on local and global scales.”
During the aero braking phase, the orbital period increased by one hour and temperatures on the spacecraft’s solar arrays climbed to 100C, reflecting the new atmospheric stresses at work. The density of the atmosphere increased 1000 times between 165 km and 130 km.
As on Earth, lightning jars the atmosphere. ESA
Venus Express launched from the Baikonur Cosmodrome in Kazakhstan atop a Soyuz/Fregat on Nov. 9, 2005, to start a $300 million exploration campaign - as valued in current-year terms. Since maneuvering into orbit around Venus five months later, the spacecraft's seven instruments have streamed back findings that point to remarkable similarities with and differences from Earth.
The operational 24-hr. orbit ranged in altitude from 66,000 km over the south pole and 250 km over the north pole.
A succession of 15 thruster burns are planned to raise the low point of the Venus Express orbit to 460 km. If the effort is successful, the spacecraft’s orbital track will be permitted to decay naturally, leading to an estimated mission end in December.
However, its possible Venus Express will exhaust the remaining fuel during the climb out. If that’s the case, communications will cease, and the probe will descend for good.