PARIS, April 21 (UPI) -- The European Space Agency says its Venus Express spacecraft used its solar wings as sails to obtain measurements of the planet's atmospheric density.
ESA scientists say the "aerodrag" test used the orbiter as a precisely accurate sensor to measure atmospheric density about 112 miles above the planet's surface.
"During five aerodrag measurements last week, Venus Express' solar arrays and control systems were operated as one big flying sensor, with the solar arrays rotated at various angles to the direction of flight," the ESA said. "The special configuration exposed the wings to the vanishingly faint wisps of atmosphere that reach to the boundary of space around Venus, generating a tiny, but measurable, aerodynamic torque, or rotation, on the satellite."
The space agency said such torque can be measured very accurately based on the amount of correction that must be applied by reaction wheels, which counter-rotate in the spacecraft to maintain its orientation in space.
ESA Spacecraft Operations Manager Octavio Camino said the study's results will be used to develop an optimized configuration for aerodrag tests to be conducted in October and during 2011.
