Washington: European Space Agency’s Venus Express has finally ended its eight-year mission after far exceeding its planned life.
The spacecraft, which has been on an elliptical 24 hour orbit, travelling 66 000 km above the south pole at its furthest point and to within 200 km over the north pole on its closest approach, exhausted its propellant during a series of thruster burns to raise its orbit following the low-altitude aerobraking earlier this year.
However, after eight years in orbit and with propellant for its propulsion system running low, Venus Express was tasked in mid-2014 with a daring aerobraking campaign, during which it dipped progressively lower into the atmosphere on its closest approaches to the planet.
Normally, the spacecraft would perform routine thruster burns to ensure that it did not come too close to Venus and risk being lost in the atmosphere. But this unique adventure was aimed at achieving the opposite, namely reducing the altitude and allowing an exploration of previously uncharted regions of the atmosphere.
Full contact with Venus Express was lost on 28 November and since then the telemetry and telecommand links had been partially re-established, but they were very unstable and only limited information could be retrieved.
Patrick Martin, ESA’s Venus Express mission manager, said that the available information provides evidence of the spacecraft losing attitude control most likely due to thrust problems during the raising maneuvers and it seems likely, therefore, that Venus Express exhausted its remaining propellant about half way through the planned manoeuvres last month.
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