It’s been a long run for the European Space Agency’s (ESA) Venus Express, a spacecraft that has been orbiting Venus for 8 years now. With the spacecraft’s propellant fuel getting low, the ESA has shut down its regular agenda of scientific tasks and is preparing it to take a plunge deeper into Venus’ atmosphere– a mission that is expected to be its last.
Since reaching Venus in April of 2006, the Venus Express has been conducting 24-hour polar elliptical orbits of the planet. During these orbits, it flew out to 41,000 miles over the Vensuian South Pole and as close as 155 miles over its North Pole. The Venus Express has provided us with valuable information in regards to the ionosphere, atmosphere, and actual surface of Venus.
Despite being farther away from the sun than Mercury, Venus is actually hotter due to a runaway greenhouse effect.
“Venus Express has taught us just how variable the planet is on all timescales and, furthermore, has given us clues as to how it might have changed since its formation 4.6 billion years ago,” said ESA’s project scientist Håkan Svedhem in a press release. “This information is helping us decipher how Earth and Venus came to lead such dramatically different lives”
The fuel that allows the Venus Express to skim the atmosphere of Venus is running low, so ESA scientists have decided to send it deeper into the atmosphere than ever before, allowing it to gather new valuable information about that section of atmosphere before it is ultimately destroyed. When it enters these deeper depths, the spacecraft will still send back data from its temperature and pressure sensors. The most important test, however, will be experimenting with ‘aerobraking‘. Aerobraking is the process by which a spacecraft uses the atmosphere of a planet to slow down, rather than relying solely on fuel for this process. If we can learn to aerobrake progressively more confidently, it will mean we can pack less fuel on board for a given planetary mission.
The video below from ESA provides a simulation of the spacecraft taking the Venusian plunge in the name of science.
While the career of one Venusian explorer is soon coming to an end, there are other models in development. The Venus Atmospheric Maneuverable Platform, or VAMP design, would be an inflatable glider full of hydrogen that could cruise Venus’ skies at about 34-43 miles per hour above the surface. One appeal of the VAMP design is that the blustery conditions of Venus could actually help it sail through the atmosphere.