ESA's Venus Express begins its descent

The spacecraft will pass closer to the planet’s hostile surface than ever before.

Venus Express has been orbiting the planet since April 2006. Credit: ESA/C. Carreau
Published: December 2, 2014 at 12:00 pm

Venus Express is beginning its bold plunge into the toxic atmosphere of Venus, the planet it has been orbiting for the last eight years.


The risky operation will push the spacecraft’s capabilities, testing what might be possible for future planetary missions.

Throughout its mission, Venus Express has given us incredible views of the planet’s ionosphere, atmosphere and surface.

Currently Venus Express’s orbit takes it from 66,000km above Venus’s south pole to 250km over its north pole in a giant elliptical loop that takes 24 hours to complete.

Maintaining the loop however, requires propellant, and the fuel on board the probe is rapidly beginning to run out.

Between 18 June and 11 July, the spacecraft will begin its daring bid to journey deeper into the planet’s atmosphere, causing it to slow down in a procedure known as aerobraking and it will sink down to just 130km above the surface.

Perhaps even lower.

“We have performed previous short ‘aerodrag’ campaigns where we’ve skimmed the thin upper layers of the atmosphere at about 165 km, but we want to go deeper,” says Patrick Martin, Venus Express mission manager.

Deadly descent

No one is sure if it will survive the plunge.

The craft was an offshoot of the Mars Express mission, and is a replica of the probe that’s still orbiting the Red Planet.

It isn’t designed to endure Venus’s crushing atmosphere.

It is possible that the craft may not have enough fuel to pull itself back out of orbit, or may succumb to the acidic clouds that circle the planet.

However, if it does survive it will continue to circle the planet for another few months before eventually running out of fuel.

Future missions to other planets may use this technique of aerobraking to slow down and insert themselves into orbit.

Traditional braking methods require a lot of fuel, so this would help to greatly cut down on the launch weight.

As well at testing this new method of braking, Venus Express will continue to monitor the planet’s magnetic field, temperature and pressure, carrying on its mission to monitor this extreme world until the very end.


“It is only by carrying out daring operations like these that we can gain new insights, not only about usually inaccessible regions of the planet’s atmosphere, but also how the spacecraft and its components respond to such a hostile environment,” says Martin.


Ezzy Pearson is the News Editor of BBC Sky at Night Magazine. Her first book about the history of robotic planetary landers is out now from The History Press.

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