Japan’s Akatsuki Spacecraft May Finally Be Orbiting Venus

The five-year wait is over (almost)

Akatsuki spacecraft
An artist's depiction of the Akatsuki spacecraft in orbit around Venus. Akihiro Ikeshita (JAXA)

After a failed attempt at entering Venus’ orbit five years ago, Japan’s Akatsuki spacecraft might finally be circling the second planet from the sun. But now, thanks to the ingenuity and patience of the weather-tracking spacecraft’s team, researchers might soon learn more about Venus’ atmosphere than ever before.

Also known as the Venus Climate Orbiter, the Akatsuki probe was meant to enter stable orbit around Venus back in December 2010 after an eight-month-long journey through space. Unfortunately, Akatsuki’s main engine failed during the main burn that was meant to place the probe into Venus’ orbit: Just a few minutes after the engine started, a fuel valve malfunction caused the engine’s temperature to spike, fracturing a ceramic nozzle in the propulsion system and sending Akatsuki in a spiral around the sun, Mika McKinnon reports for Gizmodo.

At the time, things didn’t look good for the Japanese Aerospace Exploration Agency (JAXA). The Akatsuki mission was supposed to make up for their previous attempt at entering the planetary exploration game when the Mars probe Nozomi failed to enter the red planet’s orbit in 1999, David Cyranoski wrote for Nature at the time. But instead of giving up on the $300 million spacecraft, JAXA’s engineers worked to salvage the mission.

While Akatsuki’s main engines were fried, the spacecraft still had four small maneuvering thrusters that JAXA engineers hoped could get their charge on track. To make the probe lighter and easier to maneuver, they dumped roughly 143 pound of fuel into space and waited for Akatsuki’s path around the sun to bring it back in Venus’ range, Alexandra Witze reports for Nature.

Meanwhile, the engineers hoped the heat from the sun didn't destroy the craft's instruments and puzzled over how to make the probe last longer than the originally intended two years. “It’s been quite a long period of waiting,” JAXA project manager Masato Nakamura tells Witze.

Finally, on December 6, Akatsuki flew close enough for JAXA to get one last shot at getting the spacecraft into Venus’ orbit and according to early readings it was a success, JAXA reports.

But it’s not exactly a perfect orbit. According to JAXA’s calculations, Akatsuki is taking a loopy path around the planet, and it will take a few days of measurements to see if the spacecraft is in the necessary position for its cameras and instruments to observe the planet. Even so, for some at JAXA, that’s enough of a success for now.

“We have to wait another two days to confirm the orbit. I am very optimistic,” Nakamura said in a press conference, reports McKinnon. “It is important to believe in success!”

If Akatsuki is in the right orbit, it will be the only way for scientists to study Venus’ atmosphere for the foreseeable future after the European Space Agency’s Venus Express spacecraft shut down about a year ago, Witze writes. But the spacecraft hasn’t been idle during its long flight back around to Venus: Akatsuki has helped scientists study how the sun’s turbulence affects radio waves.

Though the situation looks promising, JAXA’s team will have to hold their breath just a little bit longer to know for sure.

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