Tough loss. Beside a model of the Akatsuki spacecraft, mission manager Masato Nakamura discussed the failure to get the probe to orbit Venus at a press conference on 8 December.

Dennis Normile

Japan's Akatsuki Mission Misses Venus

SAGAMIHARA, JAPAN—Japan's Akatsuki spacecraft failed to enter its planned orbit around Venus yesterday and is now drifting through space. The main hope of rescuing the mission, intended to study the planet's climate, appears to be a second try at inserting it into orbit when it approaches the planet again in about 6 years.

The Japan Aerospace Exploration Agency (JAXA) today reported the failure on the Akatsuki homepage. At a press conference on the campus of JAXA's Institute of Space and Astronautical Science (ISAS) here, project manager Masato Nakamura apologized for "not meeting the expectations of the nation."

Dubbed the first planetary meteorological satellite by mission scientists, Akatsuki was supposed to orbit Venus for 2 years, using its five cameras operating at ultraviolet and infrared wavelengths to track clouds at different altitudes and watch for venusian lightning. The findings from Akatsuki, in an equatorial orbit, were expected to complement data coming from the European Space Agency's Venus Express, which has been in a polar orbit around the planet since April 2006.

Launched on 20 May, the mission was going smoothly until the ground crew had trouble reestablishing communications after the spacecraft passed behind Venus during its orbit injection maneuver yesterday. Using a backup antenna on the craft, the ground crew established a slow communications link, determined its position, and concluded that a thruster intended to slow the craft to allow Venus's gravity to pull it into orbit shut down prematurely. JAXA set up an investigative and countermeasures team to determine what went wrong and examine options for rescuing the mission. At a press conference this evening, Nakamura said the cause of the malfunction wouldn't be determined until more data are downloaded and reviewed, though one focus of attention is a new type of ceramic thruster being used in space for the first time.

Akatsuki is now on a course orbiting the sun. Nakamura said the team hopes enough fuel remains to retry the insertion procedure in 6 years when the satellite and Venus are once again in relatively close proximity.

A previous ISAS planetary probe, Nozomi, failed to enter an orbit around Mars in December 2003 after suffering multiple failures and was eventually abandoned. But ISAS scientists gained extensive experience getting malfunctioning spacecraft to perform beyond expectations with Hayabusa, which landed on asteroid Itokawa and returned asteroid dust to Earth after a trouble-plagued 7-year journey. Akatsuki mission scientists are hoping to apply the same never-give-up approach to their wayward spacecraft.

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