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Japanese spacecraft misses rendezvous with Venus; may try again in six years

An artist's rendering shows Akatsuki approaching Venus. The mission was going smoothly until the ground crew had trouble reestablishing communications after the spacecraft passed behind Venus during its orbit injection maneuver.
An artist's rendering shows Akatsuki approaching Venus. The mission was going smoothly until the ground crew had trouble reestablishing communications after the spacecraft passed behind Venus during its orbit injection maneuver. (AP)

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By Dennis Normile
Monday, December 13, 2010; 6:18 PM

SAGAMIHARA, JAPAN - Japan's Akatsuki spacecraft failed to enter its planned orbit around Venus last week 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 six years.

The Japan Aerospace Exploration Agency (JAXA) reported the failure on the Akatsuki home page. And 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 by mission scientists the first planetary meteorological satellite, Akatsuki was supposed to orbit Venus for two 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 May 20, the mission was going smoothly until the ground crew had trouble reestablishing communications after the spacecraft passed behind Venus during its orbit injection maneuver on Dec. 7. 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 had shut down prematurely.

JAXA set up an investigative and countermeasures team to determine what went wrong and examine options for rescuing the mission. At the press conferencet 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 type of ceramic thruster being used in space for the first time.

Akatsuki is now orbiting the sun. Nakamura said the team hopes enough fuel remains to retry the insertion procedure in six years, when the satellite and Venus are once again relatively close to each other.

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 seven-year journey. Akatsuki scientists are hoping to apply the same never-give-up approach to their wayward spacecraft.

This article comes from ScienceNOW, the daily online news service of the journal Science, which can be read online at news.sciencemag.org.


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