JAXA, the Japanese Aerospace Exploration Agency failed to insert its latest space probe, Akatsuki, into orbit around the planet Venus. The article below, from Aviation Week & Space Technology, describes the failure and the attempt to put the probe into hibernation and try again in 6 years.
Japanese Venus Probe Misses Orbit
Dec 8, 2010
By Kazuki Shiibashi
The Japan Aerospace Exploration Agency (JAXA) has confirmed that its “Akatsuki” Venus probe failed to enter orbit, but the project team still hopes to salvage the mission.
Project Manager Masato Nakamura says if the Akatsuki satellite can hold on in space for the next six years, Venus will come round again and provide another opportunity for orbital injection.
“I would like to say, with hope, that when the time comes we should then have a high probability of success,” Nakamura said Dec. 8.
Akatsuki’s design life of 4.5 years from launch was based on the expectation that the spacecraft’s batteries would slowly lose their recharging capacity after repeatedly passing through the planet’s shadow. But since Akatsuki is now flying solo around the Sun, its solar panels will be constantly illuminated, reducing battery wear.
Furthermore, analysis has shown that the spacecraft’s thrusters fired only 2-3 min. out of a planned 12 min. during the failed orbital insertion attempt, leaving an estimated 80% of its fuel intact. But that is still not enough for another immediate orbit, according to Nakamura. “Even if we were to use up all the fuel left in the tank, we would not be able to put [the spacecraft] back into Venus’s orbit as planned,” he says.
Launched on May 21, Akatsuki reached Venus Dec. 7 and attempted its orbital insertion procedure 550 km. (340 mi.) above the planet’s surface at 8:49 a.m. Japan Standard Time. An unexplained transmission failure caused the thruster to stop in the middle of its deceleration burn. This automatically switched the satellite into safe-hold mode, which prevented its scheduled 9:12 a.m. re-establishment of contact with mission control. Communications were finally restored at 10:28 a.m., but only from the spacecraft’s low-gain antenna (Aerospace DAILY, Dec. 8).
For now, JAXA controllers are preparing Akatsuki for a six-year hibernation. The team is taking inspiration from the recently completed Hayabusa mission, which was riddled with technical problems over the course of its seven-year journey but still managed to return samples from asteroid Itokawa.
The lesson to be learned here is twofold; first, even the best laid plans can fail and secondly, you should always have a backup plan ready to go in the event you need to save face. It is unfortunate that the Japanese have to wait 6 years to find out if their plan B will work.
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