Hayabusa needs help
Dear Managers of NASA, Cassini and Voygers,
As you know, JAXA/ISAS has apparently succeeded in the touch down and sampling maneuver of Hayabusa (fka MUSES-C) on the asteroid Itokawa on the 26th of November.
Soon after the autonomous sampling, JAXA has put Hayabusa into the safe-hold mode, a spin-stabilized solar-oriented attitude control to stop the excess in the propellant consumption. They are trying to establish the 3-axis control and to pin point the malfunctioning thruster since then.
Today they held a press briefing to address the current situation. A space journalist Shin-ya Matsuura wrote an article about the announcement made by JAXA on his blog, and the Q&A following the session. English translation of his article by nao is available on the comment area.
JAXA/ISAS press release:
Hayabusa has twelve thrusters, six in the system A and another six in B. During the ascent of the sampling maneuver, they detected a excess in the propellant consumption and shutdown the thrusters in System B. They have located the thruster in question.
During the 26th evening with DSN and 27th with Usuda, they tried to bring the spacecraft back from the safe-hold mode. The thruster system A did not give the full power and they were not able to establish the 3-axis control during the communication time window. They are speculating whether the fuel pipe of the system A might somehow be frozen. On the 28th they were not able to contact Hayabusa with the parabola at Usuda. Now they are trying to establish the telemetry communication and to put the probe into the safe-hold mode again.
Hayabusa's high gain antenna is fixed to the top of the probe. It does not have a movable arm and while it is in the safe-hold mode, they cannot communicate with high throughput communication.
Project manager Kawaguchi speculates the reason of not communicating with Hayabusa on the 28th as the spacecraft might be using the medium gain antenna. This antenna transmits signal into an 18 degrees cone and the communication becomes intermittent during the spin-stabilized attitude control. If the angle of the spacecraft is not appropriate, they cannot establish the communication. In this case they need to switch to the low gain antenna.
Time is quickly running out. If they fail to regain the 3-axis attitude control by early December, Hayabusa might lose the opportunity to bring the asteroid sample back to Earth.
They need to establish the communication now. They need to receive just one packet of the probe signal to re-establish the communication with the medium gain antenna. Bigger the parabola is, and sooner, the better. Kawaguchi holds NASA's 34 m parabola on the 30th and the 1st of December. But they could also make use of 70 m parabolas if possible, for several days, in a hope of quickly recovering the communication with Hayabusa, but I also understand they are allocated to Cassini and Voyger missions.
Flexible operation of NASA DSN is mostly appreciated. Thank you for your attention.
Webmaster of 5thstar
[Addendum] I wrote this message privately as one of space fans in Japan. JAXA/ISAS is not related to this activity at all. I believe Prof. Kawaguchi is already working on the official channel with NASA. Thank you for your understanding and support for the Hayabusa mission.
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