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Planetary News: Hayabusa (MUSES-C) (2005)Hayabusa: Spacecraft Did Land Last Sunday, But Did Not Get SampleBy A.J.S. Rayl 24 November, 2005 23 November, 2005 Although there had been plans for Hayabusa to make another attempt at landing and collecting a sample Friday, November 25, that plan is now on hold, at least temporarily. JAXA officials confirmed in its announcement today that Hayabusa will take at least one more flight down to Itokawa to snatch a sample of the big rock's surface soils and will announce that date by tomorrow. "It's been a wild ride," Donald K. Yeomans, senior research scientist at the Jet Propulsion Laboratory (JPL) and the U.S. project scientist for the mission said during an interview with The Planetary Society yesterday. "They've still got one more chance to get a sample, and they're feeling more and more confident with each effort they make, but they are on the clock now." Hayabusa – which means "falcon" in Japanese -- is JAXA's $170-million-dollar mission to the near-Earth asteroid named after the "father" of Japan's space program, Hideo Itokawa. It is, in fact, the world's first mission to attempt to land on an asteroid, collect samples, and return them to Earth. The spacecraft – which was developed at the Institute of Space and Astronautical Science (ISAS), a space science research division of JAXA -- launched from Japan’s Kagoshima Space Center on May 9, 2003 and arrived in September of this year. The spacecraft – which has been studying the asteroid since it arrived -- needs to propel itself away from Itokawa by mid-December in order to place itself in the right trajectory to meet the objective of returning to Earth by June 2007. The whole process of collecting the sample is designed to take a matter of seconds. The collection device is horn or scoop-shaped, "sort of like a [stubby] megaphone or a scoop," and is attached to Hayabusa. "The end is like a cone and the central part is a cylinder," Yeomans explained. "They fire a pellet down the center of the scoop into the surface at 300 meters per second, causing ejecta to explode off the surface, and as the ejecta comes up, it funnels into the chamber." As soon as the front end of the cone on Hayabusa touched the surface Sunday, a tantulum pellet should have fired and the resultant ejecta should have been captured by the device. The data returned Sunday show that Hayabusa -- at an altitude of 35 meters above Itokawa and after releasing the target marker -- switched its onboard LIDAR [Light Detection and Ranging or Laser Imaging Detection and Ranging, a technology that determines distance to an object or surface using laser pulses] to LRF [Laser Range Finder] for further descent. Then, at an altitude of 25 meters, the spacecraft shifted into a "hovering" phase by decreasing velocity to nearly zero. At an altitude of 17 meters above the asteroid, Hayabusa went into free-fall descent around 5:40 a.m., and switched its attitude control into "terrain alignment" mode. According to the data from the LRF, Hayabusa briefly touched down on Itokawa at 6:10 a.m., and it touched down a second time before it made an emergency evacuation at 6:58 a.m., as ordered by command from the mission control center in Sagamihara. Meanwhile, JAXA has spent the last couple of days "recovering" Hayabusa, getting it out of safe mode, and the team is continuing to analyze the data. Tasuku Iyori of The Planetary Society of Japan contributed to this story. |
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