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Hayabusa Probe Fails Landing Attempt
wschalle writes "Yesterday, at 3:46 PM EST the probe successfully dropped a small object onto the asteroid as a touchdown target. JAXA then apparently lost control of the probe for 3 hours. The probe went to an auto-pilot mode during the communications failure, collecting data about its flight and saving it for later transmission. The probe's exact location is unknown, but it is estimated to be between 10 and 100 kilometers from the asteroid at this time. The mission has been troubled by repeated failures, including the loss of a small robotic lander, and a gyroscope failure that was later repaired."
This is, what they'd call it, purely an engineering mission with scientific goals in mind.
In other words, they have never done any of these things (flying out autonomously, release a probe, land on an object, and return to the Earth) and this is their first test mission. It was thought to be too freaking bold to try all that at the first attempt; but they tried it anyway.
The mission is plagued with technical failures; the failure of torque wheels is probably the worst. That really made that autonomous part difficult.
I think there are an awful lot of excessively harsh comments here. These guys are trying to do a very difficult mission with virtually no applicable experience. Sure, there's a lot of information that, say, NASA (or more accurately, the contractors who work for NASA/DOD/other customers) has, but you simply can't effectively transfer the experience needed for this type of engineering.
By the way, there are some very good reasons* that US space projects take so long and cost so much. It's because there are enough experienced engineers around to know where to worry and what to worry about. That didn't build up in a few tries. Some contractors have literally hundreds, bordering on a thousand, successful space missions under their belts.
All the documents and "design processes" in the world cannot make up for having a few guys around with the necessary background to take a look at the design or implementation, and just see where the obvious problem areas might me.
It's a tough loss, but it's just the cost traversing of the learning curve.
Brett
* Of course, there are some "bad reasons" for overruns and schedule slips, too - usually, overly-optimistic schedules and budgets! In fact, a lot of the time there is no one in the entire acquisition system that has a stake in getting the *real* cost or *real* schedule.
Here is one image. Notice the shadow cast by the long boulder on the left side about half-way down.
g
http://www.space.com/images/v_itokawa_jaxa1_02.jp
Table-ized A.I.
I am getting reports that they will attempt another landing on November 25th (JST), provided that the mishap is understood and the position of the satellite is corrected.
The summary makes it sound like it's over for the probe, which is far from the case. Emily Lakdawalla of the Planetary Society has been keeping track of the latest details. According to her posts, although it will take several days to get the probe back into the proper position, they should be ready for another landing attempt sometime next week.
(i was waiting for that response...) Some bullets can, look up a paper by Williams, Hahn, et. al. http://pdf.aiaa.org/preview/CDReadyMJPC2005_1177/P V2005_3847.pdf ... I'm one of the authors and yea, there are bullets that do mid-course corrections :P (many others exist... in existance and conceptual. Just mention this paper cause i knew where it was on the top of my head)
My point is magnitudes of scale. Yes they missed, but if you compare the error - its 3E-7. JAXA was being overabmitious, if you look at their prior projects they just didn't have the experiance to do this kinda thing, they did a damn fine job doing just this.
-everphilski-