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What's Up With Hayabusa? (fka Muses-c)
RNeuhaus
post Nov 23 2005, 02:21 PM
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The first touch down occurred around 6:10. The second touch down was around 6:30 after A bounce. Another small bounce brought the spacecraft into rest, according to the LRF data.

It stayed ON the surface for 30 minutes, all the while it was being heated up by thermal radiation from the surface of Itokawa. Take OFF was performed by A command from Earth at 6:58, then entered into the safe mode.

The spacecraft was seemingly at rest with the sampler horn and an edge of the body OR A solar panel wing attached to the surface.

Because the obstacle sensor had been triggered, the sampler horn was not engaged, so the impacter was not deployed. The event happened during the switch over from NASA Goldstone station to Usuda station, so they did not confirm the landing from the Doppler data.


Incredible news for two things: Good luck for landing, bad luck for not triggering the impacter (due to the switch over from NASA to Usuda station). I am uneasy about the problem of deployment of impacter. As I have read the Impacter document (see my previous append), it will automatically (autonomously) fire impacter ball whenever the horn is blend or moved more than 1 cms of its original position. What has happened with this? Maybe, the horn was not touched but by the Hayabusa's sides...

Rodolfo
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hugh
post Nov 23 2005, 02:51 PM
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QUOTE (Jkoro172 @ Nov 23 2005, 02:18 PM)
There was high possibility that the dust flew up and reached into the sampling capsule. The door of capsule is designed to be closed by the landing sequence, but it continues to (be) open. The scientists of planet insist to close the door.
*


I imagine they insisted pretty strongly...
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Rakhir
post Nov 23 2005, 04:00 PM
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5thstar.air-nifty.com :
Currently Hayabusa is approaching to Itokawa at 4 km per hour. As it closes up, it slows down for delicate positioning. It depends on whether they can bring it back to the starting position, and also on the stamina of the operation team members, to have the second attempt on the 25th.

Let's order two or three more cases of LIPOVITAN D ! biggrin.gif
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The Messenger
post Nov 23 2005, 04:09 PM
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QUOTE (RNeuhaus @ Nov 23 2005, 07:21 AM)
Because the obstacle sensor had been triggered, the sampler horn was not engaged, so the impacter was not deployed. The event happened during the switch over from NASA Goldstone station to Usuda station, so they did not confirm the landing from the Doppler data.[/i]

*


If I am reading this correctly, this is another programmer oversight: the Impactor did not know how to respond if an obstical overide nixed a limited abort command.
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ElkGroveDan
post Nov 23 2005, 04:21 PM
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QUOTE (foe @ Nov 23 2005, 01:55 PM)
QUOTE
As reported previously, the target marker that successfully landed on ITOKAWA on Nov. 21st, 2005 is etched on an aluminum foil with the names of 880,000 applicants  .... From now on, their names will spend an eternal time with Professor Itokawa. Does anyone of you say, “Damn it! I should have applied to the campaign, too”?

I have many regrets in life, but somehow I'm just not losing sleep over that one. Maybe I'm not drinking enough LIPOVITAN D.


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jaredGalen
post Nov 23 2005, 06:10 PM
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QUOTE (RNeuhaus @ Nov 23 2005, 02:21 PM)
It stayed ON the surface for 30 minutes, all the while it was being heated up by thermal radiation from the surface of Itokawa. Take OFF was performed by A command from Earth at 6:58, then entered into the safe mode.
*

I know it's not the first man made object to land on an asteroid, but I think it is the first to land for an extended period and then take off again.
Am I understanding correctly that it stayed on the surface for 30 minutes and then took off on the command from the ground. This in itself is brilliant in my opinion and is sure to provide great lessons for the future, right?


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helvick
post Nov 23 2005, 06:26 PM
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QUOTE (jaredGalen @ Nov 23 2005, 07:10 PM)
Am I understanding correctly that it stayed on the surface for 30 minutes and then took off on the command from the ground. This in itself is brilliant in my opinion and is sure to provide great lessons for the future, right?
*

I'm completely in agreement. Huyabusa managed to land itself on an asteroid and does not appear to have damaged itself at all. It stayed there for 30 minutes and then took off (safely) when instructed to do so. Finally it is now ready to repeat the exercise and hopefully the other objectives (firing the projectile and collecting some debris) will be achieved.

OK so this wasn't 100% according to the ideal plan but this is a robotic lander that was intended to do some very complicated stuff autonomously in an environment that was not known in any detail when it was built and programmed. The fact that it did land and take off is an outstanding achievement.

As far as I know this is the first time any unmanned probe has landed on an extraterrestrial body and taken off again in a controlled manner. That's one heck of a milestone for JAXA.

Respect!
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odave
post Nov 23 2005, 06:42 PM
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QUOTE (The Messenger @ Nov 23 2005, 11:09 AM)
If I am reading this correctly, this is another programmer oversight: the Impactor did not know how to respond if an obstical overide nixed a limited abort command.
*


Maybe. I haven't had time to read through the PDF posted by RNeuhaus, so this is semi-informed conjecture.

I read it as: The obstacle sensor indicated that it found something. This overrode the sample horn software, which means that the impactor was prevented from firing.

If this is the case, the override seems reasonable to me. If the spacecraft hit an obstacle, it is possible that it got tilted at such an angle as to point the horn in an unfortunate direction, which may fire the impactor out to space. That is something you'd want to prevent.

Maybe a more robust way to handle this is for the software to get a second opinion from other sensors: "Hmmm. There's an obstacle. Are we oriented up/down OK? Yes. Is the horn deformed? Yes. OK, let's fire it anyway."

And maybe they already do that - we don't know the code...


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odave
post Nov 23 2005, 06:51 PM
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QUOTE (Jkoro172 @ Nov 23 2005, 09:18 AM)
There was high possibility that the dust flew up and reached into the sampling capsule. The door of capsule is designed to be closed by the landing sequence, but it continues to open. The scientists of planet insist to close the door.
*


I think this means that Hayabusa needs to come home to Earth no matter what happens in the next sampling attempt. If there is any chance that a sample was taken accidentally, it needs to be recovered.

IMO this would qualify the sampling process as an "ugly win". Being a Detroit Lions fan, I've learned to be happy with any kind of win, ugly or otherwise biggrin.gif


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JRehling
post Nov 23 2005, 07:13 PM
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QUOTE (helvick @ Nov 23 2005, 10:26 AM)
As far as I know this is the first time any unmanned probe has landed on an extraterrestrial body and taken off again in a controlled manner. That's one heck of a milestone for JAXA.

Respect!
*


Three Soviet sample returns from the Moon took place, so this is a new accomplishment still, but you have to qualify it a bit carefully.

One quibble I have is that the procedure seems to have been a bit "blind" -- the autonomy that makes the re-launch impressive in one sense means that we lack much data describing the event, at least as far as I can tell now. That makes it harder to benefit from in future missions. But perhaps more data (and close up images) from the event have been recorded for post hoc replay?
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odave
post Nov 23 2005, 08:06 PM
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...but maybe there's another reason Hayabusa aborted...

"This is Red 5, I'm going in!"

Attached Image

original image credit: JAXA/ISAS

tongue.gif


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helvick
post Nov 23 2005, 08:12 PM
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QUOTE (odave @ Nov 23 2005, 09:06 PM)
...but maybe there's another reason Hayabusa aborted...

"This is Red 5, I'm going in!"
*


Use the Force dude, that targetting computer is way off...
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Omega
post Nov 23 2005, 08:15 PM
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Yahoo! is reporting Hayabusa touched down on Itokawa for half an hour on Sunday, but didn't collect samples. It was 62 or 63 miles from the asteroid at last report, being prepared for another attempt.
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Holder of the Tw...
post Nov 23 2005, 09:30 PM
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QUOTE (helvick @ Nov 23 2005, 12:26 PM)
As far as I know this is the first time any unmanned probe has landed on an extraterrestrial body and taken off again in a controlled manner. That's one heck of a milestone for JAXA.
*


Besides the before mentioned Soviet Lunas, an American Surveyor lunar lander, I believe it was Surveyor 6, briefly re-fired it's engines to lift off the moon, and moved a few feet away before landing again. This was the first controlled extraterrestrial liftoff.
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helvick
post Nov 23 2005, 09:42 PM
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I respectfully bow to the collective wisdom of UMSF.

This place is fantastic for suppressing guesswork, conjecture and supposition.

Love it. smile.gif
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