[X] My Assistant

[Guest_BruceMoomaw_*]

James Oberg has a piece on the failure ( http://www.msnbc.msn.com/id/10013920/ ), and there's a very protracted excerpt from the press conference at http://smatsu.air-nifty.com/lbyd/cat679792/index.html which can be run through Babelfish. (One passage seems to say that Minerva did indeed hit escape velocity from the asteroid.) As Rakhir says, one would think that they would have included an elementary software precaution against releasing the rover while Hayabusa was rising -- but then, the Japanese retain an eerie talent for bungling space exploration at virtually every opportunity, due mostly, I presume, to their obsession with trying to do it on a shoestring. I just hope they don't bungle the sampling operation itself, but I'm not taking any bets.

[RNeuhaus]

That is too pity to miss it for lacking a simple solution by including a new algorithm software to avoid the release of Minerva when there is an escape velocity greater than the gravity tugging velocity after collecting the data from two or three distance measurement instruments incorporated to Hayabusa.

This has surprised me that Hayabusa is highly publiced as an autonomous space probe and it is lacking this very important part and am afraid it would be lacking too the control to fire and suck the sand samples from Itokawa land autonomously. (hitching the hair)

It would be silly to release Minerva by a control command when the response time would take 32 minutes later after a correct or required event. Otherwise, it should not be done.

Rodolfo

[mike]

Maybe they never thought that Hayabusa would enter 'object avoidance' mode while dropping Minerva.. still, it seems like a bit of testing would have easily revealed this flaw, and it does seem like this flaw would be quite simple to fix (just ignore the 'release Minerva' command), and oh yeah, testing, testing, testing.

The sample return will be entirely successful, though - the I Ching says so?

[The Messenger]

Maybe they never thought that Hayabusa would enter 'object avoidance' mode while dropping Minerva.. still, it seems like a bit of testing would have easily revealed this flaw, and it does seem like this flaw would be quite simple to fix (just ignore the 'release Minerva' command), and oh yeah, testing, testing, testing.

The sample return will be entirely successful, though - the I Ching says so?

Was there an object avoidance command, or did Huyabusa descend faster than expected? Two days ago, when the abort command was issued at ~700m, Huyabusa came at least 200m closer (70m!) to the asteroid than expected, after the abort command.

From Oberg's article:

"We performed the touchdown test with success," mission managers reported on the Web site of the Japan Aerospace Exploration Agency, or JAXA.

So why wasn't Minerva released before or at touchdown? The most obvious answer is that the touchdown occurred sooner than expected, due to either poor thruster control, or a greater mass of the asteroid than expected.

The failure of programmers to plan for a contigency where touchdown occurred before probe release is not unlike the Beagle failure - where an impact switch likely sensed-and-held a 'landing signal' that occurred during parachute deployment before the retros were fired.

Jaxa's proprietary software could have benefited from more scrutiny at the block diagram level.

[odave]

Jaxa's proprietary software could have benefited from more scrutiny at the block diagram level.

I agree - there should have been a software interlock between Minerva's release and the descent abort sequence.

But before we get too harsh with JAXA, remember that NASA has messed up on obvious things too - english vs metric on MCO, and possibly on MPL with the software mis-handling the leg deployment switches. These robotic space critters are complex devices, and it's hard to predict every failure mode. And with projects being run on such tight budgets, I'm sure testing time gets cut.

JAXA may have aimed beyond its means with this mission, but I respect them for having the guts to at least try.

[Guest_BruceMoomaw_*]

I'd have more respect for Japan if they hadn't ridiculously bungled literally every space mission they've launched in the last decade with the (partial) exception of the MUSES-B orbiting radio telescope. They are obviously trying to achieve too much with far too little money, in order to prop up the prestige of the ruling Liberal Democrats, and the whole farce is collapsing as dramatically as the farce of the manned US program. Maybe Hayabusa as a whole will be one of the rare exceptions, but I'm not counting on it -- after all, they haven't even been able yet to test tracking a landing marker against the background of the asteroid.

[ljk4-1]

I'd have more respect for Japan if they hadn't ridiculously bungled literally every space mission they've launched in the last decade with the (partial) exception of the MUSES-B orbiting radio telescope.  They are obviously trying to achieve too much with far too little money, in order to prop up the prestige of the ruling Liberal Democrats, and the whole farce is collapsing as dramatically as the farce of the manned US program.  Maybe Hayabusa as a whole will be one of the rare exceptions, but I'm not counting on it -- after all, they haven't even been able yet to test tracking a landing marker against the background of the asteroid.

I wonder how hampered they are also by the fact that they cannot launch for half the year because it would disrupt some nearby villages whose main industry is fishing?

Does Japan have any suitable offshore islands away from population centers that it could conduct its space program year round?

And here are the desperate questions of the day: Is there any way to recover Minerva to try another landing attempt? Can it work even if it is not on the planetoid? They could at least test out the systems.

[djellison]

Hayabusa's goal is to return a sample from an Asteroid. It is not a failure yet.

http://www.jaxa.jp/missions/result/rocket-result_e.html
Not all "ridiculously bungled" as you insist.

Given the budget, Hayabusa's achieved astonishing things already.

Doug

[Harder]

From my Japanese colleague:
'Minerva' has been released. It is still communicating with Hayabusa but its exact movement is unknown. Minerva was released by a signal from earth at the time when it was thought to be at the right altitude. However, because of the time lag for the signal to reach Hayabusa, its position had drifted and altitude had increased to 200m. For this reason, it is believed that landing of Minerva was unsuccessful. In any case, the communication continues to be monitored and information will be released once it is clarified.

One success during the trial descent was the successful test of the leveling lasers. Hayabusa has an altitude measuring laser but it also has four lasers that measures the surface of the Itokawa at four points to level the probe when landing.

This message was sent to me 8 hours earlier but unfortunately I wasn't on-line then. Another case of time lag while I was sleeping..

[The Messenger]

I'd have more respect for Japan if they hadn't ridiculously bungled literally every space mission they've launched in the last decade with the (partial) exception of the MUSES-B orbiting radio telescope. 

I picked up a possible explanation for this one from a surprising source: The NASA channel. During one of the final testing phases (in the USofA) , a leak was discovered in the Helium dewer delivery system; but rather than replacing or retooling the leaking section, it was 'patched'.

So while the scheduling pressure was obviously a factor, it was the American part of the team who are most likely responsible for the loss of coolant.

[Guest_BruceMoomaw_*]

I presume you're referring to Astro-E2 rather than to Muses-B (which didn't have any helium). At any rate, it's interesting news -- but the record of Japanese space exploration since about 1990 is still monumentally dismal. We'll see whether Hayabusa manages to interrupt this.

[Rakhir]

The failure of programmers to plan for a contigency where touchdown occurred before probe release is not unlike the Beagle failure - where an impact switch likely sensed-and-held a 'landing signal' that occurred during parachute deployment before the retros were fired.

You are describing the failure of MPL during the leg deployment.
If I remember well, Beagle II failure is supposed to be due to an atmosphere density lower than expected.

[Harry]

From my Japanese colleague:
'Minerva' has been released.  It is still communicating with Hayabusa but its exact movement is unknown.  Minerva was released by a signal from earth at the time when it was thought to be at the right altitude.  However, because of the time lag for the signal to reach Hayabusa, its position had drifted and altitude had increased to 200m.  For this reason, it is believed that landing of Minerva was unsuccessful.  In any case, the communication continues to be monitored and information will be released once it is clarified.

One success during the trial descent was the successful test of the leveling lasers.  Hayabusa has an altitude measuring laser but it also has four lasers that measures the surface of the Itokawa at four points to level the probe when landing.

This message was sent to me 8 hours earlier but unfortunately I wasn't on-line then. Another case of time lag while I was sleeping..

The owl of Minerva had flied at last night...

[Bob Shaw]

Does Japan have any suitable offshore islands away from population centers that it could conduct its space program year round?

JAXA has, I believe, been looking at several Pacific islands to launch from - such as Christmas Island (where they have already carried out ALT tests of their HOPE mini-shuttle).

Bob Shaw

[Guest_BruceMoomaw_*]

Actually, we don't know what caused the Beagle 2 failure, and will never know -- as with Deep Space 2, there are too many possible alternative causes due to sloppy design and testing. But low air density is certainly a possible cause; it came within a hair of killing Spirit. (I'll have something to say on this subject, and COMPLEX's reaction to it, in my "Astronomy" article.)