[X] My Assistant

[ljk4-1]

One has to remember that Nereus was the original target for the mission.  Due to a launch slip, this opportunity was lost so they moved on to this asteroid.  Nereus is much larger and would have filled more of the field.  It is important to remember that while the images look small, they are similar in resolution to a high resolution MOC image - this is just a very little asteroid!  Also remember that when it goes in to sample and deploy Minerva, it will obtain images from closer range, which will be larger.  As for the raws, I am very happy with the fact that they have released PNG versions of a lot of the releases so there haven't been JPEG effects in the press images, making them closer to raw.  And the images are supposed to be released in both some Japanese archive AND on NASA's PDS after the year-long proprietary period.  So this won't be like dealing with ESA.  I think that part of the reason that JAXA hasn't crowed about its planetary missions more in the past is that it hasn't had much to crow about, especially with regard to things that would garner public interest.  In other areas, it has been much better.  Look at Yohkoh (I hope I spelled that right), their highly successful solar satellite.  They were extremely cooperative in releasing all the data immediatly and cooperating with NASA and NOAA.  And their press releases, while a bit awkward due to the extreme language barier, are at least informed and accurate.

Will there be any problems with Minerva, since I am assuming it was designed to work on a bigger planetoid?

And to restate a question I had asked earlier, but I think got lost admist the images and potato comparisons: If Deep Space 1 had taken better images of Braille, do you think it would have looked similar to Itokawa?

And I think Japan deserves to crow about this mission!

[Gsnorgathon]

Say - does anyone have any notions as to how (if at all) Minerva's camera lenses are to be protected from Itokawa's dust? Rakhir posted a pdf about Minerva earlier in this thread, but it doesn't mention any means of protecting the camera lenses.

There are 8 pins that protrude from each end of Minerva. I'm wondering if they're supposed to hold Minerva far enough off the surface that no other protection is necessary. Seems a bit dodgy to me.

[tedstryk]

Will there be any problems with Minerva, since I am assuming it was designed to work on a bigger planetoid?

And to restate a question I had asked earlier, but I think got lost admist the images and potato comparisons:  If Deep Space 1 had taken better images of Braille, do you think it would have looked similar to Itokawa?

And I think Japan deserves to crow about this mission!

I would definitely agree that they deserve to crow! They should be proud of this (and no doubt are). I am pretty sure they did tests to make sure Minerva would work on Ikotawa.

As for Braille, it was similarly lumpy and somewhat larger (somesing like 1.3x0.6 km), very similar in size to Dactyl on its long axis. But Braille was of the Vesta family, and had a basaltic composition. I believe Ikotawa is a chondrite. So while their overall shapes are similar, they might have a different appearance at high resolution - but of course with Braille we are left guessing. Here the best I could get out of the two views DS-1 got. The reddish color is based on spectral data indicating that it is reddish.

[dilo]

Noticeable rotation between the filters there.....

Almost anaglyphable

Doug

Great idea, Doug! (I have impression that anaglyph colors should be inverted - I must rotate my glasses to see it correctly!)

[Guest_BruceMoomaw_*]

Is Itokawa a contact binary, or just a single asteroid with one extremely large chunk lopped out of
one side?

http://www.hayabusa.isas.jaxa.jp/e/index.html

http://www.hayabusa.isas.jaxa.jp/e/index_14.html

At any rate, we still are not seeing any major craters whatsoever, but we're
seeing what looks like a VERY rough, textured surface. It may be that (in
accord with http://www.aas.org/publications/baas/v37n3/dps2005/381.htm ),
Itokawa is a "rubble-pile' NEA which happened to fly close to a planet not
too long ago and had its surface so affected by the tidal forces as to erase
all its crater population up to then -- and it may even have been almost
pulled in two by the same tidal forces (as Abell predicts often happens).

[edstrick]

I think they've probably done very very little to protect the cameras on Minerva. The hopper is probably pretty much a high-tech jury-rig that cost relatively little using mostly off-the-shelf hardware to achieve fairly impressive ability. Even a few pictures before lenses get bunged or dirty will be very valuable. Having extra cameras increases the probability of success.

I'd assumed it was battery powered, but has solar cells. So I wonder what it's real lifetime is limited by.. it may surprise us and last and last.

I'd land it in a flatter but non-dust surface in one of the hollows in the rough terrain. Give the best views of rock and dust.

If it lands in dust, they might get some interesting views from the main probe of it kicking up dust during hopping or landing.

[djellison]

The force of 'gravity' will be so very very weak for Minerva that even though it's held up by little more than some knitting needles, I doubt it will sink in much

It'll be our first images-from-the-surface-of-a-new-body since Hugyens

Doug

[mhall]

> It'll be our first images-from-the-surface-of-a-new-body since Hugyens


Gosh, it'll be nearly a whole year between extraterrestrial landings!

Time was, we got one or two a decade, and were grateful; these days, I think we're getting spoiled, I'm glad to say.

[abalone]

The force of 'gravity' will be so very very weak for Minerva that even though it's held up by little more than some knitting needles, I doubt it will sink in much

Doug

I did a back of the envelope calculation that a 1000Kg car would weigh the Earth equivalent of 3 grams and escape velocity is an energetic rollover in bed.

This last point could well account for the extinction of the Itokawans and the apparent inexplicable uninhabited nature of this otherwise desirable piece of Solar Sytem real estate. They either all rolled off into orbit in blissful ignorant unconsiouness while sleeping, or simply refused to engauge in their normal acts of procreation, form fear of a lustful orbital insertion manoeuver at the hands of an overenthusiastic bedspring. Either way extinction was just around the corner.

I expected to see a thiving community after following a discussion along those lines in another thread recently, I know that Bob Shaw will be equally dissappointed.

[RNeuhaus]

It is possible that Minerva will have bouncings of different height due to the different impact absorption capacity between the dusty and rocky parts of Itokawa. The best hope is that Minerva will not be lost due to much bouncing. I think that Hayabusa will release it VERY SLOW to the surface as one very good billboard player can do.

Rodolfo

[Bob Shaw]

Nice Earth swing-by screensaver from JAXA:


http://www.jaxa.jp/news_topics/vision_miss...a/index3_e.html

[elakdawalla]

Thought I'd point out A. J. S. Rayl's interview with Hayabusa Project Manager Jun'ichiro Kawaguchi, which was posted yesterday....

--Emily

[dilo]

Thanks, Emily, this article is very interesting...
By reading it, however, a lot of questions hit my mind.
For example:
1) how Hayabusa wills stay anchored (if so) to Itokawa during sample collection?
2) Are we sure that 'target marker' fired on asteroid's surface will stay here and will not bounce in the space or will be buried under the powder?
3) Which kind of 'state-of-the-art material' will be used for heatshield?
4) How collected samples will be preserved from Earth chemical/bilogical contamination?
Do anybody already knows some answer ? (probably no one knows exact #2 answer!).
Thanks again...

[Guest_BruceMoomaw_*]

I can answer questions #1 and 2 immediately:

(1) Hayabusa will just use its thrusters to press the bottom edge of its "sample collection cone" onto the surface very briefly -- just long enough to fire a gun at the top end of the cone, whose bullet will kick a few bits of surface debris back up into the collection chamber at the top of the cone. The craft will then immediately take off from the surface again after just a couple of seconds. (This very-brief-touchdown mode seems to be the best way to collect samples from the surface of very-low-gravity small bodies -- at any rate, there are variations on it in the "Hera" and "Hummingbird" proposals for collecting surface material from a near-Earth asteroid and a comet nucleus, although they use a sticky pad or a short high-speed drill instead, to obtain bigger samples.)

(2) The landing marker will just drift down very slowly onto the surface in the asteroid's extremely low gravity. Even if it bounces slightly, it makes no difference. (Indeed, as I understand it, Hayabusa can land even without the marker -- it just makes it easier to come down with no relative horizontal velocity as the asteroid rotates slowly at about 5 cm per second.)

[dilo]

Thank you very much, Bruce!