[X] My Assistant

[ljk4-1]

Not just fifteen minutes but 16 minutes from Hayabusa to command center and another the same time to Hayabusa. a long delay, perhaps over than 32 minutes. This would work if the descending motion is constant and *WITHOUT ANY PLAN CHANGE UNTIL RELEASING THE MINERVA PROBE* so Hayabusa can go up or stir away from the low rotation motion of about 5cms/sec.

Rodolfo

Dumb question of the day: Why didn't the Hayabusa mission team assume for contingency reasons that many places on the planetoid might be really rocky for landing?

[RNeuhaus]

Dumb question of the day:  Why didn't the Hayabusa mission team assume for contingency reasons that many places on the planetoid might be really rocky for landing?

Hayabusa has no legs. The trunk is only long leg under the Hayabusa's belly. At the four corners of belly there are thrusters. So Hayabusa is not designed to pose to anywhere. If try to pose, it is very probably that one of solar panel might break because of trunk.

Rodolfo

[Phil Stooke]

Before the close approach plans were announced I had assumed that they would occur near one of the poles (the one with the best lighting). The surface would not be moving sideways under the spacecraft, and you don't have to worry about the 'small end' swinging round and whacking into it if you hover too long. Also, the target will always be illuminated so descent timing is more flexible, which helps with limited ground station coverage. I'm still surprised that's not the plan. There may be good reasons for not doing it - such as hardware limitations on communication in that orientation - but I don't know what they are. The poles are nice and smooth, too.

Phil

[Guest_Myran_*]

Phil Stooke said: Before the close approach plans were announced I had assumed that they would occur near one of the poles.

So did I, for the very same reasons that you pointed out. And I also posted here saying so. The extremely low gravity cant pull Hayabasa down so insetad there have to be corrections actively made with 30 minute plus lag. So the bottom line from me isnt that they are overcautious, but trying to do the sampling it in a way to difficult way.

[Comga]

Before the close approach plans were announced I had assumed that they would occur near one of the poles (the one with the best lighting).....

Phil 

Isn't this prohibited by the orientation of the solar panels? Does keeping them normal to the sun line force them to travel pretty much up and down that same sun line? That would agree with seeing Haybusa's shadow so often on the asteroid. They did make special excursions to get high and low lattitude images, so perhaps is is not easy. I guess it was just bad luck that the poles of Itakowa point so close to perpendicular to the ecliptic, or that right now is the equinox on Itakowa.

[ljk4-1]

ASTEROID LANDER LOST IN SPACE

On November 12th the Hayabusa spacecraft guided itself to within 55 meters
of the surface of 25143 Itokawa, then backed away, completing a dress
rehearsal for its upcoming sampling of the asteroid. During the test the
spacecraft released Minerva, its small robotic lander, which was supposed
to drop gently onto the asteroid and begin relaying images and temperature
data to the main craft.

However, Minerva never reached the surface....

http://SkyandTelescope.com/news/article_1626_1.asp

[Phil Stooke]

Comga - yes, the solar panels... good suggestion. I said maybe communication, but looking at the pics of the spacecraft again, both might be the issue. That could very well be it. OK, I'm satisfied now.

Phil

[elakdawalla]

Just got this from TPS/J (I added time conversions to UTC, apologies if I got any wrong): "ISAS re-scheduled Hayabusa's sampling activity as below. Time is JST. At around 9p.m. on Saturday, November 19 [noon UTC], Hayabusa will start descending. At around 3 a.m. on Sunday, November 20 [6 p.m. Nov 19 UTC], ISAS will announce status of Hayabusa. At around 5a.m. [8 p.m. UTC], ISAS will decide on "go or no go." If "go" command is sent from Earth, Hayabusa will make the closest approach to Itokawa at around 6 a.m. [9 p.m. UTC] At 6:30 a.m. [9:30 p.m. UTC], ISAS will announce whether or not the target marker containing approximately 880,000 names was released. At around 10:00 a.m. [1 a.m. Nov 20 UTC], ISAS will annouce whether or not Hayabusa made the contact with Itokawa's surface. Around noon, a press conference will be held for the results."

--Emily

[foe]

Here!

http://www.jaxa.jp/news_topics/hot_topics/index_e.html

[foe]

related links


by ISAS
http://www.isas.jaxa.jp/e/

Today's HAYABUSA
http://www.isas.jaxa.jp/e/enterp/missions/...usa/today.shtml

HAYABUSA LIVE
http://www.isas.jaxa.jp/home/hayabusa-live/
http://jaxa.tv/video.html

HAYABUSUA (Summary by Project manager)
http://www.isas.jaxa.jp/e/special/2003/kawaguchi/index.shtml

ISAS News Archives
http://www.isas.jaxa.jp/e/snews/



by JAXA
http://www.jaxa.jp/index_e.html

HYABUSA
http://www.jaxa.jp/news_topics/vision_miss...ayabusa1_e.html

Report from the HAYABUSA operation room
http://www.jaxa.jp/news_topics/column/special-3/index_e.html



by The Planetary Society of Japan
http://www.planetary.or.jp/en/

Y.M. Coulum
http://www.planetary.or.jp/en/column/


I think that you will get certain information from these links.

[hugh]

Here is a rough translation of the 11-15 JAXA press release which compared the highest resolution images of NEAR and Hayabusa. I couldn't include the two images but the original release is at :

http://www.isas.jaxa.jp/j/snews/2005/1117.shtml


The Most Detailed View Ever of an Asteroid’s Surface

How many pixels does your digital camera at home have? A CCD (charged couple device) which has about 1000 by 1024 0.012mm wide pixels a side making about 1000000 in total, is carried in the telephoto optical navigation camera (ONC-T) carried on the Hayabusa space probe , which picked up sunlight reflected from asteroid Itokawa and imaged the surface. From an altitude of 5km the ONC-T can resolve about 50 centimeters per pixel. What we call "spatial resolution" is the standard of our ability to distinguish detail on the Itokawa surface. Because the width of the ONC-T’s field of vision stays the same, its resolution improves as Hayabusa lowers its altitude, and detailed topography and small features become distinguishable on the asteroid’s surface.

(1) Details of the sample collection point

On November 12 during the second descent rehearsal, Hayabusa approached to about 55m from Itokawa’s surface and did imaging with the ONC-T during this time. As a result, from an altitude of 60-75m, which is about the lowest altitude the ONC-T can focus at, we succeeded in imaging very small details of the asteroid surface. From this altitude the resolution of one pixel is about 6-8mm. This is comparable to being able to distinguish an ant crawling on the ground from a distance of about 6-8m on earth. This level of resolution could be said to belong not so much to the field of “remote sensing” as done by conventional planetary probes, but rather stepping into the domain of surface geology, distinguishing the texture and cracks in individual rocks, as has been done by NASA’s MER rovers, which discovered sedimentary rocks and other rocks made by the action of water. As for the rocks of Itokawa’s surface, they would all be meteorites if they reached the earth, so we can see here a true "home of meteorites".

Figure1

(Caption) Figure 1 shows the "Muses sea" including the destination sample collection point (point A) and the border of a rock area that was captured with the telephoto optics navigation camera (ONC-T) at the time of the November 12 second descent rehearsal.
The image on the left has a resolution of 1.5~2.0cm- the highest resolution obtained. The shadow of Hayabusa appears in the right-hand picture.

Figure 1 is a close-up image (left) of the border of the “Muses Sea" and the rocky area to the left that was imaged by the ONC-T when Hayabusa descended to an altitude of around 160m. The right image was obtained with the wide-angle optics navigation camera (ONC-W1). The right border of the close-up image is at the edge of the 60-meter wide “A point” target area for the sample collection attempt on the 19th. It is, so to speak, a "beach of the Muses Sea" here, and the depth of Muses Sea increases as we look from the rocky lower left area towards the upper right. We can see that around the sample collection area the rocks not only become fewer, but the size of the particles burying the cracks in the rocks decreases. The resolution of this close-up image is about 1.5~2.0 cm per pixel, about the size of the smallest particles visible on the upper left.

The grained material covering solid celestial bodies without atmospheres is called “regolith”. It is thought that pieces of material ejected by impacts on these bodies for the most part settle back on the surface. On rocky Itokawa, Muses Sea is the largest area where regolith has accumulated. Small particles ejected by impacts can easily achieve escape velocity on Itokawa. Because the gravity is so low, Itokawa has an escape velocity of only about 20cm per second. Therefore the finest particles of regolith smaller than 1mm which are ejected do not remain, and some scientists predict that even some particles that slowly fall back are blown away by the effects of solar radiation and static electricity. This image provides indirect evidence to support this hypothesis. In addition to performing the sample collection experiment from bedrock and small particles, the Hayabusa sampler team, by firing a bullet of about a diameter of 1cm into grains of about the same size, can anticipate being able to confirm if a sufficient quantity of particles has been released..

Detailed observation of an asteroid’s surface surpassing NEAR Shoemaker

Figure 2 :

(Caption) Itokawa and Eros: Comparison of high resolution approach images of the two S type asteroid surfaces.
(left) " Muses Sea" and a border of a rock area on asteroid Itokawa which Hayabusa imaged from an altitude of about 160m on November 12, 2005.
(right) The last image captured before the NEAR Shoemaker space probe made a landing on the asteroid Eros surface on February 12, 2001. The reduced scale is approximately the same. (the left-hand image shows only 1/4 of the ONC-T’s total field of view.)

In figure 2, we can compare the last image taken by NASA’s NEAR Shoemaker space probe, which rough-landed on the asteroid Eros on February 12, 2001 after a year of remote sensing observations, with the " beach of the Muses sea" image taken by Hayabusa. Although Eros is an S type asteroid like Itokawa, it is dozens of times larger. Taken from an altitude of 120m, NEAR Shoemaker’s last image has a resolution of approximately 1.1cm. However, it has only about 1/8 the number of pixels that are in the Hayabusa image. Eros’s surface in this image is divided into an area of regolith of about cm scale coarseness on the right, an area of finer regolith on the left, and a large rounded boulder. When we compare the two asteroids, Itokawa has a smaller surface area covered by regolith than Eros, with only a thin layer covering the big boulders, and the regolith of the smaller asteroid is relatively coarse-grained.

This ONC-T image has captured an asteroid surface in the highest resolution ever obtained, surpassing that of the image made before the landing of NEAR Shoemaker . This record will be renewed by Hayabusa unless "Minerva", discharged at the time of the rehearsal, lands on Itokawa in future and breaks the record. Of course we plan to attempt imaging of the sample collection spot in the center of Muses Sea" during these descents. It is thought that with these observations we can supplement much of the scientific work in the world's first asteroid surface examination that was expected of Minerva. Itokawa joins the moon, Venus, Mars, and Titan as one of the solar system bodies whose surfaces have been examined in the highest detail.

[RNeuhaus]

Just got this from TPS/J (I added time conversions to UTC, apologies if I got any wrong): "ISAS re-scheduled Hayabusa's sampling activity as below. Time is JST. At around 9p.m. on Saturday, November 19 [noon UTC], Hayabusa will start descending. At around 3 a.m. on Sunday, November 20 [6 p.m. Nov 19 UTC], ISAS will announce status of Hayabusa. At around 5a.m. [8 p.m. UTC], ISAS will decide on "go or no go." If "go" command is sent from Earth, Hayabusa will make the closest approach to Itokawa at around 6 a.m. [9 p.m. UTC] At 6:30 a.m. [9:30 p.m. UTC], ISAS will announce whether or not the target marker containing approximately 880,000 names was released. At around 10:00 a.m. [1 a.m. Nov 20 UTC], ISAS will annouce whether or not Hayabusa made the contact with Itokawa's surface. Around noon, a press conference will be held for the results."

--Emily

Thank you for the clarification of schedules and timings, I have expected to start to monitor the Saturday early morning but now I see a new schedules. However these timings are driving me crazy to sum and rest, set back or advance the time. I am leaving an useful URL:

World Clock
World Zones Times

Rodolfo

[elakdawalla]

Our press officer just got this email, the pages seem to have lots of interesting stuff on them.

Dear Sirs and Madams,

Japan's astroid probe Hayabusa is now scheduled to touchdown on Itokawa in early morning of Nov. 20 (SUN) JST.

As a team member of Hayabusa spacecraft design and development, we, Space Robotics Lab. at Tohoku University, have been updating outreach pages regarding the touchdown and sampling sequence: (Japanese versions were released long before, but we recently translated them to English.)

http://www.astro.mech.tohoku.ac.jp/hayabus...ge1_english.htm
http://www.astro.mech.tohoku.ac.jp/hayabus...ge2_english.htm
http://www.astro.mech.tohoku.ac.jp/hayabus...ge3_english.htm

Please visit and find the above pages include a number of simulation movies for different conditions. And please cite the link information of the above pages, when you will release further news and information about Hayabusa mission.

Thank you.

Kazuya Yoshida, Professor, Tohoku University, Japan

[Holder of the Tw...]

Is anyone laying bets on whether Hayabusa lands in Woomera with a gram sized sample of signature disk shrapnel?

[Toma B]

Does anybody on this forum lives down under (Australia)?
Woomera precisely...
Maybe he get to that capsule before the "japanese" , then we can make them exchange it for some Hi-res pictures of Itokawa...