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PostPosted: Thu Feb 21, 2019 1:24 pm 
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EDITS : I'm adding a couple of images from time to time, with the time-stamps, to show the "ground rush" effect. I've had people describe "ground rush" to me from a BASE jumper's point of view, which sounds rather adrenaline-ish. but it's buzzy enough abseiling a 100m (~4sec) drop or doing 5m fall/grab/slither/crunch when rock climbing. Every Commander will have had the effect, shortly before hitting the space bar. In either sense.

I have a slight concern about nasty loadings on JAXA servers, but since they're running public large screen displays in at least one city centre, I suspect they're already holding the bedposts, ready for a ride.


The Hayabusa2 probe is coming in for it's touchdown on asteroid Ryugu, and the near-real-time navigation camera images are being posted during the docking manoeuvrer.
Commanders might feel a frisson of familiarity. Along with the "ground-rush" effect as your crushing impact looms.
The spacecraft has currently slowed it's descent rate to 40cm/s and will be decelerating towards contact.

Project pages
Image galleries (updated regularly, but transmission is concentrated on science and operations data, not pretty pictures).

EDIT : While I wait for the next image, I'll append this note from the image gallery page :
Quote:
We cannot obtain real time images during the touchdown-phase. To know the operation information of that period, please see Twitter and/or Youtube Live (not started yet).


Unlike the cuboctahedra (or truncated cube, or truncated octahedron) of a "Coriolis" station, the rotation axis is approximately in the plane of the picture and the contact site is not at the sub-spacecraft point. Hey, it's actually nice to not have to think how to explain that to an audience, because you'll all have pulled sharply back on the stick while firing the retro-rockets.
There are "shape models" and I think image maps on the JAXA site, which may appeal to the station-modders and such like.

EDITS : Images moved to the end. refresh every so often.
Image 12:49
Image 13:18
Ground-rush : First image above is the 2019/02/21:12:49 image. The next posted is for 13:18, it is noticeably larger, the south-polar boulder is rotating in the view, and you can start to see why finding the "docking pOOint" has taken months of mapping and surveying.
Image 13:47
This series of three shows about quarter a rotation of the asteroid. (From Wiki, "Rotation period 7.627±0.007 h")
http://www.hayabusa2.jaxa.jp/en/galleri ... 211415.jpg 14:15
Half-hour images are probably a bit much. I'll dial it back a bit. But you can still see the rotation. Can you guess where the docking pOOint will be?
Ah, if I make alternating images into URLs ... ? Yeah, that looks OK.
Image 14:44
http://www.hayabusa2.jaxa.jp/en/galleri ... 211513.jpg 15:13
Image 15:42
Boulders, boulders!
http://www.hayabusa2.jaxa.jp/en/galleri ... 211611.jpg 16:11
http://www.hayabusa2.jaxa.jp/en/galleri ... 211640.jpg 16:40
http://www.hayabusa2.jaxa.jp/en/galleri ... 211709.jpg 17:09
A bit samey, but there is what looks like an eroded crater coming into view on the approaching limb. Annoying that the solar panel/ antenna orientation constraints mean the Sun, Hyabusa, Ryugu and Earth need to be roughly co-linear, so it's hard to see the shadows. 2.17km to touchdown. They'll be touching the retro-thrusters soon.
Image 17:38, and the obvious boulders have rotated out of view. Unfortunately, with a mere 1m between the rim of the sample-collecting horn and the base of the spacecraft, a small boulder is all it would take, 1.9km to go.
http://www.hayabusa2.jaxa.jp/en/galleri ... 211806.jpg 18:06
http://www.hayabusa2.jaxa.jp/en/galleri ... 211835.jpg 18:35
http://www.hayabusa2.jaxa.jp/en/galleri ... 211904.jpg 19:04
Image 19:33
The large boulders visible at the start of the series are coming back into view, and mutely answering any questions about why they're not in the landing zone. The spacecraft's off-set from the sub-solar point is starting to show in the illumination pattern.
1.33km altitude.
I can park my Cobra faster than that. But that's on an engineered artefact, not a pile of rubble glued together with a little bit of gravity and a lot of vacuum welding.
The slightly "equatorial ridge ridge on a spheroid" structure is reminiscent of the "WTF ??" that accompanied the first post-flyby images from MU-69/ Ultima Thule.

Teatime break - updates
http://www.hayabusa2.jaxa.jp/en/galleri ... 212002.jpg 20:02 Only half of this image came down for some reason.
http://www.hayabusa2.jaxa.jp/en/galleri ... 212030.jpg 20:30 The south pole boulder field is coming back into view. Quite what the geometry is to get such large shadows, I'm going to have to twist my braincells to work out. Maybe it's where the Rock Hermit hangers his Krait?
Image 20:59 And the South Pole Hanger complex is really showing up. There's a little dark spot in the bright, flat illumination of the "sub-Solar point".
Image 21:31 And the sub-Solar shadow has become clearly two-lobed. It's the shadow of the spacecraft. 560m from the asteroid centre, but 250m from the surface.
http://www.hayabusa2.jaxa.jp/en/galleri ... 212202.jpg 22:02 image, with a really pronounced shadow and zoom has got so close that the touchdown point has gone out of the FoV. (I think.)

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Last edited by RockDoctor on Thu Feb 21, 2019 10:37 pm, edited 7 times in total.

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PostPosted: Thu Feb 21, 2019 2:02 pm 
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Fascinating - thanks, Doc! Go JAXA!

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PostPosted: Thu Feb 21, 2019 2:32 pm 
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Quote:
Fascinating - thanks, Doc! Go JAXA!
I was just browsing to try to work out how to control the images a bit better, something like (in BBCode) {img=width,height}url{/img}. There is an RTFM at https://www.phpbb.com/community/viewtop ... &t=2105534, but that's probably more like hard work than the Admin (Giles?) is interested in. A couple of more images popped up while I was doing that, which I'll append, since the series is ... nerdishly exciting.

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PostPosted: Thu Feb 21, 2019 3:04 pm 
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It's going to be a tight fit. This image shows the "docking pOOint", with the spacecraft to size, and a 3m-diameter docking circle. Fancy trying to parallel-park your car, with those solar panels, amongst those boulders?
Image

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PostPosted: Thu Feb 21, 2019 4:15 pm 
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There is a live track of the spacecraft orbit and descent to surface at http://www.lizard-tail.com/isana/hayabu ... /hy2trj3d/ (mouse to adjust orientation through spacecraft ; zoom in/ out to see the asteroid, and the previous parts of the spacecraft track.
Box Link

Ducking and diving.

EDIT : Using Chromium (with less suspicious security settings, because I rarely use it) , I can switch view point between Hayabusa2, Ryugu (barycentre?) and the "docking pOOint". 2570m to go.

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"I'm just stepping out of the airlock for a breath of fresh vacuum. I may be gone some time."


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PostPosted: Thu Feb 21, 2019 6:21 pm 
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Would this version display the image? I've forgotten how to do this directly.
https://app.box.com/file/408864973669
Caption :
Quote:
View of the descent of Hayabusa2 towards asteroid Ryugu. Spacecraft coming in from image left ; several trajectory gateways, go/no go decisions, spacecraft events shown as boxes to pass through.

_________________
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"I'm just stepping out of the airlock for a breath of fresh vacuum. I may be gone some time."


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PostPosted: Thu Feb 21, 2019 7:55 pm 
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That Box link is asking for a log-in.

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PostPosted: Thu Feb 21, 2019 11:00 pm 
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I don't know about the Box link (kludge!), but they've re-oriented the spacecraft to ground-parallel (which breaks the high-speed data link), moved down to the surface (at a speed that shows up in less-directional radio Doppler), and touched down. They're just assessing the data over whether to send the "Fire" command. According to the Youtube link I mentioned somewhere.

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PostPosted: Thu Feb 21, 2019 11:02 pm 
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Quote:
According to the Youtube link I mentioned somewhere.
https://www.youtube.com/watch?v=qeMwAdquDYM

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PostPosted: Thu Feb 21, 2019 11:09 pm 
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Spacecraft has launched, re-oriented towards Earth, and data is flowing again.
Quote:
返信先: @haya2e_jaxaさん

[TD1-L08E1] 2/22 at 7:48 JST. We have confirmed the spacecraft began to rise as planned. This was announced by the Project Manager and everyone clapped again.

_________________
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"I'm just stepping out of the airlock for a breath of fresh vacuum. I may be gone some time."


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PostPosted: Thu Feb 21, 2019 11:12 pm 
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Where is that bloody timeline ...

Found it.
http://www.hayabusa2.jaxa.jp/en/topics/ ... _Schedule/

Good luck getting through. Jaxa seem to be getting SSS = "Sweaty Server Syndrome"

_________________
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Shooting aliens for fun and ... well more fun.
"I'm just stepping out of the airlock for a breath of fresh vacuum. I may be gone some time."


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PostPosted: Thu Feb 21, 2019 11:29 pm 
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Should be getting back to using the high-gain antenna soon.
http://www.lizard-tail.com/isana/hayabu ... /hy2trj3d/
is showing spacecraft about 250m altitude (500m from barycentre).

_________________
--
Shooting aliens for fun and ... well more fun.
"I'm just stepping out of the airlock for a breath of fresh vacuum. I may be gone some time."


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