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Mission: Hayabusa 2
Hungry4info
post Jun 23 2018, 04:29 AM
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If my math is right, assuming a radius of 450 metres, Ryugu needs a density of at least ~0.26 g cm-3 to have a Hill sphere out to Hayabusa 2's distance. So that sounds plausible.

Edit: Apparently that's what the mission team thinks too.
https://twitter.com/haya2_jaxa/status/1009368813429592064

QUOTE
From now on, the gravity of the asteroid will dominate the area (Hill area: Within about 90km from the asteroid)!


--------------------
-- Hungry4info (Sirius_Alpha)
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Therion
post Jun 23 2018, 08:55 AM
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QUOTE (Explorer1 @ Jun 23 2018, 04:04 AM) *
They are definitely in Ryugu's sphere of influence... the last maneouevre brought the velocity to 9 cm per second, and over the last day or so it accelerated to 10 and now 11 cm/s. That has to be the asteroid's gravity giving a slight speed boost, right?


There is also acceleration due to solar radiation pressure which has to be accounted for.
Other effects (like Coriolis force and gravity of other bodies) should be negligible or not relevant at this point.
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mcmcmc
post Yesterday, 09:31 AM
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TCM08 confirmed but different from planned:
QUOTE
Our 8th Trajectory Control Manoeuvre (TMC08) for optical navigation was made on June 24, 2018 from ~09:30-09:40 JST. Trusters gave a velocity change of ~0.2cm/3 (+y), 2cm/s (+z). The distance to Ryugu from Hayabusa2 was 38km & the relative speed after TCM08 was ~0.08 m/s (8 cm/s)

https://twitter.com/haya2e_jaxa/status/1010759732515098625

Planned:
58293,013888 2018/06/24T00:20:00,0 -0,0541 0,1376 27,1238 0,001939 -0,002281 -0,123958
58293,020833 2018/06/24T00:30:00,0 -0,0529 0,1363 27,0494 0,002306 -0,000590 -0,010717

Actual:
58293.018055 2018/06/24T00:26:00.0 -0.1998 0.2395 38.3500 0.002254 -0.002601 -0.106281
58293.025000 2018/06/24T00:36:00.0 -0.1991 0.2386 38.2940 0.000540 -0.000687 -0.084732

Hence, new TCM added on 26/6:
58295.045833 2018/06/26T01:06:00.0 -0.1652 0.0514 21.0219 0.000191 -0.001503 -0.114487
58295.052777 2018/06/26T01:16:00.0 -0.1638 0.0508 20.9933 0.003624 -0.000580 -0.003281


Final TCM on 27/7 as planned:
58296.018055 2018/06/27T00:26:00.0 -0.0001 0.0002 20.0049 0.000394 -0.000642 -0.020535
58296.025000 2018/06/27T00:36:00.0 0.0000 -0.0000 20.0001 0.000022 0.000000 0.000111


(but actually after TCM08bis the speed will bealready just 3 mm/s)


No new images yet.
No English translation of latest press release yet:
http://www.hayabusa2.jaxa.jp/topics/press/
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pandaneko
post Yesterday, 09:57 AM
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QUOTE (mcmcmc @ Jun 24 2018, 06:31 PM) *
No new images yet.
No English translation of latest press release yet:
http://www.hayabusa2.jaxa.jp/topics/press/


I hesitate to add what follows, but just in case....

P
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mcmcmc
post Yesterday, 10:21 AM
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What is going to happen after Hayabusa flies down to next orbits (5km and 1km):

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mcmcmc
post Yesterday, 10:33 AM
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QUOTE (pandaneko @ Jun 24 2018, 09:57 AM) *
I hesitate to add what follows, but just in case....

P

Yes but there is another one dated 21/6!
http://fanfun.jaxa.jp/jaxatv/files/20180621_hayabusa2.pdf
Only in Japanese! :-(
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mcmcmc
post Yesterday, 10:40 AM
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Possible places for press releases:

http://global.jaxa.jp/projects/sat/hayabusa2/pdf/
http://fanfun.jaxa.jp/jaxatv/files/
http://www.hayabusa2.jaxa.jp/topics/press/doc/

Not browsable, but just add filename to download it:
Japanese:
20150128_hayabusa2.pdf
20170712_hayabusa2.pdf
20171214_hayabusa2.pdf
20180419_hayabusa2.pdf
20180607_hayabusa2.pdf
20180614_hayabusa2.pdf
20180621_hayabusa2.pdf


English:

Hayabusa2_Press20180607e.pdf
Hayabusa2_Press20180614e.pdf
Hayabusa2_Press20180621e.pdf <<-- Where is it?!?
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pandaneko
post Yesterday, 12:19 PM
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QUOTE (mcmcmc @ Jun 24 2018, 07:33 PM) *
Yes but there is another one dated 21/6!
http://fanfun.jaxa.jp/jaxatv/files/20180621_hayabusa2.pdf
Only in Japanese! :-(


My guess is as follows. This document in Japanese dated 21 June does exist somewhere, but not yet archived. I dug into this FANFAN site
and what follows is its URL.

http://fanfun.jaxa.jp/countdown/hayabusa2/

and towards the end of all this you will see what is below. The latest that they carry here is not 21, but 14 June. So, although 21 June
document exist on somebody's disk, but it has not been properly integrated into their listing database, let alone an English version.
An English version may or may not exist. If it does exists it has not been listed properly on tbis FANFAN web site. That is my guess.

P


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pandaneko
post Today, 06:41 AM
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40km image, yes, lots and lots of craters. It must have been quite violent...

P
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Adam Hurcewicz
post Today, 08:52 AM
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here is english version: http://www.hayabusa2.jaxa.jp/topics/20180625je/index_e.html



--------------------
Adam Hurcewicz from Poland
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mcmcmc
post Today, 09:18 AM
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First ONC-Wide photo!


We are just 27 km high now.
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mcmcmc
post Today, 09:28 AM
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QUOTE (pandaneko @ Jun 25 2018, 06:41 AM) *
40km image, yes, lots and lots of craters. It must have been quite violent...

P

Original, non-zoomed image (256x256):

Each pixel is around 3.8-3.9 meters, so smaller boulders are as big as your house, more or less.
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pandaneko
post Today, 10:09 AM
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No, this is no longer a puff fish. It very much looks like a pomegranate in my garden!

P
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