Author Topic: JAXA Hayabusa2 Mission : General Thread  (Read 9061 times)

Offline Galactic Penguin SST

JAXA Hayabusa2 Mission : General Thread
« on: 06/08/2018 02:22 AM »
Starting this thread since the spacecraft is about to reach its destination this month and it has already switched off its ion engines for final approach, reaching about 20 km from Ryugu on June 27!


Launch thread: https://forum.nasaspaceflight.com/index.php?topic=22015.0

Firstly, here are the slides from a press conference yesterday (in English) about the mission status and future plans:
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline mcgyver

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #1 on: 06/08/2018 07:44 AM »

Reference links:
https://twitter.com/haya2e_jaxa  (english)
https://twitter.com/haya2_jaxa (japanese)
https://twitter.com/mai_hayabusa (japanese)
https://twitter.com/haya2kun  (japanese)

Official site:
http://www.hayabusa2.jaxa.jp/

Questions and answers:
http://planetary.jp/hayabusa2/FAQ/QA/index.html

How to search for news in Japanese: はやぶさ2 is "Hayabusa 2" in Japanese.

Press briefings list:
http://www.jaxa.jp/press/hayabusa2/index_j.html

Rover Minerva-II locomotion mechanism:
http://mineta-lab.yz.yamagata-u.ac.jp/HAYABUSA2.html


Images resolution calculator:
http://win98.altervista.org/telescopio.html


Possible future repository for images?
http://www.darts.isas.jaxa.jp/pub/hayabusa2/onc_bundle/browse/



Current location:

https://twitter.com/haya2kun

Location trend:

Note the braking maneuvre to reduce speed while approaching down to 20 km.
Arrival scheduled for June 27th.
https://aliveuniverse.today/rubriche/mission-log/3387-hayabusa-2-approccio-a-ryugu


« Last Edit: 06/08/2018 07:57 AM by mcgyver »

Offline mcgyver

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #2 on: 06/09/2018 07:18 PM »

Quote
We've done our 1st Trajectory Correction Manoeuvre (TCM01) on June 8 ~12:30-13:40 JST. Using thrusters, Hayabusa2 was accelerated by ~24cm/s (-x), 5cm/s (-y), 14cm/s (z). The distance from the spacecraft to the asteroid was ~1900km & the relative speed after TCM01 was ~2.35m/s.[/font][/size]
https://twitter.com/haya2e_jaxa/status/1005080912340512768




Now at 1594 km.
« Last Edit: 06/09/2018 07:18 PM by mcgyver »

Offline yoichi

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #3 on: 06/11/2018 06:28 AM »
http://www.hayabusa2.jaxa.jp/topics/information_e/
Jun. 11, 2018
We have carried out the second optical navigation trajectory correction manoeuvre (TCM02)

On June 11, 2018 at around09:30 - 10:40 JST, the thrusters were fired several times to give an acceleration of 13 cm/s (x-direction), 1 cm/s (-y-direction), 26 cm/s (z-direction). The distance from the spacecraft to the asteroid during the manoeuvre was about 1320km and their relative speed after TCM02 was about 2.1m/s. Until now, Hayabusa2 was approaching Ryugu from the side. But with TCM02, the asteroid is now directly in front of the spacecraft, along the direction of travel.

Offline mcgyver

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Offline yoichi

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #5 on: 06/11/2018 09:37 AM »
http://www.hayabusa2.jaxa.jp/topics/20180611b_e/
Ryugu seen from a distance of 1500km

Figure 2 shows a photograph taken at approximately the same time but using an exposure of about 0.09 seconds. Here, only Ryugu is imaged as a point and the background stars are now too faint to be seen. In expanding the section of image that contains Ryugu, the asteroid can be seen to have a diameter of about 5 or 6 pixels but this is still not sufficient to see the shape. However, from this image is does seem that Ryugu is not elongated like Itokawa.

Offline mcgyver

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #6 on: 06/11/2018 12:51 PM »

Offline mcgyver

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #7 on: 06/12/2018 06:55 AM »
Found additional infor about the "mysterious flyng camera" DCAM3 :


Quote
DCAM 3
Isolated camera
It is a camera separated from the main unit. DCAM was first adopted in solar sail experiment machine "Ikaros". Hayabusa 2 uses a collision device, impactor to expose samples of deep underground asteroids, but it is a camera that shoots the situation. Two of digital cameras and analog cameras are installed.
We shoot so that both analog cameras that can acquire continuous images with low resolution and digital cameras that can intermittently acquire high resolution images will compensate each other.
(google translation)
http://spacenuclear.jp/spacecrafts/hayabusa23.html


As far as I can understand (but no info available around), camera has no propulsion system, it's just stabilized by spinning; it will be just "left behind" by H2 while moving "down" toward the "dark side" of the asteroid to use it as a shield against "shrapnel" produced by impact of SCI.


Also found some new images never seen before but ONC cameras (ONC-T and ONC-W1) are still barely visible, they are very tiny w.r.t. all other instruments!

http://spacenuclear.jp/spacecrafts/hayabusa23.html




Interesting (but useless because all captions are in japanese...) comparison between Hayabusa 1 and Hayabusa 2:
http://www.hayabusa2.jaxa.jp/mission/orbiter/


H2 now at 1100 km from surface; possible resolution for new images: 110m/pixel

Offline Lampyridae

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #8 on: 06/12/2018 08:23 AM »


I'll take a crack at it with my bad Japanese.

1. Ka-Band antenna allows more data to be transmitted
2. Ion engines seem to be more powerful
3. MASCOT rover provided by France and Germany
4. More reaction wheels (4 vs 3)
« Last Edit: 06/12/2018 08:23 AM by Lampyridae »
SKYLON... The League of Extraordinary Gentlemen's preferred surface-to-orbit conveyance.

Offline mcgyver

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #9 on: 06/13/2018 06:53 AM »

Quote
We're now less than 1000km from Ryugu! The asteroid is so close, we've had to change our website header so you can see the approach trajectory: the horizontal scale is now 10 x larger than the vertical scale.
https://twitter.com/haya2e_jaxa/status/1006669149832077312

Offline mcgyver

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #10 on: 06/13/2018 01:05 PM »
I found source of raw data used by hayabusa page:
http://www.hayabusa2.jaxa.jp/hy2sc2/data/hy2_trj.txt

According to page javascript source, this should be the interpretation of the columns (these are the names of the variables):

Date:
1) mjd
2) epoch

Position:
3) x_hp
4) y_hp
5) z_hp

Speed:
6) vx_hp
7) vy_hp
8 ) vz_hp


Lidar enabled (since june 26th):
9) lidar_hit



Let's see if future data will change, which would mean that simulated data are replaced by recorded data.
« Last Edit: 06/13/2018 01:19 PM by mcgyver »

Offline mcgyver

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Offline mcgyver

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #12 on: 06/14/2018 07:33 AM »
New press conference held yesterday.



Presentation in Japanese, lot of veryu interesting info! (Probably English version is coming soon).[/size]
http://fanfun.jaxa.jp/jaxatv/files/20180614_hayabusa2.pdf






Offline mcgyver

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #13 on: 06/15/2018 06:27 AM »

Online Chris Bergin

Re: JAXA Hayabusa2 Mission : General Thread
« Reply #14 on: 06/15/2018 08:35 PM »
ARTICLE: Sample return mission Hayabusa2 approaching Asteroid Ryugu -

https://www.nasaspaceflight.com/2018/06/hayabusa2-asteroid-ryugu-sample-return/

- By Justin Davenport

Offline plutogno

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #15 on: 06/16/2018 11:26 AM »
first hints of surface features from 700 km
http://www.hayabusa2.jaxa.jp/topics/20180616je/index.html

Offline Star One

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #16 on: 06/16/2018 11:40 AM »
Looks curiously diamond shaped.

Online Svetoslav

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #17 on: 06/16/2018 12:39 PM »
I am extremely pleased about how fast JAXA distributes images to the public! I still remember the Rosetta debacle with OSIRIS images, but now... now we had the chance to follow the mission so closely.

Offline yoichi

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #18 on: 06/16/2018 01:06 PM »
first hints of surface features from 700 km
http://www.hayabusa2.jaxa.jp/topics/20180616je/index.html

english
http://www.hayabusa2.jaxa.jp/topics/20180616je/index_e.html
From a distance of about 700km, Ryugu's rotation was observed.

Using the ONC-T (Optical Navigation Camera - Telescopic), asteroid Ryugu was photographed continuously from June 14, 2018 at around 21:00 JST through to June 15, 2018 at around 05:10 JST. Figure 1 shows a looped animation of the 52 captured images.

The distance to Ryugu when the images were captured was between about 700 - 650 km. In these photographs, Ryugu is approximately 12 - 13 pixels in diameter. The animation in Figure 1 shows the photographs after image processing has been performed to smooth between the pixels so that the asteroidís surface looks smooth.



Offline sghill

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Re: JAXA Hayabusa2 Mission : General Thread
« Reply #19 on: 06/16/2018 01:47 PM »
Looks curiously diamond shaped.

I think we'll find there are large craters that make it appear diamond shaped at this distance.

We are only a week away now. Can we get a discussion thread going to keep the update thread quiet (or change the title of this thread to include discussions)? Yes, I know I added to the noise....
« Last Edit: 06/16/2018 01:51 PM by sghill »
Bring the thunder Elon!

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