Mission: Hayabusa 2 |
Mission: Hayabusa 2 |
Jun 14 2018, 08:58 AM
Post
#301
|
|
Forum Contributor Group: Members Posts: 1372 Joined: 8-February 04 From: North East Florida, USA. Member No.: 11 |
|
|
|
Jun 14 2018, 08:59 AM
Post
#302
|
|
Forum Contributor Group: Members Posts: 1372 Joined: 8-February 04 From: North East Florida, USA. Member No.: 11 |
|
|
|
Jun 14 2018, 09:25 AM
Post
#303
|
|
Member Group: Members Posts: 817 Joined: 17-April 10 From: Kamakura, Japan Member No.: 5323 |
What follows is only the gist of latest news to us in today's press release, since a lot of the press release is
based on earlier press materials. Currnt status as of 14 June: Distance to Ryugu is 750km. We conducted TCM-3 today (14 June) and the approach velocity as a result is 1.7 m/s. Optical/radio navigation will continue. Light curve measurements and satellite search have been conducted, expected arrival at Ryugu is currently 27 June. Both OCN-T and OCN-W are now being used for: 1. Optical/radio wave navigation 2. satellite search 3. Light curve measurement (self-rotation period) At current distance with OCN-T is still about 10 pixels. Mid infra red camera (TIR) was activated for: 1. tests 2. Light curve measurment OCN-T is more precise and OCN-W is being used as a backup. We have conducted 4 light curve measurements and we now know Ryugu's spin rate is about 7.6 hours, as previously estimated. About the absolute signal strengths, we will be looking at them still further. About NIRS3: It was powered on at the same time as RIDAR and it is working normally. Reasons for combined optical/radio wave navigation is as follows. It is absolutely vital to use it given the error of about 300km with previsouly used RARR (Range and Range Rate) method. It can be reduced to a few km using DDOR (Delta Differential One-way Range) method. 900m error at Ryugu is equivalent to 6cm at 20,000km (Japan-Brasil distance). About satellite search: Even small ones are dangerous. We conducted our observation from a distance of 2100km. (Satellites can exsist stably below radius of 90km). Im diamiter was the smallest possible at this distance. (This kind of operation was also conducted with Hayabusa 1) Date (7 June) and time of observation. 1. 08:03 - C8:09 2. 11:06-11:12 3. 14:17 - 14:23 4. 16:35 - 16:41 Exposure time was 178 seconds, 30,000 times longer than usual. Result: Unable to find any smaller than the detection limit of 50cm. Therefore, we will be able to approach the stable orbit for satellites smaller than 50cm (raidus of 50km). We will continue to minitor for smaller ones as we approach Ryugu. About future press briefings: 27 June as we reach 20km, and thereafter on : 19 July, 2 August, and 23 August during the next two months period. P |
|
|
Jun 14 2018, 11:35 PM
Post
#304
|
|
Solar System Cartographer Group: Members Posts: 10145 Joined: 5-April 05 From: Canada Member No.: 227 |
-------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
|
|
Jun 15 2018, 04:59 AM
Post
#305
|
|
Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
|
|
|
Guest_mcmcmc_* |
Jun 15 2018, 06:31 AM
Post
#306
|
Guests |
|
|
|
Jun 16 2018, 07:08 AM
Post
#307
|
|
Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
TCM 4 was performed today between 9:30 and 10:40 Japan time (0.30 to 1.40 UTC)
delta-V: 10 cm/s (-X), 1 cm/s (+Y), 44 cm/s (+Z) https://twitter.com/haya2_jaxa/status/1007839905752363008 |
|
|
Guest_mcmcmc_* |
Jun 16 2018, 08:23 AM
Post
#308
|
Guests |
Extended version of the twitter aggregator:
http://win98.altervista.org/hayabusa2/TwitterAggregator.html |
|
|
Jun 16 2018, 11:09 AM
Post
#309
|
|
Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
first hints of surface features from 700 km
http://www.hayabusa2.jaxa.jp/topics/20180616je/index.html |
|
|
Jun 16 2018, 06:32 PM
Post
#310
|
|
Member Group: Members Posts: 289 Joined: 29-December 05 From: Ottawa, ON Member No.: 624 |
Mine is the only generation to have witnessed the unveiling of the planets and their satellites by spacecraft photography. I still recall the fascination of a book on Mariner IV my brother gave me, the National Geographic map of the moon, and later Mars. Voyagers epic missions revealing all those new worlds. Seeing Hayabusa 2's fleeting glance at the first features of yet another new world still stirs the excitement in me. I can never get enough of it. Looking forward over the next 18 months for this mission, and of coarse, this New Year's day!
|
|
|
Jun 16 2018, 09:41 PM
Post
#311
|
|
Solar System Cartographer Group: Members Posts: 10145 Joined: 5-April 05 From: Canada Member No.: 227 |
-------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
|
|
Jun 17 2018, 12:24 AM
Post
#312
|
|
Junior Member Group: Members Posts: 80 Joined: 18-October 15 From: Russia Member No.: 7822 |
-------------------- |
|
|
Jun 17 2018, 06:54 AM
Post
#313
|
|
Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Great movie, Roman!
What an odd-looking little beast. Markedly different from the regular 'battered potato' look of the smaller asteroids, though we're a long way still from seeing enough of them to say what's 'normal' and what's not in that regard. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
|
|
|
Jun 17 2018, 08:49 AM
Post
#314
|
|
Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
I wonder if the apparent equatorial ridge is merely an effect of Ryugu spinning around the axis of maximum inertia, or if it formed from loose material pooling on the equatorial plane as in the case of asteroid Steins.
we will soon know: if the ridge is cratered the former is true, if it's smooth it's the latter. I am betting on the latter, as equatorial ridges seem to be common on small, relatively fast-spinning objects. |
|
|
Jun 17 2018, 08:49 AM
Post
#315
|
|
Forum Contributor Group: Members Posts: 1372 Joined: 8-February 04 From: North East Florida, USA. Member No.: 11 |
Great movie, Roman! What an odd-looking little beast. Markedly different from the regular 'battered potato' look of the smaller asteroids, though we're a long way still from seeing enough of them to say what's 'normal' and what's not in that regard. You just contradicted yourself... |
|
|
Lo-Fi Version | Time is now: 16th April 2024 - 10:10 PM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |