Mission: Hayabusa 2 Options

[Paolo]

more information on the extended mission is available in the latest English press release
http://www.hayabusa2.jaxa.jp/enjoy/materia...2_ver14_en2.pdf

[stevesliva]

Looks like an interesting decision to make: a trajectory with a longer travel time to the rendezvous but another asteroid flyby in the meantime, or a shorter flight time but including a Venus flyby.
Either way, these rocks are absolutely tiny (Half the size of the ISS), definitely the smallest objects ever visited by a spacecraft (including the Didymos moon). Exciting!

Sample return same for either -- Dec 2020. The options are EVEEA: Venus (2024) Asteroid (2029) --or-- EAEEA: Asteroid (2026) Earth (2028) Asteroid (2031)

So not all the earth swingbys are mentioned in either proposal.

[Marcin600]

During July 25 talk event “From the scene of Hayabusa 2" (Hamagin Space Science Center) Mr. Takahisa Saeki, project engineer of Hayabusa 2, was talking about collision device (SCI) and artificial crater.

The event is recordet on YouTube (in Japanese) - here

Cool video from SCI ground tests (fragment of the presentation: 30:49-31:07):
© JAXA

Attached File(s)

 SCI_impact_test.mp4 ( 2.48MB ) Number of downloads: 699

 

[Hungry4info]

I don't mean to be that guy but... are you sure this is a real video?

[Marcin600]

I don't mean to be that guy but... are you sure this is a real video?

This is fragment of the official JAXA's presentation (see link above)... It's in slow motion and it's very cool, but so far I didn't suspect that there might be something wrong with it. And now I have some doubts. (but I'm not a video specialist)
Why do you think it's not real? Do you think it can be some kind of computer animation or modification?

PS. To me, it looks like it was shot with a camera placed at ground level, behind the glass. The whole thing is magnified, so the soil fragments look much larger (and heavier) than they really are...

[Xerxes]

I don't see anything in this video that would raise any kind of doubts. They show the entire setup of the experiment, and it looks just like other high-velocity impact experiments I've seen. The Planetary Society covered the test here: Planetary Society on SCI and another angle on the experiment is here: SCI impact test

[Marcin600]

I think this video is cool not because it's spectacular, but because it corresponds quite well to the actual SCI impact on Ryugu (I mean the development of the debris curtain).
Of course, apart from the dust floating in the air, and the surrounding landscape...

[Explorer1]

According to this recently released CGI animation of the sample return ( http://www.hayabusa2.jaxa.jp/galleries/oth...Mission_en.html ), the spacecraft will take photo of the re-entry of its capsule!
Are there any scientific benefits to attempting to snap the capsule in flight, apart from practicing spacecraft attitude/camera settings?

Obviously Hayabusa 1 was unable to do the same; so unless anyone knows better, I think this would be a first in (robotic) space history (excluding the various ISS-taken photos of returning vehicles re-entering after a stay at the station)? If nothing else, I really need to update my avatar....

[Paolo]

the only similar experiment I that can think of is Pioneer Venus Orbiter trying to image Magellan firing its retrorocket to enter orbit in August 1990. The plume was too faint to be detected.

[JRehling]

The ascent of Apollo 17 from the Moon's surface was captured on color TV; I'm not sure if that counts as similar.

[djellison]

Are there any scientific benefits to attempting to snap the capsule in flight, apart from practicing spacecraft attitude/camera settings?

It's analogous to the HiRISE imaging of Phoenix and MSL ( and unfortunately missed imaging of InSIGHT ) during EDL.


It's just damn cool.

[rlorenz]

Are there any scientific benefits to attempting to snap the capsule in flight, apart from practicing spacecraft attitude/camera settings?

Yes, in the sense of 'rocket science'. It won't tell us anything about Earth or the planets, but emission during entry is of interest for understanding the aerothermodynamics of atmosphere/heat shield response to hypersonic entry. There have been several campaigns of (mostly ground-based, but some airborne) observations of re-entries - Hayabusa 1 (much more spectacular than 2 will be, since the 'mother ship' entered as well), I think Stardust, and some of the ESA Ariane Transfer Vehicles returning from ISS.

I was awarded time on HST to try to look for the Huygens entry on Titan (this would have been a spacecraft observation of an entry!), but the STIS instrument failed a few months before the observation was to be executed, so it didnt happen. Frank Crary IIRC got time on HST to observe Cassini EOM, but the timing didnt work out (HST on the wrong side of the Earth)

[Explorer1]

It appears that 1998 KY26 is the final target.
The illustration comparing it with Hayabusa 2 in this release really gives a sense of scale

[Marcin600]

Similar results as for Bennu (Vestoid fragments on the surface) appeared (in English) in the same issue of Nature Astronomy, September 21..

They are also discussed on the Hayabusa2 website (but only in Japanese).

Unlike Bennu, on Ryugu have been found fragments of S-type asteroids (ordinary chondrites).
In addition, there are also bright fragments of rocks with indications of thermal metamorphism, which probably come from different parts of Ryugu's parent body...


I think that the analysis of delivered samples in the laboratory will require caution in drawing conclusions as to the nature of Ryugu himself, and probably also of Bennu!
They may contain a lot of "exotic" material!

[Marcin600]

as above - now in English