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Mission: Hayabusa 2
pandaneko
post Aug 12 2010, 11:37 AM
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My apologies, an explosive charge will be used to send out a metal chunck to the asteroid to create a crator. That makes me wonder about the potential damage to the mothership...

Pandaneko
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pandaneko
post Aug 12 2010, 11:50 AM
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Further apologies

Please do not blame me. As I look around for more info I get slightly different versions. The latest finding is that the projectile itself will have an explosive charge in it and it will create a crator, 4m in diam, and 80cm in depth.

Pandaneko
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AndyG
post Aug 12 2010, 03:58 PM
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A crater that size would mean blasting out over 10 tonnes of regolith (5.3 cubic metres @ 2 tonnes/m3) - and the idea is Hayabusa-2 would be near this to collect material? blink.gif

Andy
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Drkskywxlt
post Aug 12 2010, 06:08 PM
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My understanding is the spacecraft will be in a stand-off position during this phase and then approach later to sample/collect the (hopefully) pristine material inside the crater. I guess this supposed "sticky" collection device would operate in some sort of fly-through of the ejecta?
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pandaneko
post Aug 13 2010, 12:09 PM
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There was a repeat TV programme on Hayabusa and Hayabusa 2 on NHK today (13 August). I had not watched it before. What caught my attention most was the shape of the impacter as they called it and the sequence of crater making.

The impacter had a shape of a typical drum, but about one third of the way down from the top it had a disk sticking out all around the drum. The disk width was about one third of the drum diameter, I think.

Detonation sequence is something I do not trust my memory about. It was so brief, literally a few seconds. Now, there was a clear explosion on the asteroid surface, but, at that same moment the drum was still in the air, that is what I remember. I may be wrong, of course...

Pandaneko
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pandaneko
post Aug 14 2010, 08:52 AM
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What follows is from WIKI on Hayabusa 2. I had a look at WIKI in English and there was little. Proposed improvements are as follows.

1. Instead of a parabolic antenna an array antenna as used with Akatsuki will be used.

2. Pipe lining for chemical thrusters and reaction wheels will be improved.

3. Ion engine power will be increased from 10 micro N to 10 milli N.

4. Sampling sequence will be improved. For instance, a fish eye lens will monitor sampling process and optical monitoring of grains being retrieved.

5. Projectile's shape (sampler horn) will be changed from ball bearing shape to conical bullet shape at 90 degrees.

6. Impacter is 20 cm in diameter and weighs 10 kg. After seperation from Hayabusa 2 it will be deformed in shape by the explosive pressure to smush into the asteroid.

What surprised me was that Hayabusa 2 is very similar to Hayabusa, even with a sampler horn! I would have thought that they have given it up...

Pandaneko
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nprev
post Aug 14 2010, 05:16 PM
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Thanks, Pandaneko!

10^3 uprating--that's a dramatic improvement in engine thrust. I wonder if that indicates advancement in the technology, or just more confidence in pushing the existing design harder based on all the experience gained with Hayabusa 1?

Retaining the sampler horn schema is surprising as well. Don't see why they'd do that unless they feel very certain that they understand what went wrong on H1...has anything been published to indicate that? (I would be surprised if much of the post-flight engineering analysis has been translated into English, if it's even been publicly released in Japanese in the first place.)


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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.
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pandaneko
post Aug 15 2010, 12:10 PM
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I should imagine that JAXA itself cannot carry anything on Hayabusa 2 because of yet undecided budgetary confirmation. However, what follows appears to be the most official hideout for them.

http://b612.jspec.jaxa.jp/mission/e/index_e.html

Also, I now know that there will be two MINERVAs and 4 reaction wheels and that the stay period around the asteroid will be 1.5 years.

Pandaneko
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spdf
post Aug 16 2010, 01:02 AM
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http://www.planetaryprobe.eu/IPPW7/proceed...sion7B/p456.pdf

Hayabusa 2 might carry a DLR lander called MASCOT.
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pandaneko
post Dec 23 2010, 09:22 AM
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This news just in!

Hayabusa 2's budget request was fully approved by the government here!!!

It will go in 2014 as planned!!!

Pandaneko
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nprev
post Dec 23 2010, 09:40 AM
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GREAT news!!!!

P., I know that Emily will ask for a reference in the event that she decides to write about this (and it wouldn't surprise me if she did; Hayabusa 1 enjoyed considerable mass media attention by the normal standards of UMSF); do you have one handy in either Japanese or English?


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pandaneko
post Dec 23 2010, 10:15 AM
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Yes, though only in Japanese, from the web digest version of the Yomiuri newspaper. URL here.

http://www.yomiuri.co.jp/science/news/2010...-OYT1T01175.htm

There may be an article in English with the Daily Yomiuri, but this news will be reported widely by other media too from today on, I think.

Pandaneko
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centsworth_II
post Dec 23 2010, 08:08 PM
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Here's the English version:
http://www.yomiuri.co.jp/dy/national/T101223003538.htm

"The government will give the science ministry the full amount--3 billion yen--it requested for development of the Hayabusa 2 space probe in the fiscal 2011 budget, sources said...."

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pandaneko
post Dec 24 2010, 09:15 AM
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I have got this feeling that we may shift this topic into Hayabusa 2 which already exsists. The reason is that Hayabusa 1's news will continue to come in, I think, in the next year and it might become confusing to talk about the two within the same stream...

Perhaps, I should have done just that myself in the first place, if I come to think about it...

Pandaneko
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pandaneko
post Jan 25 2011, 10:10 AM
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Another crazy thought... I was not sure where I should put this in and in the end chose this place. I am still talking about the need for engineering cameras.

Although, not directory relevant to interplanetatry missions, I tell you one episode about Hayabusa's capsule helicopter recovery. Heat shield and its inrared signnature and all that.

They did a rehearsal before hand, and what they used was a traditional Japanese feet warmer used in your bed filled with warm water. These things used to be made of corrugated metals, but increasingly these are now made of plastics, to hold warm water inside them.

I do not use one, as I use my electric bluncket, but there are still people, eldery people, who prefer these traditional warmers. Having said that, let me come to the main issue, engineering cameras.

With Hayabusa Minerva was lost (and only one image returned to earth, I think), and it must have been a very expensive system. However, prior to that deployment they sent a target marker down to the surface of the asteroid. That thing was remarkably primitive, with multi-rfelection surfaces, but what it boiled down to was another traditional thing, called ohajiki, for mainly small girls to play with.

Ohajiki is made of small beans and enclosed in a cloth (here on earth, that is) container to make it roughly round, about 5 cm in diam. With Hayabusa, two of them was used, as I remember, and the idea was that on landing they do not rebounce.

Now, if we have an engineering camara, with a fish eye lens attached to it, can we not forget about MINERVA kind of sophisticated and expensive monitoring devices? Whether angle setting is right or not should not matter as long as a fish eye lens is attached with the marker. It does not be firmly fixed, for cost saving, I think.

If we can arrange for that kind of markers, then we should be able to see what is coming down from above, and even what went wrong on landing, etc, etc. Of course, we should have another camera on board the probe itself.

Pandaneko



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