Spacecraft to Bring Back Bits of Sun

krugdm writes: "NASA will be sending up a robotic spacecraft named "Genesis" which will bring back specks of solar wind in order to study what the solar system may have been like when it was first forming." According to the article, this will be the "first U.S. spacecraft since the Apollo moon ships to return samples from outer space," and the planned recovery involves a Hollywood-sounding helicopter catch of the reentry pod.

Re:It's not hollywood.

[NNKK]

wow, that IS new
one question, how durable is this thing? a ram-air inflated wing seems like it could get ripped in half slowing down from reentry if the materials weren't strong enough
there's ways around making a simple parachute out of absurdly heavy materials, but a wing would be a little different

Re:It's not hollywood.

[tesserae]

It's plenty strong enough -- it's based on the same technology (and the same materials, in fact) that skydivers have been using for close to twenty years: parafoils (commonly known as "square parachutes" back then) became practical in the early 70's. The Genesis parafoil is based on the design of a parachute long used for tandem skydiving instruction... long history there. (I've used similar devices a few thousand times myself; they work! And I don't just use 'em -- I design parachute systems for a living.)

And yeah, you can't just open it supersonically in Earth's atmosphere -- the vehicle slows considerably on its own, and it's further slowed by a drogue parachute before the parafoil opens at 20 Kft or so. IIRC the parafoil (at around 420 square feet planform area) weighs about fifteen pounds... not too shabby. You just have to remember that it's not extremely rigid: the airfoil shape is controlled by the ram-inflated fabric, but the load structure is all in the reinforcing tapes and suspension lines. My personal parachute weighs in at less than six pounds and is good for at least a thousand uses, and I'm not a little guy...

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measurement units (fifth post)

[jerkface]

I wonder why the NASA geochemist thought "grains of salt" was the best unit of measurement to use to describe the samples.

Also, I got fifth post.

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Vying for noble gases?

[tsarina]

I wonder what you can learn from a single noble gas atom. Sure, it existed when the solar system hadn't even been formed yet, but so did every other atom that you could find here on earth. Noble gases don't combine or change when in contact with other elements, so I wonder what's so special about those which are found in space. It doesn't seem like a single atom could tell you more than an atom on earth could. Is there something special about elements found in the solar wind that I'm missing?

Oh boy, more customs forms!!!

[einhverfr]

Remember that when the Appolo astronauts returned, they had to fill out customs forms for the moon rocks. I want to see what the solar wind customs forms look like... Assuming, of course, the craft lands in international waters....

Sig: Warning The following may be illegal under the DMCA (rot-13 decoder):
ABCDEFGH I J KLM

If only my budget had room for diamond wafers...

[tsarina]

"Each panel has rows of hexagon-shaped wafers made of ultra-pure silicon, diamond, sapphire, gold, aluminum or germanium, all of which will serve as, basically, flypaper." No wonder NASA projects cost so much! If ultra-pure silicon can be flypaper and so can ultra-pure diamond, why use two? The silicon's a ton cheaper! Is it that one substance can catch only a few elements of solar wind, or what? Otherwise it just seems like a waste of money.

It's not hollywood.

[NNKK]

Helicopter and planes have been able to catch capsules falling to earth since the 60's, it's difficult, but quite possible.
The Corona project, the first real useful spy camera in space, used a system whereby the capsule containing the film was dropped to earth at a predetermined time, and planes were standing by to catch it.
If they failed, it would stay afloat for a couple hours to give them a chance at recovery, and after that would let water in so the Soviet's couldn't get it.

Re:It's not hollywood.

[tesserae]

You're right about the history of midair returns, but this one is different: the parachute is a parafoil, a ram-air inflated deployable flying wing. AFAIK this is the first time a spacecraft will be recovered in the air under a parafoil...

It makes a lot of sense: the parafoil gives a much lower rate of descent than an equivalent-weight round parachute could, and also gives a large horizontal velocity component -- so the relative closing speed of the helicopter is minimized, and it doesn't have to be in such a dive, either. IIRC the vertical rate is about 13 ft/sec, and horizontal is around three times that.

It's a pretty cool system; I got to work with it a bit, and saw quite a few of the test flights.

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