Comments on: More on EPOXI flyby

By: StevoR

StevoR — Wed, 02 Jan 2008 14:32:58 +0000

EPOXI : A resin used to continue flying after a Deep Impact
Sorry couldn’t resist it.

Well done NASA - & don’t forget add the sub-orbital private “space” entrepreneurs to the “you showed ‘em” listing. NASA - and national space agencues generally maty not be perfect but they - esp. NASA - have achieved a huge amount and we should never forget that or fail to be appreciative and respectful of it.

Call Deep Impact or call it EPOXI this lil’ robot wanderer has gone a long way …

Thumbs up!

By: Bruce Moomaw

Bruce Moomaw — Wed, 02 Jan 2008 02:21:30 +0000

I’m a little bit surprised (to say nothing of gloating) that Phil hadn’t heard about the HRI mirror problem on Deep Impact — they discovered it right after launch, and the similarity to the Hubble mirror fiasco was positively embarrassing. It turned out that Ball Aerospace had optically tested the HRI mirror at room temperature, without considering the possible that its near-cryogenic temperature in space might warp it. Deconvolution did a lot to improve it, but its resolution is still only about 2 or 3 times better than the unaffected MRI camera (instead of 5 times better, as planned).

It is nice, though, that the problem won’t affect the EPOXI part of the mission — that is, they’ve found a way to cure EPOXI…

By: Mark Martin

Mark Martin — Tue, 01 Jan 2008 14:31:13 +0000

“…but the amount that the Earth receives relative to its pre-flyby energy is so small as to be a rounding error, much like if a flea were to leap off of you, you might not even feel it, but the flea definitely would.”

Effectively a gigantic Mössbauer effect.

By: Michael Lonergan

Michael Lonergan — Tue, 01 Jan 2008 02:40:42 +0000

I wonder if I can use the effects of this flyby for not being able to walk straight or stand up? Tomorrow, when I wake up with a headache, I’ll just blame EPOXI!

By: Paul M

Paul M — Tue, 01 Jan 2008 02:30:55 +0000

Thanks Mandy, it makes sense to me now…

By: MandyDax

MandyDax — Tue, 01 Jan 2008 02:13:22 +0000

@ Paul & Michael:
BA said: “The spacecraft has very little mass compared to the Earth, so while it loses a lot of energy relatively, the Earth gains very little [relatively].” There, I fixed it. Energy in the flyby is conserved, but the amount that the Earth receives relative to its pre-flyby energy is so small as to be a rounding error, much like if a flea were to leap off of you, you might not even feel it, but the flea definitely would. So, yes, you’re both right, and so is BA.

PS @BA: A zillion is 10^x; what is x? Does earth have that much time left? I think I’ll go outside during the flyby and pull the earth in the opposite direction so it all evens out.

By: Astronomy Pictures - Images of moon

Astronomy Pictures - Images of moon — Mon, 31 Dec 2007 23:55:39 +0000

[…] More on EPOXI flyby By The Bad Astronomer The team compensated by using a technique called deconvolution, which sharpens up an image but can introduce artifacts (like overly bright or overly sharp features; I used this technique ad nauseum on my early Hubble images). … Bad Astronomy Blog - http://www.badastronomy.com/bablog […]