Discovery Program 2006 and Missions Of Opportunity Options

[nprev]

Jim, I didn't understand your comment.

[edstrick]

"...would return a sample of an enigmatic asteroid,..."

The <derogatory-scatalogical-term-deleted>-wits in the PR office were too stupid to indicate what asteroid or (equally important) what KIND of asteroid in the press release.

morons.

[mchan]

It's an E-type asteroid.

[Phil Stooke]

nprev:

"This "EPOCh" mission for DI sounds intriguing:

"The Extrasolar Planet Observations and Characterization (EPOCh) mission would use the high-resolution camera on the Deep Impact spacecraft to search for the first Earth-sized planets detected around other stars. L. Drake Deming of Goddard is EPOCh's principal investigator."

...what does DI have that Hubble doesn't? Are we just talking availability here, or does DI's HRC have better resolution for such a task?"

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I know nothing about EPOCH and was very surprised to see it here. The only thing Deep Impact can have that Hubble doesn't is time. It could stare at a transiting exoplanet for long periods, monitoring multiple eclipses - well, not stare presumably, but take lots of pics, or maybe do a deliberately blurred and offset image like Galileo with Comet SL9 - whereas Hubble time is far too valuable to deploy like that.

Phil

[gpurcell]

Given the missions selected, I think the odds are HEAVILY slanted towards the next Discovery selection being VESPER.

[gpurcell]

Seven months and counting.... and the Discovery mission canidates are finally chosen.

http://www.nasa.gov/home/hqnews/2006/oct/H...scovery_AO.html
The moon mission seems somewhat lacking in scope.... a dedicated gravity mapping mission. I'm sure you can learn a lot doing that, but it also seems like it could be a rather limited payload, and cheap mission. I find myself wondering if the reason it made the cut is to have a fallback mission if the other two come back as too expensive or infeasable for some reason.

I agree. It may also preserve ability to do Moon science needed for VSE if the robotic portion of that program gets axed.

[tty]

"Origins Spectral Interpretation, Resource Identification and Security (OSIRIS)"

That must be some kind of a record for a contrived acronym.

tty

[Paolo]

I like the new missions for Deep Impact and Stardust, though.

This "EPOCh" mission for DI sounds intriguing:

"The Extrasolar Planet Observations and Characterization (EPOCh) mission would use the high-resolution camera on the Deep Impact spacecraft to search for the first Earth-sized planets detected around other stars. L. Drake Deming of Goddard is EPOCh's principal investigator."

...what does DI have that Hubble doesn't? Are we just talking availability here, or does DI's HRC have better resolution for such a task?

I think it would be something like this proposal http://www.stelab.nagoya-u.ac.jp/hawaii/ha...ME_jan2004w.ppt
Speaking of the new Stardust mission, this somewhat reinforces my belief that Deep Impact was a sort of job unfinished

[Paolo]

Given the missions selected, I think the odds are HEAVILY slanted towards the next Discovery selection being VESPER.

IIRC VESPER was not too different from Venus Express when it was proposed a few years ago.

[Mariner9]

"...would return a sample of an enigmatic asteroid,..."

The halfwits in the PR office were too stupid to indicate what asteroid

How about Asteroid 624 Victor?


I found a scientific paper called:
Trojan Asteroid 624 Hektor: Evolution of an Enigma
by W.K. Hartmann.

http://adsabs.harvard.edu/abs/1980BAAS...12Q.837H

The great thing about the internet, there is hardly a question that can't be answered (with tongue firmly planted in cheek) using Google.

[OWW]

I don't understand why Deep Impact is considered for an extended mission when its High Res imager is Badly Blurred Beyond Belief. I remember a lot of talk about deconvolution, but a year later all I see on their website are these pictures:

http://deepimpact.jpl.nasa.gov/gallery/jpg...HRI_Impact1.jpg
http://deepimpact.jpl.nasa.gov/gallery/jpg/goneinaflash.jpg
http://deepimpact.jpl.nasa.gov/gallery/jpg/nucleus-516.jpg

What's the point of flying this camera to another comet?

[Mariner9]

There are a lot better pics out there than the ones you picked.

http://deepimpact.jpl.nasa.gov/gallery/jpg/HRI_937_1.jpg

As I understand it, the idea is that we have only seen 4 comets close up, and each one looked very different from the last.
As I recall, the best resolution on Deep Impact images were around 10 meters per pixel. Compare that to around 100 m at Halleys back in 1986, and over 30 m at Borelley (Deep Space 1), and you can appreciate the improvement.

The Contour Discovery mission was funded at around 150 million to get a look at only 2 comets (maybe 3 if lucky, which it most definately was not). So NASA was willing to spend about 75 million dollars per comet on that mission. 30 million for the Deep Impact extended mission seems like a good bargain in comparision.

[nprev]

I think it would be something like this proposal http://www.stelab.nagoya-u.ac.jp/hawaii/ha...ME_jan2004w.ppt

Okay, I think I get it now...long-parallax baseline imaging of nearby stars looking for Earth-sized object transits? Sounds interesting, but I have to wonder just how many extrasolar systems would happen to have ecliptic planes along our LOS for a given observation...

[djellison]

What's the point of flying this camera to another comet?

Because it's still the best camera for looking at Comets during a flyby we've ever had, and combined with its ability to take IR Spectra, it offers a very very cheap way of exploring another comet for something less than 10th the price of a new dedicated mission.

And - when it comes to measuring transits with an out of focus camera....all you're doing is counting photons, and that can be done just as well with an out of focus instrument in actual fact...it's not ideal, but it will do the job (and if it couldn't, they wouldn't have been selected for the next study phase)

Doug

[ugordan]

all you're doing is counting photons, and that can be done just as well with an out of focus instrument in actual fact...it's not ideal, but it will do the job

It may in fact be ideal because you don't want sharp images of the stars as the physical structure of the CCD pixels has discontinuities. If you had a very sharp, point-like star image, small attitude disturbances will project the image on different parts of the pixel region, possibly on the boundary between two pixels. This would make the brightness appear to oscillate. With an out-of-focus image, you sum up the smudged area which is less prone to such artifacts. A similar think is done in star scanners, AFAIK.