ExoMars Options

[mwolff]

Does anyone know if an occultation spectrometer can differentiate isotopes, e.g., C14 vs. C12? I haven't seen it mentioned.

There is nothing intrinsic to the occultation technique that would prevent isotope differentiation. However, detection is a question of the amplitude of the isotopic shift and the abundance of the trace isotopes. For carbon, such shifts would be much larger in the IR and sub-mm...where the literature seems to place the proverbial observational action. Even at the allegedly observed methane abundances, one might suspect that the differentiation of C(12)H4 from C(14)H4 in the near-infrared is likely to require more S/N and higher spectral resolution than available from a MATMOS observation.

[SteveM]

Aww, shucks! It was my pleasure.

Actually, our leader may have been setting you up for that pun, since the SI prefix is tera, not terra. </pedantic mode>

Steve M

[eoincampbell]

There is nothing intrinsic...

Inspiring...

[Drkskywxlt]

There is nothing intrinsic to the occultation technique that would prevent isotope differentiation. However, detection is a question of the amplitude of the isotopic shift and the abundance of the trace isotopes. For carbon, such shifts would be much larger in the IR and sub-mm...where the literature seems to place the proverbial observational action. Even at the allegedly observed methane abundances, one might suspect that the differentiation of C(12)H4 from C(14)H4 in the near-infrared is likely to require more S/N and higher spectral resolution than available from a MATMOS observation.

Thanks! I read the report from the ExoMars Joint Instrument Development Team that vjkane posted on his futureplanets blog. It makes a mention of isotopic differentiation, but goes no farther than that.

[lavaphile]

There is nothing intrinsic to the occultation technique that would prevent isotope differentiation. However, detection is a question of the amplitude of the isotopic shift and the abundance of the trace isotopes. For carbon, such shifts would be much larger in the IR and sub-mm...where the literature seems to place the proverbial observational action. Even at the allegedly observed methane abundances, one might suspect that the differentiation of C(12)H4 from C(14)H4 in the near-infrared is likely to require more S/N and higher spectral resolution than available from a MATMOS observation.

In its press releases MATMOS does not claim to differentiate isotopes but SOIR-NOMAD is supposed to be able to differentiate a few variants of methane, carbon monoxide and carbon dioxide (see factsheet at http://www.aeronomie.be/en/press/soir-nomad.htm).

[monitorlizard]

I was surprised (and disappointed) to read that the currently planned weight for the MAX-C rover, to be landed with the ExoMars rover, is now down to 65 kg:

http://en.wikipedia.org/wiki/Mars_Astrobio...Explorer-Cacher

Yeah, I know wikipedia isn't always the most reliable, but this entry draws on reputable JPL/MEPAG documents. A little more than a year ago, I was reading that the MAX-C strawman design was for a rover larger than MER with a sophisticated astrobiology payload. Funny thing is, the wikipedia entry still infers a capable astrobiology suite, but at 65 kg I can't imagine MAX-C having much more than a couple of cameras and the sample collecting/caching hardware.

Perhaps someone at the upcoming MEPAG and Mars landing site meetings will clarify what the current thinking is on this. I'd like to know what's driving the MAX-C shrinkage. Reduced performance of the skycrane relative to previous estimates? Growth in the weight of the ExoMars rover?

[Drkskywxlt]

I was surprised (and disappointed) to read that the currently planned weight for the MAX-C rover, to be landed with the ExoMars rover, is now down to 65 kg:

No way this is correct. The JPL report to MEPAG that's linked on that page says the mass is expected to be much less than MSL but larger than a MER. So maybe 650kg? Dropped a zero? 65kg sounds more reasonable for the instrument payload alone. It's possible that MAX-C could get downsized no/cancelled, much will depend on the Decadal Survey. But, it's hard to imagine ANY 65kg rover could get the kind of science done that NASA's expecting for the Mars program now.

[Stu]

Nice report here...

http://www.telegraph.co.uk/science/space/8...red-planet.html

[tanjent]

That's the first time I ever saw the adjective "doomed" applied to Mars Express.

[helvick]

Yeah that was a bit of an unfortunate editing mistake - very nice article apart from that blip though.

[Paolo]

this week in Aviation Week: ESA Hones Design For Mars Orbiter/Lander

[Stuart H]

Yeah that was a bit of an unfortunate editing mistake - very nice article apart from that blip though.

Apart from the other errors:
1. "When Beagle 2 got lost on its journey – it is thought to have fallen into a crater, smashed on impact or failed to land on the planet at all "

a. It did not get lost on its journey - it was never allowed by ESA to radio home during its journey.
b. It is a myth perpetuated ad nausiam[/i] that Beagle 2 crashed or missed the planet or fell into a crater. There is NO evidence for any of these suggestions as there is NO published evidence at all.

2. "the £66 million Beagle 2 spacecraft...."

a. The published cost of the programme was £42.5 million.

3. Beagle 2 was built at the OU in Milton Keynes in an 'Aseptic Assembly Facility' of the highest quality (way better than anything NASA have done) in terms of cleanliness and sterility. It had to be, because its life-detecting Instrument was much more sensitive than anything NASA have done (or are planning to do). If you don't bel;ieve me, ask Dr. Everett Gibson at NASA

[Citymarks]

Full inline quote deleted - ADMIN

But why we dont build quickly new Beagle 2 spacecraft and send it to Mars? Are the blueprints lost/deleted ? Do we save money and time to not makeing new blueprints for the spacecraft ? I admire Chinas desision to send twin to orbit. Why we cant do it ?

[Explorer1]

There are other replacements in the planning stage already, Exomars, MSL, etc (with mobility this time).

[djellison]

I'm sure all the CAD and other detailed specs are safe and available. What's not available is a budget to build it or a ride to get it to Mars. Moreover, Beagle 2 didn't work. We don't know exactly why, but the fact is that it didn't. Building another and sending it straight away would have been like launching the 2001 Mars lander after the MPL failure. The sensible thing to do was stop, figure out why, and then only fly once they were sure of what had happened and how to fix it. Hence Phoenix landed 7 years after the 2001 lander should have done.

I do hope landers at the scale of B2 ( certainly in the <150kg class ) make it to Mars eventually - but they'll be derivatives of that design, not a build to print.

And it's worth mentioning, whilst B2 was in itself not a success, it brought Mars into the media spotlight like nothing has ever done before in the UK, it inspired a lot of interest in STEM subjects, and some of the instrumentation has found a home in the medical industry - so it was a project worth doing all the same.