It is indeed true that if this kind of thinking prevails, we will be unlikely to ever see cameras added mostly just for pretty pictures.

If properly designed, they needn't introduce a failure mode.

But they do cost resources, and pretty pictures alone aren't usually considered worth it. But there are sound engineering reasons to want to view parts of the spacecraft (to verify deployments, for example) and these may end up flying if the need is judged sufficient. An example would be the RocketCams on various launch vehicles.

Payload items in general are designed so that the worst-case failure modes (dead shorts on the power bus and data lines, usually) don't affect anything else. You don't have to test this, it's shown by design.

Spacecraft designers never trust payload to not screw up in the worst possible way

Alas, the cited article is nearly content-free about the actual problems MSL had. Your "best defense" above; I don't disagree, but how do you pay for "predesigning" a mission? You're just moving the cost from one column to another, you may not save anything.

The best defense against overruns is to relax the requirements/descope as the cost ceiling is approached. If you don't do this, you better make sure you can cover the costs, because you can't have it both ways.

In my experience, the first may be a problem (though just because thin sections are used traditionally does that mean you have to have them?) but the second is at least partially masked by the fact that few people who do ground-based analysis build instruments at all, and most of those who do don't know much about what it might take make a flyable one. We have certainly come nowhere close to exhausting the capabilities of in situ instruments.

As I said before, this could be a cost-benefit tradeoff if it could be done objectively, but I've never seen an objective analysis, just partial arguments from both sides of the issue and a lot of unsupported philosophy.

I'm concerned that we just don't have enough money to do MSR, so it really doesn't matter how superior it may be in the abstract.

Certainly there is some useful information gained by unmanned missions for manned missions, but from a practical engineering requirements perspective the two have so little in common that the connection is weak at best.

For example, the US never did unmanned sample return as a precursor to Apollo, and the role of Surveyor in the development of Apollo was quite minimal (the LM had already been largely designed when Surveyor 1 landed, and I can't think of a single change in Apollo that came out of Surveyor experience; maybe someone can correct me.)

What use would an STM be for geologic or astrobiological applications? For that matter, even electron microscopy was more confusing than useful in the case of ALH84001.

Phoenix has a mass spec, evolved-gas analyzer, and atomic force microscope. MSL has X-ray diffraction, mass spec/GC, and laser-breakdown spectrometry.

I'd be curious to see an objective analysis of the tradeoffs between sample return and in situ. You'd think one would exist.

It seems to be a foregone conclusion among many that MSR is the next major goal for Mars exploration.

I'm confused by this for two reasons (neither new to this forum but worth reminding everyone of):

1) I haven't seen any objective evaluation of the cost of sample return versus the cost of in situ measurements. For some large class of measurements, in situ would be far cheaper. Presumably this was the motivation for the "Astrobiology Field Lab". Is there a "sample return mafia" pushing for samples?

2) Fear of the "Andromeda Strain" scenario (justified or not) will impose all kinds of sterilization requirements on the returned samples, making MSR even more expensive.

I think MSR would be extremely cool, but I fear it won't happen for a long time.

I also note that Stern was pushing MSR back in mid-07, which seems at odds with the perception that he was advocating fiscal responsibility.

Is what the actual MSL? The box on the right in the latest update is an actual Rover Compute Element, but I'm not sure if it's a flight unit or an engineering model. Certainly the "scarecrow" is not actual flight hardware.

I don't know if they're "official" but I see these shirts all over the place at MSL reviews.

Don't get me wrong, it may not be. I'm only involved with Odyssey to the extent that I get consulted when there's a hiccup with the THEMIS hardware, which hasn't happened for a while now.

EDIT: GRS is still releasing products to the PDS (last was in Jan 08). Could you be thinking of MARIE, which has been shut down for a while now?

That message is explicitly stated as a requirement in every RFP for every spacecraft I've ever worked on, except it's usually 3x longer than the expected mission duration.

I've worked on spacecraft that blew up, were misnavigated into a planet, crashed, and were miscommanded into oblivion (and even a few that worked.) After all that, I'm skeptical that an explicit shutdown for cost-saving reasons would have much of a chilling effect.

I'm the representative of the orbital community? Then why am I working so hard on MSL?

Seriously, as others have said it's pretty hard to put a dollar figure on data bits. Certainly more GRS integration time leads to better SNR and higher spatial resolution in elemental abundance maps, and more THEMIS images is more coverage of more places in more bands. And THEMIS can monitor atmospheric temperature and dust globally. But there's some overlap with the MRO payload in that regard, so I would think the GRS dataset was the unique contribution of Odyssey.

I would argue that Odyssey is far more likely to yield more good science than either of the rovers, which will be lucky to go a few more km and which have pretty much already exhausted the capabilities of their payloads to find anything more out about the landing sites (barring some unpredictable serendipitous discovery.)

But, as usual, the orbiter missions are "boring" and the rovers aren't. Though this budget business is the only rover news I can remember getting any media attention for quite a while (years?)

At the risk of being virtually pilloried by this crowd, would you prefer that they killed a rover through
miscommanding, like VL1 or MGS?

This is a pretty obvious "Washington Monument" ploy, not worth being that upset about yet. That said, does anyone think much more good science is going to be coming out of Spirit?

"No one dared disturb him or interrupt his thoughts: and presently he turned his back upon the dwindling Sun."

Thanks for everything, ACC.

From Emily's blog on planetary.org about Ulysses: "In preparation for the mission's end I started rereading the Odyssey to look for a good epitaph. I haven't come across anything yet..."

Surely Teiresias' speech in Book 11 about how Odysseus will die: "It shall come to you out of the sea, death in his gentlest guise."

Don't mean to rain on your parade, but it doesn't seem like it's worth the cost and significant technical hurdles. After all, we don't even have that capability for Earth, and yet geologists manage to figure things out.

And call me a skeptic about these being avalanches as opposed to some kind of longer-duration wind phenomenon. Probability alone would argue against having caught such a transient thing in an image that took a few seconds, at most, to acquire.

Zero descent images. MARDI operations were deleted from Phoenix.

Brighter doesn't mean spectrally different; this could be a simple albedo change, not influencing the spectrum.

As for your "pet theory" remark: it's equally likely that refutations of a successful theory are made for compromised reasons, because it's fun to upset the apple cart.

That said, I completely agree with you that discussion is good, it'd just be better if it wasn't mostly stuff already discussed and rejected in the original paper. At least the UofA work is using new data and new simulations and should serve well to further the debate.

The pretty pictures in the UofA press release aside,
in general I'd be skeptical of computer modeling results, as they can easily be based on flawed assumptions, initial conditions, be too oversimplified, etc. For one thing, I'm not sure how accurate the DEM was with all the albedo variations caused by the flow. Malin and Edgett did not arrive at their water conclusion lightly. Branching statistics as used in geomorphology is not just "it looks like"; go back and read their papers, especially the 2000 paper.

One big reason is that the Cassini and CRAF missions were not really very similar, so the idea of sharing a common spacecraft was not that valid to start with.

As I have pointed out before when these "common spacecraft" discussions come up, there is huge commonality at the box level. Regardless of how different spacecraft may look on the outside, much of the guts are built out of catalog items.

Certainly once the s/c loses attitude control the mission is essentially over.
The S-band and X-band both go through the high-gain antenna, but the S-band output power is only 5 watts compared to 20 on X-band, so the maximum data rate is pretty limited (I believe 128 bps compared to 1024 bps on X-band through DSN 34m).

Presumably, if they didn't have the power problem as well, they'd keep the mission going on S-band.

Lots of good info at
http://ulysses-ops.jpl.esa.int/ulsfct/spac...ft/scframe.html

No, but since I'm kinda busy building instruments for MSL, I assumed you might take the time to look at them yourself.

Rather than debate this, though, I suggest you read pages Sci-153 through Sci-158 in the in the FY09 budget. On page Sci-156, we see that the current total development cost estimate for MSL is $1.035B, increased by $66.4M from the base year (2007) estimate. The total cost of $1.66B shown on Sci-153 includes formulation and operations costs. One would have to look at previous year budgets to assess how much this has increased, but I find it hard to believe that the mission ever cost the claimed $800M in an apples-to-apples comparison; budgets are all online at http://www.nasa.gov/news/budget/index.html

How about the annual NASA budgets from the beginning of the MSL project to now? It's a matter of public record how much has been spent to date.