It's worth noting that http://www.r00t.cz/Sats/Grail was able to decode the Grail signal all the way to the actual strings in a spacecraft directory listing, which is quite impressive. I think commanding ISEE-3 is likely out of reach, but decoding the telemetry might at least be possible for these folks.

"Better is the enemy of good enough."

Go back and read the 2020 AO PIP and observe all the stuff about Technological Readiness Levels.
http://soma.larc.nasa.gov/mars2020/programlibrary.html

Every rover system is going to be a build-to-print copy of MSL unless there is a really good reason to change.

Most of the suggestions Doug was reacting to were for changes to hardware, not operations.

I don't know how you're going to change the planning cycle very much, as it's dependent on the relative diurnal cycles of Earth and Mars and how much time it takes to do planning.

Also, the mission is highly cost-constrained and any change that costs money is probably DOA.

I thought I had posted a link to this a long time ago. Here's a public page from 2012, though I don't know where the ground image came from. http://dot-color.com/tag/msl/

Hot pixels like this one are worse at higher temperature and longer exposure time. It shouldn't really be changing for equal values of those two parameters. I haven't noticed any systematic changes and I haven't heard any reports of them, but I'm not sure how carefully people are looking.

Detecting a signal is a good deal easier than decoding it, much less generating an uplink, of course.

Thermal expansion/contraction can break solder joints, internal bond wires, etc.
Some components (e.g., electrolytic capacitors, batteries) have goop that can freeze.

In general it's not that hard to build something that can survive Mars surface temps, but it gets colder and hotter on the Moon, so more stress.

Maybe all those ham radio operators who are complaining about the ISEE-3 situation should try listening for downlink from Yutu instead.

Given all the negative comments this is producing on the web, whoever is writing this stuff would be well-served to give more technical detail. I found http://ipnpr.jpl.nasa.gov/progress_report/42-76/76K.PDF which indicates that ICEE-3 was never designed to use the DSN for communications and a special filter had to be added to the Block V masers at DSS-14 and DSS-63 in the mid-80s to communicate with it. According to http://deepspace.jpl.nasa.gov/dsndocs/810-005/101/101E.pdf the maser was replaced at DSS-14 (Goldstone) in 2010 but the one at DSS-63 (Madrid) isn't going to be until this November, but S-band uplink isn't supported at Madrid because of frequency conflicts.

Is this the first Earth image?
http://mars.jpl.nasa.gov/msl-raw-images/ms...0000E1_DXXX.jpg

https://xkcd.com/1319/

See page 16 of http://books.google.com/books?isbn=1402016964

This is complicated by the eccentricity of Mars' orbit and the higher-order terms of the planet's gravity field (since sun-sync orbits are driven by the orbital precession caused by the planet's oblateness.) And other factors like atmospheric drag, radiation pressure, etc.

And because of regular adjustment it's not a big deal. There is a huge body of literature going back to Mars Observer discussing these orbit designs; try the JPL tech report server if you want to be inundated in this stuff: e.g., http://trs-new.jpl.nasa.gov/dspace/bitstre...7/1/03-0272.pdf for MRO.

It would be fairly easy to compute the position and orientation of MAHLI. In theory I think there's enough information in the SPICE kernels (if you look at the five joint frames) to back out the 5 joint angles that define the arm pose. But the data products that the team gets just have these angles in them directly (you can see this, I think, in the PDS products), so I don't immediately know how to do it.

As an exercise someone should figure out how to move the LEGO model's arm based on those five angles.

If you read the NSF thread I linked to above, you'll find that the general rule of thumb is that the fairing diameter should be no more than 1.5x the diameter of the core stage. ULA advertises custom fairings up to 7.2 meters for Atlas V, but I'm not sure anyone has taken them up on this. Obviously larger fairings or asymmetrical fairings are possible up to the size allowed by the pad infrastructure, if cost is no object.

In the real world of robotic mission design, any proposal that doesn't use a standard fairing available from the LV vendor with flight heritage is likely to be DOA.

A kilogram is a measure of mass, not weight (I misspoke in my post; the turret mass is 34 kg). The arm has the same mass on Mars that it does on Earth. You say this yourself but I'm not certain what your point is.

That said, the resulting pressure on the wheel surface would be lower on Mars.

Of course, something is making holes in the wheels; it's either pressure (depends on weight); impact forces (depends more on mass); or some dynamic combination.

NSF is probably a better resource for this type of question:

http://forum.nasaspaceflight.com/index.php?topic=29319.0

Not doubting Doug at all, but just to put some numbers on that: according to http://www.esmats.eu/esmatspapers/pastpape...ling.pdf‎ the arm mass without the turret is 67 kg, and the turret weighs 34 kg. So it is quite heavy, and I could imagine that it does load up some of the wheels pretty significantly in some poses.

I'm not certain if the high-time-res rover orientation data makes it into the SPICE kernels, but if it does, it might be interesting to visualize how much movement the rover actually undergoes when it's nominally stationary.

I think this is an interesting speculation, but given that the whole vehicle was hung from the descent stage with the arm stowed like this, I'd suspect it was fairly well-balanced and not much heavier on one side than the other. But I don't know for sure.

BTW, I put together the LEGO model of the rover yesterday. I can't say enough good things about it as a visualization tool for both the suspension and the arm. Highly recommended! http://shop.lego.com/en-US/NASA-Mars-Scien...ity-Rover-21104

AFAIK, this is just a concept for a mission. NASA doesn't usually fly missions that aren't formally proposed to a program like Discovery, so unless an AO is released and this mission is selected, this is just an idea.

http://www.lcpm10.caltech.edu/pdf/session-...-10%20FINAL.pdf

Probably, but I don't remember the details. Most of it was probably under the blankets.

The official NASA model of MCO, which we have one of, has essentially no details on the nadir deck.

My last look at MCO was at Pad 17A, lying on my stomach looking through a little hatch in the side of the fairing with a gale of air conditioning blowing in my face. But it was dark in there, and it's been a long time.

Depends on what you mean by testbed. The VSTB (which Doug has posted pictures of) is a flight-like rover and probably has a mass similar to that of the flight system (I don't know if it has ballast for the RTG or not.) The "scarecrow" is 1/3rd mass but I don't know what the state of its wheels are/were.

Of course some of the dynamics depend on mass, not weight, so there's no way to perfectly mimic the behavior on Mars on Earth.

Instrument proposals for 2020 were due a half hour ago. Now to see what gets selected. We put in some interesting proposals, about which I can say nothing more.

The selections are supposed to be announced in April.

Not exactly. The main goal of the self-portrait positioning was to keep the camera nodal point remained fixed in space, so no parallax effects would confuse mosaic generation. Not having the arm appear was a secondary goal, and given the number of times we've had to explain it, I sort of wish we had taken a version where you could see the arm.

I used to try to visualize it this way, but really MSL is much more constrained than your arm, since the center 3 of the 5 degrees of freedom are all constrained to be in a plane.

Hopefully the Lego model is correctly articulated; mine hasn't shown up yet. [Based on the box art it looks exactly right.]