It's clearly intended for that, but obviously the programmatic/budgetary considerations involved are above the pay grade of anyone here.

Removing full inline quoting isn't though - ADMIN

If you read the tech reports so far, that's how it's being sold, since the payload design is decoupled from the descent stage design.

I'm neutral on the skycrane concept at the moment; I haven't seen definitive trade studies and some of the literature seems more like marketing than engineering to me. But we'll see.

That's not clear; the original rover design when they were still talking about pallets could have been quite different.

Maybe, maybe not. The propellant is at least a known mass quality given the mass of the descent stage, while the ramps could be pretty involved depending on the design constraints (rock size distribution, allowable tilt, etc.)

I haven't found a definitive trade study analysis of the skycrane, but http://trs-new.jpl.nasa.gov/dspace/handle/2014/40017 is a start.

The primary advantages are not having the mass of the airbags, which doesn't scale with landed mass, and not having the mass of any roll-off/airbag support structure (what was called the "lander" for MER.) As noted, MSL still has a parachute.

The simplification of the pendulum is a non-issue, and I would argue that MSL is no better, and maybe worse, for contamination potential compared with a "rover-enclosed" design like MER.

The main reason for not using airbags is that you can't have a rover with mass higher than MER with airbags, at least not without paying a huge mass penalty.

http://web.archive.org/web/20010415134940/....nasa.gov/home/ has a few, but I haven't browsed extensively; many links are dead.

http://cloud.ucsd.edu/dscovr.html has some renderings but no photos I could find.

Again, not to be a wet blanket, but Weiler and the leaders of CNES made a similar agreement in 2002. Talk is cheap, funding reality something else.

Not to rain on anyone's parade, but this is about the fifth such solicitation in the past 15 years. They result in some viewgraphs but nothing much else.

Changing planes is expensive in delta-v and unlikely to be done unless needed to cover the MSL EDL.

Having three rovers to service given the relatively low UHF rates that MER can use shouldn't really be very stressing if MRO is the relay. The return from two MERs is lost in the noise of what we expect to get from MSL. If Odyssey were the relay, it would be more constrained, and you might see the MERs using more DTE than they do now, depending on their condition in this scenario.

Certainly. A typical UHF pass is only 5-10 minutes long (satellite rise to set), whereas a DTE pass in theory could be for as long as the Earth was in view, less DSN station handoff. MER DTE passes are as short as they are for power and thermal reasons. DTE is much less efficient than relay on an energy/bit basis, and that's probably the big disadvantage of DTE.

True. Assuming it scales like MER does, DTE will only (!) be about 10-15x slower than relay (as far as I can tell, MER DTE rates are around 20Kbps maximum, while the Odyssey UHF is being run at 256K.)

It should be noted that MRO had a failure in its telecom system in 2006 which rendered its X-band downlink single-string, so it is one amplifier away from losing the high-gain X-band downlink, and the Ka-band downlink is also suspect though it might be a usable backup. See "In-Flight Anomalies and Lessons Learned from the. Mars. Reconnaissance Orbiter Mission", Todd. J. Bayer, 2008 IEEE Aerospace Conference.

Of course, there's no explicit lifetime for electronics, so MRO could keep going for many years anyway.

There's a big difference between a one-off, short term activity and ongoing operations for years. I'm not sure what kind of capability MEx would even have for that given its elliptical orbit.

Need or not, there's no money for such a thing.

I guess if Odyssey and MRO (and MEx?, not sure about the politics there) have failed by the time MSL lands, then MSL will be DTE-only.

Would they launch MSL if all the orbital assets were failed at the time of launch? I have no idea.

Thanks for pointing that out, Doug. It's gotten to the point that there are some sites (I think you know which one I mean speciifically) that I can't look at any more because of an overfocus on the Decadal Survey cost, which has almost nothing to do with the mission that NASA HQ ultimately selected for funding.

Give me credit for knowing a little more about my instruments than Griffin.

In general, cruise T/V doesn't involve the surface payload.

To an extent, obviously, but at least I won't be sitting in our clean room doing calibration on Christmas as previously planned.

At this late date (launch is about 2.5 years from now), I'd say the chances of adding another payload element to Juno are effectively zero.

Note that I neglected the ultraviolet imaging spectrometer in my earlier post. I don't know what the resolutions of either JIRAM or UVS are, but there is public information available if someone wants to make the effort.

I believe imaging is only possible if the target happens to pass through the spin plane +/- half the FOV of the instrument involved. JIRAM has a 1-DOF scan mirror, I think, I don't know how UVS works, and Junocam is mostly insensitive to spin rate owing to our ingenuity in designing it

The field of view has no direct relationship to "sufficient light", this is a function of f/number and exposure time. See the thread http://www.unmannedspaceflight.com/index.php?showtopic=2890 for some insight into how Junocam works.
It's required to have the wide field of view to meet the requirements on Jupiter polar imaging, and as I noted before, it has no requirements to image the satellites at all.

Alas, Juno is not that mission, and I don't think any money is available for enhanced imaging. The Italian IR imaging spectrometer (JIRAM) is the only other imaging system on Juno. http://adsabs.harvard.edu/abs/2007AGUFM.P51A0208A

I'm not sure if anyone knows how conservative the radiation models are, but the lifetime issues are driven by radiation dose.

Photon transfer is a technique to compute the gain and noise of a camera system from multiple images at different signal levels, originally developed by Jim Janesick when he was at JPL.

http://www.couriertronics.com/docs/notes/c...tion_Method.pdf

The spacecraft is spinning all the time, and Junocam points at the planet once per revolution, so this is not as unlikely as you might think.

Comparing Junocam to NH is apples and oranges. Note that LORRI did its imaging from something like 3 million km away and got about 15 km/pix, where Juno will be about 5000 km from the planet at closest approach, where we will get about 4 km/pixel. LORRI is about 150x higher-resolution at a given distance than Junocam, but Juno gets a lot closer to Jupiter than NH did.

As noted before, I don't know what the geometry will be like (we can't be sure until after launch, really), but Junocam is not capable of seeing the satellites with good resolution unless it's quite close to them. At a typical distance of say 500,000 km, Junocam resolution is about 400 km/pix, and Io will be about 9 pixels across.

"Pretty crude"? I'm insulted. Despite the spacecraft spin. the Junocam images should be extremely good; comparable to or better than the best Galileo images of Jupiter. That said, we'd have to get pretty close to one of the satellites to get good images, because Junocam has a wide field of view.

As for asteroid flybys: I can't speak for the rest of the payload but for any plausible flyby distance, asteroids would be barely resolved from points by Junocam.

I think it's around 4 km/pixel. The 15 km/pix is for the polar case when perijove is near the equator.

Junocam already has to work with the spacecraft spin. Orbital motion is only a small fraction of that, so perijove imaging would work fine.