With all due respect to my colleagues at USGS, I think this product will take them several more years to produce. I think one should expect a product from ASU before that.

Of course, the IR resolution is "only" 100 meters/pixel. THEMIS will probably not obtain global coverage at VIS resolution (18 m/pxl), or even 2x summed VIS (36 m/pxl.)

The next thing to hope for will be a CTX global mosaic at ~12 m/pxl.

Interesting, but I don't think AW&ST's track record on this sort of thing is too good. For every success (they broke the story of the F-117, IIRC) there are two or three questionable bits of uncorroborated science fiction. I'm remembering a story they did in the early '90s on a saucer-shaped military aircraft that was powered by the Earth's magnetic field, or some similar bit of fringe science. And of course there's the "donuts on a rope" pulse-detonation engine sightings, "Darkstar November", etc.

Not for nothing is it called "Aviation Leak and Space Mythology."

DI has only about 340 m/s of delta-v left. I think it would need many km/sec to get to the main belt, even with an Earth gravity assist. I'd be happy to be proved wrong, though.

Deep Impact's aphelion is at about the orbit of Mars, so it's got no chance of getting to the main belt. Stardust's is at 2.7 AU and Ceres' orbit is from 2.55 to 2.99 AU, so it's a much better prospect; of course, the orbits are unlikely to be in phase to allow a close approach, and Stardust only has ~140 m/sec of delta-v left.

http://discovery.larc.nasa.gov/discovery/dpl.html has some information on these spacecraft.

I know Alex understands this, but let's be clear. NuSTAR was given additional phase A funding in 2005 with the understanding that a flight decision would be made in early 2006. That decision was made on schedule, in the negative. To say, therefore, that NuSTAR was "cancelled" is wildly inaccurate. Now, it would be interesting to know what the basis for that decision was: developmental risk, change in science emphasis, NASA-wide budget problems, or something else. But no one on NuSTAR should have had any expectation that they were flying for sure if they were just in Phase A.

Also, the politics of the mission can't be helping. Most of the payload is European, so there's no constituency there. And Orbital's lobbying position has always been unclear to me; they seem to spend more effort on bigger-ticket defense-related items. If JPL is making a big stink about the cancellation of Dawn, I haven't heard anything about it yet; it's probably small potatoes compared to MSL or even Juno.

The cases may not be equivalent. The Mars Surveyor '01 lander didn't fly largely due to timidity and lack of confidence on the part of NASA HQ; no one involved in the project thought it was terribly risky (although Squyres' book makes it clear how much of the science had already been descoped, and that couldn't have helped its case -- PHX has a significantly different science payload.) And the Pluto mission was just a question of money.

While without detailed documentation it's hard to be sure, the Dawn situation seems to be that the spacecraft contractor just screwed up, and the hardware is badly flawed and in need of substantial additional funding to repair. And NASA is being asked to give that money to the same company that failed to deliver on earlier promises. One might almost argue that they should do that more often, not less.

Of course, it's not helping NASA's case that no such documentation has been publically released. I'd like to see more disclosure on that.

I think you must not have dealt with NASA HQ much; it's not that small a community and the word of mouth between inside the Beltway and everywhere else is much thinner than you might think. And I'm not sure what "press release" you're talking about -- I haven't seen any confirmation about the Dawn cancellation, just the NASA Watch item -- and Cowing clearly has an axe to grind concerning Mary Cleave, which may or may not be justified but as usual makes him sound peevish at best.

In all fairness, is NASA HQ supposed to keep track of this sort of thing? How would they reasonably have known?



I'm not sure if publishing this was hubris, chutzpah, or just utter cluelessness on his part.

I hope Phoenix lands in the daytime; I could quit working on MARDI/PHX if it doesn't.

We tried imaging the entries of both MERs using the MOC WA, and didn't see anything definitive.

I'm skeptical about that. The relative sizes of Mars and the Earth from martian orbit make an Apollo-style Earthrise picture impossible. And the martian limb is pretty diffuse. With the degree of magnfication required to resolve the Earth, the limb would be huge and probably featureless. I tried to take a "Phobos rising over the limb" image with MOC (see http://www.msss.com/mars_images/moc/2003/06/23/ ) but test images of the limb with the NA were so bad that I quit trying to get the limb and Phobos in the same NA swath (which was hard anyway due to timing and data volume constraints.)

The altitude at MOI has little to do with either the aerobraking altitude or the final mapping orbit altitude. These altitudes are:

400 km at MOI (press kit, page 27)
~100 km during aeropass (press kit, page 30)
320 km x 255 km in final mapping (press kit, page 28)

What's so confusing?

You're quoting the altitude during aerobraking, not the altitude at MOI, which is much higher.

I think there's some confusion. The aimpoint altitude at MOI is 400 km, not anything lower. After MCO, they're unlikely to try anything much lower.

"The three cameras from the science payload -- the High Resolution Imaging Science Experiment, the Context
Camera, and the Mars Color Imager -- will take their first test images of Mars as the orbiter passes low over the southern hemisphere near the end of the third orbit, on March 14."

Now that the press kit has let this out of the bag, I'll note that the timing and location moved by ~2 hours and ~30 degrees of longitude between the mid-January predict and the most recent one -- so the imaged areas will be in the southern hemisphere, but we probably won't know exactly where until after MOI.

I don't know yet when we can expect to have the image data back.

I don't take issue at all with the crux of your argument in this thread; I agree with some parts of it and not with others. What I object to is that you rarely acknowledge that anyone else's insight has any validity or adds anything to the discourse. You're pretty well convinced you're right about most things, and for you that's usually the end of it.

Of course, the rest of us might learn to just read your messages without responding, because your initial messages are usually worthwhile at least at some level, the subsequent responses unfortunately less so. I try to follow that strategy as much as I can, but sometimes, like now, I can't help myself.

I think GMT can do this, but be warned that the learning curve is very steep.

http://www.soest.hawaii.edu/gmt/

No doubt this explains why the Russians have never lost people on Soyuz flights. (Well, no: four people dead in two entry accidents. Would you argue that the US would never have accidents like those? We came fairly close to losing the US crew of Apollo-Soyuz to an accident similar to Soyuz 11.)

Forgive my lack of confidence in your ability to flawlessly predict these alternate-history outcomes. And I'm not sure what this CEV-type vehicle would have been doing; certainly neither DOD nor NASA had any interest in such a thing in the time frame we're discussing. For that matter, I'm not sure what the current CEV is supposed to be doing either

Regardless of the merits of Truax's technical points, the first rule of aerospace is that paper studies like his Sea Dragon are worthless by themselves. Until you have actually built, tested, and flown a system multiple times, you are only extrapolating based on incomplete data how it will perform, how well, and how cost-effectively. Talk is cheap, and aerospace is riddled with large and embarrassing failures based on ideas that seemed great on paper.

There's no shortage of people who trash the Shuttle with 20-20 hindsight, but the engineers who designed and built it did the best job they could under the technical and budgetary constraints at the time, and it's quite an achievement in that light. Within the limits of statistical error, its failure rate matches pretty well with the original honest assessment of 1 in 100 flights. If you want higher reliability than that, you'd better be prepared to pay for it, in money or capability or something.

See the Global Spacecraft ID document: http://public.ccsds.org/publications/archive/320x0b1s.pdf

Of course, these are only 8 or 10 bits long.

But has been already pointed out, just relying on an ID field to reject commands would be foolish in the presence of bit errors. If you were designing a mission-critical system based on Ethernet (which probably wouldn't be a good idea anyway because of single point failures in the shared transmission medium) you would hopefully not rely on MAC uniqueness to keep the wrong receiver from doing something. It might be unlikely for a burst of errors to corrupt one MAC address into another in such a way to get past CRC checking, but it's not "fail-safe". Even with your home LAN, there are acknowledgement protocols in TCP/IP to keep such problems from happening.

Underexposure isn't much of an issue; at some point in overexposure you start to get "blooming" where excess charge from a photosite starts to leak to adjacent pixels.

The largest problem is that to make this work you'd have to use more bits per pixel, and I suspect that the current number (12 bits for raw images, 8 bits for square-root-encoded) is deeply wired into the software.

Of course, nothing's stopping them from commanding separate images at different exposures and merging them on the ground. I haven't heard of that being done, but it would be fairly straightforward if one was willing to accept the penalty of downlinking the extra data.

We have no plans to build this into the image acquisition process for MSL -- we've got our hands full there as it is.

The first few were named before anything like the current IAU regime, but weren't the Saturnian satellites Epimetheus and Pan named after the Voyager flybys? So that's clear modern precedent for recycling of asteroid names. Eat that, IAU Commission 20!

The basemap used for the mosaic (a hand mosaic of global map swaths) wasn't useful south of 60S. While the actual Geodesy Campaign data goes down to 65S (it was taken during southern winter so areas south of there were in darkness), the basemap control rendered the area between 60S and 65S too dark to use. And the south polar coverage we took later started at 65S.

This could all be reprocessed and fixed, and it's on my list of things to do, but not very close to the top.
The gap was fixed for the "Mars Atlas" but that was only produced at 64 pix/deg -- see http://www.msss.com/mars_images/moc/moc_atlas/

There's at least one overlaps between moons and asteroids: for example, 593 Titania and the moon of Uranus. Are these grandfathered or something?

Cerberus and Orthrus?

The five rivers of the underworld are mentioned in the Aeneid: Acheron, Phlegethon, Styx, Cocytus, and Lethe. Styx and Acheron are traditionally associated with Charon. That leaves you with three more names in case new moons are discovered.