You can add dyes during the anodizing process and get most any color you like, but as I said before, I think it's more likely that the booster is chromate-conversion coated, because that would leave you with a natural golden-coppery color. But I couldn't find any confirmation in the Atlas documents I looked at. I can say for sure they didn't make the stage out of any AlBe or AlLi alloy, though.

Right. I believe this is the chromate conversion coating (aka "alodine" or "chem-film") on the aluminum structure of the first stage. The white on the Centaur is from the cryogenic insulation.

It's not usually a good idea to rely on press release info for hard numbers. For velocities one always has to ask "relative to what?" MRO should be moving at something like Mars' escape velocity near MOI relative to Mars. That's about 5 km/sec. MOI delta-V is about 1 km/sec. The capture orbit is 300 km x 45000 km with a period of about 35 hours. MOI is not an instantaneous impulse, but if you figured out the periapsis speed of the capture orbit and added 1 km/sec you should get roughly the velocity at MOI. I leave the math as an exercise for the student

You'll also note that all the images of MSL on the website appear to have the power source "airbrushed out". As far as I can tell, this is NASA PIO's way of dealing with anti-nuke sentiment.

I haven't seen any indication that the MMRTG is not the power source. Solar would require a complete redesign of the system, if it was viable at all (certainly the MER experience is that you can go for a long time on solar, but I don't think one can count on random wind cleaning events for mission success.)

Yes, I think that's right. From the Delta 2 Payload Planner's Guide:

"1.4 LAUNCH VEHICLE INSIGNIA Delta II users may request a mission-specific insignia to be placed on their launch vehicles. The user is invited to submit the proposed design to the Delta Program Office no later than 9 months prior to launch for review and approval. The maximum size of the insignia is 2.4 by 2.4 m (8 by 8 ft). Following approval, the Delta Program Office will have the flight insignia prepared and placed on the uprange side of the launch vehicle. "

I expect that Lockheed-Martin does the same.

George R.R. Martin, "FTA", Analog, 1974.

If you had some analysis to support this (using phase angles of the illumination, optical depth, scattering properties of the droplets, and factoring in dust loading) then the idea might be plausible. As it is, it's just based on your intuition, isn't it? Direct observation of H20 absorption bands of these areas with TES has shown no unusually high column density.

You're reversing my point about Antarctica -- I am simply skeptical that even 10x more water than on Mars, what is seen in the Dry Valleys, would be a useful resource for exploration.

As for fog-covered sites -- you are looking at a picture and simply assuming that there must be a lot of water vapor in it. If you read the link I cited above, you will see that fogs can be formed by nucleation on dust particles at very low column densities -- under 1 micron.

All that said, I concede that there is water on Mars, maybe even transient liquid water/brine at some times and seasons and certainly frost. I don't think anyone finds that controversial. But there isn't enough in the atmosphere to be practical as an exploration resource, and I don't think it implies anything especially favorable about the possibility of extent martian life.

It would help, of course, if there was a non-negligible amount of water vapor in the atmosphere.
Typical water vapor column densities in Antarctica are around 600 precipitable microns, 6X the maximum value observed on Mars and something like 40X more than the typical martian values. Column densities in martian ground fogs are even smaller -- see http://www.aas.org/publications/baas/v34n3/dps2002/158.htm

It'd be interesting to know if using a solar still in Antarctica would be worth the effort.

I don't disagree, but...

Optical has the same problem, if you're counting as "wasted" any power that doesn't fall on the receiver's mirror. They're both EM radiation, after all. I'm not sure what the actual efficiency tradeoffs look like, but optical isn't such a slam dunk over RF from a system perspective, because the real engineering-acheivable efficiency gains aren't just the ratio of the wavelengths.

And there's cloudy days, what you do near conjunction, etc.

http://lasers.jpl.nasa.gov/PAGES/about.html has some good background, but obviously optical researchers aren't going to present a completely balanced story.

If you wanted to reduce operations costs for deep-space RF, there would be ways to reduce costs below those of DSN. Some Discovery teams have proposed using USN ( http://www.uspacenetwork.com/index.html ) instead of DSN to save costs.

Do you have hard numbers on how much over budget they are, and what the budget of the Office of Space Science is to support overruns? I wouldn't be eager to see other science programs be raided to fund Dawn overruns, but that's what would likely happen.

I don't have any inside knowledge, but I don't think that a mission that was solid and under control would be told to stand down. Based on the available information, Dawn has had some serious developmental problems, and fairly or not there is some skepticism outside the project that the spacecraft is going to work. NASA is supposed to release the results of an independent evaluation at the end of this month, and I hope we see then what the issues are.

From http://www1.jsc.nasa.gov/jscfeatures/articles/000000415.html

"Atlantis was named after the primary research vessel for the Woods Hole Oceanographic Institute in Massachusetts from 1930 to 1966. The two-masted, 460-ton ketch was the first U.S. vessel to be used for oceanographic research."

I have heard, though I can't prove this, that one of the people on the naming committee was associated with WHOI and got this name selected. I think it's fair to say that it doesn't have as much historical significance as a lot of others they could have picked.

I'm not so sure they did retain the post-landing DTE capability on PHX except for EDL tones. The latest renderings of the lander on the PHX web site don't show a steerable DTE antenna, though earlier ones did. I really haven't kept track of how this ended up.

I believe that for PHX relay MRO is the prime and Odyssey is the backup. It might be possible to send data through MGS in a pinch, but as with MER, they prefer not to do that since it's lower rate and incurs some loss because of the way the MGS relay works (it doesn't have handshaking like the later designs.)

MOC images Mars Odyssey:

http://www.msss.com/mars_images/moc/2005/05/19/

Outcrops in East Candor:

http://www.msss.com/mars_images/moc/2005/05/30/

MOC's 200,000th image:

http://www.msss.com/mars_images/moc/2005/06/03/

MGS/MOC keeps cranking out images; I guess one of our favorites from 2005 is the cPROTO mosaic of Chasma Boreale:

http://www.msss.com/mars_images/moc/2005/0...eale/index.html

A couple of points:

MRO's mapping orbit isn't at 150 km -- it's between about 250 km and 320 km. Early in mission planning a lower periapse was considered, but this wasn't chosen.

Both MGS and I believe Odyssey routinely went below 150 km during aerobraking.

Technically, what they are using is what we call "pushframe" imaging -- they have an area sensor with regions of different colors, and they take an image roughly every band height's advance over the surface. Pushbroom imaging uses a single line array; this is what is used by MOC and MEx.

I won't claim to have been the first person to have ever thought of this, but I independently developed it for an unselected Discovery proposal in 1994, and we first used it in a flight instrument for the MARCI on MCO. THEMIS is the first time it was used in Mars orbit, and the MRO MARCI also uses it, as will the Wide Angle Camera on LRO.

Typical ESA press release.

I suspect the best reason is that designing such a disk is a political/PR hot potato and adds nothing to the actual mission of the spacecraft, whatever its other value might be. One only has to look at the Cassini fiasco to understand why avoiding such a project would be the natural inclination of mission planners.

Also, the amount and size of ballast is hard to predict in advance, by definition.

The crater was clearly too large to have been created by the Beagle impact, as noted on the MSSS page. I think we would have been open to the possibility that Beagle was inside a pre-existing crater, had the image supported that interpretation. There are many craters in the search area that have dark sand in them; it's not at all unusual.

This is, of course, not an official MSSS statement, but I don't think anyone here would argue with it.

Well put. It also seems to me that many of the "features" are aligned with the downtrack direction of the image and are thus likely to be residual pixel-to-pixel variations.

People can believe what they want, but I think there is an element of wishful thinking in the Beagle team's claim. MSSS took these images in 2004 and examined them closely. The MSSS position is made pretty clear on the page at http://www.msss.com/mars_images/moc/2004/08/31/ -- "no incontrovertible evidence of the Beagle 2 lander was found within the areas imaged by MOC". To make claims that the Beagle landing system was without flaws and failed only due to highly-improbable terrain factors would, it seems to me, require evidence far less equivocal than this.

It seems a bit odd that it took them over a year to "painstakingly study" this image and come to their conclusion.

I believe that Viking had pretty good margins against density variations. The best way to get margin is to have more propellant available. Much of the "difficulty" of landing on Mars comes from using a landing system like MPF/MER, which has very, very thin margins because the RAD firings happen so late in the descent and don't provide all that much delta-v. To a certain extent, the MPL/PHX system is tight because of propellant mass constraints, but I don't think those margins are nearly as tight as MER's.

Is there some publically-accessible writeup about the "near-disaster" on MER? I've only heard these rumors.

Cool stuff, but
it's important to note that they are *detecting* the signal, not extracting the data from it. I doubt if they have anything close to the SNR to do that, since otherwise the DSN wouldn't need a big antenna to do so.

And transmitting is a lot harder; it requires a big antenna *and* a lot of transmit power.

Typical thermal blankets (also known as Multi-Layer Insulation or MLI) are many layers of metal-coated kapton film separated by nylon mesh or an embossed pattern to minimize thermal conduction through the blanket. Analysis depends on the "e*" or effective emissivity (how much heat from beneath the blanket radiated to space.) The absorptivity of the blanket matters a little, but it's not really that critical how hot the blanket itself gets since its heat doesn't effectively radiate or conduct in (as long as the blanket doesn't melt or something). You typically see either second-surface aluminum (the orangish-gold stuff) or carbon-filled "black Kapton" (like on Galileo); NH was the first time I even knew about the Au blankets.

You typically use blankets when you have heat dissipation you want to trap, or when you have a non-dissipator you want to isolate from the external environment. You usually don't completely blanket a dissipator like electronics, because even out at Pluto you don't want the electronics to cook themselves. So there are probably several radiators on NH as well. Thermal design is something of an art.

And when we say "radiation" in this context we only mean visible and infrared EM radiation, not X-rays, charged particles, etc. MLI contributes negligible shielding to those.

It looks to me like it uses gold. What is usually called "gold Kapton" (at least all the places I've worked) is really second-surface aluminum and is orangish-gold because the aluminum is below the orange-tinted Kapton. But the first-surface gold would be more yellowish-golden in color and has a lower emissivity, so it would probably be preferred. All the KSC photos of NH shows it as yellowish-golden. For NH, they are probably trying hard to keep internal heat from radiating to space.

If you had followed the link, you'd have found aluminum/kapton products which are often used (for example, on MRO) but which don't have any gold, and a gold/kapton product that I hadn't known about before but which does contain gold, so I'm agreeing with you, only noting that most blankets I've seen, while called "gold", don't really have any gold. OK? I was wondering about the color of NH (the aluminum/kapton blankets are more orange) and you cleared that up, so thanks!