Remember, though, that we may be talking about really, really tiny microbes, here -- there are terrestrial analogues of very tiny cellular life (which also happen to be extremophiles). And if the formations in that AHL meteor really are fossilized bacteria, and if they represent an average size population, we could be talking truly tiny microbes, indeed.

At those sizes, you are dealing with such little fluid compared to the overall biomass that you don't need a huge amount of liquid H2O2 to sustain a subsoil biosphere.

I'd be interested in seeing a chemical analysis of the types of recognizable (or even semi-recognizable) biochemical functions that can be supported by H2O2 before I made a final judgment. And I'd want to know if you would need as much carbon to support such functions as is required by terrestrial biochemistry.

The real issue in re fossilized Martian life, of course, is that the AHL formations occur within carbonate clasts of the rock. We've had precious little luck identifying *any* carbonates on the surface of Mars, from orbit or from the surface. I get the feeling that Mars has lost or hidden most of the carbonates it once had, and thus most of its fossil record (if one exists at all) is either gone or inaccessible.

-the other Doug

I still think a small compressor, a thin-walled tank (since it doesn't have to hold that much pressure) and a series of lightweight tubes arrayed at crucial spots around the solar panels makes the most sense. A couple of kg mass investment lets you create your own cleaning events.

You could even re-use a tank used during coast for other purposes. All you need is a vessel that can be pumped up to three to four times the ambient atmospheric pressure and then released through the blower pipes. You can use a very small, very light pump, since you won't have to clean your panels but every few hundred sols, so you don't need to spend an awful lot of time or power at any one given time pumping it up.

I still believe such a system could be designed and implemented that only weighs a kg or two, and considering how much of an impact such a system could have on a solar-powered vehicle, it would be well worth the investment.

-the other Doug

Are the red dots spurious noise in the data, or do they actually indicate some radical difference in surface composition? And if so, what does red really indicate in this context?

I have to say, from the looks of it, they look like noise to me. But I'd enjoy knowing, one way or the other.

-the other Doug

My favorite Willy Ley story comes from Isaac Asimov's autobiography, in which Asimov tells of an early science fiction convention attended by, among others, Willy Ley. Willy was in fine form, apparently, entrancing the ladies with his charming, thick German accent and his boundless energy when it came to putting words to his visions of space exploration. He was so impressive to the ladies, apparently, that on Sunday morning, the running joke around the convention was that if you posed Willy's name as a question -- "Willy Ley?" -- the answer was an obvious and resounding "yes."

-the other Doug

In the sixties, I watched the countdowns for the Mercury and Gemini flights, enraptured. I also enjoyed the coverage of the flights themselves, but until we got to Apollo, there wasn't all that much to see while the flights were in progress -- just animations and artists' renderings. And even the entry and splashdown phases weren't all that visually interesting at first -- it took until the middle of the Gemini program before there was live TV coverage from the recovery vessels. I can still recall that the very first live, on-the-scene images from a Gemini recovery was for Gemini V, and it wasn't TV coverage. The press had set up a photofax link by which photographs were taken, quickly developed and printed, and then scanned and transmitted back to the shore. The very first close-to-live images of astronauts on the carrier deck were still pictures of bewhiskered Cooper and Conrad.

Of course, Apollo ushered in the era of live television from American spacecraft in flight, and that changed a lot of things. The very first TV shows from Apollo 7 held me in complete thrall, especially when they pointed the camera out the window. Then, of course, came Apollo 8, and the wonder of live (if crude) TV images from the Moon. It excited my sense of wonder like nothing else ever had.

But the countdowns... those were the best. When the flights weren't scrubbed, anyway. I remember a lot of scrubs, in specific the various scrubs of Gemini VI (once after I had enjoyed the Atlas launch of the Agena that never made it into orbit, another after the shutdown on the pad), and the multiple scrubs of Gemini IX and IX-A. I can recall very, very clearly that I spent a hot and muggy June day at an aunt's house because I was visiting with my grandmother, who had no TV set, and I *needed* to see the Gemini IX launch. So I agitated to go to my aunt's house, where there was a TV (but where there was also an aunt I didn't particularly care for) so I could watch the launch. I saw the Atlas launch, but then the Agena failed on its way into orbit and the Gemini launch was scrubbed. I felt so cheated that day... *sigh*...

The perils of Tom Stafford notwithstanding, however (he who ended up involved in more Gemini scrubs and Atlas/Agena failures than any other pilot in the program), Gemini was the best for a countdown lover. I got two countdowns and two launches (first of the Agena, second of the Gemini) when things went right. And they did go right on four of the flights; for Geminis VIII, X, XI and XII I was treated with dual-launch spectaculars, and I truly enjoyed them.

I don't want to get into the Apollo 1 fire in any great detail, except to say that if it had not happened and had Apollo 1 flown as scheduled, the next mission (which might not have flown for more than a year afterwards) would have been another spectacular dual-launch, with LM-3 being launched by one Saturn IB and CSM 101 (the first of the Block II CSMs) being launched by another, roughly 90 minutes apart. With the exception of the dual IB launch, this would have been pretty much the exact mission eventually flown as Apollo 9. And while I enjoyed every single Saturn V launch I ever watched (none in person, drat the luck), I would have enjoyed seeing such a dual-launch spectacular in Apollo.

Don't get me wrong, I enjoy unmanned spacecraft launches, too -- I've especially enjoyed the Delta II launches which feature the live camera feed from the nose fairing. But those halcyon Gemini days still bring up fond memories.

-the other Doug

Yes, indeed, Cernan holds the record for a human being spending time in cislunar and lunar space. I don't have the figure handy, but Apollo 17 was the only J mission that spent the extra two days in lunar orbit after ascent/docking (thought it was planned for both 16 and 17), so Cernan does hold the record.

Cernan, along with Stafford and Young, also hold the record for the fastest speed ever achieved by humans (relative to the surface of the Earth), and Young, along with Duke and Mattingly, hold the record for the highest latitude ever flown over (due to their course, they ended up flying directly over a point some 61 degrees or so north latitude post-TLI).

-the other Doug

It's really very simple to tell the gender of the robots -- just check whether they use testosteroil or femzoil!

BTW -- ships are referred to in the feminine gender in only some cultures. I have it on good authority that any Russian sailor you may meet would say that his ship, he is a good ship. He is a strong ship. He serves well the Rodina.

Then again, maybe Russian just has more masculine nouns than other languages. I probably ought not speculate -- the only two phrases in Russian I know are "na gavareet Russki" (which means, in pidgin Russian, "I don't speak Russian,") and another one that I know how to spell and how to pronounce, but I dare not repeat here since I know we have at least one Russian speaker here. And it's one of the rather nastier epithets found in the language, as I understand. All I will say is that it is a comment on one's mat.



-the other Doug

Just remember, from the best HiRISE images we have of them, neither of the Viking landers was significantly dust-covered prior to this storm.

And they've been through 31 years of Martian weather.

I think the rovers will be relatively clean again. Whether that happens in time for the batteries to remain fully operational, I can't say...

-the other Doug

In addition to the other excellent responses, Andy, I'll also note that one of the driving forces in global Martian dust storms is the heating factor of the dust in the air. Unlike on Earth, where thick clouds that block insolation *cool* the planet below it, a major dust storm tends to make Mars *warmer*. The air is so thin that solar heating of the dust particles in suspension is one of the main factors in atmospheric heating. Increase the amount of dust entrained in the Martian atmosphere and you raise its overall temperature noticeably. This also increases the volume of the atmosphere, which reduces overall average pressures but raises the top of the atmosphere above non-storm altitudes, sometimes by tens of kilometers.

One of the better (IMHO) theories about how dust storms propogate on Mars has this non-homogeneous heating effect creating streams of "warm" air, which pick up and entrain greater amounts of dust, which then warm up and expand the air mass they're entrained in, which causes it to press more forcefully against adjacent, cooler air masses, causing more unstable air, which causes more streams of "warm" air invading new portions of the planet... until you begin to see very complex and energetic atmospheric circulation patterns that drive the storms along for months. It's the very effect of dust entrainment leading to air heating that contributes a lot of the energy which drives the storms.

-the other Doug

Frankly, I don't think we're going to see that much greater an accumulation rate on the solar panels after the storm than we did in prior dusty seasons. And I definitely don't think it will accumulate in a different fashion that it already has.

We have some decent (if indirect) evidence that winds blow around the inside of Martian craters; Oppy did't get nearly as dirty as Spirit during the time she spent in Endurance, right? That was probably due to wind enhancement within the crater bowl.

I have a feeling that the best place for Oppy to go, once tau lightens up a bit, will be *down*... into the windy upper reaches of Duck Bay. Yes, dust will fall, but with higher winds, it will be less likely to stick.

-the other Doug

I was about to say "Just try telling that to several hundred thousand of my fellow Minnesotans," but you beat me to the punch, Shaka...

-the other Doug

Someone correct me if I'm wrong, but the retirement of the Shuttle fleet in 2010 is not a simple, negotiable funding decision. It's the result of a very thorough review of the Shuttle system performed during (and, if I recall correctly, as a part of) the investigations of the Columbia Accident Investigation Board.

As I recall it, the report stated that the Shuttle fleet could fly beyond 2010, but would require a complete overhaul and re-certification of each orbiter and of the launch pads and ground support equipment. A dollar figure was placed on this option, and it was astronomical. The finding was that it would be unsafe to continue to fly the Shuttle fleet after 2010 without such a thoroughgoing set of overhauls and re-certifications. (We're talking about checking and replacing pieces of the airframes, not just changing out cockpit elements or somesuch.)

The development of EELVs and a new generation of big, (relatively) dumb capsules was seen as a far more cost-effective means of extending the American manned space flight presence, and to begin to build an infrastructure that would allow America to fly to the Moon and Mars. So, the decision was simple -- go with Ares and retire the fleet.

From the beginning, it was obvious that the 2010 deadline was too soon to allow the development of Ares in time for a seamless handover to the new spaceflight architecture. NASA has been playing catch-up ever since.

Of course, if Endeavour burns up or has to be abandoned on-orbit, the entire point could be moot. I'm afraid that losing this crew will end the era of American manned space flight for good, and that abandoning the orbiter could have nearly as devastating an effect on the future of manned American missions.



-the other Doug

There are some important things to remember, here...

1. The dust mass raised into atmospheric suspension by this storm is not evenly distributed throughout Mars' atmosphere. As has become very obvious, the atmosphere in some places is holding more dust than in others. And while the dust is being circulated semi-globally, circulation patterns will not generate a homogeneous dust suspension around the gobe.

2. The dust in the air column directly above a point on the Martian surface will not fall straight down onto that surface. The air moves in relation to the planet -- often circulating from the evaporating pole to the condensing pole.

3. While a good amount of the dust in the air right now will be deposited all around the globe, a preferential amount will be deposited in places where large-scale eddies in the circulation pattern cause it to drop out of suspension. Also, a preferential amount ought to be deposited at the condensing pole. (The air can hold more dust the warmer it is, so the air over the poles will tend to drop dust more quickly than air over the equator. Add to that the tendency for the airmass to sink as it flows to the condensing pole, and you get decent conditions for preferential pole deposition.)

It's always tempting to think of other planets in general terms, and we need to remember that they're usually a heck of a lot more complex than we expect.

-the other Doug

Crack enough cold ones and you'll end up in Robot Hell -- which is, as everyone knows, located in New Jersey...

-the other Doug

More specifically, the LRVs were referred to as simply "the rover" in most instances. Each did have its own designation, of course -- LRV-1, LRV-2 and LRV-3. (LRV-4 was partially built and then converted into a one-G trainer.) LRVs 2 and 3 each benefitted from experience on the previous missions, and LRV-3 was outfitted rather differently from the first two, with significant changes to the geology pallet (where the tools were kept), the removal of the 16-mm DAC and its mounting pole, and the addition of the SEP receiver and antenna.

-the other Doug

The I-35W bridge over the Mississippi River here in Minneapolis collapsed in the midst of rush hour this evening. I knbow a lot of people here (of whom I am rather fond, in fact) are aware I live in Minneapolis, and I just wanted y'all to know I'm all right, was nowhere near the bridge at the time.

-the other Doug

Yes, it's hard to say how reliable the stereo effect actually is in the images in ugordan's post. However, even without the stereo effect (but very much suggested by it), it sure looks like the bright markings along the left side of "New Manhattan" are tectonic features. Looks like the island pushed into something and its left edge was somewhat crumpled up. Whatever the juncture of the two masses looked like, it's now been completely eroded away into the channel that lies between the left side of the island and the larger "land" mass to its right.

-the other Doug

It reins supreme in terms of efficiency. I never said it got you there faster, it just gets you there with minimum spacecraft weight per m/sec of delta-V. And I dispute that no one will wait ten years to get to Vesta -- though this isn't a method you'd use when you transport people. For people, who need to dash from one radiation-safe spot to the next, you need to opt for speed and deal with the incredible hit you take in performance.

And it has been discussed in detail how much more energy it takes to ionize hydrogen than xenon... we're also talking about what can be done feasibly with our current technology.

-the other Doug

We all have to remember that the use of rocket propulsion for spacecraft falls into two very distinct categories.

To launch from a planetary surface or out from a low orbit requires sufficient thrust to overcome the relentless pull of the body deep into whose gravity well you are located. In this situation, impulse takes a back seat to thrust; you need to have enough thrust to counterbalance gravity, or else you're never going anywhere. The Saturn V needed to develop more than seven million pounds of thrust not primarily because of the required specific impulse, but because the entire fueled rocket weighed more than six million pounds. It needed the short-term thrust required to counter-balance the extreme weight of the vehicle and get it moving out of the bottom of Earth's gravity well.

However, once you are in a trajectory that does not intersect any other solar system body, specific impulse reigns supreme. Now you're in the world of Newtonian physics, in which your spacecraft continues to move along a vector, losing little speed, and doesn't need to fight to keep from falling back down into a gravity well. As long as you work *with* gravity and not against it, the thrust needed to overwhelm the effects of a gravity well just isn't needed. Now is the time when you want to max out the specific impulse of your engine, since even a very low thrust engine can apply a considerable amount of acceleration to your spacecraft if you let it continue to run for weeks or months.

So, the decision becomes pretty simple -- you need high-thrust engines while working in and close to gravity wells, and you don't end up caring as much about the efficiency (i.e., specific impulse) of your engines. But once you get out into space, you're better off using low-thrust, high-impulse engines. It's not necessarily intuitive, but that's how it works.

-the other Doug

I can see it now:

Chapter 1, "Death at the Dursley's"

Harry opened his trunk, working through the accumulation of, well, stuff that collected over six years at Hogwart's. As he reached inside, a green flash filled the room. Harry dropped down dead.

The End



Seriously, I had reserved a copy of the book at a local bookseller's -- a nice little place that primarily sells new-age and spiritual books, incense, jewelry, that kind of thing. A nice little store called "Eye of Horus." The book is selling retail for $35 USD, but for those who reserved a copy and chose to come and pick it up at midnight, there was a $10 discount.

So, I gathered up two of my girlfriend's sons and her daughter-in-law (who were also picking up a copy), arrived at 11:30 at the nice little store (which threw a little party for the occasion), chatted with some old and some new friends, and picked up my copy at midnight. Checked the final two pages plus the "afterword," and, satisfied that I could read the book without any really nasty surprises, brought it home.

I'm now probably going to spend much of the weekend reading it, but I have enough to do today that I won't even try to read all 759 pages today...

-the other Doug

You know, being 13 at the time of the first manned lunar landing had its plusses and minuses. On the plus side, I was old enough to have been highly aware of what was going on. Heck, even at that point, I knew more about the Apollo spacecraft and operations than most anyone else my age, and more than some people who worked in the program. I have very clear (and cherished) memories of mankind's first hesitant steps into what we used to call "outer space," going back to Mercury shots.

On the minus side, witnessing such events at such a young age set up a whole slew of expectations that led to a whole slew of disappointments. Heck, even in the short term, the shadowy, low-resolution TV images from Tranquility Base, while exciting, were a little disappointing in their quality. When Apollo 12 was cleared for the higher-resolution color camera, I was excited, and I really enjoyed the down-the-ladder activities. But the loss of the camera after only a fleeting glimpse of the LM sitting on the surface was a disappointment.

So, I then looked forward to Apollo 13, wanting to once again see new vistas play out live in my living room. It had been 9 months since I had last been able to watch a full moonwalk, I was getting impatient to see another one! And then, of course, 13's landing was aborted and the following missions delayed. Quite disappointed, once again.

Which brings us to Apollo 14. I was so worked up by February of 1971, a full nineteen months since I had been able to watch a moonwalk, that I could barely think straight by the time Antares landed. I was finally rewarded with another high-quality down-the-ladder sequence (though unaccountably marred by video blooming of the bright soil beyond the LM's shadow) which showed unprecedented detail in the suits and LM structures -- while the camera was sitting in the shadows. As soon as it was deployed out into the sunlt surface and was pointed at a brightly lit scene, everything bloomed horribly and the moonwalk for which I had been waiting for more than a year and a half consisted of white blobs bobbing around a bright featureless scene with a big gold-and-silver blob sitting behind them. The image quality improved a little for the second EVA, but for most of that EVA the crew was out of sight of the TV camera. For as much as I was looking forward to these moonwalks, the TV coverage was, well, disappointing. I think the scene would have been better documented had they disconnected that lousy color camera and hooked up the duplicate of the Apollo 11 B&W camera they brought as a backup. It would have been shadowy and motion-smeared, but the resolution would have been quite a bit better.

And then the gods smiled down, and Apollo 15 happened. The quality of the TV was incredible, approaching studio-quality at times. The down-the-ladder stuff was amazing, and was followed by an even more amazing sequence of LRV deployment and loading. I was very pleased with the quality, and looked forward to seeing similar excellent scenes of ladder descents and LRV deployments on the final two missions...

Which is where the final disappointments came in. While the quality of the TV improved on each of the following two missions, on each I was denied the down-the-ladder and LRV deployment sequences. On Apollo 16, the LM's high-gain antenna didn't work (someone left a binding tape on the antenna, so it was unable to move in yaw and was therefore useless on the surface) and they could simply not pump enough signal through the omni antennae to get a usable TV picture down. Once deployed on the rover, the TV worked outstandingly, and I was not disappointed with the rest of the coverage. But the lack of the opening sequences left me feeling like the experience was incomplete.

And then came 17 -- and the ::bad word:: engineers decided they really didn't need TV coverage of the ladder descent or LRV deployment, so they saved a little weight by pulling the wiring and TV tripod out of the LM and thereby deleted the capability to send TV from the surface until the rover was deployed. Once again, the rest of the coverage was fine (although it was difficult to see much of it, since the moonwalks were held in prime time here in the U.S. and the networks decided no one wanted to see their regular programming interrupted by sharp, clear color TV scenes of people working on the Moon). But I was indeed disappointed that, after Apollo 15, we never again were treated to watching the ladder descents or the LRV deploys.

So, after all of this, I settled in and waited for a Shuttle-launched lunar exploration program to be developed. I figured you could launch a TLI stage in pieces on two or three orbiters and a seperately-launched propulsion stage (probably developed from Saturn technology). I figured that I would have to wait maybe a dozen years before I could once again revel in watching humans exploring the Moon, but that it would be worth it if the quality of the TV coverage of the scene was improved by advances in the technology.

So, I waited.

I'm still waiting...

-the other Doug

Well -- I just got home from picking up the latest, and final (probably) Harry Potter book. And of course, I skipped right to the end to see how it all comes out. I won't say anything, but I'm not displeased. As for light reading, though -- this one is 759 pages long.

And now, off to the summation of the adventure...

-the other Doug

Slightly off topic, and just for the record:

MER-2 = MER-A = Spirit
MER-1 = MER-B = Opportunity

-the other Doug

My Mom's folks (my grandparents) were visiting our family that day. They had arrived on Saturday and stayed through Monday. (My Mom is one of eight siblings, and it was common back then for my grandparents to make the rounds of their kids' places during the summer, seeing as many as possible and staying a few days at each place.)

I can recall many very vivid things. For example, since my grandparents were there, my folks stocked up on various types of soda we usually didn't have in the house, including ginger ale. I drank a couple of ginger ales that afternoon, and discovered for the first time that my esophagus doesn't get along at *all* well with ginger ale. At the time Eagle touched down, I had a tremendously bad case of heartburn.

My brother, a couple of years older than I, was in high school already (in the summer between his sophomore and junior years), while I was looking forward to entering high school the following September. He worked on the school newspaper during the school year (as I would go on to do, as well), and he arranged with the journalism teacher to borrow one of the school's Yashica-Mat twin-lens reflex cameras. He set up that camera and took a roll of black-and-white pictures of the EVA from the TV screen. For all subsequent landings which featured extensive TV coverage of the EVAs (specifically, Apollos 14-17), I took over that function, borrowing the same Yashica for the purpose as my brother had used. (Unfortunately, the prints and negatives were lost when my vindictive ex-wife destroyed them in spite when we separated.)

On Sunday afternoon, July 20, 1969, I was very aware of the timing of the various mission phases. I knew that PDI was scheduled to begin just after 3 p.m. Central Daylight Time, aiming toward a landing at roughly 3:15. At the time the PDI burn began, I was in my Dad's car as he ran in to the local drugstore to pick up film for my brother's attempt to shoot the EVA later that night. I was vehement that he get us home in negative elapsed time, as I recall.

I can recall that I was determined not to sleep Sunday night, saying to myself that it was simply impossible for me to spend any time whatsoever unconscious while humans were actually on the Moon. I didn't make it, I slept for about four hours beginning at around 6 a.m. I was up and awake in time for the liftoff and rendezvous, of course.

Finally, I remember one last thing. My Dad was a bombardier on a B-17 during WWII. He had a private pilot's license (though we weren't wealthy enough for him to buy the Beechcraft Bonanza he always desired). He took only a minor interest in space exploration, more of a pilot's interest than anything else, but as we settled into our chairs and couches on that hot Sunday evening, in our darkened family room, watching the round-tube color TV we had bought only three years before, I remember my Dad taking in the family scene around him, hugging my Mom, and saying to no one in particular, "This is history. This is it, the real thing. Really something."

As Armstrong set foot upon the lunar surface, even while I paid careful attention to what he said and what the poor TV image showed... I thrilled. I rejoiced. My sense of wonder expanded until I felt that I must be as large as the Universe itself. I felt what it must be like to be one of a race of gods.

My life has been downhill, pretty much, from that time on... *sigh*...

-the other Doug

I not only remember, very clearly (I was 13.5 y.o. at the time) the first manned lunar landing, I can remember Ranger IX's death plunge into the Moon. The image output from one of the cameras was played out to the TV networks (and hence the very first use of the subtitle "Live from the Moon" on any television broadcast).



-the other Doug