There is much more data to collect before any theory is proven. I really do appreciate your efforts, Professor. And I surely understand the difficulty in direct observation of large impact events. Even if you eventually are proven wrong, we will always need people to challenge the conventional wisdom, or else misinterpretations will never get addressed!

Thanks again for joining this forum.

-the other Doug

Not to belabor a point, but it gets down to how you exercise the scientific process.

Gravitation, terrestrial crustal movement and even diversification and radiation of species are not theoretical, they are observed phenomenah. They are objectively, empirically observable. The mechanisms involved in how they operate are theoretical. (This is the argument I get into with my girlfriend... )

You cannot open your assumptions so broadly that you begin to treat empirical observations as unproven theories. That sabotages the scientific process and leads to festoons of tin-foil hats...

-the other Doug

Remember, "shades" are just another form of filter. What spectral range will you be getting through your preferred shades? That will make some difference in terms of the details that will be visible to you. Also, polarization will make a difference, too.

Back during Apollo, the most common sunglasses were green-tinted. The Apollo 12 crew really needed the sunglasses at times, but Pete Conrad decided not to use them at times because he didn't have nearly the visual acuity on the lunar surface through the green-tinted lenses that he had without them. So, the wavelengths passed through your shades, and those blocked, do make a noticeable difference.

-the other Doug

I respectfully disagree with this statement. The processes are proven. Some of the mechanisms by which these processes function are not proven, and are therefore theoretical. (I have the same argument with my girlfriend... )


Now, here is where you get closer to some of the mechanisms than many others, I think. While I truly believe that the Merdiani landforms and minerology were formed by groundwater and standing water (among other things), we have to be aware that impacts have modified the Martian surface far more than they have modified Earth. Impact is a primary agent in much planetary surface formation, and I agree that when you invoke Occam's Razor, the first thing you need to look at are impact processes.


Hey -- as long as you don't mind our honest responses (and you don't start wearing tin-foil hats), we *love* pontification around here! Please, keep it up. Or, paraphrasing what someone once said, I may not agree with all of your hypotheses, but I defend to the death your right to express them...

-the other Doug

There is also a question as to whether shorelines might have been altered due to glaciation effects. Any liquid ocean did probably end its life as a frozen-over body of water, which could have induced glaciation effects, especially around the fringes (which happen to be the shorelines).

We shouldn't necessarily expect that ancient Martian shorelines will resemble ancient Terrestrial analogues.

-the other Doug

Just saw an interesting (and disturbing) report on CNN. As y'all have probably heard, as soon as the new set of solar arrays was deployed and activated, the computers in the Russian segment of the ISS went offline. Attempts to reboot them and bring them back online have failed. The best they have done is establish "limited communication" with a couple of the "lanes" of communication between the computers (the main and terminal systems) on the Russian segment and the equipment they control, but that the communication is not trustworthy. They've now been shut down totally while ground experts study the problem.

According to the Russians, the best guess right now is that the new American solar arrays are generating an induced EM field that is blowing the Russian computers out of the water. There may be no choice but to leave the Russian segment without its main control systems until the computers can be replaced -- which is not a simple process.

This isn't a minor glitch, folks -- for one thing, there is apparently no way to use the Russian attitude control system without the computers. If for any reason the primary attitude control system -- the CMGs -- has to be taken offline (due to gyro saturation or any other reason), this would leave the entire complex uncontrolled in attitude. The Vozhduk (sp?) air regerator system is also controlled by the now-disabled computer system.

For me, this kind of thing is why you have to gain experience in deploying large structures in LEO before trying to send them elsewhere in the Solar System. Certainly the best American and Russian engineers never considered the possibility of induced EM fields from the solar arrays that could have such a devastating effect on the internal electronics. In my humble opinion, this is *exactly* the kind of learning experience that ISS must provide before humans can move out to the asteroids and planets. Let's just hope it's not a show-stopping lesson...

-the other Doug

So, what you're saying is you went to Mars with a couple of *little* guys, eh?



-the other Doug

Yes, Stu. I do.

Reminds me of a song lyric from the musical "1776":

"Is anybody there?
Does anybody care?
Does anybody see
What I see?"

-the other Doug

Ah, so now we know how Emily keeps up with NASA TV...

-the other Doug

No, the bottle would have shattered. And the combination of the wine and the glass shards would have managed to debond the cork insulation on the upper stage, forcing a launch delay, which would have been the cause of yet another delay since they wouldn't be able to find the proper bonding agent, and/or it would be applied incorrectly...

"Destiny! Destiny! No escaping it for me!"



-the other Doug

You make some truly excellent points, Littlebit. It seems that the one area in which aerospace holds a greater appeal than other, more highly compensated and stable engineering disciplines is in its intrinsic appeal to sense of wonder. It's "cool" and "sexy" to work on spacecraft systems. For some engineers, this is enough to lure them into aerospace engineering. For others, it just doesn't outweigh the disparities in compensation and job security.

Y'all have to remember that in the late 1950s through the late 1960s, America so highly encouraged its best and brightest to specialize in aerospace engineering that we created a crop of people who were literally able to put men on the Moon. And then we thanked them, gave a few of them some medals, took most of their jobs away, and said "We don't need what you do anymore -- go find something worthwhile to do."

The engineering community hasn't forgotten the massive layoffs of the late 1960s into the early 1970s, and I can't blame them.

So -- what do we do to make aerospace engineering a well-compensated and nationally critical discipline once again? As much as people don't want to hear it, I think the first step is that more money needs to be spent on aerospace projects, and those projects need to have enough committment from the people and the government to make the discipline seem worthwhile to those who are making their career decisions today.

How do we accomplish that? I wish I knew.

-the other Doug

Ah, gotcha...

Well, it was worthwhile to debunk the "objection" you cited, anyway...

-the other Doug

Well -- you also can't underestimate the potential hazards. For many, many years, the orbiters came back with varying degrees of damage to the TPS, and had only minor damage. One flight even came back with burn-throughs down to the aluminum airframe in a couple of places (I want to say it was STS-37, but I'm working from memory and could be wrong). All of them survived, though, so it was believed that the TPS could sustain pretty much *any* damage that foam strikes could inflict and still survive.

That belief was tragically wrong.

Just because every Shuttle that has sustained damage to the TPS on the OMS pods (including the very first flight of Columbia) has come back without mishap doesn't mean you can make the same mistake that was made on STS-107. You can't even risk the remote possibility that something worse could happen *this time* than has ever happened before. Remember, those pods are literally *glued* onto the Shuttle main airframe for each and every flight -- even one instance of thermally-initiated debonding could result in a partial or complete separation of the pod from the vehicle, and if that were to happen at *any* point in the descent trajectory, you're talking about a Very Bad Day.

It's not just that they want to make for good PR -- this is an example of how decision-making has necessarily been adjusted based on lessons learned during the investigation of the Columbia accident. Even if you don't believe that something like this loose blanket can pose a risk of loss of vehicle and crew, you have to admit in your decision-making process that you cannot ever be *certain* of that. So, you do what you can to make the vehicle as clean as possible prior to de-orbit.

I wouldn't have expected any other decision.

-the other Doug

While the setting was less connected, Stu, I once had a similar experience. In the summer of 1993, I believe it was, I was attending a Grateful Dead show in central Indiana. A shuttle was up and flying at the time. During the second set, I saw what could only have been the Shuttle flying overhead in the just-post-twilight skies. The juxtaposition of the music and the crowd and the Shuttle serenely streaking by overhead was impressive, especially since I was likely the only person out of the tens of thousands there who realized just what was happening...

-the other Doug

Yes, any shoreline must follow the "areoid" because of how water collects on a planetary surface. This is a basic element of physics.

However, it is more than obvious that the "areoid" has changed over the past couple of gigayears. The Tharsis bulge was very likely emplaced *after* any such northern ocean had dried up, evaporated and/or been incorporated into underground reservoirs. This impressive pile of volcanics reshaped the very planet -- and rebalanced it, too. For example, the great canyons of Valles Marineris were formed as rifting occurred, due to the reaction of the crust to the immense amount of lava that was poured out onto the Tharsis region. The building of the Tharsis bulge is what likely caused mars to topple on its side, to place a majority of the mass now newly distributed onto the surface as close to the equator as possible.

That kind of activity, occurring over a billion years or more, would naturally crumple the crust up in some places and tear it apart in others. It is no more reasonable to expect that the areoid is the same now as it was when conditions allowed for oceans on Mars than it is to expect that the mountaintops in the Himalayas were always uplifted to the top of Earth's sensible atmosphere. Since there are fossils of seabed creatures in the rocks at the tops of those mountains, we know for a fact that those rocks once lay under an ocean. To say that there cannot be ocean-floor rocks at the top of Himalayas because the geoid doesn't allow it is just as spurious an argument as to claim that shorelines can't exist on Mars along its dichotomy boundary because the current areoid doesn't indicate them.

-the other Doug

EC, it's funny you mention Ulysses -- I was watching the Discovery Channel's documentary "The Savage Sun" yesterday, which included a nice sequence of Ulysses' deployment from the payload bay. A nice set of sparklies flew out of the payload table/spacecraft interface as she lifted out of the bay.

And Toma, the Apollo 12 patch was probably my third favorite. My favorite was the Apollo 8 patch, incorporating the great figure-8 trajectory of a lunar spacecraft into its design. My second favorite was the Apollo 14 patch, with the astronaut pin worn by all astronauts of the day streaking from the Earth towards the Moon. However, my *real* favorite patch was the Apollo 14 back-up crew patch. Gene Cernan had a patch designed for his back-up crew that mimicked the prime crew mission patch, but showed a version of Wile E. Coyote, complete with gray beard (to symbolize Al Shepard), arriving at the Moon to find the Roadrunner (symbolizing Cernan's backup crew) already there, having leapfrogged the prime crew. Along the bottom of the patch, it read "Beep Beep Your Ass!" Cernan had hundreds of those patches made up and had them secreted all over the spacecraft. There was even a decal of that patch affixed to the MET, the lunar "rickshaw" used by Shepard and Mitchell in their assault on Cone Crater.

Ah, the good old days...

-the other Doug

Thanks, climber! I surely appreciate the kind words.

As a final off-topic comment, here, there was a coincidental arrangement of numbers that made me feel very much in synch with the Apollo program. Even though the flights of Apollos 15 through 17 occurred over a period of only 18 months, due to the placement of my birthday (mid-October), it happened that I was 15 years old when Apollo 15 flew, I was 16 when Apollo 16 flew, and I was 17 when Apollo 17 flew. Had I truly believed in numerology, I would have been positively freaked out...

-the other Doug

I dunno -- it seems to me that to move across the surface of a small body which has such little mass that it's truly what I would call a microgravity environment, you can't rely on the possibility that you will encounter a natural handhold when you need to slow down, stop, or change directions. Grab hold of a rock sitting on the surface, and you're not going to stop yourself, you're going to pull the rock off of the body and bring it with you.

I think you'd have to somehow implant anchoring stakes on such a surface and string lines between the stakes. The stakes would have to be driven deeply enough to be able to stay anchored as the mass of your body, plus your environment suit, pulls at them with the force of your momentum. So it looks like small bodies may have to be "prepared" for human exploration before anyone can actually touch them and maneuver around on them.

This wouldn't just apply to small icy bodies like Atlas, but to most small bodies like asteroids and comets. You'd have to pre-emplace anchors and lines in order to safely move around the surfaces of such bodies. Otherwise, you'd either fly right off (though I imagine you'd be tethered to your ship) or you wouldn't be able to easily maneuver to the location on the surface you want to visit.

Your other option, of course, would be to use something like the AMU, a self-contained, RCS-controlled backpack that would move you along the surface and automatically adjust for the tiny pull of the body you're studying. It would be more like flying along, facing an icy or rocky wall, than "walking" on the body.

-the other Doug

I wasn't trying to incite a rant, Doug -- honest! After Alan Stern's reference to this particular forum as "the bloggers," I figured it was a reasonable request for clarification.

-the other Doug

To be fair, the makeshift fender was assembled (i.e., taped together) inside the LM cabin between EVAs 1 and 2. That wasn't done because the tape wouldn't work in a vacuum, it was done because it's easier to manipulate the tape and cards with bare hands. The tape certainly held up fine when it was taken out into a vacuum, though. And though the fender failed near the end of EVA 3, it was because one of the two AOT light clamps used to attach it failed. The tape stayed on just fine the whole time, and yes, they brought the piece back and it is currently on display at the NASM.

However, to support the successful use of tape on Apollo 15 that I mentioned, here are a few snippets of the air-to-ground transcription, courtesy of Eric Jones' Apollo Lunar Surface Journal:

- - - - - - - - - -

138:51:57 Fullerton: Okay. (Pause) Let me cross-check that here and see if we can get any more words on that. Let me give you one other suggestion and that's for securing the high-gain antenna cable on the Rover (to prevent snags such as occurred at Station 2). We'd like to suggest that you get the roll of tape out, strip off about 1 foot, and fold a 1- to 2-inch tab on one end of it and wrap that piece of tape around the CDR camera so that after you get down to the Rover you can use it to secure the high-gain cable to the high-gain antenna mast and keep it from flopping around. Over.

- - - - - - - - - -

In this snippet, CapCom Gordon Fullerton is telling the crew to wrap a piece of tape around Dave Scott's camera before they get out so they can tape up the cabling and prevent it from hanging up the TCU (Television Control Unit) as it tried to pan, as happened during EVA 1. What the crew actually did was to put strips of tape onto their wrist-mounted checklists which, made of plasticized paper, was the only surface on the suit which was dust-free enough for the tape to easily stick to.

- - - - - - - - - -

142:32:52 Allen: Okay. And while you're working there, Dave, you did such a beautiful job on fixing Jim's PLSS antenna, we've got another Walter Mitty repair job we'd like for you to carry out for us, please, on the cable lead from the high gain antenna to the LCRU, and when you think you're at a good place to do that, I'll go through a description of what we need.

[Mitty was the fictional hero of the James Thurber story, The Secret Life of Walter Mitty. In real-life, Mitty was an unremarkable, inconspicuous, henpecked man who, in his daydreams, was courageous and resourceful and lived a life of high adventure.]

142:33:20 Scott: Gee, I'm right there, Joe.

142:33:22 Allen: Roger, Dave. Basically, our camera keeps hanging...

142:33:25 Irwin: And, Joe, I'm going to put...

142:33:27 Allen : ... our camera keeps hanging up on that cable, and we'd like for you perhaps, if you think it's feasible, to tape a part of a cable below the fastening device on the staff of the high-gain antenna. If you think a piece of tape right there might help, we suggest you go ahead and do that now.

142:33:52 Scott: Joe, I just completed that little task. It's all done!

- - - - - - - - - -

This exchange covers the actual use of the gray tape to pull the high gain antenna cable out of the way of the TCU. The tape was applied in the lunar vacuum, and held for the rest of the surface activities (including the periods after the crew left the Moon and the ground commanded the TV camera on for post-EVA site surveys).

- - - - - - - - - -

141:44:46 Allen: ...and, Dave, while you have the tape out there, from the sound of things, maybe you'd better put...

141:44:51 Scott: (To Jim) Wait a minute.

141:44:52 Allen: ...some of it in your pocket for later.

[The Apollo 16 and 17 crews each took a roll of tape out with them and put it to use several times during their EVAs.]

- - - - - - - - - -

This exchange, which followed a discussion of using the tape to fix Jim Irwin's broken PLSS radio antenna, includes a comment by Journal editor Eric Jones which confirms that both the Apollo 16 and Apollo 17 crews took rolls of the gray tape out onto the surface during their EVAs and used it on several occasions.

I'm sure I could comb through the Apollo 16 and 17 transcriptions and find more than a dozen other examples of the gray tape being used on the lunar surface, in a vacuum.

Short summary: John Shannon is absolutely mistaken.

-the other Doug

Oh, I'm human, I make mistakes and at times my memory becomes slightly faulty and I confuse a few real facts together to get something that doesn't *quite* live up to my high standards. And I've eaten crow more than once for making minor errors. For example, I recounted some information on the early Apollo crew assignments over on the NASA Spaceflight.com boards, and got a scene from the miniseries "From the Earth to the Moon," which was somewhat dramatized, confused with accounts I thought I had read of the same incident. Had Michael Cassutt, who wrote Deke Slayton's biography, correct me with a bit of a huff... though I still am under the impression there was more fact to the scene in the film than Cassutt gives credit for.

But I have *so much* data crammed into my head about manned spaceflight history (especially pre-Shuttle) that the minor errors are more than compensated for by the vast number of applicable facts I can pull from that era to illustrate processes and happenings that are occurring even today. In that way, I modestly accept your praise -- but warn all and sundry that I am human, and have an age-eroded recall mechanism. I get it right about 96% of the time or so, but I can sure pull some beauts when I get it wrong!!!

That said, I am *confident* that sticky tape, essentially identical to modern duct tape (or duck tape, as you prefer) was used quite successfully several times on the lunar surface. Which was indeed in a vacuum.

-the other Doug

OK -- so, the million-dollar question is:

Is UMSF considered a blog? Are posts here eligible for submission?

-the other Doug

Well, Tim, I know that they're a lot more recent than 2Gy old (the estimated age of the Martian shorelines, at least according to the article at Space.com), but the shorelines of southwest North America's great inland sea have always been pretty obvious to me when I have flown in to Phoenix from the midwest. I surely don't know any other explanation for the extended wall-like structures that separate higher, slightly hillier terrain from the lower, flatter desert floor.

Granted, those shorelines are much younger, and therefore are also a lot more discernible. But any theory that even approximately accounts for the Martian dichotomy has to be at least seriously considered, IMHO.

I also find the concept of the Tharsis deposition toppling the planet over to be attractive -- if the Tharsis bulge originated well away from the equator, over billions of years the whole planet would tend to shift to place the heaviest portion of the bulge much closer to the equator. I may not be a professional geologist or planetologist, but the theory feels truthful to me...

-the other Doug

OK -- that does it. Whoever hired Joe Btfsplk as Chief Engineer for Dawn just has got to be fired...

-the other Doug

Well, if that's the case, someone should tell the Apollo astronauts, who used what they always called "the gray tape" on the lunar surface very successfully on many, many occasions, that their impromptu repairs really didn't work.

The only reason for tape failure on the lunar missions, AFAIK, was that dust easily stuck to the sticky side and rendered it less than usable. But if you could manage to apply the tape without getting much dust into it, it worked just fine on the Moon. And last time I checked, the lunar surface is in a pretty hard vacuum.

I recall in specific that the cabling from the comm unit (the LCRU) on the Apollo 15 rover was interfering with the TV camera's pan movements. Scott and Irwin simply taped the cabling to a convenient post (the mast for the high gain antenna, IIRC) and voila, no more problems. That tape certainly worked longer than the crew remained on the lunar surface.

-the other Doug