The drive-direction wheels are still sitting on top of the soil.... that's a good sign, at least.

Looks like the "back" end broke out a few times getting to our current position, though. Rather like we're on a sideslope -- but it really doesn't look like a sideslope in the images.

I'm not real comfortable with this light-sand box we find ourselves in...

-the other Doug

We did -- we just were higher up, on the side of Husband Hill, and since we were on a north-facing slope anywhere we moved, we moved around a little more. But we stayed put, pretty much, on the side of the hill throughout the winter months. And didn't do a whole lot.

-the other Doug

Just to start a general topic, we've discussed some aspects of the old Soviet planetary exploration programs, but we've never had a topic devoted to the discussion, where we can discuss it in general terms.

So, the question is, did the Russians have significantly more problems with their early lunar and planetary probes than the U.S. did? How about ESA or JAXA? How do they all compare?

And what would y'all say is the reason for differences in success/failure rates, and quality of data returned, by probes built and flown by the various polities which have attempted them thus far?

I can think, specifically, of Russian lunar orbiters that returned image data of far poorer quality and usefulness than contemporary American orbiters... of the '71 Mars debacle, in which a functioning Soviet orbiter couldn't be re-targeted real-time and spent all of its pre-planned science program photographing the blank, featureless top of a global dust storm... of more than their fair share of probes ending up as junk decorating the steppes of Kazakhstan.

But, then again, you can always bring up the failures of Rangers 1-6, two of the seven Surveyors, the partial failure of Lunar Orbiter 1, etc., etc., etc., while the Russians were merrily taking pictures (albeit low-quality ones) of the far side of the Moon and landing small pods on its surface.

What do y'all think the balances were? What learning-curve lessons-learned are we seeing repeat themselves in the ESA and JAXA programs?

Just trying to get a sense of the group on this one.

-the other Doug

Actually, Alan, I think that instead of saying "Here There Be Dragons," it may be more appropriate to say "Here They Drag Beacons"...



-the other Doug

Yes -- but poor Mike and Piers. They wasted about 20 minutes trying to figure out what to do about a tether reel that had jammed, wouldn't retract into the reel. Finally, someone on the ground asked if they had taken the lock off, and it turned out that they hadn't. The tether was locked in place, not malfunctioning.

Mike said it all -- "Gee, how embarassing."

-the other Doug

I will make a point about the Lunakhods... yes, they put in impressive numbers for distance traveled by an unmanned rover.

But they did precious little science while setting those records.

As I recall (and someone please correct me if I'm wrong), the Lunakhods carried no sensors for in-situ analysis of rocks or soils. Not even any "sky science" sensors to detect radiation or magnetic environment details.

The only active scientific experiment I can recall, on Lunakhod 2, was a soil penetrometer. Which gives you more in terms of engineering information -- about bearing strength, cohesiveness, etc., of lunar soil -- than it gives you real scientific data. (Yes, they also had passive laser reflectors, one of which has never been acquired and the other of which is in an unknown location on the lunar surface, making its use somewhat less than useful... in point of fact, the return from the laser reflectors may have been greater had they been attached to stationary landers and not to rovers.)

In other words, the Lunakhods were primarily engineering demonstrations, with almost all scientific return removed to ensure the success of the engineering tasks. (And they were propaganda tools, to show that the USSR was more capable of roving the Moon than Apollo was, though that's a very debatable point.)

So, I'd be a little wary of comparing Lunakhod performances to those of the MERs, or the projected performance of MSL or ExoMars. If all you want to do is demonstrate speed (and, specifically, a speed or range of exploration greater than that of your political rival's system), without giving more than a passing nod to science, it's a little bit easier to accomplish.

Let's hope no one decides they need to prove their bravery or masculinity or any other such nonsense by making a Mars rover that's fast, but not much else...

-the other Doug

Yeah -- just ask Joe Allen sometime about his experiences holding a 3-story, multi-ton comsat in place with his hands for about 45 minutes while his partner worked on its aft end, preparing it for latching back into the payload bay...

-the other Doug

I think an engineering demonstration might be in order for a Discovery or New Frontiers mission, depending on its overall cost...

We want to place seismometers on a lot of bodies out there via penetrators, right? Well, why not practice and demonstrate the technology fairly close to home?

Send a small fleet of penetrators to the Moon, each equippped with a seismometer. This way, you demonstrate the ability to emplace such devices on airless (or nearly airless) worlds, *and* you get a lunar seismometer network out of it.

-the other Doug

In re the drive-to concept:

The thing that bothers me is that, as I understand it, MSL's more sophisticated sensors will require dirt and rock samples to be ingested into the sensor, and that there will be a very limited number of processing cycles on these devices. Something like between 12 and 45 separate analyses, and after that, the device is inert and can never produce any further data.

If we had sensors like this on Spirit, what are the odds that your most important devices would be used up and no longer available by the time Spirit reached the Hills, thereby reducing the real interesting science quite a bit? As it is, Spirit's RAT was used up mostly on hard lava chunks out on the plains -- so, in a sense, we did run across this issue on the MER missions.

If you decide to wait to use your instruments until you reach your target location, there is the issue of landing a good, working scientific payload on Mars and willfully refusing to use it for a few months, while you drive to your "interesting" location -- all the while betting that nothing bad will happen to your rover on the way... and also betting that you don't run across an invaluable find en route, that you pass up because you're hoarding your processing cycles for after you reach Location X.

NASA probes to other planets have been designed to acquire enough data to declare "mission success" within the lifetime of the shortest-lived components on the spacecraft. Only after that is accomplished do they plan for delayed science vs. travel and/or engineering evaluations.

Whatever they do with MSL, I cannot imagine that they will design the mission to have to rely on 100+ sols of roving before the main science investigations can begin -- not with all the ways Mars can potentially kill a rover.

-the other Doug

Yeah -- I've heard described John Young's reaction, during Columbia's maiden return, as he watched the stagnation point move off the nose and start to march steadily toward the cockpit windows, before he grabbed the stick and took over.

On a bit of good news front, NASA is now saying that the thing the crew took to be FRSI material was actually a chunk of ice. How you confuse ice for FRSI, I have no idea...

-the other Doug

In comment to the original question of the thread...

If we can't drive into Victoria, perhaps we can drive into Beagle. Or the small dimple crater on Victoria's southeast corner, almost directly on her rim.

There are several other small craters in the area, but most appear to be pretty well filled in. I'd say Beagle or that unnamed dimple crater would be our best bets to find a north-facing slope on which to winter.

-the other Doug

Looking at the bedding in the ripples, you can see that there are some compositional changes over time in the grain deposition. That's the only way you get this kind of bedding.

So, the layers in the ripples (which seem relatively evenly spaced) speak to epochs of ripple deposition, I think. The way that the layers tend to have partially-cemented surfaces (similat to the cementing we see on the surfaces of the ripples today) hint that each of these layers was once the surface of the ripple.

So, what could occur in epochs on Mars that would result in the building of material on top of existing, surface-cemented (and therefore probably relaytively static for a time) ripples?

Cyclic, drastic climate change, due to Mars' extreme wobble, could just fit the model. I think.

So, perhaps we are seeing layering in these ripples that is built up every time Mars goes through a given portion of its extreme climate cycle. Possibly, you only get rapid ripple/dune deposition during those times when the maximum amount of Mars' atmosphere is gaseous for the greatest amount of time during the year. I'm not sure which portion of the climate cycle would offer these conditions -- but I bet the planetary climatologists will have it all figured out in a decade or two...

-the other Doug

Getting into this a little late, but... guys, think of the hard basalts and other lavas we've seen at the other landing sites, that have been carved and polished by the winds over the aeons into perfectly smooth surfaces. If y'all have ever seen chunks of this kind of rock, you'll note that in its more natirual state it doesn't feature such nice, gently curved, smooth surfaces.

These ventifacts, which are ubiquitous wherever you find hard rock, are even more compelling mute testimony to the powerful, if slow, erosive force of the Martian winds than are the ripples/dunes.

-the other Doug

OK, here's a question that reveals an area of ignorance on my part...

We have a pretty decent idea of the energetic cosmic radiation levels outside of Earth's protective Van Allen belts. We also know we can see a certain number of these particles on Earth's surface itself (ever seen one of those nifty cloud scintillation chambers that were all the rage 40 years ago?), so we know that not all of these particles are shielded at the Earth's surface. (At least, when I saw one in grade school, they told me that the trails were energetic cosmic rays.)

The question is, what is the relative level of shielding provided by the Earth's magnetic field? I'm just looking for an order-of-magnitude feel for the thing -- is 1/10,000th of the unshielded flux coming through, or more, or less? That kind of thing.

-the other Doug

So, we're scrubbed for today, I take it... Recycle for tomorrow, or is there any word on that?

BTW, thanks, Doug!

-the other Doug

If possible, can someone post some updates here? I'm at work, and the anal-retentive, um, front-office folks set these little computers up to disallow any installations. So I can't install the Java plug-in to get into the chat room... *sigh*...

-the other Doug

Why send such things, when you can use piles of rock and ice that Nature has provided? Assuming you can find piles of ice and rock in the orbits you want to use, of course.

Really, though -- just dig into a low-mass moon or asteroid, and you're all set. This would work for most of the worlds in our system, with the exceptions of Mercury and Venus...

-the other Doug

Were there ever a set of results posted for the ALFMED experiments flown during Apollo lunar missions? They had a nice setup, with a head-enclosing box that contained film on five of six sides. The idea was that you'd be able to calibrate film hits against taped reports of light flashes reported by the test subjects.

One of the things this was supposed to settle was whether the crews were seeing real light generated inside their eyeballs, or whether the flashes were indeed the result of direct hits on the optic nerves of the brain.

I don't ever recall seeing any results that settled this question. Anyone have any more info about it?

-the other Doug

Speaking of naming things, I heard a guy yesterday who said he wanted to open a restaurant and call it "Thanks for Calling, How May I Help You." That way, anytime anyone called the restaurant, the poor person answering the phone would have to say "Hi, thanks for calling 'Thanks for Calling, How May I Help You,' how may I help you?"



Of course, if you were to play such a trick on your child, Emily, I wouldn't blame the kid for planning matricide...

-the other Doug

Yes, the company was quite excellent -- but for a BBQ, I think next time I'll suggest Venus. Because, at this event, no matter how fast I ate my food off the grill, it was always cold!



-the other Doug

Don, I must say that, with your clarifications, I agree with you much more than I don't.

This thread is good, I think -- though there is a definite self-limiting factor to a manned Venus orbiter right now (energetic cosmic rays and solar flares, with no really good way to shield against them). To safely operate manned vehicles at Venus, I think you'd first need to maneuver an asteroid into orbit around it and dig your manned vehicle into that asteroid. (Unlike Mars, Venus doesn't present us with a ready-made natural piece of real estate in the right location.)

I somehow get a feeling that, by the time we know enough to be able to maneuver asteroids into planetary orbits, we'll have come up with a shielding solution for energetic particles...

-the other Doug

Enough with the anti-manned-spaceflight agenda?

Please?

-the other Doug

Oh, but don't y'all think that it's essential to encourage the debate by presenting *all* points of view when it comes to cosmology?

:::ducking quickly:::

Seriously, guys, while it makes for poor television, we can do with this what we do with other pieces of mass-media fluff that masquerade as informational programming -- ignore it. Assign one of us as a guinea pig to watch any new Horizons episodes and let the rest know if it's worth watching in re-runs. If we can spread this into a large-scale network, we can affect the one thing that *will* bring about change -- the show's ratings.

Besides, none of that astrology stuff can shake my very firm world-view, so I don't see any of it as any kind of threat to my beliefs. Which, of course, all derive from the fact that it's turtles all the way down...

-the other Doug

Reminds me of some idle speculation I encountered, a long time back...

We all know that Francis Scott Key's "The Star-Spangled Banner" was written to be sung to the tune of an old British drinking song, "To Anacreon in Heaven." The idle speculation was, what if it were written to the tune of some *other* drinking song? What we got was this:

"Thirteen stars and bars on the flag,
Thirteen stars and bars!
Rockets red glare,
One less there,
Twelve stars and bars on the flag..."

Good thing they didn't go with that one -- it takes forever for a baseball game to start as it is.

-the other Doug

I'm just a little amused when I recall that, in less than nine total days on the lunar surface, the three Apollo lunar rovers traveled on the order of 50 km, total.

I know, I know -- the circumstances are entirely different. And you *do* get a more thorough investigation of the site when you stop every few meters than if you sprint for three or more km at a time. It's astounding and greatly appreciated, what these rovers can do.

I guess I'm just saying there's a long way to go... and I look forward to every step along the way.

-the other Doug