Okay, we now have definitive pictures of VL1, 2, Spirit, Opportunity, and a Pathfinder coming up soon. So, now, what would the lost landers look like, starting with Beagle, MPL, and Mars 6, which will be the easiest to find of the landers. Just curious to hear your thoughts. Thanks!

> So, now, what would the lost landers look like ...

Mmm, do you already know the answer, tuvas?

Nope, I sure don't, yet. Keep in mind even if we did know what to look for, it's a large area, and without having a really good idea, well, it'd be quite near impossible...

As to why, well, let's just say Alfred is getting tired of being asked about one of these landers, and wants to be able to give them a definitive answer sometime relatively soon. Of course, that could be a few weeks, or a few months, but sometime in that time range.

MPL will have to wait until Southern Summer I presume - we should know where it is FAIRLY well from tracking etc. and we know we should be able to find a parachute VERY easily, as well as Backshell and Heatshield. As for the lander itself - slightly smaller than the viking spacecraft if memory serves me right - and likely to be a lot 'shorter' (i.e. crushed landing legs etc ) - and if there were any 'splat' mark from leaked fuel etc - i would have thought that 3 winters would have eliminated much if not all evidence of that.

Beagle 2, well that supposed MOC target would be an interesting starting point. How far B2 got through its landing sequence before failing will dictate how much 'stuff' is on the ground. The Chute - if 'entry' worked - deflated airbags should be visible as well, if it got further than that. The heatshield, backshell and indeed the lander itself - I would say no - going on the sim I managed which seems to be something roughly indicative going on MER experience...
http://www.unmannedspaceflight.com/index.p...ost&id=8409

As for pieces of the historic Russian landers - I would be doubtfull. They were comparatively small, and their Parachutes and indeed any other hardware- if anything like V1 and V2's chutes - will almost certainly be dust-covered and hard to identify.

Doug

Has anybody derived an estimate of the overall dust deposition rate yet based on the MRO VL1 & 2 observations? This might help to identify the 'lost' landers by providing contrast models, etc.

BTW, did all the Soviet landers use chutes (whether they deployed or not)? These seem to be the most detectable artifacts, generally speaking. I seem to recall that Mars 2 was a hard lander, but not sure if that was a cover story myth or not...

It was a de facto hard lander. It wasn't supposed to be. It entered the atmosphere at an angle that was too steep, and the parachute never got a chance to deploy before impact.

I wonder how visible the impact points of the DS2 landers would be?

Obviously, they were pretty small, but they may have kicked off something when they hit.


Bob Shaw

Let's see, a couple of responses, here...

Doug, I'm not sure we have a really good idea of what the MPL remains might look like. The greatest rate of landform change observed on Mars is in the polar regions; an awful lot of material moves around every Martian year when literally trillions of tons of solid CO2 gets laid down and then sublimates off.

Just for starters, I have to wonder what the simple weight of the dry ice built up on and over the crash (and the backshell & heat shield, for that matter) might have done to them. Just how deep does the dry ice layer lay down at MPL's latitude, anyway? Even if it wouldn't cover over MPL entirely, I'd think you would see some serious effects from being buried in dry ice.

Ditto for the 'chute. I don't know what was used to pigment MPL's 'chute, but I know a lot of dyes fade in extreme cold. After three winters, and dust deposition from the winds during sublimation season, I'm thinking that the 'chute may not be recognizable anymore.

And, yes -- the winds. We see that polar latitudes sublimate somewhat unevenly, with "warm" spots (thinner ice layers or rocks which receive more insolation through the dry ice cap and sublimate the frozen CO2 from below) clearing off and blowing dust onto adjacent dry ice surfaces, which creates more preferential sublimation, which creates more clear spots, until the whole surface is clear. The lander and any of its related EDL equipment might have created warm spots and been the sources of early clearing spots -- which means they might have been exposed to pretty stiff winds as pent-up CO2 gas blew through the ice ceiling. Hey, we *know* they blow through energetically enough to spray dust out onto adjacent dry ice-covered surfaces. What would such events do to the 'chute fabric (especially if it's super-cold)? What would they do to the wreck of MPL itself?

I mean, it's even possible that some pieces of MPL have been blown several meters away from the main crach site.

And to Bob, I'm on the fence as to whether the DS2 impact points would be obvious. We know that Spirit's heat shield drew a gouge into Bonneville's rim, which was extremely dark and contrasty with the surrounding materials. It was quite obvious in both MOC imagery and in the ground-level images from the far rim.

However, while MRO's view of Bonneville shows the heat shield, the albedo difference seems to be almost completely gone. I'll grant you, wind smoothing is probably at its peak effect at crater rims, but this would seem to argue against there being much in the way of identifying marks on the craters made by the penetrators. It might well be possible to identify the impact sites in other ways, but (especially after three Martian winters) I'm not all that sanguine that we'll be able to find them.

-the other Doug

I will bet, umm...a $5 donation to UMSF that the MPL crash site will be very noticeable, due to the effect it has on the environment around it. Here's my wild scenario:

1. SW failure causes the engine to prematurely shut down.
2. Crash, with a small chance of a catastrophic explosion (although I personally doubt it)
3. Lander embeds itself into the ground, creating a depression and disturbing the dust around it.
4. Winter arrives, with the frost deposition covering the area.
5. Spring arrives, and as the sun starts warming the crash site, several things happen:
* MPL itself will heat up faster than the surroundings because of its albedo, and the pyramidal shape of the lander. Even if it is completely under the CO2, as the ice thins it will be heated below by MPL. My prediction is this will cause a "spider" or "geyser" vent to form at MPL's location, on the north side, while the south side stays mostly ice-locked. If any darker dust was exposed during the impact, this would accelerate and intensify the effect.
* The crash site is its own mini-crater, which will sublime faster on the south wall than the north wall, since the south wall faces the sun more directly. This will make MPL look like it is in an oval crater as the CO2 sublimates. If the crater is small enough, MPL's shadow might prevent this from happening.
* The view of the location would, obviously, change based on when during the thaw it is viewed.

So there you have it, my prediction is that MPL will be the first artificial geyser on Mars!

Of course, if it landed in a boulder field, the boulders could also cause a similar effect, potentially hiding the tree among the forest, so to speak.

Terminology point: The Soviet Mars landers, as well as the early Luna landers including successful Luna 9 and 13, Pathfinder, and MER landers are all HARD landers. (Also Venera 4 through 8.) None of them were landings you could walk away from, the payloads were "armored", and the vehicles were not attitude controlled after touchdown.

The US Surveyors, the later Soviet Lunokhod carrying and Sample-return-vehicle carrying Luna landers, The later Soviet Venus landers, the US Vikings, Mars Polar Lander, Phoenix, and MSL are all soft landers.

The Deep Space 2 probes were impactor/penetrators, while the US Rangers and Deep Impact probes were impact missions.

The Soviets were true pioneers of lithobraking!

http://www.lpl.arizona.edu/tekton/crater_c.html

Could be usefull

I've got a segment of the B2 failure report that suggests, if it just splatted in without chute etc - total feature about 5 - 6m across. A crater approx 1.5 metres across, with a rim of about 7cm - think Genesis impact sort of scale.

Doug

And the Ranger seismic capsules were also rough landers (NASA uses 'rough' in their SP-4210 Lunar Impact: A History of Project Ranger, and to be honest I think 'rough' is a better description than 'hard'!).

NEAR, Hayabusa, Phobos 1&2 and Phobos-Grunt are in a class of their own! 'Featherweight'?


Bob Shaw

I just found it ironic that you sent a link to a website from the department that I work at. Wow, I didn't know LPL had QUITE so much fun stuff. Still, it shoulld be useful. It will be quite a challenge to find the lost probes, assuming indeed that they are lost, but who knows, we might have a chance somehow. We'll at least give it a shot. Who knows what'll happen.

What we need is an MSL proposed landing at Isidis Planatia - then you could wallpaper the Beagle 2 Ellipse with a proper reason

Doug

I was a bit disappointed to learn how small the Russian landers were. So... given the poor knowledge of their locations, pretty much the only hope of identifying them even IF Hirise hits them, is a parachute that has somehow managed not to be covered with dust in 35 years...

...but it worked for VL-1!

-Tim.

Mars 2-3 have only been on Mars for 5 years more than Viking, and Mars 6 for 2 years longer. the biggest problem I quess is the certainity of their position.

Jon

"...NEAR, Hayabusa, Phobos 1&2 and Phobos-Grunt are in a class of their own! 'Featherweight'?"

Near and Hayabusa soft-landed, even though they weren't designed to land and sit still.

The Phobos mission "hopper" was essentially a hard lander, though first-impact speed would have been less than any large body hard lander. I have no idea what the predicted orbital evolution of Phobos 1 would have been after failure and communication loss in phobos-synchronized orbit. It was in an orbit with the same period as Phobos, as I recall, but somewhat elliptical, crossing the moon's orbit ahead or behind (or both) the moon as it orbited Mars. Seems likely to eventually impact Phobos, but I never heard a prediction.

The Pioneer Venus probes were "atmosphere descent probes" with end-of-mission at impact, but one nightside probe survived for a second and the Day probe survived for over an hour before it ---> FRIED <---, so it ended up being an inadvertent hard lander.

"Rough" lander might contrast with "smooth"... uh... I prefer Hard-impact and Soft-landing as the un-contracted ideas behind the terminology. The basic distinction is how "ruggedized" the lander must be and how protected it must be from the rough-and-tumble after uncontrolled hard impact vs. the requirement to remain stable after controlled soft impact.

Though the odds are small until we can actually visit the site in person,
I wonder if the little tethered rover on the Mars 3 lander ever activated?
The tether was apparently 15 meters long.

So perhaps MP and the MERs were not the first to make tread marks on Mars.

http://www.planetary.org/mars/tpr_rover-rus_first-rover.html

Man, those were ambitious missions...I sure wish that they had succeeded despite the limitations of their technology & the odds! Thanks for the link, ljk4-1.

Given the (apparently still current) thinking that Mars 3 was overturned by winds, I sincerely doubt that the rover could have deployed. Neat thought, though...

'Wun away wittle wed wover, wun awwaaaay!'

(crunch)


Bob Shaw

Can't remember if they were 2 or 4! I think 4. Do you know how close of each other they were scheduled to "land"? That has always anoyed me that Both MPL and DS2 failed. Hope it's not the whole package that had trouble way before landing. Anyway, I bet we'll see the probe since MRO's has been so amazing so far. I know I'm an incorigible optimist.

The more likely answer is that the Mars 3 relay orbiter went out of range for the
lander or there was a communications problem with the orbiter. The whole bit
about the dust storm disrupting things has been overblown, pardon the pun. I
believe that Martian winds are not quite as fierce as on Earth, even the ones that
whipped dust all over Mars in 1971.

Note that the Soviets were quite big on blaming natural causes for the failure of
their space probes, rather than any problems with their Glorious People's Technology.

When Mars 1 stopped transmitting before it reached Mars in 1963 (even though it set a
distance record at the time), the Soviets blamed a meteor hit rather than any problems
with the communications equipment. It was purely a guess on their part, as they had
no way to detect such a strike, especially one that would knock out the probe as a result.

At least we know that Mars 3 is intact on the surface and its parachute and heatshield
are not too far off. As for Mars 2 and 6, I wonder how easily MRO can tell a relatively
recent artificial crater from an older natural one?

Yeah, I'd buy that as a probable alternative explanation.

IIRC, a 200 mph wind on Mars is equivalent in force to something like 25 mph wind on Earth, and the 1971 dust storm was a beaut. Might have been enough to tip a lander during terminal descent (esp. if it also hit a rock! ), but we probably won't know until somebody physically stumbles across Mars 3 during an EVA. (In fact, it'll probably be a homesteader circa 2600 AD...lucky guy! )

The Mars 3 lander transmitted from the planet's surface for 90 seconds, 20 of which
involved returning an image that likely contained nothing but noise.

Would the lander have been able to transmit at all if it had been tipped over? And
would it have survived landing on a rock in the first place? Just imagine if Viking 1
had come down on Big Joe - we never would have found out what happened to
Viking 1, that's what.

Actually, that's an extremely interesting & pertinent question: How 'directional' was the Mars 3 lander antenna for transmission? The answer may go a long way towards resolving this controversy.

Recall also that Oppy's initial landing was confused by multipath reception due to its location within Eagle Crater; they thought it was still bouncing for a LONG time. Was the Mars 3 transmission just maybe a secondary reflection? This might account for the apparently high SNR...

One theory put forth is that the parachute blew over the lander. My hunch is that the transmitter was the problem, since the Mars 2 and 3 orbiters didn't have a fully working transmitter between them.

So far we've only got a good up close look at one Martian crater definately known to be artificial.

http://antwrp.gsfc.nasa.gov/apod/ap050209.html

Notice how this mini crater displays the dark ejecta seen around far larger and natural recent craters.

I think natural and artificial craters will be indistinguishable unless some debris is still present.

As I think I've pointed out in discussions here a year or two <?> ago, the 1971 global dust storm was in the decaying phase or at most a "plateau" phase at the time of the Mars probe and Mariner arrivals. When the dust fills the atmosphere and pushes tau <opacity, as is currently bothering Spirit rover> to two or more, thermal contrasts in the atmosphere vertically and horizontally are much reduced. The intense variation in solar energy absorption between dusty and non-dusty atmosphere that plays a role in dust storm generation and spreading is gone. There's an increase and change in thermal tides from daytime heating and nighttime cooling of the atmosphere directly, instead of by contact with the heating and cooling surface, but that's generalized, not localized.

It's most unlikely that storm specific winds caused the failure of Mars 3. It's more likely that it hit hard due to imperfect landing system design or poor quality control, or the sorts of problems with the dust-inflated atmosphere that almost caused problems for the MER rovers. It could have had high lateral velocity due to winds and been smacked against a rock..... Whatever. The real problem is that there wasn't any real diagnostic telemetry (so far as we know) reporting on the descent and landing transmitted in real time or after landing. If any was stored on board for eventual relay, I suspect it was rudimentary anyway. There were signals during descent, but I think at a very low data rate.

It's also possible that the dark ejecta could be due to it's recent nature. You can't really rule out anything, at this point in time. Few recent craters have been observed anywhere, and we still have alot to learn about those that we have.

The ejecta color also has to be at least partially a function of local soil composition.

Hmm...odd thought. On Earth, we generally observe that recent impact ejecta (from whatever event) exhibits color differences from the surface, and this phenomenon is usually--not always--due to the fact that the surface has undergone exposure to the elements, and therefore a myriad of chemical changes that the substrate has not experienced.

In this vein, I suggest that the MGS portfolio of recent impacts might merit detailed re-examination by MRO (esp. spectroscopic) in order to try to identify any effects that might be caused by differential oxidation. I'm thinking of the Viking LR "super-oxidant" theory, here...this might offer some new data and/or constraints.

About 40 cm, based on http://ltpwww.gsfc.nasa.gov/tharsis/snow_paper.html -- it would take 3x that much to cover the lander over.

It seems that the hunt for Beagle 2 has already begun.

http://hiroc.lpl.arizona.edu/images/PSP/di...PSP_002347_1915

I do wonder when MRO will start imaging the MPL terrain.

When the seasons allow. The MPL site is in total darkness now.

Doug

Emily L. at Planetary society posted this today:

http://www.planetary.org/blog/article/00000858/

Seems like Beagle2 is NOT sitting in this crater deployed or undeployed. This is the crater that some hopeful B2 people thought held a deployed, but non functioning, Beagle2. Fuzzy pictures stretched to the limit seemed to show, at least to wishing eyes, that the craft was there.

The HiRise picture of the entire landing ellipse is very large, so it may be lurking in the pixels down there somewhere. But as Emily points out, if the parachuite did not deploy, then the craft is very far downrange and therefore out of the ellipse.

Rob

Rob, you'll find the Beagle 2 discussion here.

--Emily