Mars 3 (Various Topics Merged) Options

[tedstryk]

On my website sometime back, I added a page on the image fragment sent back by the Mars-3 Lander. I released serveral versions, including the best quality processing using othodox techniques I would use on other images plus colorization here:
http://pages.preferred.com/%7Etedstryk/fragmentc.jpg
However, I released another image, which I called a "What if" image. This image can be seen here http://pages.preferred.com/%7Etedstryk/m3s5b.jpg It was produced via extreme processing of the original data to make a Mars-like scene, but I made it clear on my website it was only a speculative image. I strongly doubt if the raw data even shows Mars at all - it could be all noise. But since this mode of processing looked strangely Viking-like, I figured I would put it on the web. I was warned by several, who said that while fun, some kooks might take it seriously. My response was that I really don't care what kooks think. Then I noticed this web page:
http://en.wikipedia.org/wiki/Mars_2
They used the overprocessed image. I feel like it is being presented as a true photograph. This is of concern.

[lyford]

Since it's Wikipedia, can't you just delete or edit it yourself?
But I guess the genie is out of the bottle, so to speak....

BTW, I really appreciate your work on your website. Thanks!

[tedstryk]

Thanks. I will be updating the Phobos-2 section soon. I have some reprocessed Thermoscan stuff about ready to go up.
As for the Wikipedia problem, I have been able to edit the caption one sees when one clicks on the image. However, it won't let me edit the caption under the image on the original page. But at least I did get a disclamer in. It is neat to speculate that this might be a glimpse of Mars, but it most likely is just noise. I don't want people to come to a different conclusion based on this image, which, as I said, is very much overprocessed. It is, as I said, an experiment in the area of "what if"

[PhilHorzempa]

[size=2]


With regard to the Soviet Mars landers, I now think that they may have
been "done-in" by the lowdensity Martian atmosphere. Perhaps, the three
Soviet probes that did land on Mars came closer to success than may have
been earlier believed. The recent realization that low density during the
EDL of Spirit may have brought that mission to a sad end has caused me to
reconsider other missions, such as Beagle 2, the MPL and the Soviet Mars 2,
Mars 3 and Mars 6 landers.

It appears that the Mars 2 qnd 3 landers were notdesigned to communicate
back to the Earth until after landing, much like the Mars Polar Lander. If this
is true, then perhaps Mars 2 didn't simply "plow into" Mars as is popularly believed.
Perhaps, its EDL sequence was executed, but low density Martian atmospheric
conditions caused it to be damaged upon landing. The same may be true for
Mars 3 and Mars 6.

In addition, it appears that the Soiets modified Mars 6 so that it did transmit
during EDL as it radioed back data on Martian atmospheric composition (which
threw a scare into the Viking mission sceince team).

I would be interested in the thoughts of others in the UMSF community and
in any additional info that they may have on the Soviet missions.


Another Phil

[Guest_BruceMoomaw_*]

The Soviets actually do firmly know why Mars 2 failed, as V.G. Perminov said in his interesting historical document "The Difficult Road to Mars". They didn't trust the accuracy of their radio tracking network, so they incorporated an optical guidance system into the Mars 2 and 3 orbiters to allow them to calculate the optimal course for their final pre-arrival midcourse correction. Unfortunately, the Soviets had slightly inaccurate data on Mars' ephermeris, and so -- while Mars 2's onboard system worked as planned -- it ended up putting its lander onto a course directed at too steep an entry angle, which would have led to the lander crashing in any case before its parachute could properly brake it.

The Bad Luck Fairy that has always haunted the Russian Mars program struck in a particularly brutal way that time. First, the next year the US (as part of a planetary science data exchange program) provided the Soviets with a corrected Martian ephemeris -- and, second, it turned out afterwards that if the onboard optical system HADN'T made that correction, Mars 2's preexisting approach trajectory would, by pure luck, have put the lander on a properly shallow entry!

The failures of the Mars 3 and 6 landers remain more mysterious. Perminov expresses his suspicion that Mars 3 might perhaps have been knocked out by an electrostatic discharge from the giant dust storm it landed in. As for Mars 6, it failed at about the time its final solid-fueled braking rocket was supposed to fire -- meaning that the rocket could have fired at an inappropriate time due to Martian conditions, failed to fire at all, or exploded.

[tedstryk]

As for Mars 6, it failed at about the time its final solid-fueled braking rocket was supposed to fire -- meaning that the rocket could have fired at an inappropriate time due to Martian conditions, failed to fire at all, or exploded.

It is thought that it probably fired too late...in other words, it was too close to the surface when it fired, so it was still going too fast when it hit. It is because the timing was a bit off. Still, the fact that the timing was as close as it was is remarkable, given that, due to computer problems, Mars-6 had been unable to receive ground commands for five or six months at this point! It was purely operating on pre-programed sequences. In fact, the Russians were expecting this, although they were hoping for a stroke of luck, because they realized, as it approached and the trajectory was refined, that this was a problem, but, since Mars-6 couldn't be commanded, they were helpless to do anything about it.

However, the failure of Mars 4/5/6/7 was really not bad luck. It was bad microchips (which is what made Mars 6 uncontrollable, Mars 7 miss the planet, Mars 5 depressurize, and Mars 4 unable to fire its breaking motors). The scientists and engineers knew it and wanted to delay the mission until the next window to replace them, but since there was a chance that, as Mars-6 came very close to doing, they still might last just long enough to arrive and touch down for a brief surface mission to get the "first," the political powers ordered them to proceed with launch. They were going to try again in 1975 with a similar lander with good microchips, which may well have suceeded, but since Viking was much more capable (although it would have had some experiments that Viking didn't), and the Soviets had already made it to Venus, once it was clear that Viking would launch in the 1975 window, they mission was cancelled. Had Viking been delayed, it would have launched.

[Guest_BruceMoomaw_*]

Oh, yes, Perminov goes into great detail about the lousy microchips (due to a decision made by one lower-level manager to cut costs by manufacturing them using aluminum instead of gold). However, it's doubtful that a "timing error" was the problem, because the ignition moment for the braking rocket on the Soviet landers (as for our own three rough Mars landers) was supposed to be triggered by a radar altimeter -- one could hardly depend on a preset timer for it. Of course, the microchips could very easily have fouled that up. (Or, of course, given what we now know about the atmosphere-related dangers of Mars landings, it could have been a simple wind gust or lower-than-normal upper air density than ruined Mars 6.)

As for their instrumentation (on which Perminov also provides useful data), the only instruments they carried that were not on the Vikings were the penetrometer and gamma-ray densitometer on that tiny tethered matchbox-sized "rover" they carried. The other instruments were two facsimile cameras, weather sensors, an atmospheric mass spectrometer, and an X-ray spectrometer for soil analysis on a boom fastened to one petal tip. No life-related experiments at all, but of course the additional surface geological data they could have provided would have been useful.

[The Messenger]

The Soviets actually do firmly know why Mars 2 failed, as V.G. Perminov said in his interesting historical document "The Difficult Road to Mars". They didn't trust the accuracy of their radio tracking network, so they incorporated an optical guidance system into the Mars 2 and 3 orbiters to allow them to calculate the optimal course for their final pre-arrival midcourse correction. Unfortunately, the Soviets had slightly inaccurate data on Mars' ephermeris, and so -- while Mars 2's onboard system worked as planned -- it ended up putting its lander onto a course directed at too steep an entry angle, which would have led to the lander crashing in any case before its parachute could properly brake it.

The Bad Luck Fairy that has always haunted the Russian Mars program struck in a particularly brutal way that time. First, the next year the US (as part of a planetary science data exchange program) provided the Soviets with a corrected Martian ephemeris -- and, second, it turned out afterwards that if the onboard optical system HADN'T made that correction, Mars 2's preexisting approach trajectory would, by pure luck, have put the lander on a properly shallow entry!

The failures of the Mars 3 and 6 landers remain more mysterious. Perminov expresses his suspicion that Mars 3 might perhaps have been knocked out by an electrostatic discharge from the giant dust storm it landed in...

This is a discussion we should have been having two years ago, right after the MER's descended more rapidly than expected...and it would be helpful if complete engineering Doppler and accelerometer data would be made public so that we can work the problem. Sheeesh.

Perminov's speculation that Mars 3 suffered a static incident is just that: He pointed out probes entering the Venician atmosphere snap crackled and popped, but he has no data from Mars to support this guess. We have had two probes scurrying around Mars for two years now without a single mention of a static event, making Perminov’s theory even more suspect. (Spirit and Opportunity didn’t even experience plasma blackouts.)

Likewise, blaming the Mars 2 failure on both a bad ephemeris and a bad self-correction is a little like insisting the failures of both Beagle and the Polar Lander were absolutely caused by bad engineering, now that another likely suspect has emerged.

There have been a lot of hints something isn’t right in earlier missions: Both Viking craft experienced accelerations that indicate an ‘over performance’ of the parachutes, while the Pathfinder EDL indicated an ‘under performance’ of the same design. I think both characterizations are in error: The Pathfinder did not contain accelerometers, relying on Doppler, while Viking did not have Doppler, but did have accelerometers. If you run the numbers, it is easy to see how in both cases greater acceleration than expected would end up as puzzling drag coefficients. Too many degrees of freedom! More sensors needed!

It is no secret my own bias towards an exceptional solution skews my interpretations of these events, but until we have all the facts on the table, it is difficult to judge which of the many possible scenerios have led to so many failures. PhilHorzempa’s correct; a reevaluation is in order, and for heaven’s sake let’s figure out how to properly characterize the atmosphere!

[mcaplinger]

and it would be helpful if complete engineering Doppler and accelerometer data would be made public so that we can work the problem. Sheeesh.

Have you actually looked at the data that have been released to assess their adequacy? The pre-entry state of the MERs, which is what people have complained about, are on the NAIF FTP site, I believe. All of the raw data appears to be out there to do whatever EDL reconstruction you want; I don't think that the MR doppler tracking is actually useful for the reconstruction, but I believe it was archived with the MOC PDS releases quite a while back.

[PhilHorzempa]

[size=2]

This discussion is very relevant to future Mars landers such as Phoenix and MSL.
I have heard that significant funding ( about $20 million?) was added to the Phoenix
project in response to results from the MERs' EDL. Other than that cryptic info,
there has been silence about this from the Phoenix team. In fact, in an exchange of
emails with one of the Phoenix team, I learned that they are convinced that the MPL was
desroyed by the famous software bug that the Mishap Board uncovered.

The software reset error on the Polar Lander is a good suspect. However, I worry
that, with a suspect in hand, the other risks are being ignored. To me, the biggest
risks are this uncertainty in Martian atmospheric density and the unexplained
oscillations experienced by the ME Rovers.

I agree with TheMessenger that we need to adequately instrument ALL future
landing missions. Also, NASA should be more open about this issue and open
to assistance from the UMSF community.

Does anyone have insight into what, if anything, the Phoenix and MSL teams
are doing to deal with this landing risk?

[tasp]

Sorry I can't cite a reference for this, but it seemed I read somewhere the electrical effects noted during Venusian atmospheric descent were thought due to various compounds and elements in the atmosphere condensing onto the relatively colder external surfaces of all the Venus probes. Local precipitation if you will.

If this be the case, would there be a similar mechanism for Mars?

(other than aerostatic charging as a result of friction with the Martian air)

[The Messenger]

Have you actually looked at the data that have been released to assess their adequacy?

Yes and no. I have made inquires, and been told the engineering data is not going to be made publicly available.

The pre-entry state of the MERs, which is what people have complained about, are on the NAIF FTP site, I believe.

All of the raw data appears to be out there to do whatever EDL reconstruction you want; I don't think that the MR doppler tracking is actually useful for the reconstruction, but I believe it was archived with the MOC PDS releases quite a while back.

Paul Withers wrote in an MER EDL paper he has submitted to Icarus, that he had to make a lot of approximations concerning initial conditions - perhaps the needed information is available now at the NAIF FTP site...whatever and where ever that is. If it is where I have been looking before, there are a lot of 'expected' tables, but the "reconstructed" or actual descent data is just not there. Paul emailed to me that he thought some of the data is ITAR restricted, but I don't see why. He also said that a well-funded study of the MER EDLs - comparable to earlier missions, is not 'in the budget' - I assumed he meant NASA isn't really taking these things apart, but I have been wrong before.

I've been raising my hand and holler'n that I think I can see a stunning trend for a year-and-a-half now. It is hard to get attention when so few people seem to know that the MERs almost splatted - Pathfinder too. As far as I know this is the first really public admission the missions were in jeopardy:

Remarks by NASA Administrator Michael Griffin at the National Space Symposium

At least now I can go to my congressman and tell him why we need to fund more Mars science before we can even dream of going there, because something is not well understood.

[ljk4-1]

Two very relevant documents to this thread online:


The Difficult Road to Mars: A Brief History of Mars Exploration in the Soviet Union

http://klabs.org/richcontent/Reports/mars/...oad_to_mars.pdf


Soviet Veneras and Mars: first entry probes trajectory reconstruction and science

http://trs-new.jpl.nasa.gov/dspace/bitstre...8/1/03-2619.pdf

[tasp]

http://pages.preferred.com/%7Etedstryk/m3s5b.jpg

I realize it will be many years before the Mars 3 site is investigated first hand, but I do hope the team has your enhanced photo with them.

I realize you are qualified to judge the degree of image processing you administered to get the 'Viking' looking result, but, can any amount of processing put consistent shadows on the correct sides of all the boulders in your enhancement? Me thinks there is more than a slight chance you've come up with something significant.

Fun if you 'nailed' it.

[mcaplinger]

Paul Withers wrote in an MER EDL paper he has submitted to Icarus, that he had to make a lot of approximations concerning initial conditions - perhaps the needed information is available now at the NAIF FTP site...whatever and where ever that is. If it is where I have been looking before, there are a lot of 'expected' tables, but the "reconstructed" or actual descent data is just not there.

If you're going to make sweeping assertions, it might help to exhibit more cognizance of the process involved. The NAIF FTP site (naif.jpl.nasa.gov) is the standard place where JPL trajectory information is released. The file /pub/naif/MER/kernels/spk/spk_a_c_030610-040104_recon.bsp on that site is, according to its label, "a reconstructed cruise trajectory for MER-A, beginning at TECO and ending at atmospheric entry." There is a similar file for MER-B. If Withers is unaware of those files, you might want to make him aware. If there's something inadequate about the information, I'd be curious as to what.

As previously noted, that state information and the EDL engineering telemetry archive, which has been released and is available on the PDS atmospheric node, are all the information I can think of that would be useful for reconstructing the entries of the MERs.

I'm no apologist for JPL, but carping on this topic would appear to be unjustified.

Now, it may be that what Withers is lacking is a detailed description of the MER aeroshell composition, shape, etc. The design details of reentry vehicles are covered under ITAR for what would seem to be legitimate reasons. I haven't tried to find those details, nor do I know what data precision might be required. There's a fair bit of info in http://library-dspace.larc.nasa.gov/dspace...ndle/2002/11213

[Phil Stooke]

tasp said "can any amount of processing put consistent shadows on the correct sides of all the boulders in your enhancement? Me thinks there is more than a slight chance you've come up with something significant."

I know Ted's perfectly capable of answering this himself - and nobody appreciates his work more than I do - but I want to follow up on this issue.

tasp - don't be misled by the appearance of the image. The bright and dark spots are not boulders and shadows. Ted knows this, I know it, but it's important that everybody knows it. The raw image is a sea of noise. It is just faintly possible that behind the noise is a view of the horizon of Mars, though I don't really think this is true. But the smaller details are just random areas of more or less noise, made to look like landscape features by Ted's careful manipulation. This is a nice image, but it's art. And that's OK.

Phil

[djellison]

My take on it is - it might be a real picture, and if it is - then this might be what it saw - but we don't really know if it was a proper picture or if it actually saw anything.

Doug

[tedstryk]

My take on it is - it might be a real picture, and if it is - then this might be what it saw - but we don't really know if it was a proper picture or if it actually saw anything.

Doug

This is true. That is why I call it a "what if" image. It is the most optimistic processing possible, and then is aesthetically cleaned up. The lower verions on my site are more modest interpretations. Short of finding the original transmission tapes and discovering that modern enhancements can carry the signal out longer, getting more of the image, there will always be mystery around it.

Even if it did see rocks, without a stereo image, some known object for context, or some knowledge of their distance from the lander, it would be impossible to measure their sizes.

Oh, yes, Perminov goes into great detail about the lousy microchips (due to a decision made by one lower-level manager to cut costs by manufacturing them using aluminum instead of gold). However, it's doubtful that a "timing error" was the problem, because the ignition moment for the braking rocket on the Soviet landers ings, it could have been a simple wind gust or lower-than-normal upper air density than ruined Mars 6.)

I don't mean that the clock wasn't working. It was a problem that resulted in a timing error. Basically, when the engine needed to fire was based on the exact speekd of the spacecraft as well as altitude, and these things were to be determined based on data from the orbiters on approach. Defaults were programmed in case of a situation like this, based on best guesses. Exact trajectory, entry angle, and atmospheric conditions effect the altitude such firings need to be made at. For example, if the atmospheric density was lower than normal, the engine would have to begin firing longer because the lander would need to slow down more, and thus it would have to fire at a higher altitude. There is no way to be sure, but the lack of ability to adapt to conditions certainly could have caused timiing problems.

[ljk4-1]

As I recall, the famous Mars 3 image was first shown in the West on
the BBC series The Planets in 1999. Perhaps someone who worked
on the series and obtained the image from the Soviet scientists can
help here?

http://www.bbcshop.com/invt/bbcdvd1003

http://www.bbc.co.uk/science/space/solarsystem/index.shtml

[Guest_BruceMoomaw_*]

I don't mean that the clock wasn't working. It was a problem that resulted in a timing error. Basically, when the engine needed to fire was based on the exact speed of the spacecraft as well as altitude, and these things were to be determined based on data from the orbiters on approach. Defaults were programmed in case of a situation like this, based on best guesses. Exact trajectory, entry angle, and atmospheric conditions effect the altitude such firings need to be made at. For example, if the atmospheric density was lower than normal, the engine would have to begin firing longer because the lander would need to slow down more, and thus it would have to fire at a higher altitude. There is no way to be sure, but the lack of ability to adapt to conditions certainly could have caused timiing problems.

No, the braking engine on all four Soviet Mars landers was (as with our three rough landers) a solid retrorocket fastened to the parachute, triggered by a radar altimeter, and intended to fire for just a few seconds only about 60 meters above the surface -- it had to be riggered entirely by a radar altimeter because (just as with our landers) there was no conceivable way to know in advance exactly what altitude the craft would be at at any given moment.

[tedstryk]

No, the braking engine on all four Soviet Mars landers was (as with our three rough landers) a solid retrorocket fastened to the parachute, triggered by a radar altimeter, and intended to fire for just a few seconds only about 60 meters above the surface -- it had to be riggered entirely by a radar altimeter because (just as with our landers) there was no conceivable way to know in advance exactly what altitude the craft would be at at any given moment.

Atmospheric conditions would have a lot to do with that. But I can see where this is going, so I digress...

[Guest_BruceMoomaw_*]

Yeah, atmospheric conditions would have a lot to do with how FAST the lander was dropping at the time the altimeter triggered its retrorocket, and could have killed it that way -- and there are of course plenty of ways the faulty microchips could have killed it. But fouling up the precise firing of its retrorocket with a timer malfunction was not one of them. Still, this is something we'll never know the precise cause of, even if some traveller in that antique land someday stumbles across the remains of the lander.

[The Messenger]

If you're going to make sweeping assertions, it might help to exhibit more cognizance of the process involved. The NAIF FTP site (naif.jpl.nasa.gov) is the standard place where JPL trajectory information is released. The file /pub/naif/MER/kernels/spk/spk_a_c_030610-040104_recon.bsp on that site is, according to its label, "a reconstructed cruise trajectory for MER-A, beginning at TECO and ending at atmospheric entry." There is a similar file for MER-B. If Withers is unaware of those files, you might want to make him aware. If there's something inadequate about the information, I'd be curious as to what.

As previously noted, that state information and the EDL engineering telemetry archive, which has been released and is available on the PDS atmospheric node, are all the information I can think of that would be useful for reconstructing the entries of the MERs.

I'm no apologist for JPL, but carping on this topic would appear to be unjustified.

I appreciate the help, but I am not the only one who is finding it difficult to chase down relevant data:

http://nesc.larc.nasa.gov/admin/documents/...ition_Paper.pdf

3. Finding: The overall EDL reconstruction process is not well documented, making it very difficult for an oversight group such as the Red Team to penetrate and assess.
Recommendation: The EDL technical processes, as well as the processes and schedules for required output products and key decisions, should be well documented in a form that is usable by independent experts.

I'm still trying to figure out how close the actual landing times of both MERs were to the expected atmospheric descent - relative to the time of entry: How fast did these puppies fall?

[mcaplinger]

I appreciate the help, but I am not the only one who is finding it difficult to chase down relevant data:

http://nesc.larc.nasa.gov/admin/documents/...ition_Paper.pdf

This is primarily a human factors study, and while it has some interesting tidbits, the notion you seem to be dancing around, that there's some big conspiracy of silence surrounding the MER EDLs, is simply not supported by the evidence.

I'm still trying to figure out how close the actual landing times of both MERs were to the expected atmospheric descent - relative to the time of entry: How fast did these puppies fall?

http://techreports.larc.nasa.gov/ltrs/PDF/...a-2004-5092.pdf -- the "reconstruction" column in tables 3 and 4 seems pretty clear to me. The MER-A RAD firing was 339.4 seconds from entry; the expected 3DOF Monte Carlo range was 317.3-376.2 sec. The MER-B RAD firing was 336.3 seconds from entry; expected 3DOF was 317.1-372.2 seconds.

I'll leave it to Doug to move this discussion to the MER area; it's clearly pretty far off topic here.

[ljk4-1]

This company (which I have no involvement with) is selling an actual
small model of Mars 3 in orbit around its namesake.

See here:

http://apollomaniacs.web.infoseek.co.jp/ap...rtales2b_05.jpg

[Bob Shaw]

This company (which I have no involvement with) is selling an actual
small model of Mars 3 in orbit around its namesake.

Try searching eBay for StarTales and you'll find *lots* of lovely little Japanese 'Candy' models like this - Viking Lander, Lunokhod, Voyager, Sputnik, Ranger to name but a few!

Bob Shaw

[tedstryk]

I have one, and am quite fond of it

[vikingmars]

.../... but I made it clear on my website it was only a speculative image. I strongly doubt if the raw data even shows Mars at all - it could be all noise.

When I was working on Russian planetary data at Brown University in 1984, Russian scientists told me that (i) the Mars 3 "image" is a strip that should be seen vertically and NOT horizontally, (ii) in the 20 seconds of data, NO contrast was transmitted : it was just a kind of "carrier"...
Sorry, but as Ted said, NO real imaging data there. The Viking landers were the 1st spacecrafts which succeeded in taking images from the surface of Mars...

[tedstryk]

When I was working on Russian planetary data at Brown University in 1984, Russian scientists told me that (i) the Mars 3 "image" is a strip that should be seen vertically and NOT horizontally, (ii) in the 20 seconds of data, NO contrast was transmitted : it was just a kind of "carrier"...
Sorry, but as Ted said, NO real imaging data there. The Viking landers were the 1st spacecrafts which succeeded in taking images from the surface of Mars...

In my talks with a few Russians, they have contradicted each other on that...some they it is the very beginning of a scan, others do not. The other issue is orientation...Our understanding of the orientation of the "horizon" line, or even where the horizon should be, could be way off, because we don't know the orientation of the craft, given the possibility that the lander didn't fully open up or tipped over, etc.

[djellison]

Might it be a vertically oriented image, but with a cover or piece of structure blocking the first part thus giving the illusion of a horizon?

Doug

[tedstryk]

Might it be a vertically oriented image, but with a cover or piece of structure blocking the first part thus giving the illusion of a horizon?

Doug

All these things are possible. Part of the problem, coupled with the small size, is the amount of noise. And, if one explaination I have heard, that being that it is some sort of prescan, it may be significantly horizontally compressed. The only possible ways to resolve what happened to Mars-3 are a) send and astronaut or rover to examine it (this will not happen any time soon, but perhaps, if it is something obvious enough, an eagle-eyed orbiter will spot it) or if the original transmission tapes still exist, and they probably don't, use modern techniques to see if anything can be pulled from the noise beyond the 20 seconds.

[4th rock from th...]

Might it be a vertically oriented image, but with a cover or piece of structure blocking the first part thus giving the illusion of a horizon?

Doug

If I'm not mistaken, the image was scanned using vertical lines, and from left to right, the same as with the other russian probes (Luna, Venera, etc), right? So the Mars 3 image we see coming out of the printer is in fact rotated 90º.
Now the issue is to know the direction of the scanning: was it up->down? or down->up in each line?

Not knowing this, my judgement is that we are seeing a vertical image, horizontally compressed and perhaps with a flipped scaning direction. This can explain why the "sky" looks darker than the "horizon". The image might be is reversed ;-).

Here's my guess at the original image correct orientation:



White area at left is the start of the scan, with some sort of autogain feature going down until the image is correctely exposed.


And a processed version (just geometrical correction, rotation to the right and some noise reduction):

[vikingmars]

Not knowing this, my judgement is that we are seeing a vertical image, horizontally compressed and perhaps with a flipped scaning direction. This can explain why the "sky" looks darker than the "horizon". The image might be is reversed ;-).

Assuming that this is indeed a compressed vertical scan of a panoramic section : here is the 20:1 stretch with a quick contrast balance. If the atmosphere was still filled-up with dust (high opacity) the darkening of the atmosphere near the "horizon" is consistent with what was observed from VL1 (link herebelow to VL1 images before and during a dust storm)

http://www.unmannedspaceflight.com/index.p...indpost&p=23875

Attached thumbnail(s)

 

[4th rock from th...]

Just some data, to make things clearer:

The Mars 3 camera scanned vertically, and each scan line has 500 pixels at maximum.
A full 360º image had 6000 of this vertical lines at full sampling rate (1 line per second, 100 minutes for a full pan).

It's reported that the Mars 3 image was being scaned at 4 lines per second. At this rate, a full 360º pan image would be a 500x1500 pixel image.

Using the reported figure of 79 scanlines receaved from Mars 3 in +-20 seconds, the image corresponds to a field of view of 29º tall by 19º wide !!!

This is the contrary to my previous post, and as such there's not really that much horizontal compression on the original data! So the correct proportions might be something like this:

[PhilHorzempa]

I thought that we could try to get the record straight on Mars-96's official
designation on this thread. As I recall (but the memory is hazy), this probe
received the official title Mars 8 since, even though it didn't make it to Mars,
it was launched and did make it into space.

Can anyone confirm this?

If it is true, then perhaps we, on UMSF, should start calling this probe by
its proper name of Mars 8.


Another Phil

[Phil Stooke]

I have never heard 'Mars 8' used for that mission. I would be more inclined to think somebody might have said that informally, and that's what you are remembering.

Phil

[ljk4-1]

I have never heard 'Mars 8' used for that mission. I would be more inclined to think somebody might have said that informally, and that's what you are remembering.

Phil

I have seen Mars 8 used a few times for Mars 96 (and before delays it was
known as Mars 94), but seeing as the probe never got very far, does it really
matter at this point? It doesn't seem to fit in with the Mars 2-7 series other
than its destination, either.

Mariner 8 would have been called Mariner H had reporters not kept calling it
with an 8 even though it ended up in the Atlantic Ocean. Pioneer E, the last of
the long-lived Pioneer solar probes in the 1960s, would have been Pioneer 10
had it not failed, but reporters weren't as focused on it so it retained the E.

Regarding the Mars 3 image, could the lander take images if it was knocked
on its side? Perhaps the lander came down and tipped over due to the dust
storm winds or some other technical factor or a combination of both.

[tedstryk]

Mars '96 would have been Mars 8 if it hadn't been a launch failure. Other Mars spacecraft, such as third orbiter in 1971 which would have beaten Mariner 9, that failed at launch were also never given a number. That is true about the Pioneer series - "Pioneer 10" should have gone to the fifth spacecraft in the Pioneer 6-9 series (they all had letter names pre-launch). Pioneer F and G, the missions we know as Pioneer 10 and 11, would have been 11 and 12, and so on. Since Pioneer E never had a post-launch life, it never became Pioneer 10. And it was the only failure in the Pioneer series since the lettering began with 6. (They didn't count total launch failures in the Pioneer 1-5 series as numbers either, but the two programs of Pioneer 1-2 and 3-5 have nothing to do with the series of 6-13).

[Guest_Zvezdichko_*]

36 years ago, on this very same day, 2 December 1971, the Soviet probe Mars 3 successfully landed on Mars. Though it functioned for only 20 seconds and no science was returned it was indeed an engineering success.

The first and only picture from Mars 3 lander. Image Credit : Ted Stryk / strykfoto.org

[Adam]

I might be wrong, but wasn't it pretty much decided that there was little data returned and that the "picture" is only noise?

[Guest_Zvezdichko_*]

Yes. There have been speculations based on this image,however, that the lander was turned upside down and that line shows the horizon.
I hope that future probes or possibly astronauts will find out that's the reason for the failure

There are some more errr... raw images:




Image of the PropM rover:

[nprev]

A date & an achievement worth noting to be sure, ZV...and only 14 years after Sputnik I!

[Guest_Zvezdichko_*]

Yes, only 14 years after Sputnik mankind achieved a soft landing on Mars!

But... it's December already, it's an important month for Martian Exploration.
For example, tomorrow is 3th December. It's the day when Mars Polar Lander had to land, but the contact was lost. Eight years after that, we still don't know what happened to it.
Then... we have 25th December. It was the day when Beagle 2 was supposed to land... It was also lost...
So, we have several probes (Mars 3, MPL, Beagle 2) which were sheduled to land in December, and all failed. Bad statistics...

[dilo]

Perhaps a little bit OT, but not completely...
Today, when looking to last MER images, I was talking to myself once more: "Is incredible, these beautiful pictures are almost realtime shots from the surface of another planet, and they comes daily in the last 4 years!". Same feeling with Cassini gallery...
I really hope this will continue to be the normality in the future, with a continuous coverage through MSL, EXO-mars and other long-duration missions. Besides scientific return, I think is important to easily access such "alien" visions, it helps us (poor humans) to have a wider breath, avoiding humanity to collapse on herself...
Maybe I'm a dreamer, any though on that?

[nprev]

You're absolutely right, Dilo...we need to keep looking outward, always. We always have before. That's why we didn't become extinct in some forgotten African valley three or four million years ago...there were always a few rabble-rousers that wanted to see what was beyond the next hill.

If we play it right, it's our immortality... ...God, how I hope that we do.

[Shaka]

Good, that makes three dreamers at UMSF.
How many more?

The denizens of Earth need Mars...more than they know.

[PDP8E]

another more recent thread (36 years on mars) has some reference to the famous Mars 3 image and to Ted's work on that image -etc. (thanks Ted)

My question is there a known 'original' or something that the surrogate original (!?) ...something that isn't a lossy compressed image?

Or am I barking up the wrong tree here.... thanks in advance!

[tedstryk]

another more recent thread (36 years on mars) has some reference to the famous Mars 3 image and to Ted's work on that image -etc. (thanks Ted)

My question is there a known 'original' or something that the surrogate original (!?) ...something that isn't a lossy compressed image?

Or am I barking up the wrong tree here.... thanks in advance!

Well, it isn't lossy in the sense that we think of lossy today (jpegs, etc) - what we have are screenshots. Perhaps the original transmission tapes are somewhere in the Russian archives. It has been so long that even if they are still there somewhere, they may have disintigrated unless there were copies made at some point.

[peter59]

Is incredible, these beautiful pictures are almost realtime shots from the surface of another planet, and they comes daily in the last 4 years. I really hope this will continue to be the normality in the future, with a continuous coverage through MSL, EXO-mars and other long-duration missions.

EXO-mars' data released daily by ESA ? Are you kidding?

[dilo]

EXO-mars' data released daily by ESA ? Are you kidding?

Hehe, Peter, I understand your sarcasm but I deliberately included EXO-mars in the hope to see a change in the PR ESA policy in the future... at the end, perhaps, it depends also from public opinion pressure!

[marsbug]

Good, that makes three dreamers at UMSF.
How many more?

The denizens of Earth need Mars...more than they know.

I'd count myself as one more. Although I don't think we should stop at mars

[Guest_PhilCo126_*]

Wait one minute, a topic on spacecraft lost around the red planet or on its surface without mentioning the " Great Ghalactic Ghoul ", an imaginary monster living somewhere out around the orbit of the red planet that just likes to destroy spacecraft
This 'absurd' explanation for lost spacecraft was created by Donald Neff, a journalist of TIME magazine

[PDP8E]

MY SPECULATIVE ANALYSIS OF THE SOVIET MARS 3 LANDER IMAGE


I cropped the ‘probable data’ portion from the original image.




I wrote three C/C++ programs to reduce only image noise:
• Eliminate salt and pepper noise with a modified rank order filter
• Reduce Gaussian noise with a modified sigma filter
• Reduce other noise (speckle and non-Gaussian) via normalization



The modifications I made to several well known filter algorithms (Lee’s sigma filter, the Frost MSE filter, and the rank order filters, -etc.) were done in such a way as to only adjust noisy pixels and to leave the rest of the image untouched. The programs characterized each pixel as either: ‘image’ or ‘highly probable noise’; the programs then assigned the noisy pixels new values depending on their noise type: rank order median for salt and pepper, sigma values or Gaussian, -etc. In the end, over 64% of the final pixels have retained their exact original values. I then wrote another C program to zoom out the image (3x) using the bi-cubic spline interpolation algorithm from the Harley & Weeks image processing handbook.

My Top 4 Interpretations of the Resulting Image

(1) Most Probable - (bright horizontal line at the bottom) - Looking down at the ground at something less then 45 degrees, but not under the ship. The dark area is disturbed soil; may be caused by a skidding/rolling type landing. We are looking out less then 2 meters (?). The bright line is a power up artifact of the camera and/or a reflection off one of the unfolded shiny metal shrouds on the lander. This composition is reminiscent of Surveyor, Viking, Venera, and other landers looking at or near their feet as one of their first images.

( no image - just flip the one above)

2) Possible - (flip the image to any of the two vertical orientations) Looking down again at the ground, possibly an out of focus scrape mark from the ship skidding/rolling or just the soil beneath the camera. We are looking down at less than 1 meter (?)

(3) Most Wishful - (bright horizontal line at top) Looking out at the horizon with a dark ridge in the foreground – notice the ‘rocks’ in and on the dark foreground ridge... Notice the large rock near the top right near the bright horizon. Notice the rock near the bottom right at the trailing edge of the dark ridge. Notice the rock(s) on the dark ridge near the left edge of the image. Notice the dusty atmosphere near the horizon (at top). We are looking outward from meters to the local horizon (a hundred meters?)

(4) Consensus since the 1970’s - This whole ‘image’ is just noise and my programs and your programs and you and I are just hallucinating, i.e. a Soviet Rorschach test.

Some other points to consider:
- Soviet experts (early 1970s) agreed that this image was just noise.
- The camera’s longer axis should be the vertical axis of the image – making interpretation 1, 2, and 3, scenes from a craft lying on its side.
- The landing was during a regional/global dust storm
- The available lighting was supposedly 50lux (low lighting)

I interpret the uniformly bright area in the image as the point where the vidicon camera was turned on. It then AGC’ed within a few lines to a normal gain-level. I suggest this because the noise pixels in the original (un-cropped) image just above this bright area (for ~10 lines before the bright area and parallel to the bright line across the image) are uniformly brighter by a few percent - compared to the noise pixels in all the lines before it; This statistically significant observation suggests the this may be the actual turn-on time of the vidicon; then we see the vidicon ‘blooming’ (i.e. all signal, no contrast, the white area); and then the gain control takes over….and we have a noisy image for ~60 more lines before the transmission stops. Alternatively, since this ‘brighter’ noise is spatially correlated to the bright line, it just may be a photographic artifact of the stupid screen-shot that we have been forced to deal with for the last 30+ years. I would really love to get a hold of the original Soviet data!

Final Conjecture:
Mars 3 landed but may have skidded or tipped over during the final approach. The usual suspects are rocks, rockets, chutes, winds, -etc. The damaged lander started its science sequence. The first image was in the process of beaming down to Earth. The orientation of the camera to the noisy image fragment suggests that the lander is not in the upright position. After 70 scan lines reach Earth, the signal is suddenly lost. What failed? Was it the transmitter, the electrical system, the final remnants of the propellant leaking from broken rocket nozzles onto panels and into the system electronics or maybe the battered lander just slouched and started rolling over again as a result of a precarious perch or the slumping soil and rock mechanics from the hard landing…

To the MRO Crew:
Please take some lucky MRO images of the Mars 3 landing site for Christmas!
Its easy…look in and near northern Ptolemy Crater , 45° S, 158° W; you should see a dusty old parachute and a nearby shiny Soviet lander lying on its side!
Thanks!!


Parting Shot -- A False Color Image of the Wishful Horizon Interp:

Attached thumbnail(s)

 

[Phil Stooke]

"Its easy…look in and near northern Ptolemy Crater , 45° S, 158° W; "


45° S, 158° W (+ or - 200 km or thereabouts).

Phil

[djellison]

So a 400km x 400km search box. 160,000 sqkm

That's only 2500+ HiRISE images - what's the problem.



Doug

[PDP8E]

A brief scan of the web turned up these images of the MARS 3 lander in a Moscow Museum

the cameras are on the top (there were two, I believe...



Here is the ship with lander in the aeroshell



enjoy comrades!

[Paolo]

A brief scan of the web turned up these images of the MARS 3 lander in a Moscow Museum

the cameras are on the top (there were two, I believe...

Yes, there were two of them, and the black box visible on top is the amazing PrOP-M walking minirover

[Guest_PhilCo126_*]

Thanks for sharing those photos and only the black & white photo shows the arm which deployed the PrOP-M, which was a small tethered rover at the end of an arm on these Soviet-Russian Mars pod landers which were based on the Luna 9 four-petalled opening/righting mechanism!

[PDP8E]

We have had 8 more inches of snow today on top of the 10 inches from a few days ago...
...so I was shovelling the driveway and heaving snow and then watching it roll down if i didn't get it over the top of the heap...

I am putting a stake in the ground: based on the proximity of all landers to craters and then Oppy actually rolling into one, I speculate that the Mars 3 is tipped over in the bottom a crater. probably not a very deep one, but I conjecture it caught the slope and rolled over to the bottom. The picture I call 'the most probable' would then show the view at the bottom of a crater with undisturbed and disturbed soil (e.g. Oppy's airbag prints, MER tracks in general, -etc). Now if the HiRise guys just listened to my instructions on how to snap a picture of Mars 3, we will all have a wonderful Christmas present

[vikingmars]

Some other points to consider:
- Soviet experts (early 1970s) agreed that this image was just noise.
- The camera’s longer axis should be the vertical axis of the image – making interpretation 1, 2, and 3, scenes from a craft lying on its side.
- The landing was during a regional/global dust storm
- The available lighting was supposedly 50lux (low lighting)

Dear PDP8 : agreed !
Here are the original "data" in better format + its stretched on its good vertical axis.
The resulting "noise", processed this way, could easily be interpreted as a dark surface seen under a dusty sky with the Sun being hidden by the camera cover just outside the left of the "picture"... If this is indeed an "image"... If the Mars 3 s/c worked well until reaching the surface... If this successful 20 sec data is not Soviet propaganda... Too many "ifs" !!!

Attached thumbnail(s)

 

[Geert]

Various sources all seem to confirm that the camera's of the Mars 3 lander scanned vertical lines, moving from left to right, identical to the camera's on Luna 9/13 and on the later Venera landers. So, as has been mentioned here before, the image should be rotated by 90 degrees and the 'horizon' does not make sense unless the craft is lying (almost) on its side.

There is one more interesting description in 'The Difficult Road to Mars' of V.G. Perminov, who describes the receipt of the Mars 3 lander signal on earth: "The transmission of panoramic images of the Martian surface recorded on the magnetic tape was initiated. The main engineer of NII KP, Yu.K.Khodarev, who was standing close to the rack where the signal was displayed, gave a command to reduce the signal because it was too strong. Then, the telephotometer data were transmitted. There was a gray background with no details. In 14.5 seconds, the signal disappeared. The same thing happened with the second telephotometer."

I presume that the "image" we have is in fact the raw teleprint of the signal as received, in which case the quickly darkening after the white area is in fact not an automatic gain control, but a manual adjustment on receipt of the signal. With the image in its correct (vertical) orientation, the whole "horizon" is then also explained as a further manual adjustment of the gain in the hope of getting some picture...

Personally I am still convinced that the whole error was in the relay via the Mars 3 orbiter, and that the lander probably functioned normally and completed its whole preprogrammed surface schedule. Fact is that the lander survived its landing (it had to deploy its pads and antenna after landing in order to start its transmissions, so probably all the basic functions and electronics worked), and from what we now know the duststorm would probably not have had much effect on it, so it is weird that after surviving EDL and starting its surface operations, both transmitters should shut down more or less at the same time.
On the other hand we do know that the Mars 3 orbiter had some serious trouble when braking into Mars orbit. It's engineburn was cut short, resulting in a completely wrong orbit, and it lost 3-axis stabilisation untill one hour after the burn, at which time the lander data was finally transmitted to earth.
With the orbiter not 3-axis stabilised it sounds reasonable that its relay antenna were not pointing to the Mars surface and it lost lock on the lander signal quickly, in which case it is logical that all lander-channels were lost almost at the same time. The 'picture' seems to confirm this, there are black 'gaps' which seem to indicate the signal was lost, then regained, and then lost again, it did not suddenly stop but it faded in and out a few times..

Finally, the lander was pre-programmed for a surface transmission of 25 minutes, where after it would switch to hibernation mode and wait for a signal from the orbiter on its next pass (scheduled 25 hours later) before starting the next transmission. However, the orbiter burned into a completely wrong orbit, with a period of 12 days, and by the time it finally passed over the landing site again, the lander was long dead...

The only 'hope' of ever getting any information from the Mars 3 lander is finding the original tape of the transmission (the one without the manual changes to the gain), if the error was indeed in the orbiter relay due to failure of its attitude-control, then there might be some very faint whisper of the lander somewhere on the tape which was overlooked at the time, and with our modern equipment something might be retrieved from it. But I guess this is overly optimistic...

[tedstryk]

Two or three minutes into the transmission, the first data transmission (temperature, pressure, etc.) would have come in. If that could be pulled out of a tape, it would be amazing. I seriously doubt that, even if the tapes exist, that anything can be recovered, but it would be cool if it could.

[aconnell]

Dear Tedstryk. I'd be really grateful if you could re-post your images from the start of this thread as the links seem to have expired - I'm totally intrigued !!!

[tedstryk]

It was an image I clearly labeled a "what if" image, using highly speculative techniques, basically just playing around. Brian Harvey asked to use it in his book on Soviet planetary probes, he described it with a fabricated tale of it being found in Soviet archives in Moscow after the Soviet collapse. I will never work with him again. I know other contributors to that book feel the same way for this and many other issues. The first one I would still consider a highly processed image, but the second one really (that Harvey claimed was found in the archives) is more of a drawing than a processed image.

[nprev]

I don't know, Ted. They're undeniably fascinating, but it looks so rocky that I'm having a hard time deciding if this is interpolated noise or not...almost looks Gaussian.

Certainly not criticizing you or your efforts, please understand.

[tedstryk]

nprev, as I said in my description at the beginning of this thread, I think it is most likely just noise. That is why I called it a "what if" image. The only difference between the two images is the level of extreme I took it to....so no offense taken.

[Geert]

On his excellent site on Soviet Space Cameras ( http://www.mentallandscape.com/V_Cameras.htm#Luna9 ) Don Mitchell shows a pen plotter display of the signal from the Mars 3 lander ( http://www.mentallandscape.com/V_Mars3Signal.jpg ), I suspect this plot is the source of the circulating "Mars 3 image", the true plot (and tape?) must be somewhere hiding in some Russian archive if it still exists.

As explained on above site, the plotter was drawing with horizontal strokes, however the camera was scanning with vertical lines, so the image should be rotated by 90 degrees. As also noted by Perminov, the "picture" was featureless, just a grey background. I seem to remember reading somewhere that there was even doubt whether or not this was the actual video signal, the transmitter was working but the camera itself was not (yet?) online. After only 14.5 seconds the signal from both camera's was lost.

We don't know what happened to the Mars 3 lander, we DO know that the Mars 3 orbiter, who relayed the signal, had serious trouble burning into mars orbit, ending up in a completely wrong orbit (period of 12 days instead of 25 hours) and losing 3 axis stabilization for about one hour, this doesn't sound like a very favorable situation for a data relay and might explain why the signal was lost. The lander was pre-programmed to transmit for 25 minutes, where after it would go into hibernation waiting for a signal from the orbiter on its next orbit, however due to its erroneous orbit the orbiter did not pass the landing site again until the lander battery's were long dead, so they never got a second chance to contact the lander.

[aconnell]

Many thanks Ted. I can remember as a teenager in the 80s reading about the tantalising 'partial image' from Mars 3. I must have trawled through half the libraries in London to actually see it for myself - without success. I think what your images succinctly articulate is that all too human frailty of seeing what we want to see - transforming a little strip of noise into the first fleeting glimpse of another world. All I can say is thank goodness the Viking landers succeeded not too long afterwards. Can you imagine how iconic this 'image' might have become amongst the conspiracy theorists? The one and only probe to successfully make it to the surface suddenly and mysteriously falls silent. What is it that 'they' do not want us to see? And who are 'they'? Those that built the mighty Face on Mars of course!!!!!!!!!!!!

[tedstryk]

It is a shame they didn't start the transmission with a temperature/pressure reading or something like that. They would have been able to claim the first data from the Martian surface. Depending on the account, the signal dropped out after 14.5 or 20 seconds. However, the lander had already been on the surface for 90 seconds. That is part of what makes the loss so odd. The Mars-3 orbiter was in a poor position to try to recover it after the initial landing sequence, although it did try. As Geert eluded to, they placed it in a very high orbit that only occasionally brought it near the planet. It was no accident - it had leaked a lot of fuel during cruise, so the planned burn to put it in a shorter orbit was impossible. The fact that they were able to salvage anything is remarkable.

[Guest_Zvezdichko_*]

Conspiracy theorists are and will always be a lost case. Not only because they're always wrong, but because they don't understand engineering. Now we know a lot of technical information about Mars 2/3 landers, that they have a simpler design than Vikings (Ballistic entry+parachute+solid engines+protective foam) and it indeed works. It only needs to be improved. A good starting point for all organizations and agencies that want to land a probe on Mars.

[tedstryk]

Conspiracy theorists are and will always be a lost case. Not only because they're always wrong, but because they don't understand engineering. Now we know a lot of technical information about Mars 2/3 landers, that they have a simpler design than Vikings (Ballistic entry+parachute+solid engines+protective foam) and it indeed works. It only needs to be improved. A good starting point for all organizations and agencies that want to land a probe on Mars.

Well, the Mars-2 and Mars-3 landers are separate cases. Mars-2 was planned using innacurate data about the atmosphere, leading to a suicide trajectory. The only way we will ever know what happened to Mars-3 is the very remote chance that something is recovered off the transmission tapes or the more likely chance that orbital imaging picks it up and gives clues to what might have happened. In the case of Mars-3, the Soviet scientists did try to process the tapes to pull out a signal beyond the time of loss of contact (this worked for Venera-7), but with no luck. I still would love to give modern equipment a crack at it. They indeed had a simpler landing technique. Also, the Vikings are the only planetary landers to have been placed into orbit until an opportune time, after the sites had been surveyed and atmospheric conditions were checked out. A very interesting thing is the Mars'96 penatrator design, which takes the hard lander idea to a new level. The MetNet landers are basically Mars-96 penetrators with improved instruments, so that design isn't dead. The small station design was never built on, but a major reason for that is the fact that the MetNet hard landers can do almost everything that the small stations were going to do and are cheaper, so thanks to improved instrumentation, they are no longer needed.

[Guest_Zvezdichko_*]

Yeah, MetNet is an elegant decision. However, I'd like to see them traveling aboard Phobos-Grunt rather than launching them separately with a Volna rocket (which will be suicidal for the mission).

[tedstryk]

Yeah, MetNet is an elegant decision. However, I'd like to see them traveling aboard Phobos-Grunt rather than launching them separately with a Volna rocket (which will be suicidal for the mission).

Why is that suicidal? The Phobos-Grunt plan was to release the Metnet lander(s?) before entering orbit, so I don't see a difference. The only thing I wish is that they were sending more than one. A badly placed rock could ruin the mission.

[Guest_Zvezdichko_*]

I personally see Volna as an unreliable vehicle.

[tedstryk]

Oh, OK, in the sense of possible launch failure. I see what you mean now.

[Guest_Zvezdichko_*]

Yeah, that's what I meant. Volna failed to launch Cosmos 1 twice. Also we will need a new stage for an interplanetary flight + a cruise stage that has yet to be developed. If MetNet is aboard Phobos-Grunt it won't need it.

[tedstryk]

My guess is that the little Chinese orbiter took its place on Phobos-Grunt. I would imagine that funding is a major issue. The very existence of the mission owes itself to a way Russia could pay back debt owed to Finland in the late 1990s. At the time, Russia was hat-in-hand, but things have changed, and they may not want to sink more into the mission, given that they could easily afford to just pay Finland now.

[Guest_Zvezdichko_*]

I understand, but I also don't see how the design of both Metnet and Yinghuo fits in the overall mission. The oldest schemes I posess are from laspace.ru and they are in Russian (no problem for me, I can read it). How are they going to attach the orbiter? Will it be power-independent during the cruise phase? Will it use its own engines for MOI or it will relay on the engines of Phobos-Grunt?

[tedstryk]

I understand, but I also don't see how the design of both Metnet and Yinghuo fits in the overall mission. The oldest schemes I posess are from laspace.ru and they are in Russian (no problem for me, I can read it). How are they going to attach the orbiter? Will it be power-independent during the cruise phase? Will it use its own engines for MOI or it will relay on the engines of Phobos-Grunt?

I have those diagrams and have wondered the same thing. My only guess is that it will be released before MOI. Given the huge elliptical orbit Yinghuo is supposed to have, it will probably do its own MOI. I have no idea about power during the cruise phase.

[Guest_Zvezdichko_*]

You are probably right. The Chinese orbiter will be dedicated mainly to studying the upper atmosphere and the interplanetary medium. It doesn't need to be into a low Martian orbit.
As for Phobos-Grunt I have also some worries. It's more complicated mission that Phobos 1/2 and Soyuz doesn't have the capability of Proton. Does that mean that a most of its systems aboard have no redundancy?

[tedstryk]

You are probably right. The Chinese orbiter will be dedicated mainly to studying the upper atmosphere and the interplanetary medium. It doesn't need to be into a low Martian orbit.
As for Phobos-Grunt I have also some worries. It's more complicated mission that Phobos 1/2 and Soyuz doesn't have the capability of Proton. Does that mean that a most of its systems aboard have no redundancy?

I think a lot of it has to do with the fact that in the post-Soviet era, miniaturization has greatly improved. I still worry. While NASA has a nasty habit of launching missions stripped down to just a few instruments, Russia has a real problem with trying to load every imaginable device onto a probe creating very high levels of complexity (and many opportunities for failure).

[Guest_Zvezdichko_*]

Yeah, that's why the failure of Mars 96 was really bad. Some of the instruments (HRSC, OMEGA) were reflown aboard Mars Express, others ... well, that's the real loss.

One of the instruments was developed (at least partially) in Bulgaria. It's RADIUS-M. It was supposed to study radiation and if I recall correctly, it's the last Bulgarian scientific instrument which flew aboard an interplanetary mission. I'm sure that another radiation instrument, developed by IKI-BAN will fly aboard Chandrayaan and I hear unofficial rumors that Bulgarian scientists are working with Russian scientists on Phobos-Grunt. Does that mean that they are going to fly once again another radiation dosimeter? I still don't know.

Oh well, here is a link:

http://www.bnr.bg/RadioBulgaria/Emission_E...erial/April.htm - it says a little, but briefly that a "gauging instrument" will land on Phobos. So, yes, they may refly RADIUS-M.

[tedstryk]

I hope it makes it on there!

By the way, here is a link to the page in Harvey's book where he makes his claim.

http://books.google.com/books?id=jKmIclMIw...p8C54&hl=en

[Guest_Zvezdichko_*]

Ted, I'm reading the upper link with a great interest. About Mars 6: it says that the photometer took colour filter images of the atmosphere. Do you have some images (as files)? I had once, on a paper and I lost it

[tedstryk]

I don't think the Mars-6 flyby module took images. The Mars-4 and Mars-5 craft took pictures with a photometer. Mars-6 had one, but I don't think it was used (I could be wrong). Given Harvey's story about the Mars-3 "image," his book is not a credible source. Here are the Mars 4 and 5 photometer images.

http://www.strykfoto.org/mars4and5.htm

[Geert]

About Mars 6: it says that the photometer took colour filter images of the atmosphere. Do you have some images (as files)? I had once, on a paper and I lost it

The Mars-6 lander carried a photometer which was used to measure lightlevels, probably similar to instruments carried on the Venera Venus landers.
Quote: "Contrary to exaggerated press reports, it seems unlikely the instrument was able to return color images" (ref. "Mars 5 and 6 Flight Analysed", Flight International, 4 April 1974 439-440, also ref "Robotic Exploration of the Solar System" Ulivi/Harland, page 167).

I have never seen any reference to pictures taken by the flyby bus of Mars 6 or 7, only pictures taken by Mars 4 and 5 have been published.

[tedstryk]

The Mars-6 lander carried a photometer which was used to measure lightlevels, probably similar to instruments carried on the Venera Venus landers.
Quote: "Contrary to exaggerated press reports, it seems unlikely the instrument was able to return color images" (ref. "Mars 5 and 6 Flight Analysed", Flight International, 4 April 1974 439-440, also ref "Robotic Exploration of the Solar System" Ulivi/Harland, page 167).

I have never seen any reference to pictures taken by the flyby bus of Mars 6 or 7, only pictures taken by Mars 4 and 5 have been published.

I would almost wonder if that reference is to Mars-4 and 5. None of them had color photometers, but instead operated at visible and infrared wavelenths. The film cameras could take color pictures, and Mars-5 returned a few before it failed. Pverkhnosti Marsa is the best reference with regard to this mission.

[Phil Stooke]

A different story on Mars 2 and Mars 3.

Where did they land and why were those places chosen? I was just plotting the locations on maps of image coverage from previous missions. Mars 2 crashed in Hellas, in the area imaged by Mariner 7. Mars 3 landed right on the southwest corner of Mariner 4 image 13, south of Newton crater. This suggests its target was actually inside the imaged area. The target latitude would be defined by EDL design and the seasons on Mars, and is about 45 south for both missions (incidentally, Wackypedia is waaay off with Mars 2... where did that come from?). It makes a lot of sense for the two mission targets to be in the only areas imaged at that time at that latitude. The site's geological context would be known. And Mariner 7 images seemed to show Hellas was a very smooth plain (actually it was looking at clouds inside the basin), so it would be safe.

So all that looks like it might make sense. But then this can potentially be used to resolve the discrepancy in longitudes between NSSDC and Astronautix.com site locations. Astronautix longitudes are ten degrees larger than NSSDC longitudes. But the Mars 3 site wouldn't be in the image area if the larger longitude value is used.

EDIT - next day - oops, I'm maligning Astronautix, the incorrect location actually came from http://history.nasa.gov/SP-4212/ch9.html (The NASA history volume on Viking). (Possibly the website used that value earlier and has edited it recently)

Any thoughts?

Phil

[tedstryk]

According to Sasha Basilevsky, Hellas was chosen for exactly the reasons you say (based on a conversation I had with him). As far as Mars-3 goes, I have no clue.

[Phil Stooke]

Yikes - Google Mars has Mars 2 at the stupid Wikipedia location - it's a travesty ah tells ye!

Phil

[Geert]

Yikes - Google Mars has Mars 2 at the stupid Wikipedia location - it's a travesty ah tells ye!

How much certainty do we have on the Mars 2 position. According to most accounts it was released in the wrong orientation (or at least with the wrong coordinates set) after a failure of the mothership to update the lander data. This in turn resulted in a steep dive into the atmosphere and a crash before the parachutes could be deployed. This sounds to me like it went waaay offcourse. Hellas was probably the chosen landingsite for Mars 2, but it might have missed its target by an enormous distance and I doubt if there is much knowledge as to where it eventually crashed...

Given all the uncertainties with ephemeris data at the time and the various coordinate-systems used, I doubt whether any of these probes are anywhere near their stated coordinates.

[Phil Stooke]

Way off course by a few hundred km maybe, not half way round the planet.

Phil

[Geert]

Way off course by a few hundred km maybe, not half way round the planet.

I agree on you with that.

I have often wondered how the autonomous navigation prior separation/EDL worked on Mars 2-3. They had quite a big problem due to inaccurate ephemeris data on Mars, that's why they needed an orbiter around Mars prior to both landers, when that launch went wrong they had to rely on the untested autonav function from the landers.

The landers had a solid propellant retro-engine, so their retro-impuls was more or less fixed (they could change the orientation but not the duration of the impuls) and from the various accounts it reads like the whole entry sequence was mostly completely fixed and not much could be changed on the spot (even orientation engines were partly 'gunpowder' engines, so fixed impuls). Entry and landing was a parabolic trajectory. Thus everything relied on the mothership releasing the lander on exactly the correct trajectory and in the correct orientation.

The latitude of 45 degrees south for both landing sites corresponds more or less with the inclination of the final orbits of both motherships, and might thus have been a pre requisite of the automatic entry-sequence.

With uncertain ephemeris, the mothership had to update its own statevector prior to release of the lander (using Mars and Sun?), then calculate its final course correction in order to steer to the correct trajectory. Afterwards the mothership had to place itself in the correct orientation, and release the lander (sounds like lander was spin-stabilized afterwards till firing of its retro engine, and then steered into correct entry-orientation). By the sound of it, this was all done automatically and pre-programmed, quite a feat for 1971 technology. It is unclear whether there were any communications from the lander after release, on Mars 6 it is stated that an extra transmitter was added to transmit data during the parachute descent, and this sounds like Mars 2/3 did not have such a transmitter or maybe only very basic telemetry was send.

The fact that the landingsites were chosen from mariner 6/7 images is very interesting and makes sense as these images were freely available at the time and were the best there was to have, but without accurate ephemeris data and with pre-programmed entry-sequences it sounds landing accuracy must have been very low, which makes finding those probes almost impossible.

Regards,

Geert.

[tedstryk]

It is unclear whether there were any communications from the lander after release, on Mars 6 it is stated that an extra transmitter was added to transmit data during the parachute descent, and this sounds like Mars 2/3 did not have such a transmitter or maybe only very basic telemetry was send.

There were not (except for the short signal from Mars-3's decent craft after reaching the surface). After the Mars 2/3 experience, they the transmitter used during descent to Mars 6/7. Sadly, the U.S. would learn the same bitter lesson with MPL.

[DDAVIS]

'The fact that the landingsites were chosen from mariner 6/7 images is very interesting and makes sense as these images were freely available at the time and were the best there was to have'


Before the landing an airbrush map was prepared by the USGS for the Russians of the Mars 3 landing site, which as I recall was of the northern Argyre basin. I remember after the landing failure Dick Pike fretting, as if the Survey had somehow shared the blame by leading them to a bad spot!!

Don

[Phil Stooke]

Hi Don! You are thinking of Mars 6. The Mariner 9 images were not available to support that kind of mapping for Mars 3! Mars 6 landed just north of Argyre and a USGS map of Nereidum Montes was indeed published at that time, and used in a Russian paper on the mission, published in Cosmic Research.

Phil

[Phil Stooke]

http://www.laspace.ru/rus/mars23.php

Lavochkin website on Mars 2 and mars 3. Hmmm. This is the source of the Wikipedia location for Mars 2 - 4° north, 47° west, near Nanedi Vallis in Xanthe Terra. (Thanks Maxim for the information).

But this is completely at odds with information published at the time (links I'll have to dig out, but I think Marov & coauthor, Icarus, 1973) (atmospheric entry at 45 south, 313 west, with crash near 45 south 302 west).

I'm not sure where this leaves the problem, but I don't think it is likely that these coordinates can be correct.

Phil

[Geert]

I'm not sure where this leaves the problem, but I don't think it is likely that these coordinates can be correct.

I fully agree with you that they are very (unlikely) far from the planned landing at Hellas.

Perminov ('The difficult road to mars' NP-1999-06-251-HQ) does not mention any crash-location for Mars-2, and in my opinion his booklet is a quite accurate source for Soviet planetary flights in that period. If he does not mention a crash-location it sounds like nobody at the time was quite sure as to where it ended. If there were indeed no communications with the Mars 2/3 landers after release of the orbiter until after landing then how can we be sure its retro rocket actually fired? The lander might have missed Mars completely and ended up in solar orbit...

I'm still trying to work it out, but the landers used a solid propellant retro rocket, causing a 120 m/sec velocity change. They were released at 46000 km from Mars in an orientation almost perpendicular to the fightpath (drawing at page 53 of the Perminov booklet). The lander was spin-stabilised after release and automatically fired its rocket 900 seconds after release, everything completely pre-programmed. As it was released perpendicular to the flightpath, the pulse of the lander engine did not so much 'brake' its speed as well change the vector and reduce the fly-by distance from 1500 km to zero. In this scenario there is actually not so much you can do to 'steepen' the descent, almost any error in orientation will cause the lander to 'miss' Mars altogether and disappear into solar orbit.

So, it sounds like the whole scenario depended on the trajectory of the mothership at the moment of release, and this is probably what went wrong with Mars 2. According to plan (Perminov, page 53 again) the mothership would be in a trajectory with a fly-by distance of 2350 km +- 1000 km prior to its third and final course correction. This course correction was automatically computed by the onboard computer, and should have resulted in a fly-by distance of 1500 km +- 200 km, where after the lander was released. On Mars 2 the mothership was actually in a fly-by trajectory with a fly by distance of aprox 1500 km prior to the third correction, but instead of skipping the third correction, the onboard computer ordered a third correction which actually 'overcompensated' and decreased the fly-by distance too far. (Perminov, page 57). Mars 2 there after ended up in an orbit with a perigee of 1350 km instead of 1500 km.

Thus it sounds like the whole error was in the final trajectory on release of the lander, which was too steep with a too close fly-by distance. Supposing the lander rocket fired correctly (which we can't be sure of!) this would indeed result in a descent which was too steep.

However, the trajectory can't have been too far off, otherwise the mothership would have burned up in the atmosphere, which it didn't. It's all 'back of the envelope' calculations, but let's say Mars 2 was 300 km 'off track' on release of the lander, then the final entry trajectory of the lander must have been 300 km off track as well (impuls of solid rocket was fixed, lander sequence pre-programmed). Given a Mars radius of 3396 km, this would result in an atmospheric entry angle of 90 - ASIN((3396 - 300) / 3396) = 25 degrees, which is obviously too steep.
Presuming the original entry angle was close to zero, error in landing location would in this case also be 25 degrees, or 1481 km. (see attached drawing).



The very, very, worst case scenario (given the mothership did not burn up in the atmosphere, so must have passed let's say minimum 200 km) would put the lander off track by 1300 km perpendicular to its trajectory, which will give an atmospheric entry angle of 52 degrees and an error in landing location of 3081 km. That's absolutely the very worst case scenario, I can't create a bigger error given the fact that the mothership obviously survived...

So 'most likely' error would be in the range of 1481 km maximum and absolutely worst case error would be 3081 km. It looks to me like the lander was targeted for the Hellas bassin (they seem to have targeted for locations imaged by Mariner 4/6/7 so targeted area must be within one of these pictures), so draw an E-W elips with a maximum radius of 1481 km centered on the Hellas location and start searching...

Note this is all 'back of the envelope' calculating, obviously a lot of factors aren't taken into account but it give's the basic idea of what error we are looking for.

Regarding Mars 3 and 6, the Perminov booklet states a maximum allowed error in atmospheric entry error of 5 degrees, if you ignore all other factors, this gives a landing elips with a maximum radius of almost 300 km (any bigger error and they wouldn't have survived entry). It remains a very big area to search...

Regards,

Geert.

[Geert]

Forgot to mention that according to the above reasoning, the crash location of Mars 2 must be to the WEST of Hellas, as we know it entered too steep. So it must be at least 300 km west of its intended spot (atmospheric entry angle must have been more then 5 degrees too steep, otherwise it would have survived), and it is likely no more then let's say 1500 km to the west (given the final orbit of the mothership) but definitely no more then 3100 km west of Hellas (otherwise the mothership would have burned up). It remains a big, big area...



Track projected on Google Mars. If we assume a landing error of 700 km (which correspondents with a most likely offtrack of 150 km, given the mothership entered an orbit with 1350 km perigree instead of 1500 km) then the targeted landing site would be close to 45S 70E which is almost dead centre in Hellas. I am trying to find out whether this area is inside one of the Mariner 7 images.

Anyway, no matter how I try I can't get Mars 2 to end up anywhere near 4 N. This also does not work out with the mothership ending up in an orbit with a 49 degree inclination, given the relatively small impuls of the lander-engine the atmospheric entry point must be close to the groundtrack of the mothership, which is conform with the 45 deg South locations but definitely does not work out for any location on the northerly hemisphere.

Regards,

Geert.

[nprev]

Thank you for this very comprehensive and interesting analysis, Geert.

I'm more convinced than ever that the only way that these landers will ever be found is by somebody tripping over them in the year 2300 or so. We've already seen that very recent meteoritic impacts leave pronounced scars on the Martian landscape, which is a significant contribution to the S/N ratio; given also the large uncertainty in landing locations (to say nothing of circumstances), there's really no assured way to find them from orbital imagery.

Now, since historically every absolute statement I've ever made has been 100% wrong, let's sit back & wait for the break-through.