They definitely weren't. As I've stated already, they expected to get all the results during the next pass of the mothership-relay, 25 hrs later. It was just bad luck that the mothership failed to enter the correct orbit.

All the figures add up very nicely, a quick back-of-the-envelope calculation already gives you a comm-window of about 18 minutes given the orbiter periapsis of 1500 km. Next, you can calculate the lander trajectory from the velocity-changes and distances given, which indeed nicely shows you that the mothership was immediately overhead at the moment the lander entered the atmosphere. So, in that position you have 9 minutes left in your 18 minutes window. EDL takes about 6 minutes, during which time the lander quickly looses speed and the mothership descents further towards the horizon. So, on touch-down you've got about 3 minutes left in your comm-window. Then it takes 2 minutes for the lander to deploy its antenna's etc and start transmitting (also quoted everywhere by the Soviets), and foila, you've got only 1 minute left to get your picture. Any small hill or a slight tilt of the lander, and you've got only 14 seconds..

They must have known all along that they wouldn't receive much data during that first pass, at best only confirmation of landing, but there was no worry, the orbiter would pass overhead again 25 hrs later and the lander was programmed to send all its data during that next pass (just like Luna 9 and 13 also send most of their data one day after landing). However, the mothership got into a completely wrong orbit (14 days period instead of 25 hours) and the lander missed its relay. Just bad luck.

Merci.

With several sources we can put some faith in that this indeed is factual then.

And yes Mars 3 were indeed on one mechanical automatic sequence.
There's not much to add and no new questions can be asked since Mr Semitiov have passed away: Yet I tend to remember that he also claimed that the short transmission indeed were supposed to be one actual image transmission and not noise. Now that we have the possibility & hypothesis that the short sequence might show the other camera, that claim might be vindicated - though posthumously.

thinking about the foam shell that should have protected Mars-3 during impact, it should be plainly visible, being a little bit larger than the lander. is anything similar visible in the environs? I can't see any shell-like object.
or maybe it was light enough to be carried away by the wind? just pondering...

In fact the so-called "Shock Absorber" was part of the egg-shaped structure itself, covering the Mars-3 lander. I was told that the main idea was to jettison those parts only when the lander came to a rest. My guess is that the bottom section was really crushed flat on impact and most of it is probably still remaining under the lander, because it was positioned between the four petals when jettisoned. Only the segments of the topmost part of the shock absorber covering the "egg" structure should be visible lying on the surface around the lander... Now they must be covered by a lot of Martian dust and are looking like rocks !

from all of the pictures and videos I have seen (see post #24), the shock absorber was to remain in one piece (plus smaller debris), which should be clearly visible, being as large as the lander proper

Dream come true. After '42' years, we've found it. Well done all.
Looking at VikingMars pic http://www.unmannedspaceflight.com/index.p...st&id=30020
Could the dark spot to the left of the probable lander be the PropM Rover?
Seeing as the Lander was following a set routine, thereby executing its functions based on an internal clock,
could it have not released the PropM based on its subroutines. Or was the release to be commanded from the
ground?

Oh, and on the durability of electronics when it comes to impact. Don't forget, the Allies during WWII developed
anti aircraft shells with proximity fuses. They could rapid fire these AA FlaK shells to heights of several kilometres and they would detonate if they
detected the proximity of 'metal', otherwise they would fall back to the earth intact or used a timer to explode and disperse harmlessly in the atmosphere.
Used very effectively against the V1. (Not against the V2, though they where working on it).
And this was the days of Valves and paper capacitors.
Not sure of impact speeds, but the drop for M3 would probably break a mans legs, but for the instrumentation would be well within the design envelope.

ADMIN: Post edited - unnecessary comments removed

The rover was tiny - absolutely tiny. Sojourner was 65 x 48cm and its location is debatable in HiRISE imagery. PropM 21 x 16cm - less than 1/8th the 'surface area' seen from above.

I think using the word 'probable' on locating something <1/2 the size of a HiRISE pixel is a stretch, at best.

Agreed, that's indeed also my biggest doubt/puzzle with regards to the whole find. If you watch the various video's (especially the one Don Mitchell posted recently on FB) then the whole top of the egg plops off in one, big, piece, bigger then the lander itself, and comes to rest quite close to the lander, it should be visible.
On the other hand, those tests were done on Earth, Mars has less gravity so it will probably be thrown a bit further, and it might be any of the 'stones' we see lying around the lander.

The top must have detached though, otherwise the pedals and antenna's couldn't unfold and there would have been no transmission.

As to the prop-M Mars-walker, it was way too small to be detectable by HiRise, no chance we can see it, even if it detached from the lander.

The foam shell candidate suitable by size is available in 25 meters.

thanks. the find looks more and more intriguing

Also, depending on the density of the foam used in the shell, it could possibly have been blown a little in the wind over the years. Especially if it was oriented at any point with the hollow end pointed towards the direction of the prevailing winds.

-the other Doug

Make success dependent on a perfect orbital insertion and the chance to survive one long cold Martian night? They would never take such a risk. Moreover, Perminov clearly says that the duration of the second communication session would be only 0.7-5 minutes. This second session is only an encore.

I hope there are plans for future pictures of the same area.

I'm quite certain there's a translation mistake in that sentence, as only a few lines above it, he states a communication window of 18-23 minutes (page 46). He then states that the second session would be initialized by a signal from the orbiter, and depending on the location of the lander THAT signal would be 0.7 - 5 minutes. IMHO what he means to say is simply that the orbiter would spend up to 5 minutes on attempts to wake up the lander.

Just to be certain, I did the math again, it's quite easy to calculate the time the relay will be above the horizon for a stationary lander. For a 25 hr orbit of 1500-33000 km (as intended for the relay) and estimated dimensions of the lander, I get a communication window of 17 minutes. Sure, that's an optimal situation (with the orbiter passing right overhead), but that was exactly what they planned to do, that's the reason of the 25 hr orbit, synchronized with the rotation of Mars, so it would pass every day at the same time right over the lander. Given the circumstances, it was the optimal orbit for a relay (far less optimal for science operations, as a large part of Mars would remain out of view).

As to surviving the Mars night, the lander was battery powered so it wouldn't mind much about day or night (the day is just as harsh as the night, but it's none different from the situation on the Lunar surface). The lander was extensively tested for this, and would be able to survive for several days. AND remember that this is the same schedule they used as with Luna 9 and 13, although those landers communicated directly with Earth (at a very much lower data-rate) there was only one groundstation so they could only communicate when the Moon was above the horizon at Jevpatoria. Luna 9 send one partial panorama right after landing, but there was hardly anything to be seen on it. Only the next day (night) did it send it's first full panorama picture and further science data. And the same happened with Luna 13, and with Luna 3 it took even much longer before they finally got their pictures, so they weren't afraid to take these risks, it had all been done before!

And finally, offcourse the scheme is risky, the whole thing was risky, but there was no other way. I've tried the math time and time again, and every time I come up with the same answer. If you use the scheme they used (and have been documenting quite excessively, all data you need is there to recalculate this) then there is no other way: the orbiter (relay) will be more or less in the zenit position (right above them in the sky) at the moment the lander reaches the atmosphere, and given the relatively 'low' pass (1500 km) and the high speed you end up with just a few minutes of surface transmissions at the very most, probably just enough to get confirmation that the thing has landed intact (if you're lucky). I would love to see a calculation which shows that you can get 18 minutes or more of surface transmissions right after landing with the given trajectory. No matter how hard I try, I can't get more then just a few minutes at the very most. To get a longer window, the mothership should pass much further from Mars, which it didn't.

We will probably never be sure if this is indeed the whole reason why the transmissions ended abrupty after 14.5 seconds, but it certainly seems a very logical explanation to me.