Mars 3 (Various Topics Merged) Options

[Geert]

Okay, one more remark and then I leave you in peace

You quote Marov & coauthor, Icarus, 1973 for Mars 2 atmospheric entry at 45 south, 313 west, with crash near 45 south 302 west.

Now covered distance is 11 degrees longitude, this is (11/57.3 * 3360)COS(45) = 456 km
If we assume atsmopheric entry was at 100 km altitude, with a purely ballistic trajectory and discounting all atmospheric influences (..) then the entry angle must have been ATAN(100/456) = 17 degrees.

Now I remarked the lander was most probably 150 km off track on its trajectory (given the fact that the mothership ended 150 km low on perigree), if you calculate the entry angle from this fact then the entry angle must have been 90 - ASIN((3396-150)/3396) = 17 degrees !!!

Seems almost too good to be true...

[tedstryk]

The altitude typically used today is 125 km for atmospheric entry. I am not sure what was used in this mission.

[SFJCody]

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.

I think it might be sooner than that, maybe before the end of the century. Remember how distinctive in colour artificial objects imaged by HiRISE have appeared.
Perhaps some future orbiter using optical communication as standard will be capable of returning multi-spectral imagery with CTX-like coverage and HiRISE-like resolutions.

[yurdel]

please visit http://mars3.gornai.ru - my attempt of animation Mars-3 mission(in russian)

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[Geert]

please visit http://mars3.oktemlyceum.ru - my attempt of animation Mars-3 mission(in russian)

Very good and as far as I can judge technically correct animation!

You quite often see the mistake that the solid fuel engine on the lander was used for a braking manouevre, which is incorrect, it fired perpendicular to the flight path and thus only decreased the passing distance (from 1500 km to almost zero), you show it correctly in your animation.

Only remark is that you show the parachute separating on firing of the soft landing engines, the way I read the booklet of Perminov ('The difficult road to Mars') and especially the drawing on page 47 it seems to me like the parachute remained attached to the softlandingrocket and the instrument shell (similar to what was done with Pathfinder and MER), after the lander is released the softlandingrocket is shown more or less shooting into the parachute and taking the whole thing away from the lander.

I have been searching through the HiRISE images a lot in the vague hope of finding any sign of Mars 3 or Mars 6 but it's seeking for a needle in a haystack, there are lots of 'suspicious stones' but nothing which really shows hopeful. It's such a big, big, area, I'm afraid we will have to wait until somebody accidentally stumbles over the thing in a hundred years or more, and hopefully you're animation is then still around to show them what they've found!

[tolis]

Hi,

Nice video!

One search method that *might* work for Mars 3 is to scan the area by magnetometer on a near-surface balloon.
Mars 3 landed in an area that we now know is characterised by strong remanent magnetisation. Being made of metal I would imagine that
it has the same effect on magnetic field lines as, say, a submerged submarine has on Earth's magnetic field. Perhaps a balloon-suspended magnetometer
surveying the area at an altitude of a few hundred metres can pick up its signature. This is an involving process to be sure, but
not quite as involving as someone going over the surface with a metal detector.

Tolis.



Mod: no need to quote the whole previous post.

[Geert]

One search method that *might* work for Mars 3 is to scan the area by magnetometer on a near-surface balloon.

I wish somebody came up with the budget to do that

But seriously, the area is tremendously big, those landing coordinates are only very, very, vague. The soviets did not have clear ephemeris data of Mars at the time of the landing, the whole EDL process was completely pre-set and fixed, and the entry was ballistic with no guidance steering or anything. I expect only the latitude is more or less known (given the EDL procedure the lander should end up at a latitude which corresponds with the inclination of the orbit around Mars the mothership ended up in), but longitude is very, very uncertain. It can easily have ended up hundreds of kilometers off target, so even with a balloon you will have a tremendous area to survey...

The amazing fact that we still haven't been able to find the wreckage of MPL (of which we are reasonably certain where it should be..) shows just how difficult it is to find 'lost' spacecraft. Mars 3 and 6 are much smaller, there parachutes are probably (almost?) invisible by now and the craft covered by dust (and more or less resembling an average stone..). And it's not that you don't find anything, if you look in the HiRISE images there are lots and lots of big stones over there, and the more you look the more 'suspicious' objects you start to see.. The frustrating thing is that in the end even HiRISE doesn't have enough resolution to clearly identify a Mars 3/6 sized lander (covered with dust), and if you don't find a very clear sign of a parachute then in the end the only solution would be to go down there yourself to check each and every of those suspicious stones, wish I could...

[yurdel]

Very good and as far as I can judge technically correct animation!
...
Only remark is that you show the parachute separating on firing of the soft landing engines, the way I read the booklet of Perminov ('The difficult road to Mars') and especially the drawing on page 47 it seems to me like the parachute remained attached to the softlandingrocket and the instrument shell (similar to what was done with Pathfinder and MER), after the lander is released the softlandingrocket is shown more or less shooting into the parachute and taking the whole thing away from the lander.
...

Thanks!

I'm animate this picture -

Attached thumbnail(s)

 

[nprev]

That was very cool, Yurdel; extremely interesting work, thank you!

[Geert]

I'm animate this picture -

The booklet of Perminov you can download here

The drawing you animate is on page 50 of the pdf, the picture I am referring to is on page 51. There is indeed a difference in how the parachute is released. On page 49 of the book the description is:

Depending on the descent velocity, in an altitude range of 16 to 30 meters, the high-altitude radar-altimeter issues a command; the onboard radio system is disconnected, the engine that controls the soft landing is started, and a second PVM program is initiated. When the landers vertical speed of descent drops to 6.5 meters per second, the low-altitude radar-altimeter issues a command to break the metallic ribbons that attach the parachute-instrument module to the automatic Martian station. Simultaneously, the engine that controls the maneuvering of the parachute container is started.

This seems to indicate the parachute remained attached to the parachute container while the soft landing engine was firing (as shown in page 51 drawing), but I agree that the 2 drawings differ in this, I'm afraid only way to make sure is find one of the original technicians and ask...

I'm also interested in what was the color of the parachute, some of the artwork seems to suggest it was red-white which is a pity given the red colored landscape on Mars, they should make parachutes for Mars landers bright green or something...

[tedstryk]

Amazing work!

[Bjorn Jonsson]

Wow - this was and extremely interesting piece of work.

[4th rock from th...]

Very nice animation! A step by step illustrated time-line, using stills from it would also be nice and informative.

[hendric]

Yurdel,
Very cool. Did you do this for a class? Do you have plans to do other missions?

[djellison]

Very nice - I've always thought it would be fantastic to have old missions given the same CG treatment as MER and Phoenix. This is the first step on that road!