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Unmanned Spaceflight.com _ MSL _ MSL Video
Posted by: Jim from NSF.com Jun 5 2006, 08:54 PM
Saw the MSL video, which was similar to the MER video. It was awesome. Will try to get a copy
Posted by: hal_9000 Jun 6 2006, 12:12 AM
http://phoenix.lpl.arizona.edu/multimedia/videos/phoenix_animation.php
Posted by: Stephen Jun 6 2006, 04:23 AM
Very nice, but that video's for the 2007 Phoenix lander, not the 2009 MSL rover.
======
Stephen
Posted by: Toma B Jun 6 2006, 12:31 PM
Where did you saw it Jim?
Posted by: Jim from NSF.com Jun 6 2006, 02:12 PM
B)-->
Where did you saw it Jim?
[/quote]
MSL PDR
Posted by: RonJones Jun 6 2006, 04:46 PM
--><div class='quotetop'>QUOTE(Toma B @ Jun 6 2006, 08:31 AM) </div><div class='quotemain'><!--quotec-->Where did you saw it Jim?
MSL PDR
It looks like they have a place on the MSL web site where the video will be added (hopefully soon): http://marsprogram.jpl.nasa.gov/msl/gallery/
Ron Jones
Posted by: Toma B Jun 6 2006, 05:55 PM
There is GIGANTIC image of MSL http://marsprogram.jpl.nasa.gov/msl/gallery/spacecraft/MSL_ultra-hi-res-300dpi.html.
http://marsprogram.jpl.nasa.gov/msl/gallery/spacecraft/images/MSL_ultra-hi-res-300dpi.jpg
Is that maybe still from that animation you were talking about Jim?
Looks to me like there is some work to be done on that rendering like adding RTG's...
Posted by: Chmee Jun 6 2006, 08:21 PM
B)-->
Looks to me like there is some work to be done on that rendering like adding RTG's...
[/quote]
It is strange that nearly every image of MSL has it without its RTG. Very strange, is it expected to be powered by dark energy?
Probably they keep it out of the publicity images to keep a lower profile since there are some groups that adamantly oppose *anything* nuclear. Even peaceful scientific missions...
Also, the camera on the mast surprises me. Would they not have two camera's for binocular vision? How can they tell distances without it?
Posted by: BruceMoomaw Jun 6 2006, 09:07 PM
It is a stereo camera -- it just doesn't look like one in the drawing. (By the way, the "ChemCam" experiment that will fire a laser at mineral targets as much as a dozen meters away, to obtain instantaneous and sensitive spectra of their element makeup, also includes a black-and-white telescopic targeting camera that will also be used for very high-resolution long-distance images of terrain features.)
Posted by: paxdan Jun 7 2006, 07:51 AM
One thing that the MERs have shown us is that the surface of rocks on mars can have a substantial rind of altered rock or deposited material and dust coatings. How is the chem cam + laser going to detect the rock underneath this rind and not just the ubiquitous dust covering? Are they going to brush the rocks first then standoff and zap them, my understanding was that the chem cam was going to be a remote sensing instrument (as described by bruce in the above post). Will that be tempered by the need to 'clean' the rock surface first.
Posted by: climber Jun 7 2006, 08:32 AM
Any possible use to detect Purgatory's sort of trap ?
Posted by: climber Jun 7 2006, 09:31 AM
For quite a while, I've been frustrated that the rovers can't look under their deck. It would have been helpfull for Purgatory's kind of events. This could have been solved by adding a simple mirror on the IDD so the cameras would have been able to take pictures. A bit tricky but may be an idea for MSL.
Posted by: Tesheiner Jun 7 2006, 10:19 AM
Voila!
http://marsrovers.jpl.nasa.gov/gallery/all/2/f/503/2F171019233EFFAAFQP1144L0M1.JPG
And Horton did a nice work on the raw 12-bit images here: http://www.flickr.com/photos/hortonheardawho/161036378/
Posted by: centsworth_II Jun 7 2006, 03:34 PM
The laser itself clears the dust and then vaporizes the rock surface layer by layer for spectroscopic analysis (of the vaporized material, I assume). The area sampled by the laser is 0.5 to 1mm in diameter but I wonder what the maximum depth is that can be reached.
There's an interesting pdf power point presentation here:
http://libs.lanl.gov/ChemCam_Fact_Sheet.pdf
Posted by: climber Jun 7 2006, 04:01 PM
[quote name='Tesheiner' date='Jun 7 2006, 12:19 PM' post='57377']
Voila!
Do you mean, it's for REAL or is that another trick? If real, don't you think it could have been of some use while stucked in the sand ?
Posted by: Tesheiner Jun 7 2006, 04:12 PM
No trick (follow the link clicking on the image); remember that a polished metal plate acts as a mirror.
But don't ask me which IDD instrument is that black box (Mossbauer maybe?)
Posted by: jamescanvin Jun 8 2006, 12:43 AM
I think it's the electorincs box for the micro imager. There are similar shiny boxes next to all the cameras.
Posted by: BruceMoomaw Jun 8 2006, 01:37 AM
There's no Mossbauer this time. Indeed, one surprise in the MSL payload is the total absence of any devoted mineralogical instruments on MSL other than the X-ray diffractometer that requires the actual ingestion and grinding of samples -- no Mossbauer, no Raman, no near-IR or thermal-IR spectrometer (although the flash spectrometers for ChemCam can do some reflection-spectrum work as well). The only two instruments on the arm are the color microscopic camera and a near-duplicate of the APX element spectrometer from the MER rovers (which, I've been told, is there largely as a backup in case ChemCam doesn't work as well as predicted).
Posted by: hendric Jul 15 2006, 05:22 AM
Still no EDL video?? I'd like to add it to my collection.
Posted by: gndonald Jul 17 2006, 03:58 PM
--><div class='quotetop'>QUOTE(Toma B @ Jun 6 2006, 01:55 PM) </div><div class='quotemain'><!--quotec-->Looks to me like there is some work to be done on that rendering like adding RTG's...
It is strange that nearly every image of MSL has it without its RTG. Very strange, is it expected to be powered by dark energy?
Probably they keep it out of the publicity images to keep a lower profile since there are some groups that adamantly oppose *anything* nuclear. Even peaceful scientific missions...
Also, the camera on the mast surprises me. Would they not have two camera's for binocular vision? How can they tell distances without it?
I could have sworn that there were some pictures that did show the probe with RTGs fitted, which made it look somewhat like a bombardeer beetle, but they seem to have disappeared from the net unless someone has copies.
Posted by: PhilHorzempa Aug 1 2006, 03:43 AM
Any updates on the MSL entry and landing video?
Also, has anyone heard if JPL/NASA has chosen a snappy name,
for the MSL yet? Perhaps, something like Phoenix or Ares or
Lance Armstrong?
Another Phil
Posted by: Jim from NSF.com Aug 1 2006, 11:45 AM
Any updates on the MSL entry and landing video?
Also, has anyone heard if JPL/NASA has chosen a snappy name,
for the MSL yet? Perhaps, something like Phoenix or Ares or
Lance Armstrong?
Another Phil
Will be getting another opportunity this week to see the video again. Will try to get it.
Phoenix was the name of the project from since its proposal. ARES is an acronym. It is too early for MSL
Posted by: PhilHorzempa Aug 2 2006, 04:59 AM
For those interested in MSL's RTG system, here is the link
to a great paper summarizing the design. It looks like
they have it figured it out, at least in the engineering world.
Perhaps, it is the world of politics, or the availability
of Plutonium, or both, that is holding back
a definite decision.
http://marstech.jpl.nasa.gov/publications/Bhandari-final-paper-2005-01-28.pdf
Another Phil
Posted by: angel1801 Aug 2 2006, 09:47 AM
Russia has said to the US that the US can buy Plutonium-238 for $2000 per gram from Russia if and only if it is NOT used for any military purpose. Russia has lots of Plutonium-238 to give the US!
The US has said it will resume domestic production of Plutonium-238 as soon as possible.
It is most likely that there is a lot of political sensitivity to anything nuclear. Just look at the fuss over the Galileo, Cassini and New Horizons missions!
If we told the people that RTG's were used in the Viking landers, then I'm sure most of the fuss will go away.
Protestors are strange people. No one protested against the launch of the Voyager 1 & 2 probes. Why? Voyager 2 was launched on August 20, 1977, just 4 days after Elvis Presley died! And Voyager 1 launch date (on September 5, 1977) was during the immense grieving over his death!
Posted by: ljk4-1 Aug 2 2006, 02:21 PM
I recall one quite vocal anti-nuke protestor who was not only deeply
concerned that Cassini would somehow fly back to Earth and crash
on it after exploring Saturn but that during the probe's 1999 flyby of
Venus that NASA should have let the craft smash into the second
world from Sol because the planet had no atmosphere!
I was also told by a friend who attended an anti-Cassini (read anti-nuke)
group meeting in Cambridge, MA in 1997 (home to Harvard) that when
he tried to explain how safe Cassini's RTGs were even from an explosion
of the rocket, he was told they didn't want the facts because they had
already made up their minds that Cassini was dangerous and had to
be stopped.
After all that, any amount of sympathy I had with the anti-nuke groups
went right out the window.
BTW, Groucho Marx died around the same time as the Voyagers left
Earth and Elvis went into hiding, but sadly people didn't seem as upset
about his passing.
Posted by: Chmee Aug 2 2006, 05:24 PM
to a great paper summarizing the design.
http://marstech.jpl.nasa.gov/publications/Bhandari-final-paper-2005-01-28.pdf
Another Phil
The very interesting thing in this paper is that they state that thermal control will be maintained by pumping fluid heated from the RTG throughout the MSL.
Basically, MSL will be like a large car radiator!
This has to be a much simpler design than electrical heaters, but I worry about leaks that could happen (like my car's radiator ).
Posted by: climber Aug 2 2006, 07:54 PM
OK, in this case we can name MSL : Lance Armstrong** 
** see post #21
Posted by: dilo Aug 2 2006, 08:32 PM
hmm.. "The working fluid is CFC-11".
I guess we do not have an ozone depletion issue on Mars (...probably we need a little more atmospheric oxygen 
)
Posted by: hendric Aug 2 2006, 09:41 PM
This has to be a much simpler design than electrical heaters, but I worry about leaks that could happen (like my car's radiator ).Oddly enough, I would imagine it to be much more reliable than a car radiator:
- Smaller temperature change - The internal electronics are in a box, so I would expect the temperature change from day/night to be small compared to a car radiator's on/of.
- No jarring impact - Well, other than launch and landing, and falling off the odd rock.
But no speedbumps, hitting road debris at 70mph, etc. - No bugs/rocks whacking into the radiator fins -
Posted by: Jim from NSF.com Aug 3 2006, 04:20 AM
Any updates on the MSL entry and landing video?
Can't get it. It was on a DVD and not a .MOV file
Posted by: mars_armer Nov 21 2006, 07:14 PM
A search on youtube for "JPL MSL" came up with this:
http://youtube.com/watch?v=E37Ss9Tm36c
Posted by: lyford Nov 21 2006, 08:57 PM
hmmm - i didn't realize that the plan was to lower the MSL from so high above the surface before touchdown..... I imagined the hover in place would have been more similar in height to right before the airbags are cut on MER.
edited for grammar
Posted by: Stephen Nov 22 2006, 12:06 AM
http://youtube.com/watch?v=E37Ss9Tm36c
Quite a find! (I liked the blurb at the end: "Coming to a planet near you October 2010".)
I notice the video was only posted a few days ago. Have NASA & JPL posted this on their websites yet? The MSL website http://marsprogram.jpl.nasa.gov/msl/gallery/videos.html keeps saying "coming soon".
======
Stephen
Posted by: nprev Nov 22 2006, 04:46 AM
Very cool indeed, but I sure hope they don't put her in the bottom of a canyon unless there's definitely a way out... 
Posted by: MarkL Nov 22 2006, 06:55 PM
Nice video. Agreed, Lyford. I think they are nuts to depart from the proven payload delivery system that worked perfectly for Pathfinder and the MERs. The long descent with retro rockets will be treacherous and unpredictable. I don't trust a computer to do it as well as a parachute! (But major kudos if it works of course and I will be happy to come back here and eat my words).
Posted by: remcook Nov 22 2006, 07:14 PM
"I think they are nuts to depart from the proven payload delivery system that worked perfectly for Pathfinder and the MERs."
I though MER was about the limit of what you can put onto Mars with that technology... 
Posted by: centsworth_II Nov 22 2006, 07:41 PM
Lots to be scared about! What if ALL the cords connecting the rover to the decent engine don't detatch before it flys off after landing the rover?
Posted by: lyford Nov 22 2006, 07:55 PM
Scaling up MER to MSL won't work with airbags from what I have read.... and I have even come around to accepting skycrane as a workable concept. What makes me nuts is that they don't seem to be planning full scale live testing in the desert, but rather are relying on modeling. Test as you fly, eh?
Or perhaps someone can clue me in on why I should be happy about this....
Posted by: djellison Nov 22 2006, 08:11 PM
If you describe to yourself the process of the MPF and MER landings, and then do the same for the MSL landing...neither is particularly confidence inspiriing.
The thing to remember is that there is only one team of working age in the world that has landed on Mars, and it's done it three times. If they think that the MSL system is the way forward, to be brutally honest there isn't really anyone out there to challenge that imho.
" The long descent with retro rockets will be treacherous and unpredictable."
Well - that's no different to Viking (worked twice) - and indeed given that it's from only 900m altitiude, the MSL decent stage will be working for a shorter period of time than that for Viking probably. We did that 25 years ago.... to call it treacherous and unpredictable today is not true.
There was no full scale testing for Pathfinder, Viking, MER...you just can not test that sort of stuff on Earth - there's no way to replicate the conditions. You can test systems, you can simulate based on those systems - but you just have to build enough smarts and flexibility into the system to mitigate the risk.
And as someone else has mentioned - the bags just don't 'do' bigger....and as it is they take up a HUGE ammount of the payload. For a delivered rover of 180kg, you have 827kg hitting the top of the atmosphere. Scale it all up - a 500kg rover - we're talkig 2300 kg at the top of the atmosphere. The bags are good up to a certain point - but beyond that, they just don't make any more sense.
Doug
Posted by: helvick Nov 22 2006, 08:53 PM
The cord cutting event does look awfully risky when you see it on video but it's not significantly different to the risk associated with blowing the backshell\heatshield and the hundreds of other exquisitely choreographed events that are needed for any lander to get to the surface safely.
Now I would be terrified if I was the engineer actually responsible for making sure it was 100% OK but I think it's safe to say that these guys have proven (repeatedly) that they are pretty damn good at that sort of thing.
The SkyCrane is ambitious but it's not insanely ambitious and I remember prior to the Pathfinder just how insane that seemed before it was proven (again, repeatedly).
I'm a fan - and I'm really happy that we've finally gotten to see this animation. Sweet and many thanks to tubeyhowser for posting it, whoever he/she/it/they are
Posted by: lyford Nov 22 2006, 10:29 PM
I agree, but for some reason I thought they had planned live testing of the "hover and drop" bit but it had been cancelled due to budget. I may be misremembering but I would feel better if they had said that they had cancelled it due to confidence in the simulations.
Posted by: centsworth_II Nov 23 2006, 11:58 AM
No disrespect meant, I'm a big fan of those guys, but this is the point at which one must be on the lookout for hubris. I hope they keep their edge and do not get over confident.
Posted by: ustrax Nov 23 2006, 12:25 PM
I'm sure that when the airbag idea appeared there were also comments regarding the lunacy of the idea...
The time is to innovate and...roll!
Posted by: MarkL Nov 23 2006, 04:13 PM
Check out this http://trs-new.jpl.nasa.gov/dspace/handle/2014/39158 if interested in more detail on MSL EDL. Doug, no matter how you slice it EDL is treacherous and requires perfect execution. It seems like a miracle that the little guys/gals get down in one piece.
Edit: Sadly, wouldn't be complete without http://www.nasawatch.com/archives/2006/01/bob_mitcheltree.html.
Posted by: djellison Nov 23 2006, 04:57 PM
I totally and utterly agree 110% and would never suggest otherwise. However - there is much criticism of the skycrane manouver simply because it looks a bit scarey. So did Viking, so did MPF, so did MPL and so did MER. In some respects it is a hybrid of Viking and MER/MPF techniques...the throttled decent of Viking followed by lander seperation on a bridle and bridle cut at the surface.
I thnk I've been through every PDF I can find and I've even swopped emails with some JPL engineers about the MSL system. When you REALLY think about it - if it can be made to work (and I have no reason to see otherwise) it's arguably a more reliable means of getting things on the ground than the MER system, and certainly the most weight efficient way of getting a rover of that size on the ground.
Put it this way - I have a higher expectation of the MSL system than I would of a repeat of the MER/MPF system and arguably higher than the MPL/Phoenix pulse throttle system.
You are very wrong to label them as 'nuts' for leaving the MER system behind. It simply can not scale to MSL weight. They have to come up with a means of getting a rover on the ground outside that platform. The 'long decent with retro rockets' is actually going to be a shorter decent on retro rockets than was the case for Viking - only about 900 metres. Look at the efforts of Armadillo Aerospace with very little money and time to produce something which could be seen as similar to the MSL decent stage.
I'm not trying to ignore the difficulties...being here in Leicester, I really don't need to be reminded how hard landing on mars actually is... but I'm yet to see a sound argument against the MSL design based on anything other than 'it looks scarey'. With an atmosphere not thick enough to be usefull but thick enough to be a problem - landing on Mars will ALWAYS be scarey.
Doug
(PS - other cool docs - http://trs-new.jpl.nasa.gov/dspace/handle/2014/39907 - http://trs-new.jpl.nasa.gov/dspace/handle/2014/39871 and http://trs-new.jpl.nasa.gov/dspace/handle/2014/38898 )
Posted by: tty Nov 23 2006, 06:56 PM
I agree. In Aerospace applications whenever You have a one-time event that absolutely has to work (typically escape or emergency systems) pyrotechnics are normally the system of choice. They are extremely reliable, degrade very slowly and act instantly.
tty
Posted by: edstrick Nov 24 2006, 11:59 AM
they often have duplicate circuits for really critical pyrotechnics. Duplicate pyros, wiring, everything.
It's extraordinarily rare for pyros to fail to fire. Last time I remember that happening, they put one large sat on a ?Titan? built for two, and wired the spacecraft separation to the wrong pyro-lines. When the booster control sent the separation command, it went down the wires to the non-existent pyros to separate the nonexistant second sat.
That was the last one the Shuttle rescued before they stopped doing that sort of thing.
Posted by: JTN Nov 25 2006, 01:22 AM
It's going to be funny to look back and see rover tracks just starting from nowhere. Hadn't occurred to me before.
(I guess we might get a bit of a mark from the rockets?)
Posted by: Jeff7 Nov 25 2006, 01:36 AM
Exactly. The MERs could have been killed by any number of other things too. Maybe the bolts wouldn't have blown to set the rovers free of the landers. Maybe the solar panel wings wouldn't have deployed, so the rovers would have been as good as dead anyway. All kinds of things can go wrong, many of which could end the mission before it begins. You just have to hope that everything goes as planned.
The time is to innovate and...roll!
I seem to recall something from a documentary about the MERs that was to this effect, that a lot of people thought that airbags would never stand a chance of working. So I think you're right.
Posted by: Navin Mar 16 2007, 02:49 AM
http://youtube.com/watch?v=E37Ss9Tm36c
This MSL EDL video was played tonight on stage at http://www.nationalgeographic.com/nglive/chicago/boykins.html. It was fantastic. The video was longer and extended beyond the YouTube version to include more surface operations. It included a nice segment where the laser ablated a rock and an instrument recorded readings from the "smoke" wafting away and the hole in the rock. Spiffy demonstration.
The longer video also depicted a core sampling drill that could be used on rocks or on the "soil". The core sample (depicted from penetrating a rock) was slipped out of the bit and placed INTO the MSL for some unspecified analysis. Very cool. I hope the whole video makes it onto the web soon.
Kobie Boykins is a MER solar panel designer. Someone in the audience remarked that the MSL video showed no solar panels. He responded (paraphrased): "No. No solar panels. I'll let you speculate on what its power source is, since I'm not allowed to publicly discuss it yet."
Posted by: nprev Mar 16 2007, 04:24 AM
Hmm...curious, but probably wise for a mass audience.
Posted by: ustrax Mar 16 2007, 11:26 AM
http://youtube.com/watch?v=E37Ss9Tm36c
That zooming out in the end, leaving MSL all alone, gives me a chill in the stomach...
Posted by: Jim from NSF.com Mar 16 2007, 11:36 AM
I believe that the corer no longer is part of the mission
Posted by: djellison Mar 16 2007, 11:40 AM
If you feel sorry for the 3/4 ton rover with nucelar power and a frickin laser beam on its mast....what must you feel for the MER's
Doug
Posted by: ustrax Mar 16 2007, 11:49 AM
Doug...
They're grown up now, our two girls have shown to know how to take care of themselves...
Posted by: mchan Mar 16 2007, 12:02 PM
Yes!!! More of them 3/4 ton rovers with nuclear power and frickin laser beams attached to their masts!!! Throw me a bone here, I want high definition video, too!!!
Posted by: As old as Voyager Mar 16 2007, 12:03 PM
The longer video also depicted a core sampling drill that could be used on rocks or on the "soil". The core sample (depicted from penetrating a rock) was slipped out of the bit and placed INTO the MSL for some unspecified analysis. Very cool. I hope the whole video makes it onto the web soon.
Kobie Boykins is a MER solar panel designer. Someone in the audience remarked that the MSL video showed no solar panels. He responded (paraphrased): "No. No solar panels. I'll let you speculate on what its power source is, since I'm not allowed to publicly discuss it yet."
Laser sampling of a martian rock and core drilling by MSL are seen as part of the following Sky at Night extended Mars special. They may be from the same simulation as mentioned above and look pretty cool:
http://www.bbc.co.uk/science/space/spaceguide/skyatnight/proginfo.shtml
Posted by: gpurcell Mar 16 2007, 03:19 PM
Sure gives a sense of just how radical the Skycrane concept is.
That's got to be the most "science-fictiony" thing I've ever seen bent into metal.
Posted by: As old as Voyager Mar 17 2007, 11:51 AM
Upon seeing the MSL rover in simulations I'm always struck by just how scorpion-like the thing looks. That inclined rear RTG really gives it a sting in the tail and the whole thing looks quite menacing, like it'd eat Sojourner for breakfast!
Posted by: Stephen Mar 19 2007, 10:11 AM
http://youtube.com/watch?v=E37Ss9Tm36c
Came across this student project version of MSL's EDL sequence on Youtube (done "a few years ago"): http://www.youtube.com/watch?v=6KQPMpnLicY.
======
Stephen
Posted by: gpurcell Mar 19 2007, 06:35 PM
Oh, and I forgot to mention that I love the Firefly style camera work in the JPL animation....
Posted by: Toma B May 30 2007, 07:30 AM
Just find this...
Mars Science Laboratory Mission Animation - May 25, 2007
http://mars.jpl.nasa.gov/msl/gallery/videos.html
Posted by: nprev May 30 2007, 10:55 AM
Thanks, Toma!
Man...LOTS of moving parts on this critter...
Posted by: Toma B May 30 2007, 12:00 PM
I like that Hollywood-style action camera movement in and out of rover...
Posted by: Stu May 30 2007, 01:35 PM
Just watched the animation (a loooong download on dialup, but worth it! Thanks for the link!) and a whole range of thoughts went thru my mind...
Watching the initial descent: Wow, that's amazing!!
Watching the Skycrane part: *****!!! Are they INSANE?!?!?!?!?! They're really going to DO that?!?!?!?! Hang it beneath a rocket platform like something off Thunderbirds?!?!?! Are they NUTS?!?!?!?!?!?!?!?!
Watching the surface operations: oh, can't wait for that...
Watching the rover hang its head and go to sleep at the end of a sol: awwwwwwww........
Watching the rock sample going through the works: if THAT all works it'll be a miracle...
Watching the closing sequence as the dusty rover rolls away: I want that. Now.
Posted by: RedSky May 30 2007, 03:20 PM
The whole suspend and release process really scares me. I remember a probable cause for the Mars Polar Lander's failure was when the landing gear extended the "bump" that created may have been interpreted as touchdown, so the engines cut off while still at altitude. I can see a similar tug or bump possibly happening to MSL while in suspended state (from air turbulence, swinging, or reaching the bottom of the cable reel-out.)
I don't know why the "skycrane" (in basically its same configuration), couldn't just have landing leg extensions (straddling MSL) and actually land (eliminating the MSL hanging in air). Once landed, MSL could just be similarly reeled down a few inches to the surface, cut loose, and then drive away. That way, they still have their immediately rovable rover, without the dangerous in-air suspension.
Posted by: gallen_53 May 30 2007, 04:00 PM
You are not alone in your assessment of Skycrane. What's really nuts is the future of the Mars Program may depend upon the success of MSL.
Posted by: djellison May 30 2007, 04:01 PM
I think you would end up with a lot of rocket exhaust and high velocity dust impinging on the rover if you did that. The MPL failure was, so they think, a software fault. A line of code would have fixed it - there's little analogous to MSL with the MPL failure really.
And yes - MSL EDL looks crazy. Not as crazy as MPF and MER though.
Doug
Posted by: gallen_53 May 30 2007, 04:13 PM
There's a fine line in spacecraft design between aggressive and crazy. MPF and MER were both very aggressive designs. In addition, I would call MER an aggressive but excellent design. Unfortunately, the less said about MSL the better....
Posted by: AlexBlackwell May 30 2007, 04:31 PM
I could have covered up the member name of this post and still have guessed that Gary is back
Posted by: gallen_53 May 30 2007, 04:47 PM
Alex, I never really left. I've been too busy working to do anything other than lurk here.
Have you been involved in the latest Mars Design Reference Mission (DRM)? They tried to suck me into it but the activity is unfunded (that says something). I'd like to be more involved with the DRM but can't justify taking time off from funded work.
Posted by: AlexBlackwell May 30 2007, 05:41 PM
I'm not sure about NASA Ames but I believe JPL has a special financial code (like 999999 or something) for recording work time on "funding: uncertain" projects, aka "The Land of No Return."
Posted by: gallen_53 May 30 2007, 06:56 PM
About three years ago I was doing pre-Phase-A interplanetary work almost full time. Now, almost all of that has dried up. What little pre-Phase-A work that I'm still doing is unfunded, e.g. the occasional Venus and Saturn atmospheric probe. We were hoping that the Mars DRM would bring in more money but that was not the case. From my perspective there is nothing in the pipe line.
The last interesting pre-Phase-A work that I was involved in was the "CEMMENT" study. CEMMENT was essentially a Mars Sample Return mission based upon an Ares-V launch vehicle and aerocapture at Mars. The bottom line for CEMMENT was $10 billion dollars riding on a single launch.
I'm not optimistic about what's going to happen at JPL after MSL reaches its logical conclusion. It's like there's a curtain hanging over the end of 2008 and no one can see past it. I guess it all depends on what the next President has in mind for the Space Program and whether there is any money to achieve it.
Posted by: Juramike May 30 2007, 07:30 PM
Is there any possibility of mounting instrumentation (weather instruments, seismometer, etc.) on the "platform" section of the descent stage without making things too complicated?
Seems reasonable to expect that it could make a fairly soft landing and might make a nice local cross reference to data from the MSL as it wanders around.
(Imagine the PR release as the MSL comes roving into view.)
-Mike
Posted by: Jim from NSF.com May 30 2007, 11:52 PM
Seems reasonable to expect that it could make a fairly soft landing and might make a nice local cross reference to data from the MSL as it wanders around.
(Imagine the PR release as the MSL comes roving into view.)
-Mike
It isn't going to make a "soft" landing. It will have no power nor telemetry or even a spacecraft computer.
Also, MSL will probably avoid the descent stage since it will be leaking hydrazine
Posted by: dvandorn May 30 2007, 11:59 PM
Jim, I think the suggestion is that the descent stage *could* be programmed to right itself and lower itself gently. It has to have *some* amount of control function in it, since it has to indepedently maneuver itself away from the rover after it cuts the cables.
I wonder just how much mass might be available for a very small science package and a small transmitter that would relay meteorological and/or seismic data back to the rover, and thence through MRO back to Earth? You'd need some light, simple instruments, a small transmitter and a small antenna. How much would that weigh? And how much mass could MSL stand to be added to the overall package?
I don't think anyone really believes that such a capability will seriously be considered, but it's OK to at least think about it...
-the other Doug
Posted by: Jim from NSF.com May 31 2007, 12:00 AM
The "legs" would have to have a shock absorbsion system and able to handle uneven terrain. Also, they would have to be folded and then deployed adding more failure modes.
Basically, the descent stage is landing a few meters above the surface.
It is doing exactly like you said
"Once landed, MSL could just be ....reeled down a few inches to the surface, cut loose, and then drive away"
That's what it is doing, just without a gap between landing and lowering
Posted by: hendric May 31 2007, 04:48 AM
This is complex enough, adding more weight and requirements is just not going to happen. Maybe the 2nd, 3rd, 4th Mars crane, but not the first. Gotta run before you fly.
If we want a seismometer, the best way to do that is to deploy a network, and that doesn't look likely any time soon with the demise of Netlander. This would be a great Mars Scout mission, if it could be made cheap enough, with just a dead simple imager and seismometers. 4 landers would give good coverage, with the option of putting one or two in "challenging" but beautiful locations.
Posted by: Toma B May 31 2007, 07:08 AM
Are you sure about that...
As I understand it , skycrane will fly away quite fast up and away after releasing MSL lander ,suddenly lightened by about 700 kg...whooosh!
When it runs out of fuel ,poor thing will have some hight and speed so when it crashes it will burst any hydrazine reservoirs that may contain some residue of fuel...
Why do you think it will be dangerous for MSL lander to go near crashed skycrane even if it had some hydrazine left in its reservoirs as long as it doesn't fire its "laser weapon" on it ? I would like to see that thing on Mars seen through the eyes of MSL...
Posted by: Jim from NSF.com May 31 2007, 11:52 AM
Any residual propellant or products could contaminate the science instruments
Posted by: djellison May 31 2007, 12:55 PM
I think the MSL decent stage will be given the same sort of treatment as the MER backshell and chute....keep away. Although Mastcam might get us a nice shot from 100m away
Doug
Posted by: mchan Jun 1 2007, 03:29 AM
B)-->
its "laser weapon"
[/quote]
Must have watched too many bad sci-fi movies years ago as one of my first thoughts was Marvin would probably suffer sudden incontinence were he to see MSL drive over the top of a dune towards him.
Curious on the significance of "53" in members tim53 and gallen_53. Maybe it's 42 equivalent in the professional UMSF community.
Posted by: dvandorn Jun 1 2007, 03:43 AM
As long as MSL has a laser and not an ACME disintegrating gun, we're OK. We all know that when you pull the trigger of an ACME disintegrating gun -- it disintegrates!
-the other Doug
Posted by: Ron Hobbs Jun 25 2011, 12:13 AM
New animations have been posted. They look pretty good.
http://www.jpl.nasa.gov/news/news.cfm?release=2011-195
Ron
Posted by: djellison Jun 25 2011, 12:52 AM
Wow - time warp thread. Who would have thought I'd end up at the technical director for that animation :0
Fairly pleased with the end result. And yeah - it has sounds-in-space syndrome, but that part wasn't my doing
Posted by: charborob Jun 25 2011, 01:21 AM
Is that Gale crater in the animation? Also, too bad the video doesn't show the skycrane crashing after leaving the rover.
Posted by: KrisK Jun 25 2011, 02:49 AM
Fantastic!!! I noticed that just before SA/SPaH was moved Mastcam had been pointed right. I suppose the reason is to make free space for robotic arm, am I correct?
Posted by: djellison Jun 25 2011, 03:20 AM
No - it's a HiRISE DTM, but not one of the 4 final candidates.
Can you imagine the feedback if we did? A smouldering wreck with fuming hydrazine? A very expensive shot to model and animate as well. Not showing that was a very easy decision.
Yup - it's to avoid a potential clearance issue when returning the arm back to stow or for sample delivery. Well spotted
Posted by: Explorer1 Jun 25 2011, 03:37 AM
I do see a dust devil at one point; at least that's what I think it is? Nice touch.
Posted by: eoincampbell Jun 25 2011, 03:43 AM
Is a certain direction and distance from Curiosity expected of the landed descent stage, besides "far away" ?
Posted by: djellison Jun 25 2011, 04:12 AM
No, you don't. The odd gust of dust to keep it from being all too static - but not a DD.
From http://trs-new.jpl.nasa.gov/dspace/handle/2014/41629 - Page 12 specifically
first holds the current altitude for 187 msec to allow
sufficient time for the umbilical to be cut. After the
requisite hold time, the MLEs throttle up and the DS
ascends vertically for a predetermined amount of time.
Then, the DS begins to execute a turn to approximately 45
pitch. The DS holds this attitude with the MLEs at 100%
until the fuel depletes. The hold, ascent, and turn take place
within 2 seconds, and the remaining time is variable
depending on the amount of fuel remaining. The DS will
then ballistically fall to the surface at a distance of at least
150 m from the Rover
I would expect it to be significantly further than that. Perhaps 10x.
Posted by: elakdawalla Jun 25 2011, 04:56 AM
While I imagine it was an easy decision not to show the thing wrecking in detail, I have to own up to the fact that I wish the shot of it arcing away from the rover ended a little bit later, after it disappeared behind the horizon, followed a second later by a little "pfft" of dust, Wile E. Coyote style
I enjoyed the lovingly detailed shot of the MarsDial and the rover tai chi!
Posted by: eoincampbell Jun 25 2011, 05:02 AM
Cheers Doug, thanks for the link, lots of Curious goodness in that http://trs-new.jpl.nasa.gov/dspace/handle/2014/41629 !
Posted by: djellison Jun 25 2011, 05:11 AM
So do I
When it premiered infront of 400 members of the MSL project - that moment got a brilliant reaction - exactly the same reaction as you could hear in the background audio of the Mars Odyssey launch when a forward looking rocket-cam cut out the very second the upper stage was due to ignite after 3rd stage sep.
Posted by: Explorer1 Jun 25 2011, 06:07 AM
Well, MSL could do a nice hardware survey like with Oppy's heatshield (if it's not too long a detour of time and distance from the planned science of course). Though ground conditions will prove whether its even possible in the first place.
Posted by: djellison Jun 25 2011, 06:16 AM
Not of the descent stage. It will have leaked hydrazine and other ugly compounds after crashing. I would expect them to give it an exceptionally wide berth.
Heatshield, sure.
Backshell and Parachute - from a distance >> the length of all the lines and the chute.
Six impact craters from ballast ejected before 'chute deployment - why not.
But not the descent stage.
Posted by: tbruckner Jun 25 2011, 11:56 AM
Very nice animation. One question: shortly before atmospheric entry there are two little L-shaped blocks separating from the capsule. What's that?
Posted by: Astro0 Jun 25 2011, 12:16 PM
From the http://trs-new.jpl.nasa.gov/dspace/handle/2014/41629 posted by djellison above... page 4.
...Approximately 5 minutes before entry interface, two external cruise balance masses are jettisoned to create an offset center of gravity...
...In contrast to the spin stabilized entries of MER and Mars Pathfinder (MPF), MSL utilizes an offset center of mass to create a nominal 18degree angle of attack through peak heating and dynamic pressure, increasing to a 20degree angle of attack just prior to parachute deployment. This angle of attack generates lift which is used to reduce the landing error ellipse size and increase the parachute deploy altitude.
Lots more exciting facts to be found in that document
Posted by: nprev Jun 25 2011, 04:45 PM
VERY nice animation, Doug. Kay & I just watched it utterly spellbound; well done!
Posted by: Oersted Jun 27 2011, 12:47 AM
I remember discussing the fate of the skycrane with MarsEngineer on this forum a good while ago, and to my recollection he said something like that, sure, if they had time for it they might try to program a soft landing into it... Not a priority though, and since it doesn't really serve a purpose, apart from pollution mitigation, it probably wont happen. Would be neat if they tried though.
Love the animation! The only things I didn't quite like were the flyby sounds in space (I can live with the mechanical sounds and the thruster ones, since those events actually transmit sound through the structure of the spacecraft), the lack of an ionized trail through the atmosphere and the somewhat tinny sound of the skycrane rockets. I think it will be a good deal more deep and throaty in reality. The rest of the animation is top notch and you even showed us parachute deploy, which was something Maas edited out very niftily for the MER edl animation....
Posted by: nprev Jun 27 2011, 03:06 AM
Now, now, let's not forget that the primary objective of such videos is outreach...so, begging questions of credibility in minor ways is in fact an opportunity, not a fault.
All us UMSF regulars know the score, of course. Sad fact of the matter is that so many do not, and these are the people we need to reach.
PR is not easy; seems like something that really should be, but it just ain't. What this video does is capture the sheer awesomeness of the mission, and really it's okay to leave some room for questions after the flash is presented; these can only be productive in the grand scheme of things.
Yes, it's a bitter pill to swallow for all us hard-boiled rationalists (who have the presumed advantage of a decent background in science; don't forget that fact; not everyone has that!). But the whole idea is to communicate what MSL can & will do to people that are much less acquainted so that they can appreciate this marvelous thing as we do already; no need to preach to the converted, after all!
MSL is being very smart with this, and I applaud them for it. There is a consistent tendency for UMSF missions to underestimate the value of PR--apparently in the misguided belief that the scientific value of a given mission is manifestly obvious (but again: it just ain't). Gotta get past that. PIs, even if you gotta hold your noses at the very thought: You gotta really LEARN this for what I would now expect to be glaringly obvious reasons.
End of tirade. Only hope that a couple of PIs will read it & dig it.
Posted by: djellison Jun 27 2011, 05:16 AM
They wont be trying. Moreover, it doesn't help mitigate pollution. That stuff will leak out eventually anyway. The ONLY requirement of that DS after rover bridle cut is for it to get as far away as it can, as quickly as it can.
Imagine that entire sequence silent. Infact, you don't have to - you could turn your speakers off. It gets very very tedious very very quickly. The sounds were not my idea, and I'm not a big fan of them either - but I know why they're there. I've had lots of comments about the sounds being annoying. I've also had comments that it's not loud enough. That tells me it's in the middle ground.
Have you seen either at first hand? (Answer, no... no one has) I had an interesting discussion with the EDL people about the entry fireball. We went with what you see based on those discussions - the blue being a symptom of the emission spectra for CO2 (that was my cunning idea
) - the lack of a trail....I couldn't find documentation either way that would infer there would or wouldn't be one. It's also a really hard thing to try and animate well. Of course, one could counter your argument about throaty engine sounds with an argument about atmospheric density at Mars etc etc. We had one day in a studio to do the entire sound track. It's a case of using what was available. There was one sound specifically recorded for the animation though.... the sample being dropped into the instrument inlet tube. That was a sachet of sweetener from the sound studio's cafeteria being poured into a cup.I was asked again and again by project people to add loads of loud music. I said that we couldn't do that - but I'm sure the public would do it themselves once it was out there. Why not try your own pass at the audio....trust me - it ain't easy.
Posted by: ElkGroveDan Jun 27 2011, 05:39 AM
) - the lack of a trail....I couldn't find documentation either way that would infer there would or wouldn't be one.This got me to wondering, are there plans for MRO/HIRISE to have a stab at an image as they did for Phoenix? Will it even be possible based on orbits and locations?
Working on it....
Posted by: Oersted Jun 27 2011, 08:42 PM
..Hope you didn't miss the "Love the animation!"-part... But, hey, I know: it is your baby, and a lovely baby it is!
This is fabulous outreach. If you want to make a version with explanations I can recommend the annotation functionality in Youtube. It is really good. You can place the annotations exactly where you want, time them to perfection, etc, etc. I've used it myself for some fun annotations of flight sim movies (a new hi-fidelity flight sim out called Cliffs of Dover, focusing on the Battle of Britain). This is how the annotations look:
http://www.youtube.com/user/wwwDOTdalsgaardDOTeu#g/c/981CBC682E928D2A
Posted by: monty python Jun 28 2011, 07:44 AM
Beautifull morning flights there.
All you peoples great videos make me want to say - I LOVE UMSF!!!!
Posted by: Oersted Jul 4 2011, 03:54 PM
BTW, I found what MarsEngineer said about this subject... (partial quote, from the "Skycrane" thread):
I will respond to Oersted's questions by italicizing his questions
...
...It would be neat if the lander/skycrane itself could fly off and make a soft landing with its remaining fuel. There will now be to years extra for coding, so maybe a little proggie can be made for the skycrane computer that could try to effect that? Why would it be interesting to land softly? Maybe to scour some trenches that the rover could visit... Then again, a crashing lander should make a nice big hole on its own.
hmmm.... you are not the first to suggest that we try for a soft descent stage landing, Oersted. While that would not be impossible to consider, it would be a lot of work and as you know (and MSL folks know all too well) time is money. However I will be more than happy to tease my friend Jeff about it (he's one of the main developers of the code that controls the "flyaway" mode of the descent stage).
******
Comments and opinions expressed are the author's and not of JPL, Caltech nor NASA.
Posted by: monty python Nov 21 2011, 07:57 AM
Sorry to resurrect an old thread here but after looking at the MSL EDL awesome video for the 10th time or so, it dawned on me- do we know what direction the "skycrane" section of the landing system will fly after landing?
Could it fly directly into our path towards gale crater?
I would really like to see the reck.
Posted by: nprev Nov 21 2011, 09:04 AM
Not a bad question, but I don't think it will be an issue. My understanding is that after a nominal touchdown the descent stage will have enough fuel to depart in whatever random direction for quite some distance...and, frankly, MSL doesn't want to be anywhere near it, wherever it happens to crash.
The descent stage will undoubtedly have all kinds of highly volatile material--mostly hydrazine--present regardless of its end state (unless by some miracle it blows itself into literal smithereens.) Nobody wants that stuff anywhere near the geochemical science payload. Hell, I don't even want it near the optics.
Bottom line is that "ooo! cool!" would probably be the most reward we'd get for imaging the wreckage of the descent stage. The risks to MSL's mission success incurred by approaching that crap would be far greater...easy math to do.
Posted by: MahFL Nov 21 2011, 11:09 AM
I think I read somewhere the Skycrane would head off at 270 degrees. Also that they definately won't be going anywhere near the wrecked skycrane.....well at least not for the first 10 years .
Posted by: MahFL Nov 21 2011, 12:45 PM
Could it fly directly into our path towards gale crater?...
Curiosity is of course landing inside Gale Crater, I think you meant the central mound, right ?
Posted by: ElkGroveDan Nov 21 2011, 03:24 PM
As I recall (but forget where I heard it) even Opportunity approaching the heat-shield turned out to not be such a good idea. Again from memory, during that stop there was some kind of chemical or particulate residue that accumulated on the hazcam lenses. In this low-pressure, sterile environment, anything from earth that comes to a violent end on Mars is going to be coughing up all kinds of polymers, residues, and other non-propellent volatiles that were never intended to be part of a rover or lander.
Posted by: Oersted Nov 22 2011, 11:13 PM
Well, they had two extra years to enter some extra code into the Skycrane, so as MarsEngineer teasingly said, maybe they've tried to see if it can be made to soft-land, given that enough fuel remains... - Would be very cool (and environmentally responsible! )
Posted by: nprev Nov 22 2011, 11:27 PM
I think that adding a new requirement (and new software, and system-level testing, and, and) for the descent stage to soft-land would incur a tremendous amount of mission success risk for VERY limited potential gain.
Believe that we already established the fact (via Dan's post) that there's no valid scientific (or even a priority engineering) reason to approach the descent stage due to the risk of contamination. It could severely screw up the science instruments, and as far as post-game engineering analysis...hey, either it works or it don't. If MSL survives the descent, then it worked.
I think the "Skycrane" is gonna fly off once its job is done & go boom. But it will be fondly remembered.
Posted by: MarsEngineer Nov 23 2011, 01:27 AM
Hi all,
It has been a long time since I have posted. MSL has been keeping me swamped.
In answer to the question about the descent stage direction of flight after flyaway, unlike Phoenix, we have no specific requirement on the rover's compass heading upon landing. While we could have dedicated some fuel and timeline to orienting the "powered descent vehicle" configuration into a desired orientation prior the start of the skycrane phase (near the ground) we decided that the rover had enough to do in EDL so we don't bother. Once the rover lands the descent stage will either fly away from the front or away to the back of the rover (the RTG side). We can a priori select which of these two options to use by command that will be sent in the days leading up to EDL. We do not want the descent stage to bank or twist in such a way that the canted rocket engines impinge on the rover so those two are the only options. Once it tips away and heads out it essentially accelerate in a fixed attitude for a fixed duration or it runs out of fuel.
In summary we can not say today which direction the descent stage will be from the rover in advance. We will certainly know the day of landing from the data the rover sends during EDL on the UHF radio link to the orbiters. We also know that it will be around a half kilometer away (either behind or in front) of the rover.
In any case we will not drive the rover to the descent stage nor to the heatshield. We want to keep the rover clean and the descent stage has stuff that we do not want near the rover's sensitive equipment. Indeed there was a lot of concern when we drove Opportunity to its heatshield after landing (at my and my team's behest). We wanted to learn more about the heatshield performance (we learned a lot!).
Unfortunately, while the rover was near the heatshield, apparently wind picked up some particulates that got onto the rear Hazcam lenses. It may have been a coincidence and it was only Mars dust but more probably it was char from the heatshield that the wind blew onto the lenses.
We are ready! The team is working on the post-launch list of things to do (finally).
-Rob Manning
Posted by: nprev Nov 23 2011, 01:37 AM
You heard the man, people. (And thanks for posting this, sir!)
Posted by: MarsEngineer Nov 23 2011, 01:40 AM
)Hi Oersted,
Indeed I was teasing! It is not impossible, but it is really hard. Perhaps the next time?
Regardless we could never do a "soft" landing with those engines. It will have to stop and drop.
-Rob
Posted by: MarsEngineer Nov 23 2011, 01:42 AM
You are welcome nprev! Good to see you still at it!
Yes the descent stage will be fondly remembered! (imagine the cruise stage fans!).
-Rob
Posted by: nprev Nov 23 2011, 01:56 AM
...meh, I'm sometimes unpleasantly persistent.
But glad you came to visit, man. Please keep on doing so when time permits....we VERY much appreciate your insight!!!
Posted by: monty python Nov 23 2011, 07:02 AM
I love this place!!
Posted by: ElkGroveDan Nov 23 2011, 07:14 AM
Ditto Rob, in the thanks-for-dropping-by parade.
On the subject of the heat-shield recon, has there been any kind of paper, journal interview, or other public summary of what was learned? Even in a very general sense? Or is that data all still proprietary?
Posted by: remcook Nov 23 2011, 03:17 PM
Wow, it's getting really close now. Fingers crossed multiple times!
Posted by: eoincampbell Nov 23 2011, 05:13 PM
Mr Manning stopping by, how awesome is that! All the very best for the mission. MSL is lucky to have such EDL legends in attendance...
Posted by: MarsEngineer Nov 23 2011, 05:43 PM
On the subject of the heat-shield recon, has there been any kind of paper, journal interview, or other public summary of what was learned? Even in a very general sense? Or is that data all still proprietary?
Hi ElkGroveDan,
Not proprietary, just slow to come out (paper writing is becoming a more of a hobby these days - not enough hours in the day). There were at least two papers published. The summary paper was finally published at the 42nd AIAA Thermophysics Conference last June. In summary we concluded that the char depth of the heat shield material matched our predictions (yea!). We also learned that a piece of a mylar blanket that skirted the heat shield became a "flap" that induced some minor but very noticeable wiggles of the entry vehicle (capsule) during Opportunity's entry just before parachute deployment. The blanket was supposed to fully melt away during entry but we found that part of it did not (it was on Mars still attached to the crumpled heat shield). Its position and size matched our entry dynamic simulations for a flapping flap. Needless to say MSL does not have a blanket covering its heat shield (neither did Phoenix).
back to work ...
-Rob
Posted by: elakdawalla Nov 23 2011, 06:24 PM
That one took a little more detective work than usual to locate. The citation: "Mars Exploration Rover Heatshield Observation Campaign," by C. Szalai; B. Thoma; W. J. Lee; J. Maki; W. Wilcoxson; E. Venkatapathy; T. White. There's no abstract online but there is an http://www.mrc.uidaho.edu/~atkinson/IPPW-3/Manuscripts/session_3_Gas_Giants/21_Szalai_ppt.pdf (PDF, 4 MB). I was able to look at the first couple pages of the PDF but the download appears to be hanging for me.
Posted by: ugordan Nov 23 2011, 06:55 PM
Happens often to me in Firefox. I find it's safer/quicker to download the thing properly and open it afterward than let the PDF plugin handle preload.
Posted by: Paolo Nov 23 2011, 06:58 PM
had the same problem under firefox. it downloaded nicely using wget
Posted by: eoincampbell Jun 23 2012, 04:35 PM
From the animation so full of detail, could someone explain the propellant tank discoloration patterns on the descent stage ?
Some great close-ups of descent stage http://boingboing.net/2011/04/06/nasa-mars-science-la.html.
Posted by: djellison Jun 24 2012, 12:41 AM
That's just a thin foam jacket around the tanks - wrapped in kapton tape. Before launch, they also got silver MLI blankets as well.
Good photo in a more finished config - here - http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA15020
Posted by: pospa Jun 24 2012, 07:56 PM
In this traditional pre-landing video http://youtu.be/pzqdoXwLBT8 they mention 76 pyrotechnic devices that must work just perfect during EDL to have succesfull landing.
Does anybody know if some of them are in pair = main + backup pyro, or every single of them serves for specific task?
Or the best would be some list of all 76 pcs with description of dedicated function, something like:
1 - 3 : cruise stage separation
4 - 5 : balance mass ejecting (2 x 75 kg)
6 - 11 : balance mass ejecting (6 x 25 kg)
12 : parachute jettisoning
13 - 18 : heat shield separation
...
...
Posted by: MarsEngineer Jun 25 2012, 12:44 AM
Yes, 76 is about right. And yes, each is for a separate "task" (some, like the 9 pyro separation nuts around the perimeter of the heat shield that hold it in place share duties but all have to fire to release the heatshield). Nearly all 76 of these must work (there is some redundancy in the thermal batteries, but that is about it). Another handful are fired after landing in the first hour to release the equipment needed for the surface mission (high gain antenna, arm, mast, etc) for a total of about 81.
Compare with MER. MER fired 37 pyros during EDL (through touchdown and rolling to a stop in the airbags). Another 18 pyro devices were needed to get the rover upright and into a configuration with the lander petals and solar arrays open and another 9 in the days afterward for the equipment needed for the surface mission (rover stand up, high gain antenna, arm, mast, etc) for a total of 64. So MSL has about 26% more than MER in total.
Like on MER, all of these pyro device have redundant electrical initiators (mostly NASA Standard Initiators or NSI's) so if we failed to get enough current into one, the redundant circuits will do the trick.
There are a lot of other pyros you do not list, like the in-space freon vent, the filling of the propulsion lines, cable cutters (electrical), rover wheel releases etc.
I find it best not to think about it too much any more. (Because folks have - day and night for a long time now.)
We have successfully tested every one of these device (designs) many times and over the years we have developed a lot of confidence in them.
-Rob Manning
Posted by: nprev Jun 25 2012, 03:00 AM
Thanks very much, Rob; always a pleasure to hear the definitive scoop from a pro!
Posted by: MarsEngineer Jun 25 2012, 03:50 AM
My pleasure as well, nprev. It is good to see you still at it. I wish I had more time to visit more often.
For you and the gang: you might be wondering what we are up to. As seems typical of this time before landing (yeah, I should post this in the "Approach" thread), we spend 90% of our time on those 500,000 lines of code. Not that it is buggy, but we want to make sure that it works under a wide range of potential (low probability) "off nominal" (our popular euphemism for bad or unexpected) situations. So we spend a lot of time injecting these bad things into the testbed and looking to ensure that the software muscles through it. It seems to be doing well for the vast majority of the things we through at it. I am talking about both the EDL version of software (R9) and the version we will boot into in the first week after landing (R10).
It is definitely a case of fine tuning. The hard part is that we could keep doing this until the cows come home (or landing is over). We have done the same for all our Mars missions.
-Rob
Posted by: pospa Jun 25 2012, 06:43 AM
You confirmed my assumption about redundant initiators (no backup pyros). Now I can finally convince some of doubters within our "cosmo gang" in CZ.
Thanks a lot !
Also thanks for the latest team activity update.
Yours faithfully pospa
Posted by: Oersted Jun 25 2012, 01:07 PM
As for code sent to Mars, is any being uploaded to MRO/HiRise for MSL's EDL? None of us will forget the great job by you and others to capture the iconic Phoenix over Heimdall image. Are we again perhaps fortunate with the conjunction of spacecraft trajectories this time around? I won't even begin to ask about the backdrop... ;-)
Good vibes and peanut-chomping from Europe,
Oersted
Posted by: djellison Jun 25 2012, 01:23 PM
HiRISE will be trying again to get MSL during EDL. As with PHX - it will require good planning..AND good fortune to actually get it.
Posted by: MarsEngineer Jun 25 2012, 02:43 PM
Yes Doug is correct. On PHX, we actually had a better, more glancing view angle from MRO that increased the chances that we could see the PHX under its parachute. Despite the much smaller ellipse for MSL, MRO will be looking more straight down toward the ground (nadir) so the amount of "swept volume" is less than we had with PHX. So I think the odds will be about the same (I have not done the math comparison so take my words loosely please).
Hi Oersted, as far as I know, there is no MRO code update, only new sequences for the imaging and the attitude profile.
Pospa, with so many things that need to go right, skepticism is a natural and proper reaction. We live in a world where healthy skepticism is needed for success. As Adam points out in the video, if you stand back and look at all of this, one could and should be skeptical. Only by thinking critically every day about failure modes might we find a pathway to success. (Say hi to the "Cosmo gang" in CZ for me.)
On that note, one of my more odd (recent) jobs as chief engineer (which is a bit like chief of "odds and ends") is to help coordinate the contingency plans for what might happen if we lose the signal(s) from the vehicle during or just after EDL. For example, on a good day the EDL team will be tired, happy and ready to celebrate or sleep. On a bad day I need to make sure that they instead come back to work after a short sleep and help analyze the data and (UHF and X-band) signals so that they might inform the surface team about the state of the rover and perhaps allow us to regain communication with the rover. Of course losing the signals during EDL is not exactly a great sign, but we all know that there are real failure modes and conditions where we lose the signals and yet the rover will land safely. In some (fault) cases the first time we would hear from the rover would be a day or so later. (bring in the antacid!). I am also working with the MRO gang to see when we might get a post-landed HiIRSE picture. The geometries are not great until a week later, but we may try something earlier. Working on it.
That I have some time to do this is a good sign. We still have a lot of "paper work" to close out and we are madly doing that too. (Yeah, we will still land regardless of the status of the paper, but we are trying to keep our promises.)
Ok, enough procrastination ... must ... get .... back ... to .... work.
I'll stop by again in a week or so.
-Rob
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