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Simulation of the Mars Science Laboratory Sky Crane
An anonymous reader points us to Gizmodo for a fascinating video of NASA's Sky Crane. "When I read that the UFO-looking Mars Science Laboratory's aeroshell would use a floating crane — called Sky Crane by NASA — to softly land the rover on Mars, I couldn't believe it. Now, watching this hyper-realistic NASA simulation, I still can't believe how the whole thing works. I don't know about you, but the whole operation mesmerizes me to no end."
That is so complicated. The "beach ball" idea from the two current rovers was much better.
Maybe if the Sky Crane was a ballon system so it can float around Mars would make this better. But still way too complicated.
Almost realistic: the simulation approaches what the same inputs would do to the real system.
Realistic: the simulation behaves the same way as the real system.
Hyper-realistic: the simulation is better at realism that they real system?
What next, über-realistic? Or is profit next?
If I have nothing to hide, don't search me
I think the site got slashed, I can't view the vids :(
Moved to http://soylentnews.org/. You are invited to join us too!
Why does NASA have to spend money on new untested methods? If the old baloon method worked well for two previous rovers, why not use it again? It is hard to beat a 100% success rate. Does anyone know why they want to use this over other methods?
The sysadmin in me says: The more moving parts, the greater the chance something will break.
We've got to flex some of our engineering muscle in front of our Martian friends so they will less inclined to invade us. In this light, clearly this > bouncing beach ball delivery.
Maybe have an external speaker system that blasts Ride of the Valkyries during descent, too.
I know that Mars's gravity is only about 40% of Earth's, and its atmosphere is less dense. So would a parachute even work? It doesn't seem that a less dense atmosphere would be able to generate the air resistance needed to keep the rover up in the air, especially with all the gas the crane needs as fuel to generate the thrust necessary to hold the rover in the air. I don't know the exact physics of it, but just in terms of a balance of forces, this does not seem extremely plausible.
The skycrane seemed preposterous originally & still does. Having said that, autonomous helicopters are pretty germane nowadays & everyone knows about Stanford's aerobatic helicopter so maybe it's not so crazy anymore.
What are the chances it lands on its side or back? It would be very embarrassing to land the thing on its side or back, with everything otherwise functional and intact, but still completely useless.
As cool as this is, we've succesfully landed rovers on mars (and the moon, though not a robotic system), as well as landing non-motile craft on other planets. All used relatively simple delivery systems, and frankly, worked pretty well. The Apollo system (at 40 years old) landed softly enough not to smash human beings, which can be a lot more sensitive than robots. Maybe this type of technology will have a use in the future (though it's not like it's a super-high-tech idea). All of that being said, GOD DAMN that's cool!
We seem to be able to get to mars better, the Russians do land landings better than us.
why not have them design and build the landing mechanism, and we just fly it there?
_ _ _ Go for the eyes Boo! GO FOR THE EYES!
It will never work. If they do simulations and small scale testing, and say it will work, then they are fools.
It will have to be deployed full scale into the earth's atmosphere, successfully, before I would believe that the design would work...there are "too many moving parts" and the flight control is similar to the Moller Air Car...it doesn't work either...
What a shame...another space probe condemned to be space junk.
Remember the last complicated descent method of NASA's that worked so perfectly? The get-caught-by-a-stunt-helicopter-pilot method? Granted, the reason that crashed was fairly mundane, but still...
Did anyone else get a Black Mesa vibe from the wind sound effect at the end of the video?
Also, would wind sound like that in an atmosphere like mars'?
-b
No offense, but I've stopped responding to AC's.
Geeks having sex is awesome! :)
Shai Schticks:"You don't make peace with friends, you make peace with enemies"
this is way too complex and complicated... i mean sure... it looks cool, but whats wrong with the giant bouncing ball idea. If you have something that works, why change it?
That video was boring. Why dont they just make a mini helicopter to decelerate the thing? Or is the air too thin for that?
The reason why airbags won't work is because the MSL Rover is about the same size as a large car. It amazing to think something this large will be traveling around mars. http://en.wikipedia.org/wiki/Image:Mars_Science_Laboratory_empty_chassis.jpg Image of MSL under construction.
I don't think that word means what you think it does.
Here is a link to a Universe Today story outlining the difficulties of landing on Mars. This is mostly about a manned mission but it does specifically reference the MSL. http://www.universetoday.com/2007/07/17/the-mars-landing-approach-getting-large-payloads-to-the-surface-of-the-red-planet/
The guy that's been doing the 3D animations for high-profile NASA projects usually goes as close as possible to the reference. There don't appear to be any solar panels on the rover - is it nuclear-powered, or what?
That's a pretty big payload. I can't wait to see that one ton of rare earth elements get the "crane" cable fouled up in its wheels because there's no way those cables just drift away like the simulation shows. Sure, the eggheads at NASA will have a plan to have the crane boost off again once the lander touches the ground but either the rover will be flipped or dragged along the ground or those cables will continue downward into the wheels and experimental equipment on the lander itself. Murphy's Law is begging on its knees right now to get its hands on this new extremely expensive soon-to-be piece of Martian masonry.
I seem to recall Viking doing just fine with the tried and true rocket landing method.
Who is tagging every post on /. as story and why? I know this is off-topic but I'm so curious. Oh and by the way, this is how to find life on Mars.
-- Cheers!
Was it just me or did anyone else expect to see Jayne suspended from the bottom of that rover?
We always knew Comcast was corrupt, here's the proof: http://tech.slashdot.org/comments.pl?sid=1909890&cid=34545432
The problem with soft-landing heavy objects on Mars is that there's not enough atmosphere for aerobraking and parachutes to do the job, so the approaches used for Earth re-entry won't work. There's too much gravity for landing on rockets. as with lunar landers, without most of the payload being landing fuel. The problem gets harder as the mass goes up. This was realized only about five years ago, to the embarrassment of some within NASA. So there are now various complicated hybrid schemes, like this.
The scheme with the cables does not look promising. Unlike Luna, Mars has winds and weather. This looks like one of the student lander designs from NASA's high school curriculum.
One bad feature of this design is that the actual landing forces have to be taken by the rover's suspension. Previous designs had the rover inside the landing module, not underneath it. That approach uses crushable components (air bags, crushable blocks, collapsible legs, etc.) to cushion the landing. With this "flying crane" approach, the autopilot has to do a really, really smooth landing or the rover will be broken.
First off, if you saw the video, you saw that there are far too many potential points of failure, and untried methods. While our automation is a lot better than even 10 years ago, from an engineering standpoint (mine), this seems to be a bit of a stretch.
One of the reasons that Spaceship One successfully made suborbital flight when NASA said it couldn't be done on that kind of budget, is that they bypassed some of NASA's fundamental assumptions. And one of those basic assumptions has always been that you have to get something from space to the surface as FAST as reasonably possible.
While that might be the most direct approach, Spaceship One showed beyond doubt that slowing descent as much as possible first, beginning at the highest altitude (their deliberately "non-aerodynamic" mode), was more economical and efficient than the "drop like a rock" method that NASA has always used, and continues to use.
(Before you inundate me with comments about orbital velocities vs. synchronous drop velocities, let me say that I KNOW the difference, thank you very much. That does not change the basic concept.)
Even in their most recent plan for this Mars descent, their first mode of descent is to drop the module like a stone, using elaborate and expensive heat shielding to protect the even-more-expensive gear. But maybe -- just maybe -- they could take a lesson from Spaceship One and just take their time getting this thing down to the ground.
But that is something that NASA has NEVER tried before. Or, as far as I am aware, even studied seriously.
I know that the atmosphere is thin. But that presents no more problems to a slow approach than it does to the fast. If NASA would at least try -- as Mojave and Scaled Composites did -- to look at it from the standpoint of getting the payload down as S-L-O-W-L-Y as possible, rather than as fast as possible, they might find some of their engineering challenges a lot more tractable.
NASA has also long been resistant to the "atmospheric skip" mode of velocity reduction, for the simple reason that it adds (from their point of view) too much uncertainty to the place and time of re-entry... even though it can provide a huge shed of velocity, and provide cooling at the same time. It should be said that if it is done even halfway right, there is very little danger of skipping out or orbit: the danger is simply more uncertainty about the landing spot.
But wait... what about all that automation they plan to use for the super-retro-rocket module??? Wouldn't that same automation be better used for adjusting a path for some atmospheric skipping? Considering that it would take a lot less mass for the course-adjustment motors than it would for retro-rockets?
Just a thought. But I know it's a DIFFERENT thought. So I thought I would share.
Watching that and hearing the wind blow made me wonder if there have been any audio recordings taken on Mars? I'm sure it would be boring as hell but still that would be really cool for the first minute or so... you know, to listen to Mars (well whatever you can hear in the 1km radius around the rover anyways).
A fool throws a stone into a well and a thousand sages can not remove it.
You should point out it weights 1984 pounds... just shy of one ton. It makes the landing system a lot more intuitive.
Your religion is weak. Forsake your old god and embrace your new faith.
The whole operation is horrendously complicated, with dozens of potential failures at each point, and no realistic means of allowing for such failures. Every step would have to function perfectly, or we've just sent another multi-billion paperweight to a dead planet.
Whatever happened to KISS?
The engineer who proposed this really needs to look into alternate fields of employment. I suggest Fecal Matter Relocation.
kartune85 : Incapable of reason, observation or learning. A kind of dim, drab, flightless parrot.
I'm OK with everything up until they start winching the lander down under the crane. How is that better than sitting the rover on top of the retro rocket module, hovering, then landing, and having the rover drive off the top of the lander?
The number of failures that could happen to the winching system seems nuts; a line might not lower, or at the wrong speed, or a line could tangle, or a side to side oscillation while descending, or a cable not disconnect, and if any of these go wrong, you have no time to fix it.
And as you tread the halls of sanity, You feel so glad to be, Unable to go beyond. I have a message, From another time..
i for one do not trust rocket powered cranes hovering above my house while full of fecal matter.
"...mesmerizes me to no end"
You know what mesmerizes me to no end? That someone is mesmerized by a f'n crane when we have the technology to explore other galaxies in the blink of an eye.
Very interesting subject. I don't know why but after looking at it, thoughts about life and death visited my mind: Life is fantastic The beauty and sorrow Death is too drastic I can't say goodbye Golden or plastic The joys of tomorrow Life is fantastic I don't want to die
It's amazing how many people like to stick with 'tried-and-tested' methods that are less than 50 years old and have fewer than a dozen successful implementations.
As the_other_chewey said, read http://www.universetoday.com/2007/07/17/the-mars-landing-approach-getting-large-payloads-to-the-surface-of-the-red-planet/
but to paraphrase;
1) Mars has the worst of both worlds; not enough atmosphere to fly heavy vehicles as you can on Earth; too much atmosphere to hover on a simple rocket as you can on the Moon.
2) The sky crane is like the Apollo lunar lander system, but puts the centre of gravity under the thrusters for better stability, and keeps the unstable rocket plumes above and away from the cargo.
3) This will be practice for sky-craning humans, rather than mashing them up with a 10G deceleration in a beachball airbag.
I guess that if they really want to take people to mars they have to test it. After all, we're not going to drop our astronauts on a big inflatable ball with no direction control at all against a planet with a really thin atmosphere to amortiguate.
What, did they hire the New BSG CG team for this?
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
href="http://en.wikipedia.org/wiki/Skycrane" title="wikipedia.org">Skycrane has been used before.
Also, having a n00b on the construction site has been a tradtional excuse to initiate said n00b with a search for either a 'skycrane' or a 'left-handed skyhook'.
Are the younger generations just lacking in imagination, or just recycling old names/terms to confuse us old geezers...Is it Alzheimer's, or senility....Who's going to know?!?!?
I'm on to your tricks, you young whippersnappers!
Now get off my lawn!
Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
A ton would be more like... 1000 kg.
You're welcome.
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you should listen to this http://www.stablesound.co.uk/mp3/notyourblog.mp3
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
Wait wait I don't get this, what happens to be the big flying thing after it's done delivering? Where does it go and what does it do?
You just got troll'd!
It seems like their virtual cameraman had difficulty follwing the aeroshell. I was half expecting the film to switch in and out of focus, or to catch the boom mike in the corner of the frame.
But, seriously, awesome tech and awesome video. That's the kind of thing that would make me want to become an engineer, and I'm sure that I'm not the only one. If they keep this up, it think it's very likely that everyone will remember how cool space exploration is.
For those of you (like me) who can't see the Movie (for whatever reason) here is the YouTube Version:
http://www.youtube.com/watch?v=E37Ss9Tm36c
Me, I don't seem to recall the Viking landers carrying any one-ton rovers.
Google shows about 26 hits for the word, but no definition or etymology.
I have seen this on the Discovery channel a few times over the last 5 years.. hey, maybe someone can find a video of an iBook and be amazed by that next! ;)
Given the nature of our curiosity, the availability of Blender3D, and Mars based physics principles. Has anyone considered combining the two? Then anyone could have a Mars Simulator, and imagine or experiment with possible designs. That balloon idea was cool. But how about the mechanics of a Space Elevator? That would be cool to simulate. Simulation of Auto-Assembly Space Platforms could be more easily demonstrated. Given the statistics of ISS, one could infer logistics of actual engineering requirements.
Perhaps I missed it, but did anyone think of the benefits of not messing up the immediate area around the lab?
If the lab is lowered by this (admittedly gonzo) contraption, it would additionally have the benefit of placing the mechanism in a pristine area, uncontaminated and undisturbed by a landing. How many times have we seen rovers etc. having to motor away to find pristine areas to survey? If there's going to be a problem, especially with the drive mechanisms, at least they'd be in a situation whereby they'd have a surveyable area right at hand. This in addition to the foregoing points regarding vehicle weight, previous landing mechanism failures, etc.
When the going gets weird, the weird turn pro. ~~ Hunter S. Thompson
A ton would be more like... 907.18474 kg.
You're welcome.
Fixed that for you.
Reality is the ultimate Rorschach.
that would be amazing to be in the room with all those geniuses working on that. they could be speaking english and i would probably have no idea what they were saying.
I hate it when people say UFO when what they really mean is flying saucer or something along those lines.
Hello? A UFO is an unidentified flying object. Anything flying that you can't identify? yeah, that's a UFO.
When somebody says they saw a UFO it doesn't necessarily mean they saw aliens flying around in a flying saucer.
As an example an ant can fall off a 20 story building and hit the ground so softly that it hardly notices the landing. It just walks away. If you or I fell off the building we'd make a crater. The reason is simple Mass increases with the cube of size. For example a 4 foot ball is 8 times as heavy then a 2 foot ball of the same material. When you double the dimensions of any part it's weight goes up by a factor of eight and it's strenght goes up by a smaller factor So for several reasons you can't simply "scale up" a small design. What happens in the case of the airbag system is that for small payloads the bags weigh less then the payload but for large payloads the bags are a larger fraction of the total weight.
In space weight drives cost very strongly
He was speaking about a metric tonne.
1 metric tonne= 1000kg=1Mg
There are a bunch of tons. 900kg is a great approximation for the US. Ton, and a decentish approximation for the british long ton and metric tonnes.
Mod parent up! and where did "super-realistic" go, it should be in there between "realistic" and "hyper-realistic" surely? ;-)
This same video has been on the JPL Mars website for over a year.
For those criticising the seemingly complex landing method, JPL took a broad look at a lot of possible technologies. The Mars Exploration Rover and Pathfinder method of using airbags was downright out. The MER's were bigger than Pathfinder and at the limits of what such a system could handle. JPL also had a bear of a time figuring out how to fold the rovers up inside the relatively small volume of the airbags. They actually had to improve that method beyond what the Pathfinder mission demonstrated because its performance in high wind scenarios was marginal. Yet the MSL weighs over four times as much (1875 lbs versus 408 lbs) and is about twice the linear dimensions.
A conventional touchdown like the Viking landers, and more recently Phoenix used was possible, but increased the total mass and complexity as it requires a platform capable of supporting the rover, cushioning the touchdown, protecting it from debris kicked up by the thrusters, and accomodating rover deployment on the surface. Incidentally, the MER's also had such a platform, which weighed 80% more than the rovers themselves (but did include the airbags which helped save fuel mass and keep the EDL process simple). The dry weight of the sky crane for the MSL is actually slightly less than the rover itself.
The skycrane concept keeps the exhaust plume of the braking rockets well above the ground, so it will not stir up significant debris. It also allows the rover to deploy its wheels (see the video) in mid air, when they're unloaded, instead of having to stand up against the 850 kg mass of the rover. The MER deployment actually comprised several dozen individual events and took several days after touchdown.
It may look unstable, but the center of gravity of the rover lies far below the skycrane. The skycrane itself is able to control its orientation using the thrusters, which I believe have heritage to the Viking program, so their reliability is proven. Touchdown speed control is also tested on the Vikings and Pathfinder.
So it seems hokey, but it's actually pretty well thought out. They aren't messing around with a mission this big, and there's good potential for re-using not only the rover design (Mars Astrobiology Field Lab ~2016), but also the re-entry system, including scaling it up for larger payloads.
In fact, the Viking landers were slightly over 500 kg including the landing system, and they weren't mobile. If the MSL didn't have to deploy wheels and separate itself from the bulky and heavy landing system (another 800 kg for MSL), then it could more realistically use a Viking-style touchdown. The mass would be even higher for a Viking-style lander delivering the same mobile payload.
Another benefit of the skycrane, however, is that it doesn't kick up nearly as much dust and debris, since the rockets stay about 20 meters above the ground.
Deploy it from orbit. Carry a long cable with you on the way. Enter Mars orbit. Maneuver to geostationary orbit. Unreal the cable, adjusting to stay in geostationary as you go. Keep a small robot on the bottom of the cable whose job it will be to dig a pit and bury itself anchoring the cable.
The problem with deploying a space elevator on earth is that we don't (yet) have the materials science to overcome the tension strength requirements. Sssooooo.... perhaps we do have the strength to meet the Mars space elevator requirements?
It may take multiple cable stretches to bond together a bridge strong enough. That means huge dollars.
But if both atmospheric deceleration and propulsion are out, then it is time to reach for the radical.
The article to which you linked is totally irrelevant. The article itself states that the issue it covers is landing PEOPLE on mars, which entails about 6 TIMES the mass of the lander planned here.
Maybe I am not the one here who hasn't a clue? I do at least find out what an article is supposed to be ABOUT before I cite it to support my claims.
Nedlohs was speculating that the reason to lower the lander to the ground via the winches was because it was too tricky to some to a soft landing.
I was refuting that particular explanation by pointing out that if they can come to a hover close to the ground, which it is designed to do, then it is feasible to come to a computer controlled soft landing from that point, as Armadillo has demonstrated.
re: payload:
Armadillo's lander carries at least a 25kg payload to satisfy the contest rules, and they have noted that they actually carry "quite a bit" more:
http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=346
re: relative size:
I'm not sure what you are using as a basis for your 1000 multiple in the mass comparison of the vehicles, but from what I can find Armadillo's vehicle in the example weighs about 200kg. Certainly not as heavy as the Mars lander, but enough for a proof of concept, especially considering the decreased gravity on Mars.
http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=347
And as you tread the halls of sanity, You feel so glad to be, Unable to go beyond. I have a message, From another time..
but I am motivated to say it plainly here. Somebody tried to refute my statements using an article that very clearly stated that it was about something that was totally irrelevant to the issue at hand. Obviously, he/she had not even read the thing. And when I called him on it, *I* was the one who got modded down.
Sometimes the modders around here are a bunch of fucking morons.