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."

Comments

Its easy to forget how Big MSL is.

[mcwiggin]

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.

This is needlessly complicated and HERE is why:

[Jane Q. Public]

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.