Mars Science Lab

[Preston]

The Mars Science Lab lands (hopefully) Sunday night/Monday morning. Been following this project for a long time...

NASA - Mars Science Lab

Entry Descent and Landing animation: Seven Minutes of Terror

You can follow the EDL live (simulation) and preview the sequence of events: Eyes on the Solar System


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[HAL9000]

Am I ever outta the loop... didn't even know there was something heading to Mars.

[glc]

This is what it's bringing back:

[jdeb]

finally, a decent actor.

[HAL9000]

One thing I don't understand about this decent... the rocket powered lander part of it... does it actually land somewhere? Or does it just fly away, crash and become junk somewhere? This really seems to be an over-complicated landing system compared to the Viking landers or the air bag method of the first rover.

[MaxRat]

Originally Posted by glc This is what it's bringing back:

loved that show when I was a kid.... that and Merlin

[Preston]

Originally Posted by HAL9000 One thing I don't understand about this decent... the rocket powered lander part of it... does it actually land somewhere? Or does it just fly away, crash and become junk somewhere? This really seems to be an over-complicated landing system compared to the Viking landers or the air bag method of the first rover.

From all the press briefings I watched, here is what they are saying...

The descent stage flies away for what they are calling a "controlled crash".

The rover is way to heavy for an airbag landing.

The "Sky Crane" is supposedly allows for a softer and more accurate touchdown. It is also more forgiving if they land on a slope, and by suspending the rover below the descent stage they say that there will be less dust to interfere with the radar altimeters.

Putting the rover on a lander and trying to drive off was determined to be to risky, and from my understanding, the Viking type landing is a pretty hard landing.

All that being said, I agree, the "Sky Crane" is a pretty wild idea.


Here is a pretty good news conference on MSL:
NASA News Conference: MSL Engineering

Edit: About 30 minutes in a reporter asks about the Sky Crane and other options.



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[HAL9000]

Looks like it worked... images are coming back.

[Preston]

Wow, pretty exciting landing! I really nerd-ed out tonight.

[MaxRat]

looks like images right out of the original Total Recall...

I want to know how to the thrusters work to land the rover? combustion thrusters? or just pressurized gas?

[HAL9000]

I'd have to check it out, but I would almost think combustion... this rover is as large, and heavy as a small car.

[MaxRat]

it looks like combustion from the pictures... but if there is no oxygen on Mars how would that support combustion...? unless they had the fuel and added the oxygen needed at the business end of the deal? totally unsure there

[Preston]

They used Hydrazine thrusters...

Hydrazine Thrusters

More of a chemical reaction than a "burn" (I think).

[HAL9000]

Well, just my opinion, but with the introduction of a catalyst, I would classify it as a combustion process.

[Preston]

I only took one semester of Chemistry and I paid more attention to the cute girl that sat next to me than I did the professor...

I thought that a catalyst was more of an "accelerator"...it speeds up the reaction without being consumed itself.

I know that something burning is itself a chemical reaction, so that wasn't the best description...

I blame the cute girl for my low Chemistry grade!

[Preston]

I mean the answer to the question is:

"It's Technical!"

[glc]

Rocket motor thrusters.

[MaxRat]

I guess my question is... can they work in a no oxygen environment... and how do they know the environment would support a parachute and the weight of the rover without ever being there?

I mean what ever air is there can't be the same density as ours and still just cant work the same way...can it? too many questions here

[HAL9000]

They know the composition of the Martian atmosphere and the density already.... so they know the entry speed, what size of chute, the decceleration with the chute, etc.

BTW, there are other methods of combustion that wouldn't need oxygen from the atmosphere. I was watching one show about making a high powered model rocket where they were aiming for 50,000+ feet altitude. The solid fuel was rubber... yes, rubber, but to accellerate the burn, hydrogen peroxide was injected into the chamber which greatly accellerated the burning process creating a large amount of thrust.