Posted on 03/16/2018 8:16:05 AM PDT by LibWhacker
A balloon tethered to the rover would make more sense. What is the purpose of the flyer but to get an aerial view of things.
Atmospheric pressure is not as important as relative density. Mars' atmosphere is 96% CO2, which is much heavier than helium or hydrogen.
Last I checked, that “idiotic” sky crane successfully landed the largest ever rover on Mars.
yes, it worked- but it was far too complex, used far too many moving parts and motors and useless cables and fuel for all that.
Just because it worked does not make it a poor design.
Give it up.
As I recall Mars atmosphere is mostly O2 so hydrogen should work if you have a large enough envelope and a light enough membrane
A ‘Rube Goldberg’ machine technically ‘works’ too.
Look at how Elon Musk landed those two boosters on earth.
They used a lot of moving parts whose weight was useless after landing, which limited useful payload.
What are you arguing about?
If they can hover, lower a payload by cable, and then disconnect the cable and accelerate away, then they could have just landed.
All those steps introduce potential issues and risks, and involves weight and effort NOT contributing to useful payload.
You have it exactly backwards. By not landing everything, they saved the fuel, extra motors, etc it would take to land non-rover stuff.
What would you have them land? Some huge capsule? A large rigid-mount with overhead landing engines? Then some more mechanical parts to get out of the capsule or to jettison the landing rack? Mass, mass and more mass.
They had to have the propulsion gear and fuel, so that part was going to be there anyway.
The part that was NOT necessary was the cab;e to lower it, all the motors and gear to lower it, and the extra fuel to hover and then accelerate away. They should have just landed.
When spaceflight costs are calculates in hundreds of thousands per pound, that was unnecessarily complex.
I am NOT saying it was not a great accomplishment, given the complexity - it was a great success. But, the costs for that success were higher than they needed to be because of the complexity.
The previous landing was a masterpiece of simplicity- they inflated balloons and bounced to a landing. I am not sure I agree with that one either, but the payload was light enough to be worth it.
Just look at how Elon Musk landed two huge and heavy boosters. NASA would never have been able to accomplish that. It was too simple and common sense, for a government program.
The cable system also kept the rover and its instruments further below the landing rockets and their thrust, so the rover didn’t start its mission in a massive debris storm.
Around 3:55 in this animation with interviews:
https://www.space.com/16889-mars-rover-curiosity-sky-crane-landing.html
Those things added considerable weight, and so limited useful payload, and added considerable complexity.
I would have rejected that plan for a simpler solution.
Send your resume to JPL. They obviously haven’t a clue.
Do you always turn into a smarmy jerk when having a disagreement?
I disagree with this design. That’s all there is to it. I am an engineer and have often had disagreements on design decisions, and I have been right (nearly) every time.
I am fine if you like it, but i never questioned your IQ for it.
Sorry about that, but what’s your alternative?
In a few words, what’s your simpler, lighter, non-skycrane design for landing the next rover, which will be of similar mass and presumably also shouldn’t land in a debris storm.
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