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Devising a way to one day land astronauts on Mars is a complex problem and NASA scientists think something as simple as a child's toy design may help solve the problem. Safely landing a large spacecraft on the Red Planet is just one of many engineering challenges the agency faces as it eyes an ambitious goal of sending humans into deep space later this century.
At NASA's Langley Research Center in Hampton, Virginia, engineers have been working to develop an inflatable heat shield that looks a lot like a super-sized version of a stacking ring of doughnuts that infants play with. The engineers believe a lightweight, inflatable heat shield could be deployed to slow the craft to enter a Martian atmosphere much thinner than Earth's.
Such an inflatable heat shield could help a spacecraft reach the high-altitude southern plains of Mars and other areas that would otherwise be inaccessible under existing technology. The experts note that rockets alone can't be used to land a large craft on Mars as can be done on the atmosphereless moon. Parachutes also won't work for a large spacecraft needed to send humans to Mars, they add.
Thus, the inflatable rings. The rings would be filled with nitrogen and covered with a thermal blanket. Once deployed for landing, the rings would sit atop the spacecraft, somewhat resembling a giant mushroom.
http://phys.org/news/2015-01-nasa-explores-inflatable-spacecraft-technology.html
[Source]: http://www.nasa.gov/centers/armstrong/Features/HIAD_decelerator_system.html
(Score: 1) by Gertlex on Sunday January 04 2015, @07:39PM
I'm not sure I follow how the skycrane made the landing control more precise? (I suppose it's possible; rocket control of a pendulum system, vs. rocket control of a single body system.)
And what was wrong with having the rockets next to the rover once it has landed? The obvious issue is having the rockets blowing dust/rock off the ground *while* it's landing... If you had a landing pad (hah), once you've landed, as long as your rockets can detach safely and let the rover move on with a clear path, you're fine, perhaps.
(Score: 2, Interesting) by khallow on Monday January 05 2015, @01:30AM
I'm not sure I follow how the skycrane made the landing control more precise?
As I understand it, the skycrane can control how fast the rover payload hits the ground by controlled the rate at which it reels out or reels in. So if you have rockets that aren't entirely reliable in quantity of thrust, it can adjust the rate at which the cables are fed out when the payload finally hits the ground. I believe it can even handle having one of the thrusters outright stop thrusting around the point of landing.
And what was wrong with having the rockets next to the rover once it has landed? The obvious issue is having the rockets blowing dust/rock off the ground *while* it's landing...
The issue here is what do you do with the residual energy in those rockets? Because of the need for margin of safety, there will be residual propellant and energy in each rocket. There are two failure modes to consider as examples. First. that one or more of the rockets restart, moving the vehicle in unpredictable and possibly damaging ways. Second, that something pops and releases energy all at once. Even if the rockets are effectively shielded so that debris from catastrophic failure doesn't send debris through the rover, that is still a substantial shock to the delicate equipment on board. These issues remain a significant problem until the vehicle is a safe distance away from the rockets. However, with the skycrane design, the rockets are safely moved a considerable distance away (a few hundred meters or more) and use up the propellant as completely as possible from the beginning. So you don't have to rush the early stages of your vehicle start up procedures to get away from a risky situation.