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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 lizardloop on Sunday January 04 2015, @11:53AM
Reminds me of the film 2010. I believe the russian craft uses an inflatable bag to help it decelerate in Jupiter's atmosphere.
(Score: 2) by Aiwendil on Sunday January 04 2015, @12:02PM
"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"
Can someone explain why rockets can't be used? (sure, I get that rockets would add a need to carry lots of costly and heavy fuel (and oxygen) - but this is more of a "wouldn't be a good choice"/"would be expensive"/"would require a massive overdimensioning of the lander", the sentence however is that they "can't" be used)
Mainly I wonder since we have managed to land rockets on both a low gravity-no atmosphere chunk (moon) and mid gravity-some atmosphere chunk (earth (VTVL)) so I don't really see why a mid gravity-low atmosphere would prevent the use of rockets.
(Score: 1) by khallow on Sunday January 04 2015, @04:08PM
(Score: 2, Informative) by khallow on Sunday January 04 2015, @04:11PM
(Score: 1) by Gertlex on Sunday January 04 2015, @04:53PM
There's a variety of problems, it seems. I am just getting into this book [amazon.com] about landing Curiosity on Mars. One problem that pops to mind immediately is that you don't have a landing pad on Mars... So you have your rockets kicking up a ton of stuff as you approach the surface. (Why this wasn't a problem landing on the moon, I don't know, though.) This is why they had to use the tethered skycrane approach to land Curiosity using rockets.
(Score: 1) by khallow on Sunday January 04 2015, @07:28PM
So you have your rockets kicking up a ton of stuff as you approach the surface. (Why this wasn't a problem landing on the moon, I don't know, though.) This is why they had to use the tethered skycrane approach to land Curiosity using rockets.
It probably wasn't a problem on Mars either. I gather the rockets weren't precise enough for a soft landing (the skycrane approach provides enough control to make up for that) and they didn't want the rockets anywhere near Curiosity after it landed. By the above approach, you can keep the rockets firing throughout the landing and then dump them somewhere else afterward.
(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.
(Score: 1) by MichaelDavidCrawford on Sunday January 04 2015, @08:52PM
... during the early part of the space program (like in 1961 but I don't recall clearly).
Of course goodyear wants to find reasons to sell rubber so they built a prototype donut-shaped space station that provided artificial gravity by rotating.
I found a picture in a book, most likely a NASA publication but I don't recall the author or title.
Yes I Have No Bananas. [gofundme.com]
(Score: 3, Funny) by Geezer on Sunday January 04 2015, @12:48PM
Geezer's Corollary to Murphy's Law state that any device requiring pressure to operate will leak. There is no such thing as leak-proof.
(Score: 1) by khallow on Sunday January 04 2015, @04:13PM
There is no such thing as leak-proof.
This is true, but not a problem. Just don't inflate it until you need to. In the meantime, you can store the gas in a way that leaks far less.