Inflatables in SPAAACE! ISS 'nauts to enjoy bouncy castle spaceship Astronauts will be able to enjoy the pleasures of an inflatable spaceship from next year, when a blow-up craft will attach itself to the International Space Station. The Bigelow Expandable Activity Module (BEAM) is expected to be blasted into space aboard SpaceX's Dragon cargo spacecraft at some point in 2015, the firm behind …
This article sounds very interesting - I was hoping for more of an insight into the headline, instead of some jabs at some business-speak. Obviously their sales guy is going to big-up their sector, but the technology sounds interesting too.
How is this module constructed?
How does it maintain air pressure, what are the structural materials, is it comparible to a metal cylinder?
What does the module do? What is it for?
How does it work?
"I thought this was a new site, not twitter? Did I take a wrong turn?"
No. The news is that they are now announcing that they intend to launch a module to the ISS in 2015.
The technology is certainly not new; there are at least 2 in orbit and have been for years, and there is plenty written about how they work, etc. in other places, with handy links provided.
I see that there is also an article about Belkin routers melting. Should that article include pages describing exactly what a router is, and how IP packets are transferred from one interface to the other?
"How is this module constructed? How does it maintain air pressure, what are the structural materials"
Bigelow bought the technology from NASA, which had developed it as the Transhab in the 1990s. I don't know how much Bigelow has changed the materials, but here's a detailed wiki summary of Transhab including the material layering:
http://en.wikipedia.org/wiki/TransHab
Note that link has plenty of references, including even YouTube animations of Transhab inflating.
Specific Transhab materials in the flexible walls include DuPont "CombiTherm" sealing film, woven Kevlar (or Kevlar-ish) strength layers, outer Nextel ceramic fabric, and insulating foam between the Nextel layers to form a Whipple-like debris shield with thermal insulation. Overall, it was about a foot thick and compressible in addition to foldable.
The Transhab also has a rigid spine of aluminum and/or composites, including a docking interface that would plug in to normal ISS airlocks.
http://en.wikipedia.org/wiki/TransHab#mediaviewer/File:TransHab_level_3.jpg
"is it comparible to a metal cylinder?"
Yes, or it wouldn't be going up there. The strength, as I recall, was similar to a metal pressure vessel. The thick debris shielding exterior was at least as good as the armoring on the rest of the ISS.
"What does the module do? What is it for?"
It is just a demonstration of inflating module technology and some extra elbow room for the astronauts. It's really a case of history going in circles. NASA developed Transhab as a huge extension to the ISS (with ~3 times the volume as the cancelled, metal-walled Habitation Module despite similar lengths). Bigelow bought the technology to build space hotels. Now Bigelow is going back to providing extra habitat space on the ISS.
Until we get nanites that can build ultra-lightweight structures out of hollow carbon and aluminum on site, inflatables are the future of space colonization. One rocket payload could double the space of the ISS, or deliver several shelters to the surface of Mars. Self-healing goo ala fix-a-flat could deal with air leaks from micro-meteorites. Safer to sleep in a reinforced area, or underground tunnel, but these structures could prove fast and affordable for securing new areas, airlocks, and hydro/ aqua ponics.
Why not use the nanites to build with something sturdy, like iron alloys and native rock? (I'm assuming your nanites are building something on the moon, Mars, or asteroids. Otherwise, you might as well build the structure on the ground where you can test and inspect it properly.)
Floating it up would be one thing (or sending up on Virgin Spaceship Two), hooking onto ISS as it whizzes by at a jillion miles per hour is somewhat harder....
As we all know from Hollywood, everything is accessible inside the life support time of a spacesuit, no matter how much the orbits differ.
"It is just a new miles high club with no sharp corners"
Interesting idea in a microgravity environment allowing free floating fluids. Ewww....
Mine's the ISS lab coat with the wet patch on the back, and no I don't know who did it or how it got there Goddammit...
"Once it gets into orbit, the inflatable craft will attach itself to Tranquillity, which is a module of the ISS"
Attach itself? Or does it require human intervention? I would wonder if a bit of a glitch in the automation might make it detach itself with human cargo on board. Which makes me wonder if this could be used as the trash truck for the ISS?
The technology is quite interesting, though I was expecting them to attach something a little larger than this. Some astronauts who flew on Skylab and later on the spaceshuttle have been known to reminisce about the amount of space they had to "screw around" inside Skylab (Which had a 10m diameter open space). If the aim of bigalow is space tourism, at least they should have a similar space for fun times. (No no that kind. Yes, I know how that sounded. Fine, I'll get my coat.)
One said this: "though I was expecting them to attach something a little larger than this."
It's launching in a Dragon capsule's unpressurized storage section. There's not a lot of elbowroom in there.
Another asked this: "Attach itself? Or does it require human intervention?"
As noted in the article, it is being delivered by a Dragon capsule, which is docked to the station by the station's robo-arm. The Bigelow module is inside the Dragon's unpressurized storage bin, so it'll require either more robo-arm installation or a spacewalk.
"I searched for whipple shield and got no answer. "
Hmm. You spelled it correctly. Typing 'whipple shield' (no quotes) into Google gets me the illustrated Wikipedia article as the first result, and several NASA pages on orbital debris and Whipple shields in the top 10 results. Incidentally, the name 'Whipple shield' stems from the inventor, Fred Whipple, not the actual tree or harness. Anyway, explanations of the Whipple shield architecture:
This link is my favored article on the Whipple shield because it gives a quick, well-illustrated comparison of solid metal armor to Whipple shields, which are widely-spaced sheets of thin metal. The idea is for hypervelocity space debris to hit the first layer (or "bumper"), evaporate, and then have room to expand into a less-harmful cloud of debris. Ironically, a solid metal plate would help contain the blast and allow the debris to burrow deeper.
http://ares.jsc.nasa.gov/hvit/basic.cfm
Here's a wordier NASA article that explains the Whipple shield in more depth:
http://orbitaldebris.jsc.nasa.gov/protect/shielding.html
And here's a 3M bragging sheet about the use of its Nextel ceramic fabric in Whipple shields. The ultra-high-speed x-rays of a hypervelocity pellet hitting a Whipple shield and evaporating are pretty cool, and informative:
http://www.3m.com/market/industrial/ceramics/pdfs/CeramicFabric.pdf
Incidentally, the Whipple shield is roughly the starting point for the modern tank armor race that started in the 1940s. Spaced armor is fine against irregular space debris, but weapon makers have been figuring out ways to defeat simple spaced armor for decades. Hence shaped charges that produce columnar metal jets; 'long rod penetrators;' tandem charges, and so on. And hence the counter-counter-measures in armor architecture: Chobham layered armor, perforated armor, reactive armor, etc.
"In theory it's also self-sealing if there is a puncture."
Do you have a reference for that theory? The materials currently selected for it aren't the self-sealing sort. Kevlar, CombiTherm, Nextel, and foam don't flow or morph around holes. All of the references to "self-sealing" I've found in conjunction to Bigelow's modules appear in the comments section of news articles.
The only really self-sealing polymer structures I've seen were liners on aircraft fuel tanks that swelled when punctured and exposed to aviation fuel. I'm not aware of something that would do the same for an oxygen-nitrogen atmosphere.
"The ability to "give" a little on impact should make the thing a lot more robust than the metal sections of the station, "
Hypervelocity impacts happen too quickly for large-area responses in structures to occur before the impact is over. Basically, they happen faster than the speed of sound in the material. Thus, whether or not the structure "gives" is moot when an a piece of space debris hits.
Overall, the selected materials are not actually the "giving" type. Kevlar is a very stiff polymer with lower elongation-to-failure than the aluminum favored for the station (Al-6061-T6 and AL 7075-T7352). Nextel ceramic fabric (aluminum oxide) is even worse. I'm sure the foam layers stretch just fine, but they're constrained by Nextel fabric and they add negligible strength to the structure (also, their job during a hypervelocity debris impact is to evaporate and soak a little energy from the fireball generated by the debris hitting the Nextel "bumpers.") Likewise, the CombiTherm stretches nicely but it is constrained by the stiff Kevlar strength layers.
A high volume module costing under 18 million dollars? Great.
An indicator showing how things could be in the future? True.
Something you can build LEO hotels out of? Or research labs? Or entirely private space stations? Right with you.
Even something you can make a habitat module out of for astronauts going BEO? Yep.
But all of this STILL requires... low-cost access to space. 7 astronauts/passengers on a 60 million-dollar Dragon v2 equals... 8.5-and-a-bit million dollars PER PERSON.
By all means, lets have high-volume modules, they're the first step to cheaper space stations and interplanetary craft but, most importantly, gotta get the seat price down.
Skylon, taking 20 passengers for only 10 million dollars works out at 500,000 dollars.
Just saying...
I'm really looking forward to the next bit of news about progress on Skylon. I realise it's very complex engineering,
I have always felt the concept of taking in air at Mach N+1 and liquiefying it in microseconds is something that makes even cold fusion seem plausible in comparison...
(But I hope I am wrong... the idea is cool if it works ;-).
Well actually, Skylon doesn't liquefy the air in microseconds, it just cools it by several hundred degrees in microseconds. It's still gaseous, albeit cold and gaseous, when it mixes with the hydrogen fuel.
It is pretty nifty how they manage to cool, but not liquefy, the air by so much without frosting up the pipes and in such a short space of time but that's the special secret sauce that makes the idea feasible.
And yes, it'd be wonderful to get a Skylon article, maybe with some recent quotes from the REL team, outlining the next few years for Skylon...
Hint, hint, El Reg.
Costs will drop once SpaceX get their rockets & capsule fully reusable...
Costs will drop again once(if) Reaction Engines get Skylon off the ground.. (which is looking more likely with every milestone they conquer)
SpaceX = Evolutionary
Reaction Engines = Revolutionary
Both concepts are great ideas and have a market.
From the Reg article:
"NASA has handed Nevada-based Bigelow a whopping $17.8m for the mission, which it hopes will show that low Earth orbit (LEO) is the ideal place for businesses to operate"
Whereas on the Bigelow web site they say that countries, companies, or even visiting individuals can have an astronaut sent to the space station for "only $26.25 million" (nice use of "only" there guys, makes it sound much more reasonable!), or you can lease a third of one of these things for 60 days for "only $25 million"
Somehow I don't think there will be a queue, space may be commercialised one day but not at those prices, if $17 Million is "whopping" whats $25 Million "insanely, ludicrously large"?.
I wrote to NASA years ago about a dream I had where I was an astronaut, during a space walk I bolted eight quadrants together forming two large discs, about 50' across which were attached to a large ring of crumpled up fabric/foil. Then by pressing a series of buttons a triple walled sausage like foil tube was first inflated on the inside turning the object into a cylinder 100' long and then the next buttons release expanding foam into the internal wall. this formed a hardened tubular structure. Lastly the external wall was filled with water which froze to form a hard outer shell. The section of disc I was working was fitted with a twin door (inner and outer) and porthole, through which climbed, this was the air lock. Once in side I removed the suit and was free to work inside. Oh and the other end of the cylinder had a docking ring to let the shuttle connect to transport equipment on board. looks like I've missed the boat on this one.
And I thought I was crazy??? :o)
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