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Orbital Resort to Launch by 2010
Neil Halelamien writes "Popular Science has a cover feature on self-made billionaire and space enthusiast Robert Bigelow (who's been mentioned before on Slashdot). The article has new info on Bigelow's plans to launch a 'CSS Skywalker' orbital resort by 2010 and sell space habitats to others, such as scientists, manufacturers, Hollywood producers, and countries. The habitats will be made of inflatable modules with multilayered kevlar-like walls. A prototype habitat will be launching on a SpaceX Falcon V next year. To help ensure cost-effective access to the station, Bigelow is also running the $50 million America's Space Prize. In the long run, he plans to use the modules as the basis for space yachts and moon cruisers."
They got the technology from NASA in the first place. It was called "TransHab"
The lunar module in the Apollo missions had some parts of it's casing that were basically just aluminum foil. It can work if engineered right. In space conditions are much more uniform than on earth. You don't have to deal with high wind, precipitation, and a bunch of other stuff that can weaken structures easily.
The print article has a nice cutaway drawing of the "18-inch-thick shield of alternating woven graphite composite and foam to protect against orbital debris." Apparently, this layered foam shield is more protective than "aluminum three inches thick" and "no rigid spacecraft design can match this performance." (from the text of the article) It sounds like NASA's decision not to use the TransHab inflatable design was politically motivated and the program was axed before it could actually be tested.
Yes, the 2nd major revisioning of the International Space Station included a transhab module as one of two options to expand the occupancy of the station from 3 to 7. An actual inflatable module was built and tested using multi-layer kevlar skin, but the more conservative minds in NASA remained skeptical of the whole idea all along. They didn't think it could survive a direct hit by a meteor or space debris. In the end, it didn't matter, because even before the loss of the 2nd shuttle, the Bush Administration had applied their usual tactic to programs they don't deam politically useful . . . "The Great Ignore". The ISS has been essentially abandoned by the U.S. agency for over 4 years now, so the TransHab module became simply pointless.
MicroMeteoroid and Orbital Debris (MMOD) shield - "Composed of five layers of graphite-fiber composites separated by foam spacers, the MMOD is the outermost section of Nautilus's hull. Schneider's crew's original TransHab design had more stopping power than did aluminum three inches thick. Ground-testing of Bigelow's MMOD has shown that it can stop impacts by 5/8-inch-diameter aluminum pellets fired at it at 6.4 kilometers a second, several times as fast as a rifle bullet. No rigid spacecraft design can match this performance, and it's one of the reasons Nautilus has an expected life span of at least 15 years."
Here's the guff:
t en t/interactive/space/iss/1998/980824.html
... they begin to realize, 'Hey, this isn't a bad thing at all,'" de la Fuente says.
http://www.chron.com/cgi-bin/auth/story.mpl/con
"Never mind that all this luxury would be in a balloon that would be in an Earth orbit littered with dangerous space junk.
The 1-foot-thick shell would be "bulletproof" in space, de la Fuente says. The 17 or so layers would be made of ceramic fabric, polyurethane foam, polymer film and Kevlar, a tough material used in police vests, and be better than metal.
"This is very different from a child's balloon," de la Fuente explains as he shows off samples of padding. "This is much more like a football. You can drive a nail into a football and it doesn't just pop."
Like a football, the 40-foot-long, 27-foot-diameter Transhab would have a bladder system that holds in the air. The shell encompassing Transhab would have three bladders, in fact, for redundancy.
Outside these thin-film bladders would be Kevlar webbing and then sheets of ceramic fabric, each separated by 3 inches of foam. It's this ceramic, called Nextel, that would protect against micrometeoroids and other orbital clutter zooming by at tens of thousands mph.
In ground tests, aluminum marble-sized balls fired into the Transhab padding at orbital speed were pulverized by the outer ceramic layers before reaching the air-containing bladders.
Even skeptics were impressed.
"Once they see our micrometeoroid and orbital debris shots
"You also have to remember that the aluminum (space station) module is a balloon, too. Any pressure vessel is truly a balloon. Just because it's made out of aluminum you still get the same pressure stresses."
Indeed, when identical balls were shot at 1-1/2-inch-thick aluminum plates, 3-inch-wide craters emerged and the shock waves ripped chunks of metal off the back of the plates. "
It's structural rigidity comes from the interior air pressure. They're talking about filling them at 10 psi, which means 1440 pounds of force on every square foot. That's fine for something that stays in orbit, like the initial versions. A low earth orbit also offers a great deal of protection from radiation. They've already done tests firing small particles at high velocities at the fabric and say the the performance is similar to that off NASA's modules. If a bolt head hit the module (extremely low probability) they'd basically have to model it after an Abrams tank to protect themselves. In that case, it would probably be better to have something thin that the projectile would go straight through without expending much energy, leaving a small hole that can be patched and without creating any spalling. Since it's flexible, heat expansion shouldn't be a problem, except perhaps near windows and hatches, but they're already addressing that as an issue with folding and unfolding.
I personally think this has great potential to lead to, if not space yachts, at least space time shares or something similar within our lifetimes. Paul Allen, for example, might think to himself, "If I apply the law of diminishing marginal utitily, I realize I would get more enjoyment out of having one yacht in the Puget Sound and a share in this space cabin thingy than I would from having two yachts."
I am a mechanical engineering student at Texas A&M and have had Bill Schnieder (one of the former NASA engineers mentioned) as a professor. He hold a patent on inflatable space habitats, and was deeply involved in TransHab. I did a lot of work with inflatable space habitats while I was Dr. Scnieder's student for a year long senior design class. This is some amazing technology.
An inflatable structure makes complete sense. For starters, it works around one of the major design constraints imposed by rocket launch, payload diameter. This enables you to create much higher working volumes inside your spacecraft. For a space hotel this is definitely a Good Thing.
IIRC, Micrometeorite protection is better than on the current ISS modules. It works in a fundamentally different way. Several layers of a tough fiber are separated by expanding foam. When a projectile hits a layer of fibers, the fibers are so strong and hard that even though they break, they also break the projectile into smaller pieces. This dissipates a lot of energy. These pieces then move apart from each other and continue through the foam layer, hitting the next layer of fibers, but this time its several smaller, lower energy pieces each hitting a different part of the fabric, and being broken up again. This is ingenious, you essentially "divide and conquer" the incoming impact energy until your "bulletproof" fiber stop the projectile fragments completely.
The vessel cannot (ok, should not) pop like a balloon. The bladder layer is made up of a very tough polymer that is not very notch sensitive. A hole does not mean a critical failure is immanent. The plastic will probably yield slightly around the hole, but should not tear catastrophically. This leaves a hole about the size of the debris, and a slow leak that can be repaired. The bladder is supported by a network of high strength straps that actually carry the load. Think about putting a huge garbage bag of water in a hammock and then filling it with water. Normally, the bag might break under the weight of the water, but the netting of the hammock is carrying the structural load, while the bag is primarily containing the fluid. Poke it with a pin and you would get a leak. Same principle with the inflatable space habitat.
As far as radiation goes, semicrystaline polyethylene is actually pretty good at stopping the lower energy stuff. It would be comparable to what was on the lunar lander, and what is available for spacesuits. Add water, like they seem to suggest, and it can only get better. I would still probably want to hide from a solar storm, though.
Given that this structure has been receiving more support and interest lately, why has no government (especially NASA) looked at it for building a space station?
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According to this article, there have been some negotiations with the Chinese government. I believe the docking module is already being designed to fit with a Chinese Shenzhou spacecraft.
From the article:
China is eyeing participation in new privately funded U.S. space ventures, such as the Bigelow Aerospace inflatable habitat for biotech or other space-business endeavors.
A Chinese role in these ventures could challenge the U.S. government to focus more attention on space cooperation with China. This is especially so, since the U.S. State Dept. would have to rule on such commercial cooperation.
China Great Wall Industries managers recently visited Bigelow facilities in Nevada. They sounded out the company on the possible launch of Bigelow test or operational modules on Long March boosters or the in-orbit support of Nautilus by Shenzhou Chinese manned spacecraft.
The Chinese are also planning to develop their own small space station, which could theoretically provide orbital infrastructure for the docking of a Nautilus inflatable.
"We talked to the Chinese on a confidential basis, and they indicated they are thinking seriously of opening their program to space commercialization," said Robert T. Bigelow, president and founder of the company.
An entrepreneur who made his fortune as the founder of Budget Suites of America, along with other real estate deals, Bigelow is personally financing the module development, costing several tens of millions of dollars. He has not had detailed discussions with the Chinese, and has talked more with the Russians about potential Soyuz in-orbit and launch support. But he also said there's an "opportunity for America" in cooperating with the Chinese space program, and he disagrees with what he regards as the current negative U.S. policy toward such cooperation.
While I think that he can do what NASA no longer is allowed to do (take major chances with lives), you have to give the credit to who researched and developed it. This guy is simply moving to production with it. But I hope that he can really start the space drive.
I prefer the "u" in honour as it seems to be missing these days.
What actually killed TransHab was a systematic annihilation (across the 1990's) by Congress of any technology that might prove significantly helpful to a lunar or Martian expedition.
Also I think by the phrase "User Installable" the operator is meant, not the guest.
Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.
I was at the JPL facility in Pasadena last Fall (2004) and they had a 1/3 scale model of Bigelow's inflatable module on their largest shaker table. Now this wasn't a NASA project or anything, when JPL doesn't have a current project on deck they sell time on their shaker table and space chambers to industry companies. However, this would indicate that the modules are nearly ready for prime time because they're testing a full-up model. When I was talking to the director of the environmental labs I believe he said the 1/3 scale model was the largest they could fit on the shaker table, so they would be using that data to predict the full scale model's behavior. And really, the design of the modules is simplified and much of it is based on COTS aerospace technology. So, it should be pretty easy to get a module built successfully. The problem has always been getting the module into orbit and, once in orbit, getting people to and from the module. Both of these maneuvers are still extremely expensive.
You are refering almost verbatum to Heinlein's novels: The Moon is a Harsh Mistress and The Cat Who Walks Through Walls.
The latter is about a geriatric couple living in a reduced G space environment while collecting pensions. While the former has much detail regarding traversing between 1G and 1/6 G environments.