One use I thought about recently for Bigelow Olympus was for scrapping space junk eg satellites and upper stages. These could be brought inside and cut up into scrap metal which could transported to moon surface for use in build lunar bases.
Quote from: dror on 05/02/2014 03:53 amIt becomes rather silly,The Ba330 is launched within a faring that is as big as the module in it's expanded form. There is no advantage to expandable over hard shell modules.The claim from Bigelow is that they get more volume per unit mass.
It becomes rather silly,The Ba330 is launched within a faring that is as big as the module in it's expanded form. There is no advantage to expandable over hard shell modules.
Also, your hard-shell module would also have a fairing,
Quote from: dror on 05/02/2014 03:53 amIt becomes rather silly. When expanded the BA-330 has a diameter of 6.7 meters, the fairing has a diameter of 5.2 meters.
It becomes rather silly.
Quote from: manboy on 05/02/2014 05:11 amQuote from: dror on 05/02/2014 03:53 amIt becomes rather silly...When expanded the BA-330 has a diameter of 6.7 meters, the fairing has a diameter of 5.2 meters.Actually, a 5.2fairing has an internal 4.6m. And modules also need some clearance for handles and such. That's why ISS modules are 4.1m to 4.4m.
Quote from: dror on 05/02/2014 03:53 amIt becomes rather silly...When expanded the BA-330 has a diameter of 6.7 meters, the fairing has a diameter of 5.2 meters.
It becomes rather silly...
Quote from: ChrisWilson68 on 05/02/2014 04:30 amQuote from: dror on 05/02/2014 03:53 amIt becomes rather silly,The Ba330 is launched within a faring that is as big as the module in it's expanded form. There is no advantage to expandable over hard shell modules.The claim from Bigelow is that they get more volume per unit mass.Volume per mass depands on wall thickness or wall mass and could be achieved with hard composites rather than streached kevler.
QuoteAlso, your hard-shell module would also have a fairing,Not sure. Isn't dragon a hard shell module in a way? DC? CST100? Can they be extended? Why cant a module be built in the same way as any of those and exactly the same size of a fairing?
I really want to see a private space station but I don't understand why they are so keen on these balloons.
Quote from: dror on 05/05/2014 09:34 pmI really want to see a private space station but I don't understand why they are so keen on these balloons.These "balloons" as you call them provide larger interior volume for equal mass than aluminum cylinders, better mmod protection than aluminum cylinders and better GCR protection than aluminum cylinders.
Quote from: clongton on 05/06/2014 12:44 amQuote from: dror on 05/05/2014 09:34 pmI really want to see a private space station but I don't understand why they are so keen on these balloons.These "balloons" as you call them provide larger interior volume for equal mass than aluminum cylinders, better mmod protection than aluminum cylinders and better GCR protection than aluminum cylinders.Than obviously aluminium cylinders are not the way to go.
I dont know the radiation shielding of either, but I know astronauts are allowed to enter the CPM. Also, ThalesAlania have stated that the CPM can be made into a permanent module with the adition of only some plumbing. Sorry, I dont have the link for that.
"Bigelow's web site lists numbers for ISS station nodes versus their modules that show higher volume per unit mass. That seems more persuasive to me than your vague claim that the same "could be achieved with hard composites". Where's your evidence for that claim?"Bigelow's BEAM:Mass = 1.36 tonVolume = 16m3Volume/mass =11.8 m3/ton(Wiki)Cygnus CPM:Mass = 1.5 tonVolume = 18.9m3Volume/mass =12.6 m3/tonCygnus enhenced CPM:Mass = 1.8 tonVolume = 27m3Volume/mass =15 m3/tonShows that higher V/M ratios can be achieved with hard modules on the same volume range. I dont know the radiation shielding of either, but I know astronauts are allowed to enter the CPM. Also, ThalesAlania have stated that the CPM can be made into a permanent module with the addition of only some plumbing. Sorry, I dont have the link for that.
Quote from: dror on 05/06/2014 02:22 pmBigelow's BEAM:Mass = 1.36 tonVolume = 16m3Volume/mass =11.8 m3/ton(Wiki)Cygnus CPM:Mass = 1.5 tonVolume = 18.9m3Volume/mass =12.6 m3/tonCygnus enhenced CPM:Mass = 1.8 tonVolume = 27m3Volume/mass =15 m3/tonShows that higher V/M ratios can be achieved with hard modules on the same volume range. Beam is not a fair comparison. For obvious reasons, the weight to volume ratio of expandable habitats grows with the size of the habitat. Beam is only a very small test module.BA330 already has a 1:15 mass to volume ratio and that is for a fully outfit module, with environmental control and life support systems, as well as solar panels, thrusters and avionics, etc.And the even larger BA 2100 has a mass to volume ratio of 1:35.All that while providing superior protection compared to the hard modules of the ISS.
Bigelow's BEAM:Mass = 1.36 tonVolume = 16m3Volume/mass =11.8 m3/ton(Wiki)Cygnus CPM:Mass = 1.5 tonVolume = 18.9m3Volume/mass =12.6 m3/tonCygnus enhenced CPM:Mass = 1.8 tonVolume = 27m3Volume/mass =15 m3/tonShows that higher V/M ratios can be achieved with hard modules on the same volume range.
Quote from: Elmar Moelzer on 05/06/2014 03:48 pmQuote from: dror on 05/06/2014 02:22 pmBigelow's BEAM:Mass = 1.36 tonVolume = 16m3Volume/mass =11.8 m3/ton(Wiki)Cygnus CPM:Mass = 1.5 tonVolume = 18.9m3Volume/mass =12.6 m3/tonCygnus enhenced CPM:Mass = 1.8 tonVolume = 27m3Volume/mass =15 m3/tonShows that higher V/M ratios can be achieved with hard modules on the same volume range. Beam is not a fair comparison. For obvious reasons, the weight to volume ratio of expandable habitats grows with the size of the habitat. Beam is only a very small test module.BA330 already has a 1:15 mass to volume ratio and that is for a fully outfit module, with environmental control and life support systems, as well as solar panels, thrusters and avionics, etc.And the even larger BA 2100 has a mass to volume ratio of 1:35.All that while providing superior protection compared to the hard modules of the ISS.BEAM IS a fair comparison to a module of the same volume like the CPM. It is not a fair comparison to a module of a bigger volume like BA330. the weight to volume ratio of any habitat grows with the size of the habitat.Claimed superior protection yet to be proven and it is not depended on the wall material's flexability.
Than obviously Destiny is not a better module by mass/volume. But CPM is. The only theoretical advantage to inflatables is the ability to lunch a bigger diameter or a more complex structure in one piece, and that becomes minor when the difference in diameter between the fairing to the module is 1.5 meter and the volume is more or less the same.
First, the rigid pressure vessels are bounded by the fairing inner dynamic diameter (4.6m for commercial), inflatables can do at least +50% that diameter. Second, I agree that CPM and BEAM are sort of similar. But it's at the bigger scales that you have better relationships. While it's true that all benefit from scaling laws, inflatables have minimum gauge measured in feet. It has to do with MMOD protection, insulation and leak resistance. In particular, the inflatables work a bit like fiber wrapped air tanks. Thus, the pressure carrying layer (I believe they use kevlar), is the only part that you have to scale to increase the diameter. Thus, while BEAM is very heavy, it's walls are sized for at least BA330 width. CPM is optimized for weight and has as little material as possible.