so from the video it seems BEAM will inflate in all directions. Does this mean the BEAM won't have a solid "beam" going down middle? I always thought it would have to minimize torque. But since nothing is on other side of BEAM after it is docked it seems to make sense it doesn't really need one.jb
Quote from: A_M_Swallow on 01/16/2013 08:20 pmIf you are going to modify the BEAM you could simply fly a Genesis II. It already has solar arrays.http://www.bigelowaerospace.com/genesis-2-specs.phpI think Genesis 2 is smaller than BEAM, isn't it? It also doesn't come with pre-designed end plates for the docking interface and the connection to the launcher's U/S.
If you are going to modify the BEAM you could simply fly a Genesis II. It already has solar arrays.http://www.bigelowaerospace.com/genesis-2-specs.php
Quote from: e of pi on 01/17/2013 06:27 pmI think Harmony's a poor point of comparison anyway--it's a node, and thus contains 6 CBMs, to BEAM's one.Furthermore, five of Harmony's six CBM's are active CBMs, much heavier than the passive CBM on BEAM. I agree it's a silly comparison.
I think Harmony's a poor point of comparison anyway--it's a node, and thus contains 6 CBMs, to BEAM's one.
Inflatable structures clearly become more efficient the larger the volume is. A smaller module will have less weight advantages than a larger would. Just saying.
Quote from: Elmar Moelzer on 01/17/2013 07:04 pmInflatable structures clearly become more efficient the larger the volume is. A smaller module will have less weight advantages than a larger would. Just saying.It's likely to be true, but it isn't totally clear. Remember, if you're limited by material strength, the mass per volume of a pressure vessel is essentially independent of the size of the pressure vessel for the same shape.
Quote from: Robotbeat on 01/17/2013 07:07 pmQuote from: Elmar Moelzer on 01/17/2013 07:04 pmInflatable structures clearly become more efficient the larger the volume is. A smaller module will have less weight advantages than a larger would. Just saying.It's likely to be true, but it isn't totally clear. Remember, if you're limited by material strength, the mass per volume of a pressure vessel is essentially independent of the size of the pressure vessel for the same shape.If you make some reasonable assumptions about tensile strength, the mass of such a small module is absolutely dominated by the shielding mass, which scales with surface area. Only for really large diameters does the pressure vessel mass (which scales with volume) become relevant.
Quote from: rklaehn on 01/17/2013 07:13 pmQuote from: Robotbeat on 01/17/2013 07:07 pmQuote from: Elmar Moelzer on 01/17/2013 07:04 pmInflatable structures clearly become more efficient the larger the volume is. A smaller module will have less weight advantages than a larger would. Just saying.It's likely to be true, but it isn't totally clear. Remember, if you're limited by material strength, the mass per volume of a pressure vessel is essentially independent of the size of the pressure vessel for the same shape.If you make some reasonable assumptions about tensile strength, the mass of such a small module is absolutely dominated by the shielding mass, which scales with surface area. Only for really large diameters does the pressure vessel mass (which scales with volume) become relevant.That is true about shielding mass. Except shielding mass isn't that great, either, unless you're talking about GCR, which I suspect you are.Also, I'm not sure you're including the large factor of safety you might want for a permanently occupied vessel.
Apparently, Bigelow plans to have two BEAM units ready by 2016. One is the spare, of course, but that got me thinking.Possible BEAM ApplicationHSF Mission Module* Modified BEAM with Dragonrider- or CST-100-derived life support on the opposite side to the docking port;* Base permanently attached to Falcon-9 upper stage, which will also provide RCS and, through Dragon-type solar arrays, electrical power;* Dragon rides on top of BEAM or, if a Bigelow mission, the module will be enclosed with a SpaceX-standard 5.2m PLF. Alternate launch vehicle is either EELV-M (Delta-IV (5,4) or Atlas-V-5x2);* Central spine of module has five or six 'flower petal' work station mountings that fold out to the full width of the module from flush against the spine as the module inflates.The module could fly underneath a Dragon when launched by Falcon Heavy for a single launch multi-week mission. Application: Lower-cost space tourism or short-term science. The module could also fly attached to a Golden Spike-style Centaur EDS as the hab module for a lunar fly-around or orbiter mission.Reason for being: Possible Bigelow competitor to DragonLab.
Interesting. But how would it go from inside the HTV to outside the station?It also raises another question: why not make it an expendable inflated trash can to be taken down with Dragon?1- Dragon carries one empty BEAM in the trunk2- The inflatable module is moved to a docking port3- It stays there for as long as required, being loaded with high volume, low weight garbage4- Another Dragon visiting the station would take it on its trunk to be disposed
So.... They are essentially using it as a big Hefty Trash Bag...Hmmmm...Jason
“BEAM would be excellent for EVA” Bigelow told TPM, ..“You could accomodate three people in space suits in there very easily.
would allow for less nitrogen and oxygen to escape into the vacuum of outer space — which happens every time a current airlock door is opened.
No, Bigelow is planning to use BEAM as a spacious airlock that can accommodate up to 3 astronauts.