What's Happening at Bigelow?

[Orbital Debris]

From the BA Site "In The News" tab;

Bigelow Aerospace Exhibit at the National Space Symposium

Bigelow Aerospace will have a 1,200 sq. ft. exhibit at the 27th National Space Symposium running from April 11th – 14th at the Broadmoor Hotel located in Colorado Springs, CO.  We invite anyone attending the Symposium to come view the Bigelow Aerospace exhibition and learn more about our company’s exciting work and future plans.

...and please ask some really technical questions (working stress of fabric, safety factor, air recirculation rates etc) and put a report and photos in here.

Yeah, well good luck with that.  All the displays say 'no photos please', and the booth is staffed by, well, let's just say they aren't engineers.  (but as evidenced by how my day went, they will text someone who can answer some questions  

[e of pi]

Yeah, well good luck with that.  All the displays say 'no photos please', and the booth is staffed by, well, let's just say they aren't engineers.  (but as evidenced by how my day went, they will text someone who can answer some questions  

What was at the booth? Did they have any models of larger modules like the BA-2100, or maybe one for FH?

[Cherokee43v6]

This is fifth generation+, but what would a centrifugal g Bigelow require in terms of diameter (human comfort) and centrifugal floor structure (assuming it cannot be the bladder and other critical surfaces that comprise the actual wall)?

There is no space-based data on human-tolerable rotation rates, or on gravity level required to avoid the worst symptoms of microgravity exposure that I am aware of. Thus, the only guaranteed values for gravity level to provide are extremely conservative in my opinion--1 G, 3 RPM or so. This requires a 100 m radius, which is far beyond that which can be provided by a module of Bigelow's geometry--an inflated torus would be better for that. However, if only .33 G is required (Mars, just as an example) and humans can adapt to 5 RPM, then only a 22 m diameter is needed--which might be doable in a future Bigelow-style module.

This is an area I really wish we'd do more research into--beyond the biology of it, it directly effects the engineering requirements to support long-term off-planet habitation.

What about a pair of BA 330 modules with the 'vertical' (transhab)orientation, spun about their docking structure?

Vary the spin rate between missions to test different 'g' levels.

Issues that might need to be addressed (and thus asked about): 
Stress loads as the bag sags under the spin (internal rigid stabilization installed after expansion???) and on the docking ports.
Stack stabilization under spin.

[aceshigh]

This is fifth generation+, but what would a centrifugal g Bigelow require in terms of diameter (human comfort) and centrifugal floor structure (assuming it cannot be the bladder and other critical surfaces that comprise the actual wall)?

There is no space-based data on human-tolerable rotation rates, or on gravity level required to avoid the worst symptoms of microgravity exposure that I am aware of. Thus, the only guaranteed values for gravity level to provide are extremely conservative in my opinion--1 G, 3 RPM or so. This requires a 100 m radius, which is far beyond that which can be provided by a module of Bigelow's geometry--an inflated torus would be better for that. However, if only .33 G is required (Mars, just as an example) and humans can adapt to 5 RPM, then only a 22 m diameter is needed--which might be doable in a future Bigelow-style module.

This is an area I really wish we'd do more research into--beyond the biology of it, it directly effects the engineering requirements to support long-term off-planet habitation.

fine, but the smaller the diameter, the biggest artificial gravity difference will exist between the feet of the astronauts and their heads.

at 22m diameter, the center of rotation (zero gravity) would be only 11 meters from the floor (actually less, what is the standart thickness of a module´s outer shell?).

Anyway, at 11 meters radius, the zero gravity would be only 9.2 meters above an astronauts head (lets suppose he is 1.80 tall)

at 1g at his feet, what would be the gravity at his head??

and at 0.3g?

anyway, I can only guess that the gravity differential of such magnitude is much worse for the human body than a low gravity on your entire body. I mean... the blood will be REALLY pulled towards the legs... am I wrong?

[docmordrid]

If you only spun it up to have a max of 1/3 G it shouldn't be too bad physiologically. Main thing is to create just enough musculo-skeletal stress to reduce demineralization, muscle wasting and fluid shifting to the upper body. The top-bottom imbalance shouldn't be anything that most well conditioned folks couldn't adapt to, and certainly less harmful that zero G.

[Rifleman]

He planned to put 50 crew-members on the lunar surface using 3 inflatable landers. 50!

And they would then erect launch pads for modified Sargents with thermonuclear warheads for terrestrial bombardment. Also, the MPs among the 50-man crew would defend the base with shoulder-mounted Davy Crockett Atomic Bazookas.

There are times when von Braun made Bond villains look sane...

You forgot the claymore mines that shoot darts designed to puncture space suits as well. Those are the most critical part of the defense.

[joek]

If you want to do a 100m Diameters, it might be difficult, but not unfeasible. A good question is how many folds can take a bigelow wall.

Interesting question.  I'd also like to know the primary constraint on the inflated shell diameter and the fold geometry.

In the attached, the image on the right is the original TransHab fold geometry; the left is from the most recent NASA ISS Inflatable Module Mission presentation.

TransHab fold geometry was specifically intended to minimize folds; new geometry suggests it may be less of an issue today.  (Assuming the new diagram is close to reality.)

edit: the other left

[alexterrell]

If you want to do a 100m Diameters, it might be difficult, but not unfeasible. A good question is how many folds can take a bigelow wall.

Interesting question.  I'd also like to know the primary constraint on the inflated shell diameter and the fold geometry.

In the attached, the image on the right is the original TransHab fold geometry; the left is from the most recent NASA ISS Inflatable Module Mission presentation.

TransHab fold geometry was specifically intended to minimize folds; new geometry suggests it may be less of an issue today.  (Assuming the new diagram is close to reality.)

edit: the other left

You could of course launch shell in multiple launches. The first shell would be the pressure vessel only.

Then launch an impact shield - perhaps use millibar pressure to inflate, then put the first shell inside this one.

(Even better but OT, covered in something like "Very large inflatables", just have a pressure vessel without the impact shield, and inflate this below the surface of a very small asteroid or Phobos)

[joek]

You could of course launch shell in multiple launches. The first shell would be the pressure vessel only.

Then launch an impact shield - perhaps use millibar pressure to inflate, then put the first shell inside this one.

Interesting concept.  NASA's old figures for shell excluding MMOD protection are ~30% kg/m3 of the mass with MMOD protection (e.g., for use on surface where MMOD protection is provided by regolith overlay).  However, NASA's old figures appear to be quite optimistic so hard to tell how valid they are today (e.g., old estimated ~20 kg/m3 vs. current estimated ~40-50 kg/m3 for shell with MMOD protection).

With respect to Bigelow, Mr. B has stated he wants to minimize integration and assembly work in orbit.  (Apologies no reference at the moment; will update if I can find one.)  So I doubt they would go for a multi-lanuch assemble-in-orbit approach.  Eyeballing the figures...
1. TransHab fold pattern suggests inflated shell circumference is limited to ~3x core circumference (see previous post) and thus limited by core/PLF diameter.
2. ISS inflatable mission suggests that packed vs. unpacked shell depth is ~4-5x (but appears to show different packing geometry from TransHab).*

If you just want a really big shell, I'd guess (and only a guess) that PLF diameter is a nominal issue.  If you want to launch an integrated and usable system, there are obviously other factors, such as additional deployment complexity and attendant increase in deployment system size if more complex fold geometry is required; need for larger ECLSS, power, propulsion; etc.  All those would increase the fixed/core size and PLF diameter may thus be a limiting factor.


* NASA ISS inflatable diagrams show: core 3m diameter; packed diameter = ~3.6m with 3 (?) shell folds.  Thus: 3.6m - 3m = 0.6m / 2*3 = 0.1m/fold packed.  Thus: unpacked shell fold = 0.4-0.5m / 0.1m = 4-5x packed vs. unpacked shell depth.

[mlorrey]

You could of course launch shell in multiple launches. The first shell would be the pressure vessel only.

Then launch an impact shield - perhaps use millibar pressure to inflate, then put the first shell inside this one.

Interesting concept.  NASA's old figures for shell excluding MMOD protection are ~30% kg/m3 of the mass with MMOD protection (e.g., for use on surface where MMOD protection is provided by regolith overlay).  However, NASA's old figures appear to be quite optimistic so hard to tell how valid they are today (e.g., old estimated ~20 kg/m3 vs. current estimated ~40-50 kg/m3 for shell with MMOD protection).

With respect to Bigelow, Mr. B has stated he wants to minimize integration and assembly work in orbit.  (Apologies no reference at the moment; will update if I can find one.)  So I doubt they would go for a multi-lanuch assemble-in-orbit approach.  Eyeballing the figures...
1. TransHab fold pattern suggests inflated shell circumference is limited to ~3x core circumference (see previous post) and thus limited by core/PLF diameter.
2. ISS inflatable mission suggests that packed vs. unpacked shell depth is ~4-5x (but appears to show different packing geometry from TransHab).*

If you just want a really big shell, I'd guess (and only a guess) that PLF diameter is a nominal issue.  If you want to launch an integrated and usable system, there are obviously other factors, such as additional deployment complexity and attendant increase in deployment system size if more complex fold geometry is required; need for larger ECLSS, power, propulsion; etc.  All those would increase the fixed/core size and PLF diameter may thus be a limiting factor.


* NASA ISS inflatable diagrams show: core 3m diameter; packed diameter = ~3.6m with 3 (?) shell folds.  Thus: 3.6m - 3m = 0.6m / 2*3 = 0.1m/fold packed.  Thus: unpacked shell fold = 0.4-0.5m / 0.1m = 4-5x packed vs. unpacked shell depth.

To escape these limitations you'd have to build it actually as a torus that expands away from the core and is only connected to the core by some inflated tube spokes.

[joek]

---snip---

---snip---

To escape these limitations you'd have to build it actually as a torus that expands away from the core and is only connected to the core by some inflated tube spokes.

Would you expand on that?  There are obvious practical limitations on the inflated shell diameter vs. packed/core diameter today, but there do not appear to be any fundamental limitations?  Thanks.

[Jason1701]

Don't think this has been posted yet. Life Support update.

http://www.spacenews.com/civil/110411-bigelow-tests-life-support.html

Did anyone see Bigelow's exhibit at the symposium?

[Norm Hartnett]

Don't think this has been posted yet. Life Support update.

Nice comment from Eric Haakonstad, Bigelow Aerospace chief engineer:

“We’re not reinventing the wheel here,” Haakonstad said. “All we’re trying to do is take the technology development that our tax dollars through NASA have developed and package them into a more producible form factor. We’re not trying to be cutting edge in terms of technology; we are trying to be cutting edge in terms of affordability and availability and ruggedness.”

He was referring specifically to the ECLS but this comment could apply to most endeavors in commercial space.

[grr]

Don't think this has been posted yet. Life Support update.

http://www.spacenews.com/civil/110411-bigelow-tests-life-support.html

Did anyone see Bigelow's exhibit at the symposium?

I keep trying to find out how they are going to do toilet and perhaps personal hygene, but it appears that it is an afterthought.
I know that is a strange thing, but NASA has not been able to do much with the toilet, and oddly, I thought that they had a decent solution for showering (basically, a bag from your neck down), yet the ISS does not use it. Also been trying to figure out where to stash those items. Seems like at some point, somebody in the west, has to come up with decent solution and get these tested.

[Norm Hartnett]

I keep trying to find out how they are going to do toilet and perhaps personal hygene, but it appears that it is an afterthought.

I don't think I'd characterize it as an afterthought,

“Eight hours is a convenient steppingstone for us,” Haakonstad said in an April 4 interview. “It’s enough time to get to steady-state conditions but not necessarily long enough where we have to worry about — we’ll call it overnight hygiene and sleeping arrangements.”

, they are clearly aware of the problem and are developing solutions.

"He said within the next couple of months Bigelow Aerospace plans to conduct a 30-hour demonstration of the ECLS system followed by another lasting up to a week."

As I quoted above, they are looking for production capable, affordable and rugged solutions.

Edit;

I thought that they had a decent solution for showering (basically, a bag from your neck down), yet the ISS does not use it. Also been trying to figure out where to stash those items. Seems like at some point, somebody in the west, has to come up with decent solution and get these tested.

I thought that the giant wet wipe was a rather elegant solution, myself. It eliminates the problem of loose water in a weightless environment and addresses the personal hygiene issue. True it does introduce yet another solid waste that is not recyclable.

[manboy]

Don't think this has been posted yet. Life Support update.

http://www.spacenews.com/civil/110411-bigelow-tests-life-support.html

Did anyone see Bigelow's exhibit at the symposium?

I thought that they had a decent solution for showering (basically, a bag from your neck down), yet the ISS does not use it.

I believe I saw a video a while back that had an astronaut saying wet wipes were preferred over a shower.

Did anyone see Bigelow's exhibit at the symposium?

I could barely find any news stories relating to the symposium, it seems like either the media wasn't invited or they just didn't care.

[Robotbeat]

I don't think the symposium was very media-friendly. I think I remember hearing that photography was not allowed for the Bigelow stuff.

[e of pi]

I don't think the symposium was very media-friendly. I think I remember hearing that photography was not allowed for the Bigelow stuff.

It seems really odd to me to have such a big booth and then not allow any news of what you showed to leak out. Does that seem odd to anyone else?

[simonbp]

It means their audience was potential customers, not the general public.

[docmordrid]

SatNews....

Robert Bigelow, Founder and President of Bigelow Aerospace, will be the Honored Keynote Speaker at the ISDC Governors' Dinner and Gala to be held in the Davidson Center at the U.S. Space & Rocket Center in Huntsville, Alabama on May 20. >
 Mr. Bigelow will also receive the National Space Society’s Space Pioneer Award for Space Development for his efforts to advance the technology of space habitats....
>