What's Happening at Bigelow?

[docmordrid]

The plan seems to be for their modules to  go up unmanned. 

For radiation protection outside of the Van Allens it depends on the type. 

Alpha (helium nuclei) doesn't take much, but accelerated electrons needs more, but not that much outside Jupiter/Saturn space.  Positrons need more and generate more scatter, which also has to be dealt with. 

Hydrogen compounds do well for lower energy gamma, hence the water jackets, but so do dense polymers - and the walls of Sundancer/BA-330 are said to be 16"+ thick and are polymer rich indeed.  My guess is that a BA-2100's walls would be much thicker than 16".

High speed protons (much of cosmic rays) and higher energy gamma are another matter.  They can penetrate deeply and would take dense matter to reduce significantly.  Making trips short help the most.

Best lunar strategy:  lower the exposure (transit) time and stops, and have a regolith coated shelter when you get there.


 

[Lampyridae]

Even an unpressurised hangar/shelter would be nice.

True, although I thought Bigelow modules only retain their structure because of internal pressure. I suppose something like a BA-2100 could be inflated, outfitted with ribs, and then depressurized. Then again, you could do something similar with a modified SLS/Jupiter tank.

There appear to be some kind of ribs evident in the cutaway diagrams. Whether they can retain their shape after deflation is a good question (however inflatable ribs could do the same job).

[Lampyridae]

I found the interior cutaways most interesting.  It looks like most of the equipment will be attached to the central core.  That makes sense as the outer hull is inflated so you wouldn't be able to launch with anything rigid attached to it - that would have to be done on later outfitting flights.

Now... with that rigid core as an axle, would it be possible to put a centrifuge into the super-heavy model-2100?

What I've been thinking all along.

A BA 2100 would appear to have (as a rough guess) a diameter of just under 12m. If it had Sundancer's proportions (which would be better for a centrifuge) it would be 14m. That's still well short of the 30m minimum diameter thought necessary for a human long-term centrifuge. However, if a short-arm centrifuge could be proven on a Sundancer or BA 330 module, then it may be possible to put a high RPM centrifuge inside the module.

With 7 metres, Even if we stick to 4 RPM, that gives a non-negligible 1/8 of a gee. Lunar gravity is 4.8 RPM, Mars gravity is pushing the boundaries of acceptable at 7 RPM. 1g is a rather uncomfortable 11.3 RPM, even with adaptation techniques it may not be enough.

[Cinder]

Maybe Bigelow could come up with a special design dedicated to centrifuge application, that'd be wider than long.

[Jim]

I found the interior cutaways most interesting.  [snip]   with that rigid core as an axle, would it be possible to put a centrifuge into the super-heavy model-2100?

I'd like to know how big the door is? If it requires an 8 meter fairing does it have a 5 meter entryway?

I was just thinking, Orion and CST-100 about 5 meters across. If the door/airlock was made just a bit bigger, say, 5.5 or 6 meters, the entire module could be a hangar for repairing vehicles in a shirtsleeve atmosphere.

No, not feasible.  The center of a Bigelow station is its spine, can't remove it..  Anyways, what is the infatuation with "pressurized" hangars for spacecraft.  There is no need for an atmosphere.  Most spacecraft will have hazardous materials around them, which would be safer to work on in a vacuum or would require a hazmat suit anyways.

[mmeijeri]

Aren't they serviced in clean rooms on Earth?

[Lampyridae]

Best notional "biscuit" design for 2100m^3 is 3m thick and 30m in diameter. Not really usable and difficult to stow it into less than a 15m wide fairing.

Torus design (with short core):
Radius: 12m
Core (ie endplate) radius: 4m
Volume: (appr) 2500m^3
Ignoring of course the volume of the core...


I'm assuming that anything lost in increased surface area is made up for by decreased core length, staying at the 55kg/m^3 standard so a 2100m^3 fits in a 100 tonne payload.

A somewhat better design is this:
(><)
Torus R: 12m
Torus r: 3m (gives an outer rim of 15m
Outer hemitorus centroid location: 12+1.27m
Outer hemitorus centroid circumference: 83.39m
Outer hemitorus volume: 14m^3 * 83m (volume of revolution) = 1162 m^3
Inner subtractive cones volume (x2): 905m^3
Cylinder volume: 2714m^3
Less subtractive cones: 1809
Plus outer hemitorus: 2971m^3

Mass: 163 tonnes (excluding centrifuge arms, rooms etc)
If mass could be reduced to 33kg/m^3, as it might from reducing the core length and comparative size, then it could be launched on an HLV. It might take another HLV to fully kit it out, but once completed, most of the volume will be at a usable gravity. This gives you rooms that are a maximum of 6m across in the centrifuge.

Of course, this depends on how much of the actual mass is the fabric hull, so increased surface area might not be a good thing. It might be more effective to go with the biscuit-shaped inflatable and just waste the inner levels' volume, say just grow plants there.

[Lampyridae]

I found the interior cutaways most interesting.  [snip]   with that rigid core as an axle, would it be possible to put a centrifuge into the super-heavy model-2100?

I'd like to know how big the door is? If it requires an 8 meter fairing does it have a 5 meter entryway?

I was just thinking, Orion and CST-100 about 5 meters across. If the door/airlock was made just a bit bigger, say, 5.5 or 6 meters, the entire module could be a hangar for repairing vehicles in a shirtsleeve atmosphere.

No, not feasible.  The center of a Bigelow station is its spine, can't remove it..  Anyways, what is the infatuation with "pressurized" hangars for spacecraft.  There is no need for an atmosphere.  Most spacecraft will have hazardous materials around them, which would be safer to work on in a vacuum or would require a hazmat suit anyways.

So if there's a troublesome circuit board, EVA, pull the unit out and service it in a shirtsleeves environment. Just like in 2001. Except watch out for the pod.

[Lampyridae]

Posted an update in the Artificial Gravity From Rotation thread.

http://forum.nasaspaceflight.com/index.php?topic=22210.msg651608#msg651608

[mmeijeri]

There appear to be some kind of ribs evident in the cutaway diagrams. Whether they can retain their shape after deflation is a good question (however inflatable ribs could do the same job).

Foam has also been suggested.

[docmordrid]

There appear to be some kind of ribs evident in the cutaway diagrams. Whether they can retain their shape after deflation is a good question (however inflatable ribs could do the same job).

Foam has also been suggested.

From Bigelow's patent # 6962310....

The advantage of an open-celled foam is that by venting a gas (nitrogen, co2 - whatever) into its containment it expands without producing the fumes generated by chemically activated foams.

>
In the preferred embodiment, the meteor shield 24 is comprised of layers of impacting material 26 such as Nextel separated by layers of spacing material 28 . The spacing material 28 in the preferred embodiment is an open celled space rated foam that can be compressed prior to launch and then expands upon deployment. The number of layers can be determined by know techniques depending upon variables such as mission parameters and survivability requirements.

A set of longerons 30 and cross members 32 connect the opposing bulkheads 22 . The longerons 30 can be made from a variety of materials depending upon the mission characteristics. In the preferred embodiment, the longerons 30 are substantially comprised of a composite material. In an alternate embodiment, the longerons 30 can be composed of a metallic material. The volume enclosed by the longerons 30 is referred to as the internal volume 31 . An airlock 34 allows for access by individuals such as maintenance personnel. A distal end 36 can house an attitude control device, communications equipment, a power source, and a controller that is powered by the power source and operates the attitude control device. The longerons 30 and bulkheads 22 form the core 33 of the craft 10.
>

[yg1968]

Video from the symposium:

!

"Bigelow Aerospace Vice President Jay Ingham provides this overview of the company's commercial space station plans using scale models at the International Symposium for Private and Commercial Spaceflight."

Towards the end of the video you can see a small moon, wait, that's no moon...it's...it's a Bigelow BA2100...

That video has a discussion of a Bigelow module that could be lifted by a 100mt HLV. Apparently, there is also plans for another one that could be lifted by a 70mt HLV.

If purchased by NASA, could such a module be attached to the ISS? Is it realistic to believe that this could happen?
 

[e of pi]

That video has a discussion of a Bigelow module that could be lifted by a 100mt HLV. Apparently, there is also plans for another one that could be lifted by a 70mt HLV.

If purchased by NASA, could such a module be attached to the ISS? Is it realistic to believe that this could happen?
 

The 2100 would be 2.5 times the pressurized volume of ISS, and the 1150 (70 ton) module would be 1.4 times the ISS. I think at that point, it would be more accurate to say you'd be attaching ISS to them rather than the other way around.

[ChefPat]

http://www.popularmechanics.com/science/space/news/bigelow-aerospace-ba2100-hotel?click=pm_latest

But as large as the BA-330 is, it's dwarfed by the BA-2100, which is six times as large and has multiple decks. The BA-2100's docking ends are about 25 feet in diameter, and one source told PM that the module's dry mass could be as low as 70 tons. In other words, in its uninflated state, it could be placed into orbit by the heavy-lift launcher that the U.S. Senate recently approved for development. The massive structure could then be inflated and subsequently outfitted with materials carried aboard additional launches. With its radiation and micrometeoroid shielding, the BA-2100 could provide a trip for a large crew to the outer solar system.

[david1971]

http://www.popularmechanics.com/science/space/news/bigelow-aerospace-ba2100-hotel?click=pm_latest

I wonder how close this is to the truth:
"For now, Bigelow's Sundancer and BA-330 are essentially ready to launch at any time, with life-support testing reportedly under way. "

[Comga]

The plan seems to be for their modules to  go up unmanned. 

Seems to be?
It's that or go with inflatable astronauts. ;-)

[mmeijeri]

Like this?

[savuporo]

There is a joke in here about deflatable egos ..

[HIP2BSQRE]

Reality check: there are currently companies like BioServe and Nanoracks that sell space in facilities aboard ISS. Why would anyone pay hundreds of millions of dollars many years from now for services on a Bigelow station when they can pay a fraction of that for services in orbit now?

It all sounds like the plan is to wait a few years, and then a miracle happens.

I was assuming that the ISS would have been deorbited in 2020 (or 2028). It's not clear to me that everybody wants to abandon LEO all together past 2020 (or 2028). For example, Russia doesn't seem very interested in BEO for the time being. I am not sure about Europe and Japan. Canada is waiting for things to play out in the United States.

But if the CSA and ESA are willing to pay Russia for a 5th Soyuz in the next few years, I suspect that they might also be willing to pay Bigelow and SpaceX (or Boeing, etc.) for access to space for their astronauts once the ISS is deorbited.  Paying Bigelow and SpaceX is a lot less risky than investing in hardware that will never fly because NASA's program keep getting cancelled every 4 years or so.  For many countries, their human spaceflight program is their astronauts and they don't mind relying on others for ferrying their astronauts. SpaceX (or Boeing, etc.) and Bigelow can provide them such an access to LEO.

it appears to me that with his announcement of five soviegn nations booking on client a lot of this conversation may be moot.   People want to thier citizens in space.  Countries have the money the problem has never been about money it has access to space and having somewhere to go.  You do not think Brazil can find $20 million to fly an astronaut??    the problem is that you have to wait years and the only launchers were from the US and Russian govt.  and even if then the only place to fo was the ISS.  All that is about to change. 

[mmeijeri]

I'd like to hear more about those sovereign clients. Apparently the Netherlands is one of those, but we're in the middle of deep budget cuts and I haven't heard anything about it in the Dutch press.