Author Topic: Bigelow Habs - How Big Will They Go? Where Will They Go?  (Read 17939 times)

Offline docmordrid

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #40 on: 03/02/2018 03:09 AM »
Or  Bigelow could develop expandable modules to fit the existing fairing sizes.   

Exactly.

 New fairings don't just appear out of nowhere. The payload decides how big they'll be. The 2100 could be a starting point for SpaceX, BO or whoever wants to make a huge cargo fairing or whatever delivers the payload. Talk to other potential customers, of course.

In the case of Falcon 9, the rocket diameter also imposes some limit on the fairing diameter, which is important for Bigelow modules.

My notes show the B330 compressed diameter as 4.572m/180", which should fit in the now wider Fairing 2.0.  The issue appears to be insufficient  length because of an attached propulsion bus, which requires the EELV long fairing.
DM

Online speedevil

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #41 on: 03/02/2018 03:51 AM »
My notes show the B330 compressed diameter as 4.572m/180", which should fit in the now wider Fairing 2.0.  The issue appears to be insufficient  length because of an attached propulsion bus, which requires the EELV long fairing.
https://twitter.com/elonmusk/status/963095860060934144 - in response to a question on stretching stage 2.
Quote
Under consideration. We’ve already stretched the upper stage once. Easiest part of the rocket to change. Fairing 2, flying soon, also has a slightly larger diameter. Could make fairing much longer if need be & will if BFR takes longer than expected.

Of course, someone'd need to pay.

A look at the fairing diagram in the manual says that the top would probably be hit at the core diameter of 3.7m or so, at about 8m.
An extra 5m on the 11.5m fairing is what most people would call 'much longer'.

A quick check verifies the F9 users guide is unchanged from Oct 2015, with no further discussion on fairings.
« Last Edit: 03/02/2018 04:02 AM by speedevil »

Offline Prettz

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #42 on: 03/02/2018 05:45 AM »
You speak of the 330 as if it exists, or is anywhere close to being at a CDR. It is not. So they could scale it slightly and not throw away all their work. That's all I'm saying.
This fact seems to be lost in all of the conversation. And likewise, the 2100 is purely powerpoint. They can rename it any time to whatever volume they'd like. It doesn't actually exist.

Offline alexterrell

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #43 on: 03/02/2018 10:10 AM »
You speak of the 330 as if it exists, or is anywhere close to being at a CDR. It is not. So they could scale it slightly and not throw away all their work. That's all I'm saying.
This fact seems to be lost in all of the conversation. And likewise, the 2100 is purely powerpoint. They can rename it any time to whatever volume they'd like. It doesn't actually exist.
Not quite. It's probably more AutoCAD. Redoing the BA-2100 to fit whatever they want would probably be a few tens of man months.
I would assume the BA-330 is a bit more developed with pressure simulations, and don't they have a mock up?

Offline A_M_Swallow

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #44 on: 03/02/2018 04:37 PM »
The ground prototype of XBASE, NASA's NextSTEP version of the B330, is due to be delivered this month. Other companies will be providing detailed proposals for a prototype lightweight docking hatch and environmental Control & Life Support Systems (ECLSS). I do not know what the current state of the equipment is.

Offline Archibald

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #45 on: 03/07/2018 05:50 AM »
The Moon Marius Hills features some underground lava tube that would be perfect for a lunar base. I wonder how hard it would be to inflate a BA-2100 inside... what would be the risks involved ?
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Online speedevil

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #46 on: 03/07/2018 11:17 AM »
The Moon Marius Hills features some underground lava tube that would be perfect for a lunar base. I wonder how hard it would be to inflate a BA-2100 inside... what would be the risks involved ?

An obvious risk would be mission design.
You're going to need to on-site survey before you can do much mission design, meaning a lot of funding and effort before you land the module and even consider expanding it.

Obviously, inside a tube, there is no sun, so you've got to have a long cable to solar panels (or reactor of course) and access to the surface may not quite be easy.
Even before considering sharp debris in the tube wanting to puncture your module and possible structural instability. (yes, the moon is 'dead' - but can you neglect the possibility that it's on the edge without a survey)
« Last Edit: 03/07/2018 11:19 AM by speedevil »

Offline aceshigh

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #47 on: 03/14/2018 01:25 AM »
did this a while ago... trying to show a big how spacious a 2100 hab would be from inside


Offline Cinder

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #48 on: 03/16/2018 05:58 PM »
Nice video.  I would have had a segment (e.g. before and/or after) from a global POV with familiar things next to the module for scale.  E.G. have it sat in between a supermarket and an average home (all three elements in cutaway for visibility's sake).  You lose a bit of the scale of something when you are mazing through it with relatively narrow field of view.
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Offline ThereIWas3

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #49 on: 03/16/2018 08:31 PM »
The Moon Marius Hills features some underground lava tube that would be perfect for a lunar base. I wonder how hard it would be to inflate a BA-2100 inside... what would be the risks involved ?

Bigelow has said in the past that assembling habs on the lunar surface (and inside a lava tube would be even worse) is fraught with problems, due to the abrasive dust getting into everything.  That is why their early plan for a lunar facility was to be assmbled in lunar orbit, then brought down to the surface intact.  I don't know if they still hold with this idea.
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Offline Kansan52

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #50 on: 03/16/2018 08:54 PM »
This abstract seems to cover the hurdles:

http://www.isruinfo.com/docs/the_lunar_dust_problem_-_from_liability_to_asset.pdf

My take, electromagnetic fields could mitigate dust problems in living spaces. Microwaves could be used for using dust for in situ construction.

Offline aceshigh

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #51 on: 03/19/2018 11:16 PM »
Nice video.  I would have had a segment (e.g. before and/or after) from a global POV with familiar things next to the module for scale.  E.G. have it sat in between a supermarket and an average home (all three elements in cutaway for visibility's sake).  You lose a bit of the scale of something when you are mazing through it with relatively narrow field of view.

initial objective was to populate it all... have sections for habitat, an hydroponics food production facility, a lab, a socializing area, etc.

That would give more sense of scale...

Offline johnfwhitesell

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #52 on: 05/17/2018 03:36 AM »
If BFS costs $200M, that sets an obvious floor on a space station at $250K/m^3, which seems to be moderately close to prices that have been implied for the BA-330. And - well - if you want, you can deorbit it at any time. (in LEO at least).

Wouldn't the expanded habitat have better protection against micrometeorites?

Online speedevil

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #53 on: 05/17/2018 10:20 AM »
If BFS costs $200M, that sets an obvious floor on a space station at $250K/m^3, which seems to be moderately close to prices that have been implied for the BA-330. And - well - if you want, you can deorbit it at any time. (in LEO at least).

Wouldn't the expanded habitat have better protection against micrometeorites?
Marginally, if you do not cover the BFS with anything.

Offline johnfwhitesell

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #54 on: 05/17/2018 07:02 PM »
Marginally, if you do not cover the BFS with anything.

I would assume you would need to deploy the shield after it's in orbit.  And in that case, aren't you just talking about half an expandable habitat covering the heat shield?

Offline intrepidpursuit

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #55 on: 06/17/2018 07:52 PM »
(edit)BFS "pressurised volume" is given as 825m^3. Certainly more volume / mass than Falcon Heavy. It should be easy to put something like the BA-2100 into that, but it won't (or shouldn't) look exactly like the BA-2100.

In both cases, would you keep the upper stage attached, so it can be used as a booster or perhaps a volatiles store? Or perhaps something similar to the old Space Shuttle ET reuse proposals?

BFS raises the rather awkward issue of pricing.

If BFS costs $200M, that sets an obvious floor on a space station at $250K/m^3, which seems to be moderately close to prices that have been implied for the BA-330. And - well - if you want, you can deorbit it at any time. (in LEO at least).

But, if you don't care about mass, or inflatability, or anything fancy, you can get shielded 300m^3 or so 6m internal diameter modules up for not much more than 3* launch cost of BFS, even without any on-orbit assembly.

Buy 6m aluminium inch thick tank, don't tell them it's for aerospace, pressurise to 150PSI a few times to test it, add 1m of plastic water tanks to the outside (empty), glue on aluminium foil, fill in orbit, and you've got a pressurised shielded volume that you can outfit at your leisure.

This is obviously not suitable for BLEO, as it's quite high mass, but in LEO, you don't actually care about that.

On other loads, you send up 10m*3m tubes, with various 'plumbing' type fittings, made from two inch thick aluminium to be on the safe side, and just attach the tanks using these.

Of course, this rather depends on what BFS actually charges for launch - and what the market is.
If SpaceX gets involved in orbital tourism, their only reason to not consider launches 'at cost' would be anticompetitive reasons.

If they actually manage to convince people to pay $150M per launch, then you very much want bigelow type habs.

I don't think BFS will be considered an option for a permanent in orbit hab for quite a while. It is a limited commodity and gets the best return on investment by launching and returning many times. SpaceX won't be anxious to sell a custom space hab version for a long time if ever. Making a Bigelow module sized to be deployed and serviced by BFS is a much better idea.

Online speedevil

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #56 on: 06/17/2018 08:10 PM »
Marginally, if you do not cover the BFS with anything.

I would assume you would need to deploy the shield after it's in orbit.  And in that case, aren't you just talking about half an expandable habitat covering the heat shield?
No.
It doesn't need to hold pressure, or do any of the normal things that make an expandable habitat hard.


Offline johnfwhitesell

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #57 on: 06/18/2018 12:18 PM »
No.
It doesn't need to hold pressure, or do any of the normal things that make an expandable habitat hard.

I was under the impression that stopping micrometeorites was the hard part of holding pressure.

Offline envy887

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #58 on: 06/18/2018 01:24 PM »
If BFS costs $200M, that sets an obvious floor on a space station at $250K/m^3, which seems to be moderately close to prices that have been implied for the BA-330. And - well - if you want, you can deorbit it at any time. (in LEO at least).

But, if you don't care about mass, or inflatability, or anything fancy, you can get shielded 300m^3 or so 6m internal diameter modules up for not much more than 3* launch cost of BFS, even without any on-orbit assembly.

Buy 6m aluminium inch thick tank, don't tell them it's for aerospace, pressurise to 150PSI a few times to test it, add 1m of plastic water tanks to the outside (empty), glue on aluminium foil, fill in orbit, and you've got a pressurised shielded volume that you can outfit at your leisure.

Inflatables still allow much larger volumes, though. And BFR only makes them cheaper.

For example, a single BFR launch could lift a 140 tonne, 100 meter deflated Kevlar sphere with 3 mm thick walls (5x safety factor) and a 10 tonne docking port/service/propulsion module. It would take 5 BFR flights of liquid air tanks to pressurize it to 1 atmosphere, but then you have a volume equal to 635 BFSes or 1600 BA-330s. Figuring out how to manufacture that sounds like a Bigelow specialty.

It would take some outfitting to make that volume useful though, unless all you wanted was an orbital bouncy castle :)
« Last Edit: 06/18/2018 01:26 PM by envy887 »

Online speedevil

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Re: Bigelow Habs - How Big Will They Go? Where Will They Go?
« Reply #59 on: 06/18/2018 02:02 PM »
Inflatables still allow much larger volumes, though. And BFR only makes them cheaper.

For example, a single BFR launch could lift a 140 tonne, 100 meter deflated Kevlar sphere with 3 mm thick walls (5x safety factor) and a 10 tonne docking port/service/propulsion module. It would take 5 BFR flights of liquid air tanks to pressurize it to 1 atmosphere, but then you have a volume equal to 635 BFSes or 1600 BA-330s. Figuring out how to manufacture that sounds like a Bigelow specialty.

It would take some outfitting to make that volume useful though, unless all you wanted was an orbital bouncy castle :)
I wholeheartedly agree that inflatables are in principle cheaper than many other options.
I also note that 'outfitting' may get weird.
For example, it is not wholly unreasonable to consider a bare skin, with vacuum on one side and air on the other, and you rely on the skin and a couple of meters of air for debris  protection. Being able to just wander over next week and slap some duct tape on a hole  makes a whole lot of things easier.

But, if your inflatable pricing is not in fact cheaper than just using a BFS (and bigelow hasn't shown any enthusiasm for massive cheap stations), you have a significant illogicality.
Even without inflatables, or on-orbit assembly, 8m diameter * 12m aluminium cylinders tested for several cycles of 140PSI is another obvious backstop to pricing, and it's reasonable to ask if bigelow modules will go anywhere.

« Last Edit: 06/18/2018 02:12 PM by speedevil »

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