I have a piece on Bigelow’s recent announcements at Popular Mechanics.
37 thoughts on “Space Conestogas”
I really enjoyed this piece, which I found via spacetoday.net As I read it, I wondered whether you had seen it yet. Then I got to the part about the Swedish hospitality, and realized you were the author.
The photos and descriptions of the larger BA-2100 were fascinating, even if they require a heavy lift launcher that might never be built. I don’t know if zero-g sports will take off, but an empty BA-2100 sounds like a good venue for it.
BA-300 typo?
> Capable of comfortably supporting six crew members, according to Bigelow, each BA-300 module…
What do you mean by a typo? What’s wrong with it?
Rand, isn’t it BA-330?
D’oh!
Yes. I’ll tell the editor.
Am I imagining things, or did the paragraph on the Swedes get edited a bit. It painted a more colorful picture when I read it earlier today… Political correctness run amuck yet again?
The photos and descriptions of the larger BA-2100 were fascinating, even if they require a heavy lift launcher that might never be built.
2100 if think stands for 2100m^3 of internal volume (~5x that of the ISS I think). I should note that the shell alone for a habitat of this volume (including shielding, double wall redundancy, etc.) should weigh around 10 ton and be launch-able on a standard Falcon 9.
The BA-2100 is presumably a rigid ~60 ton core with an inflatable ~10 ton multiple layer shell around it. There is no fundamental reason for this having to be launched all at once, indeed launching such a habitat in ~five ton payloads seems quite practical if there is a willingness to do it one component at a time.
There are also some simple tricks for making pressure vessel sections that clip together if one wanted to uses smaller payload sizes again. This would enable the assembly of habitats of somewhat arbitrary size. Larger habitats being assembled inside smaller ones prior to taking outside and inflating. Current Bigelow modules are not fully open spaces inside and do not currently allow such use as orbital assembly hangers.
Rand, what confirmation do you have on those sovereign customers?
Just wondering about Australia being in that list, again.
Has someone from Bigelow seen that in print and confirmed it, or has it all been oral?
Any higher-res versions of those BA-2100 deck plans? I see there’s nothing on Bigelow’s website about it yet.
Little point of annoyance: A bit unfortunate that these things became known as “inflatables”. For a layperson, this associates with balloons and bursting.
Which, as we all know, is not the case here.
Flexi-wall pressure vessels doesn’t roll off the tongue, though.
reader, which is why Bigelow prefers “expandables”. Which is also a horrible name.
I’m trying to think of something that goes with pressurized inflatable structure atmospheric. I keep thinking PISA. They are towers after all.
Bigelow’s structures are not actually inflated to their rigid form.. they’re mechanically expanded. If they lose pressure they don’t deflate.. if they’re overpressurized they don’t inflate. To put it another way, they’re more like an umbrella than they are like a balloon.
Any idea what the purchase price of a BA-2100 would be? $100m is what the BA-330 was once announced. Also it would cost another $100m to put in in orbit. So what would be the ticket price to put 70 ton to orbit?
I need to update my spaceship design. One BA-2100 could replace the seven BA-330 for almost the same interior volume at a much lower cost to orbit I’m assuming. It also trims 91k kg from my 250k kg ship. That should do nice things for the delta V.
Inflatable is the standard term used to refer to such engineering structures, and not one sullied by more common associations within the field. Strictly speaking the Bigelow modules are a slight hybrid design with the rigid central core taking significant end loads, the core also serves as uninflated base structure, perhaps this is some of the reason for the use of the term expandable.
Inflatable habitats are greatly benefited by greater scale (shielding and the surface area to volume ratio). I suspect the BA-2100 could be a bit of a game changer – it would I think significantly help remove the giggle factor for space settlement. Even those unfamiliar with space settlement might look at the spacious five story BA-2100 and find it convincing.
I would reiterate that an inflatable module the size of the BA-2100 no more requires heavy lift than propellant does and such habitats could be easily launched on much smaller launch vehicles. The desire for large inflatable habitats is not a good excuse for heavy lift.
Heh, they’re obviously Transformers.
A wagon train to the stars?
And so the slow march to pump up demand for launch services continues.
Interesting that they reversed the deck attitudes on the ba-2100. At what point does it make sense to go “with the grain” as opposed to “against the grain”?
The desire for large inflatable habitats is not a good excuse for heavy lift.
In fact, inflatables invalidate one of the most frequently used arguments in favour of heavy lift: the supposed need for even wider fairings than the 7.5m ones that are possible on existing EELVs.
So, what does this do to depreciation rate of ISS, a $100B investment ?
Little point of annoyance: A bit unfortunate that these things became known as “inflatables”. For a layperson, this associates with balloons and bursting.
Which, as we all know, is not the case here.
Flexi-wall pressure vessels doesn’t roll off the tongue, though.
If he is first on the market for long enough, then Bigelow will end up having to sue competitors to prevent all future such structures from being called “bigelows”. cf. Kleenex, Diesel, Xerox
So, what does this do to depreciation rate of ISS, a $100B investment ?
Sunk cost doesn’t equal investment value. First, I think if everyone involved stripped away the technology encumbrances, like NASA’s Tracking and Data Relay Satellite System (TRDSS) or the Russian equivalent, that is, somehow made it so that you’re buying a working space station with as little baggage as possible, you’ll still looking at something that needs a crew and routine shipments, just to keep it operational. The ISS might get low billions of dollars.
G’day,
Has anyone thought of sending up a spinable wheel inflatable to produce artificial gravity?
Hi Ralph,
If I understand it correctly, you would need a wheel one kilometer in diameter to avoid the nausea from the coriolis effect. Until we can build that, we can work on rotating tethered spacecraft.
I was thinking about this after reading a report on the female reproductive system in zero gravity. A cylidrical ship could boost toward mars. Once it has the required velocity it could split in half and gently move apart about a kilometer (tethered of course). If small thrusters were employed to give the two halves rotation for “gravity”, would it totally mess up the outbound orbit?
For course changes I envision killing the rotation, retracting the tether (rejoining the halves), and proceeding with the required burn…
Is this close to what could be done?
Has anyone thought of sending up a spinable wheel inflatable to produce artificial gravity?
A possible design might be inflatable habitat modules on ~1km tethers spinning around a zero g inflatable station hub with elevators to each module. Fairly easy to add more modules as required.
Once it has the required velocity it could split in half and gently move apart about a kilometer (tethered of course). If small thrusters were employed
Leave a small central hub with an electric motor, two tethers and four capsules at the end. No need for thrusters.
It’ll be lonely for each of the four astronauts though ..
uh, “two counterrotating tethers” of course.
“It’ll be lonely for each of the four astronauts though ..”
It was the Journal of Cosmology study, and they actually recommend separating the astronauts by gender to keep sexual tensions from destroying the mission to Mars.
It’s a fascinating study, of course I went right to “sex in space” and read with semi-horror the plight of women without gravity. The concept of needing gravity to get stuff to flow was an eye opener… The prognosis for procreation in space (or the moon) is not so hot, a bit better for Mars. (I think we’re gonna need a few Kaplana Habitats.)
The constant reference to how monkeys behave was sorta funny, but not really.
“The prognosis for procreation in space…”
I meant “in zero gravity” of course.
The last I heard (and this was decades ago) was that the
The last I heard (and this was decades ago) was that the one second period/one km tether was based on a limited set of studies, that nobody really knows the limit that people can fairly readily acclimate to. And, of course, nobody knows the long term effects of various low gravity environments and what g level is sufficient to prevent difficulties. There were some rodent studies that suggested that higher than earth gravities are actually healthier for the rats; I don’t think these have been performed on humans either, even though these could be done earthside.
G’day,
The 1 RPM speed was for the Stanford Torus Space Colony. They wanted a full 1G at a rotation that would have no affect on the inhabitants. A space colony is a bit ambitious. Recent studies indicate people can adapt to RPMs as high as 10.
A wheel station with a radius of 10 meters at RPM 7.5 would provide artificial gravity 62% Earth’s normal.
ta
Ralph
Zubrin cut the radius way down in his proposals by going to Mars-standard .3G. I suspect that some compromise like this that provides enough 24/7 resistance to maintain bodies at a reasonable level but has much lower requirements than 1G will wind up winning out when the subject of gravity is finally addressed.
It’d be nice to test that out in orbit first, without adding 20 years to the timeline.
This is why you might want to send multiple independent ships of equal mass. Have three ships tethered and rotating as endpoints of an equilateral triangle (orientation wouldn’t really matter.) You could probably ride the tethers from one ship to the other if you didn’t want to stop rotation and dock them together for some reason.
I also think Bigelow should come up with design that matches a launch capability. The BA-330 is 23k kg which matches the Delta IV heavy to LEO. Other vehicles currently or soon available might take from 29k kg to 38k kg to LEO. So it would make sense for them to have something like a BA-500 or BA-1000 in that mass range rather than wait for a bigger launch vehicle for the BA-2100. OTOH, if they plan the floor space to manufacture the BA-2100 it should allow them to make smaller units as well.
In any case, it’s exciting to speculate what might be done which I suppose is why they unveiled the BA-2100 in the first place.
“Has anyone thought of sending up a spinable wheel inflatable to produce artificial gravity?”
It never flew, and I don’t know what the intended rotation rate would’ve been (pretty damn slow for people at this radius, I’m thinking), but Goodyear worked on one in the early 60’s…
I really enjoyed this piece, which I found via spacetoday.net As I read it, I wondered whether you had seen it yet. Then I got to the part about the Swedish hospitality, and realized you were the author.
The photos and descriptions of the larger BA-2100 were fascinating, even if they require a heavy lift launcher that might never be built. I don’t know if zero-g sports will take off, but an empty BA-2100 sounds like a good venue for it.
BA-300 typo?
> Capable of comfortably supporting six crew members, according to Bigelow, each BA-300 module…
What do you mean by a typo? What’s wrong with it?
Rand, isn’t it BA-330?
D’oh!
Yes. I’ll tell the editor.
Am I imagining things, or did the paragraph on the Swedes get edited a bit. It painted a more colorful picture when I read it earlier today… Political correctness run amuck yet again?
The photos and descriptions of the larger BA-2100 were fascinating, even if they require a heavy lift launcher that might never be built.
2100 if think stands for 2100m^3 of internal volume (~5x that of the ISS I think). I should note that the shell alone for a habitat of this volume (including shielding, double wall redundancy, etc.) should weigh around 10 ton and be launch-able on a standard Falcon 9.
The BA-2100 is presumably a rigid ~60 ton core with an inflatable ~10 ton multiple layer shell around it. There is no fundamental reason for this having to be launched all at once, indeed launching such a habitat in ~five ton payloads seems quite practical if there is a willingness to do it one component at a time.
There are also some simple tricks for making pressure vessel sections that clip together if one wanted to uses smaller payload sizes again. This would enable the assembly of habitats of somewhat arbitrary size. Larger habitats being assembled inside smaller ones prior to taking outside and inflating. Current Bigelow modules are not fully open spaces inside and do not currently allow such use as orbital assembly hangers.
Rand, what confirmation do you have on those sovereign customers?
Just wondering about Australia being in that list, again.
Has someone from Bigelow seen that in print and confirmed it, or has it all been oral?
Any higher-res versions of those BA-2100 deck plans? I see there’s nothing on Bigelow’s website about it yet.
Little point of annoyance: A bit unfortunate that these things became known as “inflatables”. For a layperson, this associates with balloons and bursting.
Which, as we all know, is not the case here.
Flexi-wall pressure vessels doesn’t roll off the tongue, though.
reader, which is why Bigelow prefers “expandables”. Which is also a horrible name.
I’m trying to think of something that goes with pressurized inflatable structure atmospheric. I keep thinking PISA. They are towers after all.
Bigelow’s structures are not actually inflated to their rigid form.. they’re mechanically expanded. If they lose pressure they don’t deflate.. if they’re overpressurized they don’t inflate. To put it another way, they’re more like an umbrella than they are like a balloon.
Any idea what the purchase price of a BA-2100 would be? $100m is what the BA-330 was once announced. Also it would cost another $100m to put in in orbit. So what would be the ticket price to put 70 ton to orbit?
I need to update my spaceship design. One BA-2100 could replace the seven BA-330 for almost the same interior volume at a much lower cost to orbit I’m assuming. It also trims 91k kg from my 250k kg ship. That should do nice things for the delta V.
This video says the ba2100 is about 100 tons…
http://www.youtube.com/watch?v=OqsHK2vxyzo&feature=player_embedded
Inflatable is the standard term used to refer to such engineering structures, and not one sullied by more common associations within the field. Strictly speaking the Bigelow modules are a slight hybrid design with the rigid central core taking significant end loads, the core also serves as uninflated base structure, perhaps this is some of the reason for the use of the term expandable.
Inflatable habitats are greatly benefited by greater scale (shielding and the surface area to volume ratio). I suspect the BA-2100 could be a bit of a game changer – it would I think significantly help remove the giggle factor for space settlement. Even those unfamiliar with space settlement might look at the spacious five story BA-2100 and find it convincing.
I would reiterate that an inflatable module the size of the BA-2100 no more requires heavy lift than propellant does and such habitats could be easily launched on much smaller launch vehicles. The desire for large inflatable habitats is not a good excuse for heavy lift.
Heh, they’re obviously Transformers.
A wagon train to the stars?
And so the slow march to pump up demand for launch services continues.
Interesting that they reversed the deck attitudes on the ba-2100. At what point does it make sense to go “with the grain” as opposed to “against the grain”?
The desire for large inflatable habitats is not a good excuse for heavy lift.
In fact, inflatables invalidate one of the most frequently used arguments in favour of heavy lift: the supposed need for even wider fairings than the 7.5m ones that are possible on existing EELVs.
So, what does this do to depreciation rate of ISS, a $100B investment ?
Little point of annoyance: A bit unfortunate that these things became known as “inflatables”. For a layperson, this associates with balloons and bursting.
Which, as we all know, is not the case here.
Flexi-wall pressure vessels doesn’t roll off the tongue, though.
If he is first on the market for long enough, then Bigelow will end up having to sue competitors to prevent all future such structures from being called “bigelows”. cf. Kleenex, Diesel, Xerox
So, what does this do to depreciation rate of ISS, a $100B investment ?
Sunk cost doesn’t equal investment value. First, I think if everyone involved stripped away the technology encumbrances, like NASA’s Tracking and Data Relay Satellite System (TRDSS) or the Russian equivalent, that is, somehow made it so that you’re buying a working space station with as little baggage as possible, you’ll still looking at something that needs a crew and routine shipments, just to keep it operational. The ISS might get low billions of dollars.
G’day,
Has anyone thought of sending up a spinable wheel inflatable to produce artificial gravity?
Hi Ralph,
If I understand it correctly, you would need a wheel one kilometer in diameter to avoid the nausea from the coriolis effect. Until we can build that, we can work on rotating tethered spacecraft.
I was thinking about this after reading a report on the female reproductive system in zero gravity. A cylidrical ship could boost toward mars. Once it has the required velocity it could split in half and gently move apart about a kilometer (tethered of course). If small thrusters were employed to give the two halves rotation for “gravity”, would it totally mess up the outbound orbit?
For course changes I envision killing the rotation, retracting the tether (rejoining the halves), and proceeding with the required burn…
Is this close to what could be done?
Has anyone thought of sending up a spinable wheel inflatable to produce artificial gravity?
A possible design might be inflatable habitat modules on ~1km tethers spinning around a zero g inflatable station hub with elevators to each module. Fairly easy to add more modules as required.
Once it has the required velocity it could split in half and gently move apart about a kilometer (tethered of course). If small thrusters were employed
Leave a small central hub with an electric motor, two tethers and four capsules at the end. No need for thrusters.
It’ll be lonely for each of the four astronauts though ..
uh, “two counterrotating tethers” of course.
“It’ll be lonely for each of the four astronauts though ..”
It was the Journal of Cosmology study, and they actually recommend separating the astronauts by gender to keep sexual tensions from destroying the mission to Mars.
It’s a fascinating study, of course I went right to “sex in space” and read with semi-horror the plight of women without gravity. The concept of needing gravity to get stuff to flow was an eye opener… The prognosis for procreation in space (or the moon) is not so hot, a bit better for Mars. (I think we’re gonna need a few Kaplana Habitats.)
The constant reference to how monkeys behave was sorta funny, but not really.
“The prognosis for procreation in space…”
I meant “in zero gravity” of course.
The last I heard (and this was decades ago) was that the
The last I heard (and this was decades ago) was that the one second period/one km tether was based on a limited set of studies, that nobody really knows the limit that people can fairly readily acclimate to. And, of course, nobody knows the long term effects of various low gravity environments and what g level is sufficient to prevent difficulties. There were some rodent studies that suggested that higher than earth gravities are actually healthier for the rats; I don’t think these have been performed on humans either, even though these could be done earthside.
G’day,
The 1 RPM speed was for the Stanford Torus Space Colony. They wanted a full 1G at a rotation that would have no affect on the inhabitants. A space colony is a bit ambitious. Recent studies indicate people can adapt to RPMs as high as 10.
http://www.ncbi.nlm.nih.gov/pubmed/11020210?dopt=Abstract
A wheel station with a radius of 10 meters at RPM 7.5 would provide artificial gravity 62% Earth’s normal.
ta
Ralph
Zubrin cut the radius way down in his proposals by going to Mars-standard .3G. I suspect that some compromise like this that provides enough 24/7 resistance to maintain bodies at a reasonable level but has much lower requirements than 1G will wind up winning out when the subject of gravity is finally addressed.
It’d be nice to test that out in orbit first, without adding 20 years to the timeline.
This is why you might want to send multiple independent ships of equal mass. Have three ships tethered and rotating as endpoints of an equilateral triangle (orientation wouldn’t really matter.) You could probably ride the tethers from one ship to the other if you didn’t want to stop rotation and dock them together for some reason.
I also think Bigelow should come up with design that matches a launch capability. The BA-330 is 23k kg which matches the Delta IV heavy to LEO. Other vehicles currently or soon available might take from 29k kg to 38k kg to LEO. So it would make sense for them to have something like a BA-500 or BA-1000 in that mass range rather than wait for a bigger launch vehicle for the BA-2100. OTOH, if they plan the floor space to manufacture the BA-2100 it should allow them to make smaller units as well.
In any case, it’s exciting to speculate what might be done which I suppose is why they unveiled the BA-2100 in the first place.
“Has anyone thought of sending up a spinable wheel inflatable to produce artificial gravity?”
It never flew, and I don’t know what the intended rotation rate would’ve been (pretty damn slow for people at this radius, I’m thinking), but Goodyear worked on one in the early 60’s…
http://www.nasaimages.org/luna/servlet/detail/nasaNAS~5~5~24238~127640:Inflatable-Station-Concept
…as well as a small Lunar surface inflatable.