Author Topic: Realistic, near-term, rotating Space Station  (Read 943817 times)

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8859
  • I live... along the coast
  • Liked: 10198
  • Likes Given: 11927
Re: Realistic, near-term, rotating Space Station
« Reply #940 on: 07/15/2018 09:50 pm »
All:  Gary Hudson over at the Space Studies Institute (SSI) has been beating the drum for the need of artificial-gee for human spaceflight for years now and I totally agree with Gary that before we establish long term colonies on the Earth's Moon and Mars, we had first find out if humans can breed in and live long-term under 1/6 and 1/3 gee gravity fields.

I think we should be making artificial gravity a priority, but I don't agree that we have to do it before sending humans to our Moon and Mars.

Mainly because being on our Moon and Mars is the SAME as being on an artificial gravity station, so the same experiments can be run - maybe some added risk, but there are people that would go to both locations regardless of the risk.

But we want to do a lot more than set up colonies on our Moon and Mars when we leave Earth, so perfecting artificial gravity space stations - and understanding what the minimum gravity requirements are for humans - is still a near-term need.

Quote
A good summary of Hudson's approach to finding the answer to these questions is at the below December 2015 YouTube video URL.  In this video Gary lays out a moderately low cost approach to finding the answers to these biological compatibility questions.

An interesting proposal that could be a good first step.

Thanks for sharing!
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline LMT

  • Lake Matthew Team
  • Senior Member
  • *****
  • Posts: 2351
    • Lake Matthew
  • Liked: 424
  • Likes Given: 0
Re: Realistic, near-term, rotating Space Station
« Reply #941 on: 07/16/2018 01:03 am »
The Hub





A minimal hub for a 1 g ITS space station could employ:

- propulsion:  water tank with electric resistojets, for safety as cargo

- extension:  Telescopic Tubular Mast (TTM) system as used on James Webb, upgraded to titanium and redesigned for heavy-lift:  ~ 4 MN load x 2

- control:  Dextre-class telerobotics to manage the TTM boom-and-hook vertical-integration connections

- housekeeping:  COTS hw for electrical, comm, CDH, ACS

Wet mass plausibly < 20 t.

Scheme assumes essential mods implemented proactively on ITS, especially:

- upgraded cargo vertical integration points for ~ 4 MN load

- upgraded / augmented cryo ullage connectors for ~ 3 MN load

In a first, short-duration station test the notional water ullage / transfer system could be deferred, as the extra shielding would not be needed on that flight.

Also, after the test all station modules return to Earth.  The entire system can be repaired or upgraded on Earth between missions.

--

Given all above, a first 1 g space station test could occur shortly after the first ITS LEO docking mission.

And given the hub's modest R&D requirement and its Earth-repair capacity, it's hard to see how others could offer similar station facilities at competitive price, near-term.

Pinch of salt, first spin-up conceivable circa 2022.

« Last Edit: 07/16/2018 11:37 am by LMT »

Offline HMXHMX

  • Full Member
  • ****
  • Posts: 1709
  • Liked: 2211
  • Likes Given: 662
Re: Realistic, near-term, rotating Space Station
« Reply #942 on: 07/16/2018 03:29 am »
All:  Gary Hudson over at the Space Studies Institute (SSI) has been beating the drum for the need of artificial-gee for human spaceflight for years now and I totally agree with Gary that before we establish long term colonies on the Earth's Moon and Mars, we had first find out if humans can breed in and live long-term under 1/6 and 1/3 gee gravity fields.

I think we should be making artificial gravity a priority, but I don't agree that we have to do it before sending humans to our Moon and Mars.

Mainly because being on our Moon and Mars is the SAME as being on an artificial gravity station, so the same experiments can be run - maybe some added risk, but there are people that would go to both locations regardless of the risk.

But we want to do a lot more than set up colonies on our Moon and Mars when we leave Earth, so perfecting artificial gravity space stations - and understanding what the minimum gravity requirements are for humans - is still a near-term need.

Quote
A good summary of Hudson's approach to finding the answer to these questions is at the below December 2015 YouTube video URL.  In this video Gary lays out a moderately low cost approach to finding the answers to these biological compatibility questions.

An interesting proposal that could be a good first step.

Thanks for sharing!

A more current version of the G-Lab concept is presented in the attached.  This was given as a talk at the 33rd Annual Meeting of the American Society for Gravitational and Space Research, October 25-28, 2017 in Seattle.  The baseline launch vehicle is the New Glenn, due to its 7 meter diameter.

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8859
  • I live... along the coast
  • Liked: 10198
  • Likes Given: 11927
Re: Realistic, near-term, rotating Space Station
« Reply #943 on: 07/16/2018 03:42 am »
[A more current version of the G-Lab concept is presented in the attached.  This was given as a talk at the 33rd Annual Meeting of the American Society for Gravitational and Space Research, October 25-28, 2017 in Seattle.  The baseline launch vehicle is the New Glenn, due to its 7 meter diameter.

Thanks for that. If the goal is to do testing on humans, there is a lot to like with this proposal.

Of course maybe I'm biased because I have a similar design that I've been working on that is significantly larger, but the same basic baton concept. So I can see a lot of advantages that this design has, since it's a less expensive proposal (and money is ALWAYS an important consideration).

And I was also happy to see that they upgraded their concept in anticipation of larger launchers, so this could be launched (I think) on not only New Glenn but BFS also. Which would still allow for transportation redundancy while taking advantage of lower transportation costs.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline mikelepage

  • Full Member
  • ****
  • Posts: 1218
  • ExodusSpaceSystems.com
  • Perth, Australia
  • Liked: 855
  • Likes Given: 1358
Re: Realistic, near-term, rotating Space Station
« Reply #944 on: 07/16/2018 04:05 am »
All:  Gary Hudson over at the Space Studies Institute (SSI) has been beating the drum for the need of artificial-gee for human spaceflight for years now and I totally agree with Gary that before we establish long term colonies on the Earth's Moon and Mars, we had first find out if humans can breed in and live long-term under 1/6 and 1/3 gee gravity fields.

I think we should be making artificial gravity a priority, but I don't agree that we have to do it before sending humans to our Moon and Mars.

Mainly because being on our Moon and Mars is the SAME as being on an artificial gravity station, so the same experiments can be run - maybe some added risk, but there are people that would go to both locations regardless of the risk.

But we want to do a lot more than set up colonies on our Moon and Mars when we leave Earth, so perfecting artificial gravity space stations - and understanding what the minimum gravity requirements are for humans - is still a near-term need.

I wish we could stop this pervasive notion that we're in a zero-sum game.  That we have to choose one option - or - the other.  The history of government funding being what it is, it's understandable why we've got into this habit, but I do think it can be different now that commercial space is coming to the fore, and as long as a spin gravity station can at least be revenue neutral - from space tourism, research, or whatever else - then we can stop feeling like we have to compete for existing government funding.

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8859
  • I live... along the coast
  • Liked: 10198
  • Likes Given: 11927
Re: Realistic, near-term, rotating Space Station
« Reply #945 on: 07/16/2018 06:27 am »
All:  Gary Hudson over at the Space Studies Institute (SSI) has been beating the drum for the need of artificial-gee for human spaceflight for years now and I totally agree with Gary that before we establish long term colonies on the Earth's Moon and Mars, we had first find out if humans can breed in and live long-term under 1/6 and 1/3 gee gravity fields.

I think we should be making artificial gravity a priority, but I don't agree that we have to do it before sending humans to our Moon and Mars.

Mainly because being on our Moon and Mars is the SAME as being on an artificial gravity station, so the same experiments can be run - maybe some added risk, but there are people that would go to both locations regardless of the risk.

But we want to do a lot more than set up colonies on our Moon and Mars when we leave Earth, so perfecting artificial gravity space stations - and understanding what the minimum gravity requirements are for humans - is still a near-term need.

I wish we could stop this pervasive notion that we're in a zero-sum game.  That we have to choose one option - or - the other.  The history of government funding being what it is, it's understandable why we've got into this habit, but I do think it can be different now that commercial space is coming to the fore, and as long as a spin gravity station can at least be revenue neutral - from space tourism, research, or whatever else - then we can stop feeling like we have to compete for existing government funding.

Does that mean we are agreeing?

Because I was not advocating that we have to wait to go to other planets before we build artificial gravity space stations. I think some people can go to other planets, and some people can build artificial space stations, and though they are similar they aren't really the same - but both can contribute medical information that can be used for all.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline mikelepage

  • Full Member
  • ****
  • Posts: 1218
  • ExodusSpaceSystems.com
  • Perth, Australia
  • Liked: 855
  • Likes Given: 1358
Re: Realistic, near-term, rotating Space Station
« Reply #946 on: 07/16/2018 01:08 pm »
Does that mean we are agreeing?

Because I was not advocating that we have to wait to go to other planets before we build artificial gravity space stations. I think some people can go to other planets, and some people can build artificial space stations, and though they are similar they aren't really the same - but both can contribute medical information that can be used for all.
Aha, my bad. Reading comprehension fail on my part

(IMO, if humans require a full 1g at very low RPMs, we might as well end the manned space program until someone invents some magitech that fundamentally changes the rules.)

Don't throw the baby out with the bathwater.  I suspect that (1G @ <4rpm) is exactly the case if we're talking about the full human life-cycle with minimal symptoms, but I at least hope that testing say Mars Gravity (39%) might mitigate 39% of the symptoms, or maybe mostly mitigate symptoms for 39% of the population, or perhaps delay onset of the symptoms by 39%, or some combination of the above.

The human body is extremely analog.  ;D There can't be no benefit to reducing the impact of a variable that is known to cause harm.

Offline LMT

  • Lake Matthew Team
  • Senior Member
  • *****
  • Posts: 2351
    • Lake Matthew
  • Liked: 424
  • Likes Given: 0
Re: Realistic, near-term, rotating Space Station
« Reply #947 on: 07/16/2018 02:50 pm »
I suspect that (1G @ <4rpm) is exactly the case if we're talking about the full human life-cycle with minimal symptoms

A working assumption, yes.

--

Supplanting the DSG



Ideally a 1 g station would serve multiple roles with little modification.

For example the 1 g ITS station could conceivably supplant the Deep Space Gateway (DSG) aka Lunar Orbital Platform-Gateway (LOP-G). 

DSG-class mission:

1.  Once the system has been validated in LEO, it is disassembled.

2.  Then, instead of returning to Earth, ITS craft take on propellant from tankers. 

3.  They burn to lunar halo orbit. 

4.  There the hub is redeployed and the crew begins a DSG-class mission, in heavily-shielded 1 g comfort.

5.  The notional hub telerobotics system is repurposed for real-time lunar VR, for, say, lunar base construction.

6.  A mission could run for many months without health concerns. 

7.  At mission end the station is disassembled and the crew hands off the hub and cargo ships to the next team - on Earth, in LEO, or in lunar orbit, just as system maturity or mission requirements might dictate.

Long-duration missions would validate the system in a deep-space radiation environment, while exercising telerobotics and other ITS systems for useful tasks.   Corollary:  DSG-class missions would prove out many aspects of long-duration ITS Mars flight designs.

Economics:

Meanwhile, leased LEO stations could provide revenue to help fund the DSG-class missions.  Or conceivably one and the same hub could be used at both DSG and LEO stations, alternately, much as a student might take a summer job to pay bills.
« Last Edit: 07/17/2018 02:38 am by LMT »

Offline TrevorMonty

Re: Realistic, near-term, rotating Space Station
« Reply #948 on: 07/16/2018 05:07 pm »
Any tourism station in LEO is likely to have some rotational g. Even 1/10 should be enough to make basic every day things easier eg bathroom activites, eating, sleep, cooking, washing dishes and clothes.

Tourists would still have access to 0g core for play but don't have to live in 0g 24/7.

Offline Paul451

  • Senior Member
  • *****
  • Posts: 3553
  • Australia
  • Liked: 2518
  • Likes Given: 2180
Re: Realistic, near-term, rotating Space Station
« Reply #949 on: 07/16/2018 06:41 pm »
An ISS Co-orbital Free-flying Gravitational Biology Laboratory - G-Lab copy.pdf

Odd choice of size. If you want to do human research (as well as animal), it seems odd to focus on a 1g station right out of the gate. It's the mid-g values that you want.

Using the same 4RPM and dropping to Mars gravity at the ends allows you to cut the length to 42m (say 45m total). That drastically reduces the mass of the telescoping trusses and inflatable elevator, and eliminates the entire Mars-lab module. (You can still later do a run at 1g at 6.5RPM, if you insist, once you know that your crew are happy at 4RPM.)

I'd also put the crew sleeping areas in a low gravity area. You don't gain any g-load benefit while sleeping, and it's apparently gloriously comfortable. That frees up the entire higher-g floor-space for animal work, exercise areas, etc.



But the paper's use of an inflated elevator tube brought up another possibility. Using a Bigelow skin tube at the full diameter for the entire station, perhaps keeping the hard-node at the centre. Cables running down the tubes keep them under compression, increasing stability.

At 7m inflated diam, with 30cm skin, you're looking at around 70 tonnes for the full 45m length. (In reality, two shorter arms attaching to the docking node.) Three FH/NG launches: One for a central solid docking node and two solar arrays which hang at 90° to the arms (I prefer this arrangement as it improves rotational stability.) One launch for each ~30t arm, plus whatever equipment you can carry, depending on your launcher.

Added expense is one extra launch. Volume is huge, 1500m³.



Dropping the concept down a little. Same 45m length, same 30cm skin, just 5m diameter when inflated. Mass is around 50 tonnes for the whole thing. You aren't benefiting from inflating the diameter, but from compressing the length during launch. You might be able to get it down to two reusable FH launches, but launching as three pieces gives you many a lot of launch mass to spare for extras. Still looking at 650m³ internal volume. Allow 4m height per level (3m floor-to-ceiling plus 1m underfloor/overceiling for plumbing/ventilation/etc). Roughly 11 levels at varying gravity loads, with a uniform 4.4m available interior diameter.

(Each arm goes Mars g, 2 mid-g levels, lunar g, a low-g level and then the node. So an example layout might be: starting at the end of one arm you have the Mars g animal lab; then a gym/toilet/shower level; then the major ECLLS equipment level, then the lunar animal lab; then the main storage level, including freezers; then the node which also contains power/thermal systems; then down the other arm with the sleeping quarters; then a lunar bio-lab; then another ECLLS level (with a urine-only toilet); then a galley/rec area; then a Mars bio-lab. The bio-labs could host secondary experiments, like plants, and/or preparing animal (and human) samples for return, and general practising fiddly work at lunar/Mars g. They would also provide bench space for equipment tear-downs and repairs. Two ECLLS levels for backup and experimentation. Trying to keep the worst smells on one arm, sleeping and eating on the other.)

If you make sure your node has 6 berths (two IDAs for docking, 4 CBMs for attachments), an upgrade path is to add another two arms, if there's demand/funding for it.

Rough area for each of the 11 floors, just remove a foot for the Bigelow skin but continue the walls straight:

Offline Paul451

  • Senior Member
  • *****
  • Posts: 3553
  • Australia
  • Liked: 2518
  • Likes Given: 2180
Re: Realistic, near-term, rotating Space Station
« Reply #950 on: 07/16/2018 07:29 pm »
Supplanting the DSG
For example the 1 g ITS station could conceivably supplant the Deep Space Gateway (DSG) aka Lunar Orbital Platform-Gateway (LOP-G).

BFR completely obviates the need for LOP-G. (Well, the supposed need.) Not only would it work as a vastly larger, long duration lunar orbital lab, it can land directly on the surface (and would be singularly larger than any base that could be launched on SLS, at a reasonable NASA budget.)

But more broadly,



I don't see the value in having 4 BFSes mounted so awkwardly. It's a waste of ships, once they unload their payload, those cargo ships are merely serving as mere lengthening trusses.

Assuming the engines roughly match the mass of the hab-area, a single BFS spun end-over-end (or two docked nose-to-nose) would give 1g at a bit over 6RPM, Mars-g at less than 4RPM. Plus enough volume to do plenty of research. Going up, you can attach two BFSes with a tether or truss between them. (Or use a Bigelow-skin cable-tensioned tunnel so you can transfer between BFSes.) Dial in whatever length you can afford.

That said, once you go beyond one BFS, you might as well build your own dedicated (BFR-launched) modules, since you'd have to pay the equivalent of the BFSes working-value to keep them out of work and in orbit for say 6 months at a time.

(Aside: there's no need for a central node, since the only ships you need are already "docked". And you don't do micro-g research on a spin-station.)

Offline Paul451

  • Senior Member
  • *****
  • Posts: 3553
  • Australia
  • Liked: 2518
  • Likes Given: 2180
Re: Realistic, near-term, rotating Space Station
« Reply #951 on: 07/16/2018 09:22 pm »
IMO, if humans require a full 1g at very low RPMs, we might as well end the manned space program until someone invents some magitech that fundamentally changes the rules.
Sure, but why mention RPM here? We are quite screwed if humans require full 1g, period. In that case only orbital colonies will be realistic, not surface ones, and space colonization will be quite a bit harder. But then you may as well throw more trusses and modules on the station to achieve any RPM you like. Any viable colony is going to be inevitably quite large anyway.

Sure, if we're limited to 1RPM and 1g we can still build giant cities in space... But we can't build small towns. And if you can't build a town, you sure as hell ain't building cities. There's no organic path forward. No steps.

Unless some SF technology appears to allow us to build O'Neill cylinders at commercial hi-rise prices, there's simply no role for humans in space (outside of Apollo-type stunts) if we can't handle low-g and/or high-RPM.

Offline Paul451

  • Senior Member
  • *****
  • Posts: 3553
  • Australia
  • Liked: 2518
  • Likes Given: 2180
Re: Realistic, near-term, rotating Space Station
« Reply #952 on: 07/16/2018 09:24 pm »
Bigelow modules are designed for zero-G applications, so using them in artificial gravity applications should only be done after an engineering analysis shows that they can, in fact, handle the anticipated loads.

By that reasoning, the only aluminium solid modules we've ever launched were designed solely for zero-g applications, so shouldn't you be likewise scolding anyone who suggests an aluminium module? "Bricks and concrete, sir, girders and glass! These are the only building materials I will accept."

Offline Coastal Ron

  • Senior Member
  • *****
  • Posts: 8859
  • I live... along the coast
  • Liked: 10198
  • Likes Given: 11927
Re: Realistic, near-term, rotating Space Station
« Reply #953 on: 07/16/2018 09:33 pm »
Bigelow modules are designed for zero-G applications, so using them in artificial gravity applications should only be done after an engineering analysis shows that they can, in fact, handle the anticipated loads.

By that reasoning, the only aluminium solid modules we've ever launched were designed solely for zero-g applications, so shouldn't you be likewise scolding anyone who suggests an aluminium module? "Bricks and concrete, sir, girders and glass! These are the only building materials I will accept."

I've never advocated for using ISS modules built for zero-G for artificial gravity applications, so you're using a straw-man argument.

However we do have many structures that we build on Earth out of aluminum and composites that have to withstand compression and tension loads, so we know those materials are useable for such applications. Inflatables, not so much...  ;)
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline LMT

  • Lake Matthew Team
  • Senior Member
  • *****
  • Posts: 2351
    • Lake Matthew
  • Liked: 424
  • Likes Given: 0
Re: Realistic, near-term, rotating Space Station
« Reply #954 on: 07/16/2018 11:58 pm »
a single BFS spun end-over-end (or two docked nose-to-nose) would give 1g at a bit over 6RPM

More like 6.7 RPM at 20 m effective radius, unfortunately.  Not so nice.

Quote


The value is too high for comfort or will require deliberate adaptation.

mikelepage gives the more certain case: 

I suspect that (1G @ <4rpm) is exactly the case if we're talking about the full human life-cycle with minimal symptoms

How do you propose to dock "nose-to-nose"?
« Last Edit: 07/17/2018 12:14 am by LMT »

Offline Paul451

  • Senior Member
  • *****
  • Posts: 3553
  • Australia
  • Liked: 2518
  • Likes Given: 2180
Re: Realistic, near-term, rotating Space Station
« Reply #955 on: 07/17/2018 12:33 am »
a single BFS spun end-over-end (or two docked nose-to-nose) would give 1g at a bit over 6RPM
More like 6.7 RPM at 20 m effective radius, unfortunately.  Not so nice.

SpinCalc uses intentionally conservative values, based on old research. But there were no consistent results in that research. Hence SpinCalc green/red indicators should be taken with a grain of salt.

How do you propose to dock "nose-to-nose"?

How do you dock tail-to-tail?

Offline spacenut

  • Senior Member
  • *****
  • Posts: 5181
  • East Alabama
  • Liked: 2587
  • Likes Given: 2895
Re: Realistic, near-term, rotating Space Station
« Reply #956 on: 07/17/2018 01:26 am »
The BFS from SpaceX is going to dock tail to tail for fuel transfer from a tanker BFS to a cargo or passenger BFS for the trip to Mars.  So, why not spin two of them to get 0.4g Martian conditions before going to Mars to see what the human body can take long term?  The BFS is being built for long term space travel.  This could be done in LEO for about a year to see. 

Offline LMT

  • Lake Matthew Team
  • Senior Member
  • *****
  • Posts: 2351
    • Lake Matthew
  • Liked: 424
  • Likes Given: 0
Re: Realistic, near-term, rotating Space Station
« Reply #957 on: 07/17/2018 01:27 am »
SpinCalc uses intentionally conservative values, based on old research.

Did he say "intentionally conservative"?  I thought he chose values "comfortable for normal activity within the habitat".

And you see that HMXHMX gave us a linked ref to Globus & Hall 2015 just today.  That survey also puts you in the red, unfortunately.

Which research results give you confidence in the 6.7@20 lifestyle?

Offline RonM

  • Senior Member
  • *****
  • Posts: 3340
  • Atlanta, Georgia USA
  • Liked: 2231
  • Likes Given: 1584
Re: Realistic, near-term, rotating Space Station
« Reply #958 on: 07/17/2018 01:50 am »
SpinCalc uses intentionally conservative values, based on old research.

Did he say "intentionally conservative"?  I thought he chose values "comfortable for normal activity within the habitat".

And you see that HMXHMX gave us a linked ref to Globus & Hall 2015 just today.  That survey also puts you in the red, unfortunately.

Which research results give you confidence in the 6.7@20 lifestyle?

We really don't know what the "comfortable for normal activity within the habitat" levels are. Only way to find out for sure is a spin gravity station in orbit.  Start off with the conservative RPM range at lunar gravity. Once those results are in, crank up the RPM for Mars gravity. After that, crank it up to Earth gravity. We'll learn how the body reacts to low gravity and various RPM with a smaller, less expensive station.

Offline HMXHMX

  • Full Member
  • ****
  • Posts: 1709
  • Liked: 2211
  • Likes Given: 662
Re: Realistic, near-term, rotating Space Station
« Reply #959 on: 07/17/2018 03:33 am »
An ISS Co-orbital Free-flying Gravitational Biology Laboratory - G-Lab copy.pdf

Odd choice of size. If you want to do human research (as well as animal), it seems odd to focus on a 1g station right out of the gate. It's the mid-g values that you want.

Using the same 4RPM and dropping to Mars gravity at the ends allows you to cut the length to 42m (say 45m total). That drastically reduces the mass of the telescoping trusses and inflatable elevator, and eliminates the entire Mars-lab module. (You can still later do a run at 1g at 6.5RPM, if you insist, once you know that your crew are happy at 4RPM.)

I'd also put the crew sleeping areas in a low gravity area. You don't gain any g-load benefit while sleeping, and it's apparently gloriously comfortable. That frees up the entire higher-g floor-space for animal work, exercise areas, etc.



But the paper's use of an inflated elevator tube brought up another possibility. Using a Bigelow skin tube at the full diameter for the entire station, perhaps keeping the hard-node at the centre. Cables running down the tubes keep them under compression, increasing stability.

At 7m inflated diam, with 30cm skin, you're looking at around 70 tonnes for the full 45m length. (In reality, two shorter arms attaching to the docking node.) Three FH/NG launches: One for a central solid docking node and two solar arrays which hang at 90° to the arms (I prefer this arrangement as it improves rotational stability.) One launch for each ~30t arm, plus whatever equipment you can carry, depending on your launcher.

Added expense is one extra launch. Volume is huge, 1500m³.



Dropping the concept down a little. Same 45m length, same 30cm skin, just 5m diameter when inflated. Mass is around 50 tonnes for the whole thing. You aren't benefiting from inflating the diameter, but from compressing the length during launch. You might be able to get it down to two reusable FH launches, but launching as three pieces gives you many a lot of launch mass to spare for extras. Still looking at 650m³ internal volume. Allow 4m height per level (3m floor-to-ceiling plus 1m underfloor/overceiling for plumbing/ventilation/etc). Roughly 11 levels at varying gravity loads, with a uniform 4.4m available interior diameter.

(Each arm goes Mars g, 2 mid-g levels, lunar g, a low-g level and then the node. So an example layout might be: starting at the end of one arm you have the Mars g animal lab; then a gym/toilet/shower level; then the major ECLLS equipment level, then the lunar animal lab; then the main storage level, including freezers; then the node which also contains power/thermal systems; then down the other arm with the sleeping quarters; then a lunar bio-lab; then another ECLLS level (with a urine-only toilet); then a galley/rec area; then a Mars bio-lab. The bio-labs could host secondary experiments, like plants, and/or preparing animal (and human) samples for return, and general practising fiddly work at lunar/Mars g. They would also provide bench space for equipment tear-downs and repairs. Two ECLLS levels for backup and experimentation. Trying to keep the worst smells on one arm, sleeping and eating on the other.)

If you make sure your node has 6 berths (two IDAs for docking, 4 CBMs for attachments), an upgrade path is to add another two arms, if there's demand/funding for it.

Rough area for each of the 11 floors, just remove a foot for the Bigelow skin but continue the walls straight:


Page 11 shows where I began, i.e., a zero-g free flyer with the old NASA-NASDA 2.5 meter animal centrifuges.  It was originally designed for Falcon Heavy, since at the time it was proposed, the New Glenn hadn't been unveiled.  But once it had, and given Bezos' preference for an O'Neill-type settlement vision (not to mention Elon told me studying this problem of reduced G survival wasn't a priority for him), I defaulted to NG once it became "available."

I don't understand the criticism "Odd choice of size. If you want to do human research (as well as animal), it seems odd to focus on a 1g station right out of the gate. It's the mid-g values that you want."  The G-Lab design has three "G" levels, 1, 1/3 and 1/6 earth normal. The 1G level is designed an an on-orbit control to complement the 1/3 and 1/6 G levels as described in the PDF.  By the way, shortening the telescoping tube doesn't save much mass; you still need two NG flights to deploy.

I'd expect a third flight at some future time to add an axial hub extension which would either allow another arm pair to be added or to provide more docking and zero-g working volume.

 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0