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.
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.
Quote from: Star-Drive on 07/15/2018 09:29 pmAll: 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.QuoteA 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.
Quote from: Star-Drive on 07/15/2018 09:29 pmAll: 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 from: Coastal Ron on 07/15/2018 09:50 pmQuote from: Star-Drive on 07/15/2018 09:29 pmAll: 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.
(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.)
I suspect that (1G @ <4rpm) is exactly the case if we're talking about the full human life-cycle with minimal symptoms
An ISS Co-orbital Free-flying Gravitational Biology Laboratory - G-Lab copy.pdf
Supplanting the DSGFor example the 1 g ITS station could conceivably supplant the Deep Space Gateway (DSG) aka Lunar Orbital Platform-Gateway (LOP-G).
Quote from: Paul451 on 07/15/2018 01:50 pmIMO, 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.
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.
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.
Quote from: Coastal Ron on 07/15/2018 08:24 pmBigelow 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."
a single BFS spun end-over-end (or two docked nose-to-nose) would give 1g at a bit over 6RPM
The value is too high for comfort or will require deliberate adaptation.
Quote from: Paul451 on 07/16/2018 07:29 pma single BFS spun end-over-end (or two docked nose-to-nose) would give 1g at a bit over 6RPMMore like 6.7 RPM at 20 m effective radius, unfortunately. Not so nice.
How do you propose to dock "nose-to-nose"?
SpinCalc uses intentionally conservative values, based on old research.
Quote from: Paul451 on 07/17/2018 12:33 amSpinCalc 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?
Quote from: HMXHMX on 07/16/2018 03:29 amAn ISS Co-orbital Free-flying Gravitational Biology Laboratory - G-Lab copy.pdfOdd 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: