Realistic, near-term, rotating Space Station

[punder]

Truly, I share your enthusiasm for AG. It's critically important, if we want to populate the Solar System, that we understand the full effects spectrum, from zero to 1g and more.

But your faith in NASA, in this regard, is misplaced, and you are grasping at straws in the vast Monsanto wheatfield of NASA funding priorities. (heh. I amuse myself.) Sure, tiny enclaves within the agency are looking at AG. Other tiny enclaves are looking at Mach Effect propulsion, morphing robots around Neptune, and beamed interstellar propulsion. All are there, but each is about as important to NASA as replacement cupholder sales are to Toyota.

It's up to someone else to conduct the experiment, one way or another.

Are you implying that a U.S. federal agency is unfocused, and does not prioritize the research you consider critically important? 

That's a surprising insinuation, because correct prioritization...

"would be greaaaaaaat."

--

Unlike a few people on the internet, I give credit where it's due.  NASA created an international AG roadmap, for example, and deserves credit for it.  And as you should know, they are actually walking with partners down that road, producing agreed research, somehow. 

So it's foolish to assert as others have, that NASA has "zero interest" in AG, or that the roadmap research "was never carried out".  That's not giving credit, and just... wasting bits.

--

- Does NASA have a rotating space station?  No.

- Does NASA need a rotating space station?  Almost certainly, now that long-duration cislunar+ missions are on radar.

- Is NASA saving a place in heaven's budget for an ITS best-value, Richie-class wonder-station, once the ravenous SLS program dies?  Ah, now you tell me, punder.  (And bring your best rumors.)

I'm having a lot of trouble parsing this post, but a couple of things... and if I'm misinterpreting irony or sarcasm, sorry.

Government agencies go pear-shaped all the time, and for long periods of time. The VA is a good example.

Somebody within NASA did create an AG roadmap. Great. More power to them. I wish they had a 9-figure budget. What is their current budget, again?

The last paragraph, I have no idea what you're saying, so no idea how to respond. But somehow I take it you didn't appreciate my input?   

[LMT]

You are moving the goals posts. You original stated cislunar goals (i.e. between Earth and Moon), and that is what I responded to. Now you are throwing in Mars.

Cislunar+.  Journey to Mars ambitions inclusive, naturally.

In other words, yes, you were moving the goal posts.

No, cislunar+, as I said.  If you didn't grok "+", you could've asked.

NASA the agency has no say about what NASA the agency is assigned to do. The President and Congress decide what they want NASA to do.

Advanced Concepts thread, not Federal Appropriations.  Everybody knows the D.C. stuff.

Not only are Trump and Congress are not going to get excited about a rocket test, but they certainly won't immediately jump to the conclusion that a rocket test means they should dump the SLS and pour $Billions into artificial gravity research. You are grasping at too many straws... 

Oh, a lot of people in D.C. are getting "jumpy"; if not excited, nervous. 

"Even Congressional Supporters Are Nervous About SLS"

[Rep. John] Culberson also queried Orbital ATK on whether the SLS rocket boosters are reusable…

‘If Elon Musk and Jeff Bezos are successful in launching rocket bodies and engines four to 10 times, at least, that changes the whole equation,’ Culberson said.

The SLS engines are not designed to be reused, said Brian Duffy, Orbital ATK vice president for NASA Programs.

It's entirely possible that Congress dumps the SLS, and for reasons painfully obvious at NSF.  If that happens, we'll see where the annual $2B+ goes. 

Anyone placing bets on the top recipient of that money, post-SLS?

[DarkenedOne]

NASA has no long-duration cislunar goals.

Cislunar+.  Journey to Mars this-and-that ambitions.  I think folks at NSF grok Congressional authorization and such.

You are moving the goals posts. You original stated cislunar goals (i.e. between Earth and Moon), and that is what I responded to. Now you are throwing in Mars.

Which doesn't matter since that chart from was from the Obama era of NASA, and the Trump era of NASA no longer is focused near-term on Mars. Which puts Mars decades out into the future - not a near-term need.

Plus, most of the mission time for a Mars mission would be spent in 1/3 G on the planet surface, and NASA has not been worried about the need for artificial gravity on the trips there and back. Notice none of their graphics show artificial gravity spaceships?

Find a specific budget line-item for artificial gravity and you'll be able to prove that "NASA", and not just some researchers at NASA, is focused on artificial gravity. Until then it's just research.

The problem is that we have no data on prolonged exposure to .33 g.  While it maybe safe to assume that it is no worse than 0g, it is not safe to assume it is significantly better. 

It would be great if NASA sent a couple astronauts to the ISS to for the same amount of time they think a Mars mission would take to measure the health effects.  That way we could say that the effects should be no worse than that. 

[LMT]

The problem is that we have no data on prolonged exposure to .33 g.  While it maybe safe to assume that it is no worse than 0g, it is not safe to assume it is significantly better. 

It would be great if NASA sent a couple astronauts to the ISS to for the same amount of time they think a Mars mission would take to measure the health effects.  That way we could say that the effects should be no worse than that.

Yes, many unknowns beyond 438 d.  Personally I think it'd be good to get all necessary data quickly by running a gamut of 0-1 g tests concurrently, in a small test fleet.  Should be feasible and affordable, if ITS can be leveraged aggressively.

[LMT]

I'm misinterpreting irony or sarcasm, sorry.

Oh, 'Office Space' reference.  Workaday at 'IniTech', or 'any tech'. 

"Did you get the memo?"

The last paragraph, I have no idea what you're saying, so no idea how to respond.

   Just asking.  You hear any rumors of NASA adventure post-SLS, yourself?

[Roy_H]

This discussion about SLS and Congress is getting way off topic. However I believe that Congress doesn't care at all about what SpaceX is doing. But if BFR/ITS is successful, Congress is most likely to fund L-M etc. to build a similar system, not switch to SpaceX.

[LMT]

Some interesting perspectives on SpaceX space station possibilities, at the Reddit SpaceXLounge.

And one concept art by Mack Crawford, if it hasn't been posted previously. 



Is his concept n/a for AG, or could it be modified readily?  What might be the pros/cons of his concept, vis-a-vis Richie-class and other SpaceX rotating space station designs -- most esp. wrt cost-effective achievement of AG goals?

[Coastal Ron]

NASA the agency has no say about what NASA the agency is assigned to do. The President and Congress decide what they want NASA to do.

Advanced Concepts thread, not Federal Appropriations.  Everybody knows the D.C. stuff.

No, this is not the "Advanced Concepts" thread, it is the "Realistic, near-term, rotating Space Station" thread. And what many of us have been pointing out that "realistic" does not include NASA because those that fund NASA have no interest - at this point - in funding activities in space where artificial gravity would be required.

It's entirely possible that Congress dumps the SLS, and for reasons painfully obvious at NSF.  If that happens, we'll see where the annual $2B+ goes.

NASA is not mentioned in the U.S. Constitution, which means as an agency it exists only as long as the U.S. Government has a need to do peaceful things in space, both with and without humans.

It also means there is no mandatory amount of funding that NASA should get, and over time it's clear that when the U.S. Government wants - i.e. has an agreed upon need - to get something done then Congress will provide the necessary funding for it. However Congress funds programs, not top-line budget numbers, so if a program goes away then Congress is under no obligation to keep sending the same money to NASA.

If the SLS program were to be cancelled don't expect Congress to hand NASA envelopes of money and tell them "Do whatever you want with this..." - that is not how our government works (for obvious reasons).

So my suggestion would be to not put so much stock in the idea that NASA, in the near-term, is going to be allowed to invest significant time and money in a rotating space station.

My $0.02

[LMT]

Simplified Richie-class ITS Configuration

The initial "Richie-class" options could support concurrent AG tests - for multiple concurrent mission profiles - in low g, Mars g and Earth g.  Each mission crew would switch between AG environments at each simulated mission AG transition: e.g. transition from in-transit low g to Mars surface g, or from Mars surface g to Mars surface centrifuge Earth g.  All system hardware could be returned to Earth for repair or modification between each experimental run, and then repurposed for deep-space missions at the end of AG testing.

The concurrent AG tests would use a configuration of 7 ships:



This arrangement could be simplified to support the same concurrent AG tests using only 5 ships:



This simplification would take advantage of a center-of-mass shift in the 4-ITS station. 

Rough calc, first-pass:

Offsetting the system's CoM by 45 m sets up concurrent 1 g and .38 g AG. 

This offset might be accomplished by:

1.  transferring most residual propellant from the system's other 3 craft into the selected crewed craft

2.  transferring additional tanker propellant to increase total to ~ 950 t

3.  transferring a second 150-t water payload into a cargo deck vessel

Results:

- The required rotation of 2.5 rpm can be set about the 45-m offset CoM.

- The less massive craft produces 1 g.

- The more massive craft produces .38 g.

- Radiation levels inside crewed facilities are comparable to airliner levels.

- All AG comfort parameters are "in the green".

Some trade-offs:

(+)  This simplification reduces the number of spacecraft required for AG tests by 2/7, or 29%, which should result in lower long-duration "leasing cost". 

(+)  This simplification reduces the water-shielding payload mass by 1/5, or 20%.

(-)  This simplification reduces crewed facility volume by 2/5, or 40%.

(-)  This simplification increases propellant requirement by 600-800 t.  (Most propellant is not expended, but traded between staged AG systems while in orbit.)  If ZBO is not implemented, further propellant must be transferred periodically from the low-g ITS craft, to compensate for boil-off.

[punder]

Simplified Richie-class ITS Configuration

The initial "Richie-class" options could support concurrent AG tests - for multiple concurrent mission profiles - in low g, Mars g and Earth g.

Yes. Exactly the kind of experiments that should have been done long ago. Obvious to me, not so obvious to NASA. If only they had listened to punder, that anonymous schmuck on the Interwebs.   

Seriously. This is research that, regardless of specific hardware, should have been done by now.

Edit: But as I said before, and with Coastal Ron's post in mind... The ship has sailed. Experiments in 1/6 g biology will be conducted first on the Moon. 1/3 g experiments will be conducted on the Moon or Mars itself. Too late; the responsible agency didn't get its s!?t together in time.

[LMT]

if BFR/ITS is successful, Congress is most likely to fund L-M etc. to build a similar system, not switch to SpaceX.

It's conceivable, though to my mind hard to justify.

Why might Congress do that?  "Mission-critical redundancy," perhaps?

That might sell it inside D.C., but the public isn't D.C.  How do you suppose Congress might sell such a runner-up system to the public, if, say, a simplified Richie-class system can be leased to do a job at a small fraction of the price?

[Coastal Ron]

Simplified Richie-class ITS Configuration

The initial "Richie-class" options could support concurrent AG tests - for multiple concurrent mission profiles - in low g, Mars g and Earth g.  Each mission crew would switch between AG environments at each simulated mission AG transition: e.g. transition from in-transit low g to Mars surface g, or from Mars surface g to Mars surface centrifuge Earth g.  All system hardware could be returned to Earth for repair or modification between each experimental run, and then repurposed for deep-space missions at the end of AG testing.

While interesting, the standard BFS is likely not designed for the tension loads that would come with attaching two BFS at the nose. Obviously the interior of the BFS would be able to take the micro-gravity loads, but the exterior is designed for compression loads, not tension ones.

So you would have to assume that SpaceX would design and certify a version of the BFS that could not only take the loads, but it would have to have upgraded software to manage the spin and de-spin maneuvers.

In keeping with the thread theme regarding "realistic", I'm not sure it's realistic that Elon Musk would want to modify a BFS to do something that he doesn't see as necessary.

[LMT]

While interesting, the standard BFS is likely not designed for the tension loads that would come with attaching two BFS at the nose.

AG mods were examined recently in this very thread.   

[LMT]

Yes. Exactly the kind of experiments that should have been done long ago. Obvious to me, not so obvious to NASA. If only they had listened to punder, that anonymous schmuck on the Interwebs.   

Ah well, necessity is the mother of invention.  Maybe need will cross an organizational threshold, not too far down the road.

The ship has sailed. Experiments in 1/6 g biology will be conducted first on the Moon. 1/3 g experiments will be conducted on the Moon or Mars itself. Too late; the responsible agency didn't get its s!?t together in time.

"The ship has sailed"?  Can you expand on that?  The options, timeframes and rationales aren't entirely clear to me.

[Coastal Ron]

While interesting, the standard BFS is likely not designed for the tension loads that would come with attaching two BFS at the nose.

AG mods were examined recently in this very thread.   

Anything is possible, but not everything is "realistic".

And even you admit Musk has no interest in artificial gravity, so I would call that "unrealistic", especially since early on in the BFS testing program - which includes flights to Mars - Musk is going to be focusing his time AND money on the specific BFS configuration that will allow him to get colonists to Mars.

What you are suggesting is that Elon Musk would, for no known reason, slow down his colonization of Mars, and work on something that he has stated he has no interest in.

That to me meets the definition of "unrealistic".

Aren't there more realistic artificial gravity solutions that you could suggest?

[Paul451]

While interesting, the standard BFS is likely not designed for the tension loads that would come with attaching two BFS at the nose.

The BFS is shown being hung from the nose under 1g while being craned up and stacked on the BFR.

Obviously everything is subject to modification with SpaceX. But they don't see that as a deal breaker, why should we? (Hanging from the tail, otoh...)

Life support is another issue. By you can obviously test it under 1g before launch, and in theory it should be much easier/cheaper than plumbing the micro-g side.

In keeping with the thread theme regarding "realistic", I'm not sure it's realistic that Elon Musk would want to modify a BFS to do something that he doesn't see as necessary.

If someone else pays, he'd be happy to do it.

However, attaching four BFSes together seems like a very silly use of BFSes. Presumably you'd have to buy them outright, which seems a silly use of this "someone else's" money.

[LMT]

While interesting, the standard BFS is likely not designed for the tension loads that would come with attaching two BFS at the nose.

AG mods were examined recently in this very thread.   

Anything is possible, but not everything is "realistic".

And even you admit Musk has no interest in artificial gravity, so I would call that "unrealistic", especially since early on in the BFS testing program - which includes flights to Mars - Musk is going to be focusing his time AND money on the specific BFS configuration that will allow him to get colonists to Mars.

What you are suggesting is that Elon Musk would, for no known reason, slow down his colonization of Mars, and work on something that he has stated he has no interest in.

That to me meets the definition of "unrealistic".

Aren't there more realistic artificial gravity solutions that you could suggest?

That's special-pleading the meaning of "realistic" for this one configuration.  Read the thread to see how the word has been applied throughout (phys/eng).

And Musk can't just "get colonists to Mars" without addressing well-known risks beforehand.  SpaceX probably wouldn't get NASA human-rating or FAA certification for ITS without AG testing.  How could they, given the terrible low-g medical risks at 1 yr+?

[LMT]

attaching four BFSes together seems like a very silly use of BFSes. Presumably you'd have to buy them outright, which seems a silly use of this "someone else's" money.

Lease, return, repurpose.

Is anyone else conflating "lease" with "buy"?

[RonM]

And Musk can't just "get colonists to Mars" without addressing well-known risks beforehand.  SpaceX probably wouldn't get NASA human-rating or FAA certification for ITS without AG testing.  How could they, given the terrible low-g medical risks at 1 yr+?

SpaceX has to build a base on Mars before creating a settlement. At least build a fuel depot. The crews sent to Mars to setup these facilities will show whether or not there are any short term medical issues for humans living in 0.38 g. Take some mice along for the ride and get several generations of mammal medical data.

There is no requirement for AG to get a vehicle FAA certified and NASA won't care about AG. Look at their recent Mars mission plans. None of them have AG.

I agree it would be a good idea to test spin gravity in LEO at 0.16 g and 0.38 g. However, if someone is going to send a small crew to the Moon or Mars for an extended period of time fairly soon, we can skip the spinning space stations for now.

[philw1776]

While interesting, the standard BFS is likely not designed for the tension loads that would come with attaching two BFS at the nose.

AG mods were examined recently in this very thread.   

Anything is possible, but not everything is "realistic".

And even you admit Musk has no interest in artificial gravity, so I would call that "unrealistic", especially since early on in the BFS testing program - which includes flights to Mars - Musk is going to be focusing his time AND money on the specific BFS configuration that will allow him to get colonists to Mars.

What you are suggesting is that Elon Musk would, for no known reason, slow down his colonization of Mars, and work on something that he has stated he has no interest in.

That to me meets the definition of "unrealistic".

Aren't there more realistic artificial gravity solutions that you could suggest?

That's special-pleading the meaning of "realistic" for this one configuration.  Read the thread to see how the word has been applied throughout (phy/eng).

And Musk can't just "get colonists to Mars" without addressing well-known risks beforehand.  SpaceX probably wouldn't get NASA human-rating or FAA certification for ITS without AG testing.  How could they, given the terrible low-g medical risks at 1 yr+?

1) None of NASA's numerous Mars Reference Plans had AG.  And certainly not the recent reference plans with ORION plus a tiny Hab.  Why would they suddenly impose this requirement just for SpaceX?

which makes the following moot.  But nonetheless...

2) SpaceX has no plans for ITS.  It's SO 2016.

3) SpaceX does not need any NASA human rating to fly their crews on BFS to Mars
Worse yet. It would really be embarrassing for a recalcitrant NASA to watch ESA & JAXA folks join SpaceX's crew