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NASA NAUTILUS-X: multi-mission exploration vehicle includes centrifuge, which would be tested at ISS

The latest presentations to the Future in Space Operations (FISO) group were given by Mark Holderman and Edward Henderson of NASA JSC. Their slides (available here) are really quite fascinating.

Henderson reported (ppt) on the activities of the Technology Applications Assessment Team (TAAT), which is examining several "key technologies that can advance Space Exploration" and "can be done soon" and "are affordable".

He listed six technology applications that they are focusing on: satellite servicing, ISRU on the Moon, a SBSP demo, solar electric propulsion vehicle, propellant depots, and the Multi-Mission Space Exploration Vehicle (MMSEV). He described each of these and then Holderman gave a presentation (ppt) specifically on the MMSEV study for which he is the lead.

The Nautilus-X MMSEV is intended as a reusable in-space vehicle for cis-lunar and deep space missions. It would offer a sizable volume to sustain a crew of six and hold enough supplies to sustain a two year mission.

Nautilus-X Multi-Mission Space Exploration Vehicle

Radiation mitigation strategies, such as creating safe zones with water and H2-slush tanks, are being investigated. It is "capable of utilizing variety of Mission-Specific Propulsion Units [integrated in LEO, semi-autonomously]".

Most strikingly, it would include a ring centrifuge to provide partial gravity for maintaining crew health.

The Nautilus-X centrifuge

The MMSEV would be assembled in orbit primarily from expandable structures, e.g. Bigelow modules. They believe construction would require 2-3 launches of a HLV, particularly for the core module, and the rest with commercial vehicles. Orion or commercial capsules would provide transport to/from earth and Descent/Return vehicle(s) would be used for excursions to other destinations. The MMSEV could also dock with the ISS.

Estimated cost and time: "$3.7 B DCT & Implementation 64 months"

The centrifuge includes both "inflatable and deployed structures" and could "utilize Hoberman-Sphere expandable structures". The rotational hardware would be derived from Hughes 376 spin-stabilized ComSats.

The centrifuge would first be tested on the ISS.
A demonstration centrifuge system for the ISS

This could be done in a way to "impart Zero disturbance to ISS micro-gravity environment ". The goal is to deliver the system with a single Delta-IV/Atlas-V launch.

Here is a table of partial gravity values versus RPMs and ring diameter:
Partial g values vs RPM vs Diameter

The estimate of the cost and time: "<39 months $84-143M"

Other views of the ISS centrifuge:
Centrifuge attached to the ISS


A view of the ISS with the centrifuge attached

The basic design of the MMSEV could eventually be expanded for extended duration missions -

Extended  duration MMSEV

Yes, I'm sure this will all be quickly dismissed by many as Powerpoint fiction but I still find it quite impressive in several ways:
/-- It illustrates how the use of Bigelow style expandable modules provides for great flexibility in design and in the means of delivery.

/-- It takes direct advantage of the tremendous experience in assembling structures in space that NASA has gained in the past decade. NASA knows how to do this.

/-- It would work very well with fuel depots.

/-- The contrast is striking - Constellation would have had small, single-use, expensive systems in operation perhaps by 2030. MMSEV would be a honest-to-goodness space cruiser in operation by 2020.

/-- The first pass at the design cost and schedule finds it cheaper than the Orion capsule alone.

Yes, I'm very skeptical of costs and schedule estimates for projects done in-house at NASA. The agency's overhead eats up huge amounts of money. But this is still a remarkably low cost estimate considering the incredible capabilities that the MMSEV offers. It would be interesting to see how many launches it would take if the MMSEV was built solely with commercial vehicles and how that would affect the cost.

If nothing else, it is encouraging to see NASA focusing at last on innovative concepts that will lead to genuine spacefaring.

Comments

This is some awesome out-of-the-box engineering using off the shelf components (Bigelow inflatables, Alenia PMMs) while conducting rapid risk reduction activities (ISS centrifuge) on newer technologies.

Now all NASA needs to do is to say to industry, "build me system/module X for a fixed price of Y".

Posted by anon at 01/28/11 02:58:48

Plus build a few of them so the development cost can be amortized over the run.

The first should be named "Enterprise", followed by "Challenger", "Columbia"

Bill Gates, Paul Allen, and others should buy one too (what better ego boost than your own private space cruiser).

I expect Elon/SpaceX will have at least 1, I expect Richard Branson / Virgin Galactic to buy at least one.

cue Frankie ....

"Fly me to the moon . . . Let me sing among those stars . . . Let me see what spring is like, On Jupiter and mars ..."

Posted by Anon at 01/28/11 03:05:07

I haven't been so excited about a NASA design in years - since the days of DC-X!

I hope they follow this path. Ticks all the boxes.

And I like the image of the side mount HLV.

Posted by Nathan at 01/28/11 04:20:10

"Radiation mitigation strategies, such as creating safe zones with water and H2-slush tanks, are being investigated."

Reminds me of the older Heinlein books where crew and passengers went to such safe zones during solar storms on trips to other planets.
----
"Most strikingly, it would include a ring centrifuge to provide partial gravity for maintaining crew health."
Ah. That was one of the coolest things about the Discovery One in 2001 - A Space Odyssey. Kubrik went to a lot of expense to build a special enclosed "Ferris wheel" to film the scenes inside of the ring centrifuge.

It would be so great to actually see the realization of such things that so inspired me as a youth!

Posted by Rick Boozer at 01/28/11 06:48:47

P.S.
Of course, THIS is the kind of thing NASA should be doing! Launchers and taxi spacecraft should be handed over to commercial so lots of them can be made more cheaply. The latter can do the mundane taxi service to and from such cutting edge vehicles and space stations.

Posted by Rick Boozer at 01/28/11 07:06:31

This is a great vision, and if there is to be a large government-led development effort, it should be on something like this instead of and not complementary to a government HLV. That said, it is still much too ambitious for a first step and risks another round of fruitless development with cancellation before anything flies.

As so often, a very incremental approach would be better.

We could start with something that strips off anything that cannot be done with existing technology, leaving that as simultaneous but independent work in the capable hands of Bobby Braun et al.

This means removing cryogenic reusable propulsion and aerobraking, nuclear and/or electric propulsion as well as anything that requires an HLV.

If the craft is based at a Lagrange point, departing from there and returning to it for each mission, you can then reasonably use propulsive return, which would be very expensive for LEO, thus avoiding the immediate need for aerobraking. You could then also reasonably use a hypergolic propulsion module without incurring enormous penalties. That would allow the craft to be operational much sooner. Since the plan is for modular propulsion systems anyway, this would not get in the way of a later cryogenic chemical or NTR stage. The propulsion module could be based on Orion technology and employ some of its workforce, which would be politically helpful without hurting commercial space.

Another advantage of L1/L2 as a base point would be that you wouldn't have to lift the whole craft in and out of the Earth's gravity well. Only a small commercial capsule would have to do that to gived crewed access to and return from the Nautilus. An initially expendable cryogenic transfer stage could be used for transport from LEO to L1/L2, either with or preferrably without an HLV.

This is probably still very ambitious, and could could start with something even simpler, maybe a refuelable hypergolic transfer stage based on the Orion CM + Orion avionics, but without its crew compartment, perhaps combined with a Bigelow hab, perhaps unmanned. The unmanned transfer stage could then transfer probes to and return samples from NEOs. It could be prepositioned to L1/L2, where it could loiter indefinitely and could depart as soon as a new NEO was detected, something that would be very hard from the ground. Later manned versions could then be used at a Lagrange point for access to the samples.

An even simpler version would be just a space tug, but the advantage of a transfer stage (and later a manned exploration ship) is that it could usefully consume large amounts of (initially hypergolic and noncryogenic) propellant, thus creating a large commercial launch market ASAP. This would give an enormous boost to development of commercial cheap and reliable access to space.

Posted by Martijn Meijering at 01/28/11 08:42:34

I liked their list of six technology applications. These are exactly the sorts of things NASA should be focusing on. I agree with Martijn, though, that MMSEV would not be the place to start. Instead I would suggest:

1. Start with a small, robotic LEO tug that can handle rendezvous and docking for assembling passive modules in LEO. By passive I mean, they don't have to have their own prop and nav (like the US segments of ISS).

2. Use the tug to assemble and service a LEO fuel depot (that of course, would also be able to refuel the tug itself). By service I mean it would collect full fuel tanks that have been lofted by dumb boosters and take them to the depot.

3. The first application of the tug/depot system would be de-orbiting large rocket bodies in LEO.

4. Now that you have a demonstrated a functioning tug/depot system satellite builders might be persuaded to design their birds for refueling, servicing and de-orbiting via the tug.

All of these systems would best be built via NASA/commercial partnerships. Step 4 might actually begin to produce a revenue stream, perhaps allowing NASA to reduce or eliminate its subsidy of the system, without losing the capability.

With a fuel depot built and paid for NASA can begin launching larger payloads to lunar orbit and EML-1. This enables some of the other applications such as lunar ISRU, SBSP demos and the MMSEV.

Posted by Bill Hensley at 01/28/11 09:07:15

Finally!... THIS is exactly what NASA is supposed to be doing...

Posted by David C. Neal at 01/28/11 09:24:16

Best news out of NASA spaceflight in a long time; if only we can fund this by prying most of the Exploration budget away from redundant launcher design and operations.

Posted by John Kavanagh at 01/28/11 11:01:45

I applaud the idea of finally using the ISS as an artificial-grav lab, with testing that centrifuge. But even with acknowledging that these illustrations are artist concepts, I hope any actual centrifuge will have a somewhat larger diameter (even if only 2X) to avoid motion sickness ... unless they are planning to just spin it for 0.05 grav.

Actually, as a G-lab, with variable speeds, it'd be ideal to finally dial-in that "sweet-spot" between long-term low-G and low muscle & bone loss.

Posted by BRC at 01/28/11 11:14:10

"Actually, as a G-lab, with variable speeds, it'd be ideal to finally dial-in that "sweet-spot" between long-term low-G and low muscle & bone loss."

I agree that this is a long anticipated and absolutely critical use of the ISS. Until we know what the "sweet spot" really is, we are making plans based on guesswork.

Posted by Bennett at 01/28/11 11:45:30

A very forward-looking design. It'll probably need some tweaks to make it workable but doesn't everything? Nonetheless it at least takes the issues of deep space flight seriously. It would probably need no larger a launch vehicle than the enhanced EELV-H with the proposed 5.1m Common Centaur upper stage topped up with a 7.5m PLF. In other words, essentially the same LV required for an Orion to LEO.

Now... is it possible to convince Congress to fund a program rather than jobs in key districts?

Posted by Ben the Space Brit at 01/28/11 11:52:03

Ah folks. Reality check here. This is part of the cool presentation side of NASA. The one that every couple of years comes up with great visionary future concepts that never go past presentations and occasional books. This one doesn’t even seem to be serious (NASA spec say centrifuges with RPM rates beyond 2 or at most 3 cause unacceptable degrees of motion sickness. Hence why folks talk about centrifuges hundreds of feet across. This on show a tiny centrifuge straight out of 2001 and discovery, and the presentation talks about RPM rates up to 10.

Its eye candy unrelated to any serious proposal, or budgeted program. Very nice eyecandy but I’ve seen better from NASA. Some (http://www.google.com/url?s... ) even connected to bugeted programs.

Posted by Kelly Starks at 01/28/11 11:57:25

I have to agree with Kelly Starks, this isn't a proposal for a vehicle program. It should be a way of presenting some areas for several research programs. VASIMR is already happening. Attaching a Bigelow to ISS seems that it will happen. Building a spinable torus to provide engineering data and experience with partial gravity should happen.

Posted by Dean at 01/28/11 13:41:15

"64 months" is too long

things need to start and finish quicker for evolution to work

otherwise you get shuttle

otherwise you get constellation

max 2 to 4 year plans are what need to be proposed

a 2 year bigelow module on iss is exactly the right idea

Posted by donnie at 01/28/11 14:23:18

"NASA spec say centrifuges with RPM rates beyond 2 or at most 3 cause unacceptable degrees of motion sickness. ... This ... presentation talks about RPM rates up to 10"

Yeah, I can agree this was a PPT show (Pretty Picture to Titillate); although I wonder how NASA developed that spec ( maybe a guy on a spinning table, a spinning cabinet, a tiltawhirl?) Going up to 10 rpm certainly sounds nuts ). But then again, we are talking about a Lab doing tests, not an Astro-Hilton.

Okay, so we'd make a bunch of sick people with anything over 2 rpm ,in a 30-40ft doughnut. So what partial-G can they get at that rate: I calc'd around 0.05(+/-), which seems at first blush rather useless. But on the other hand, this is meant to be a LAB; so in that vein: Go For It!! So what if they crank up the rpms and the guys all puke (it's their JOB)?? At least the stuff will go in one safe direction (the FLOOR)! Maybe if NASA can get the guts to double the diameter (60-80ft), they'll have a better chance at hitting the "Sweet-spot," w/o getting too queasy.

Posted by BRC at 01/28/11 14:29:22

I agree with David C. Neal, finally. Sorry, Kelly, this is exactly what Nasa should be doing not building uneeded HLV`s. We should get rid of the idea that we have to pull ourselves out of earth`s gravity well everytime we want to go somewhere. That`s Old Space, not New Space, that`s how politicians think. The vehicles for building it and transporting it to space in modular sections already exist. Just about everything we need to build it already exists. Although we`d have to develop miniature nuclear reactors I`m sure it could be done. Diaz`s Ad Astra is almost ready to test his Vasimr ion engines. The only thing I`d do different is build a bigger centrifuge and have some chemical engines to initiate flight and for orbital insertion but you`ve got to start somewhere. The ion drive would take care of the radiation problems with some modification. There are naysayers all over the place. If we`d listened to them we wouldn`t be in space; we wouldn`t even get out of bed in the morning.

Posted by Gary Warburton at 01/28/11 14:55:45

Anyone know how those 2-3rpm limits were defined? Where are the specs written down?

Posted by Nathan at 01/28/11 15:16:02

Back to Battlestar Galactica! Very pretty looking pictures, but this is fantasy engineering. If you want AG, which I think you do, then it is much better and easier to use a tether between your spacecraft and a counterweight. This is what was used in Mars Direct for instance, where the spent mars injection stage was used as the counterweight.

Posted by Seer at 01/28/11 15:19:18

"Anyone know how those 2-3rpm limits were defined? Where are the specs written down?"

There are no fixed limits. Adaptation can raise the rpm that people can tolerate. Also, it depends on what sort of activity is going on. For example in the study described in this article -

http://www.wired.com/wireds...

- NASA bed rest study patients underwent 2.5 g for an hour a day produced by a centrifuge going 30 RPM. They were just laying radially and not trying to do any work. I assume they might be able to read or at least listen to music or audio books. The advantage is that it eliminated their muscle loss.

With the MMSEV/ISS centrifuge above, if people were just standing radially on an exercise machine or at a workstation, I expect they could easily adapt to several RPM. If they want to do circular jogging as in the movie 2001: A Space Odyssey then they could dial down the rotation rate. With such a centrifuge on the ISS, one can study the levels of RPMs that can be tolerated and whether low partial-g can prevent the problems of zero-g.

- Clark

p.s. This site has more about small spin gravity systems:
http://spacecycle.hs.uci.edu/

Posted by TopSpacer at 01/28/11 15:58:41

A tether wouldn`t work with an ion engine.
It is much better to use magnetic bearings with a centifuge and small ion thrusters on the ship and centifuge. Access through sealed ports between the cenifuge and core ship could even be possible while the centifuge is in motion providing the centrifuge is big enough with a proper design and with little loss of air.

Posted by Gary Warburton at 01/28/11 16:18:09

It looks interesting, but I agree with the skeptics. If it can't be broken up into segments that take no more than 2 to 4 years and result in useful hardware/tests at each step of the way, this will simply not work.

The DoD has managed to set up successful multi-year budgets with Congress for really important procurements, but NASA's budget and plans are tweaked every single year. Continuity comes because the same people are working at NASA from year to year, not because the programs stay the same.

If you want to research how much artificial gravity is needed for health, resurrect the ISS's Centrifuge Module that was already designed (and possibly built too) for this very purpose and use mice.

If NASA wants to test an inflatable module, why not buy a Sundancer off the shelf from Bigelow (or a competitor)? If Sundancer is too big such that it interferes with other stuff on the ISS, then I could see getting a custom version.

Posted by Tom D at 01/28/11 16:51:44

How about two counter-rotating centrifuges?

Posted by anon at 01/28/11 17:10:32

ISS is a good test center. Add a small filling station for hypergolic fuels and put out a commercial contract for LEO space tugs, something capable of moving a 30MT passive module from a standard parking orbit to ISS. Add VASIMR, add a Bigelow module, add a centrifuge module and you have an analogy of the NAUTILUS - X.

Posted by Dean at 01/28/11 17:10:51

"broken up into segments that take no more than 2 to 4 years"

That's the idea with doing the centrifuge module on the ISS first. Time and cost est: "<39 months $84-143M"

"resurrect the ISS's Centrifuge Module that was already designed (and possibly built too) for this very purpose and use mice."

As I understand it, there is no module anywhere near ready for launch. The cost for the MMSEV/ISS module looks comparable to what it would take to resurrect the old centrifuge module and it has the advantage of working with people. (What happens with mice often doesn't happen with people.) Plus you have the advantage that the ISS module will then be a proven system for a MMSEV.

"why not buy a Sundancer off the shelf from Bigelow (or a competitor)?"

That plan is in the works:
http://www.space.com/10686-...

Bigelow is crucial to all of this. Such projects would never have been considered plausible without the proven success of the Genesis modules and Bigelow's development of the larger modules.

- Clark

Posted by TopSpacer at 01/28/11 17:30:04

"How about two counter-rotating centrifuges?"

No need for that since the ring's rotation is driven by its own thrusters. There is no need to balance the torque on the ring. This assumes there is no friction on the bearings. The presentation said the centrifuge would not impact the micro-g of the station so that implies the friction is truly zero.

- Clark

Posted by TopSpacer at 01/28/11 17:38:00

Won't you get some torque on the rest of the station? There's a giant gyroscope attached to one end and the station must be rotating once per orbit to keep the nadir side pointed Earthward.

Posted by Andrew Platzer at 01/28/11 20:48:11

Hmm. To avoid impacting the micro-g environment you'd have to counteract any mass you put in the centrifuge with an equivalent mass on the other side. I can't think of any other way.

Posted by ian at 01/28/11 21:12:54

"To avoid impacting the micro-g environment you'd have to counteract any mass you put in the centrifuge with an equivalent mass on the other side. I can't think of any other way"

I kinda did, same subject (artificial-G), different space forum. Ian, you're quite right about the counter-balance issue. Wherever there is an astronaut or piece of equipment at one end of the centrifuge, there had better be an equivalent mass at the opposite end, to ensure that the total center of mass of that spinning contraption remains FIXED at DEAD CENTER. Otherwise, you'll soon experience a slight wobble that will build up into a more violent shaking and will in turn -- by its attachment to the ISS, drag the rest of the station along for an unpleasant and hazardous ride. This is not unlike balancing tires for your car.
But with crew needing to move around and randomly at that, we find ourselves needing a system that will continually & fluidly balance this rotating "space tire."

One idea would be to have a fluidic ballast distribution system. That is, they might consider using small water reservoirs, ringing the circumference of this torus, with the ability of piping water in varying quantities from one container to another (or maybe forgo containers altogether and just use the plumbing) to compensate for not only the various equipment installed within, but also the crew as they move all around the centrifuge. (Obviously they will also need to have extremely quick motion sensors to handle this.) In the future, they may eventually have to consider a larger, more complex system, for when we move onto building the seriously large rotating stations and even colonies.

Posted by BRC at 01/28/11 22:49:05

Judging from the response to this article people are beginning to realize that a trip to Mars is going to take a long time to prepare. It is not like going to the moon. A ship like this is going to take a long time to develop. But if it is developed incrementally it could be done. Building a HLV that takes off from Earth is foolish. It would take forever to get there and probably drive the astronauts batty on their way there. If they were lucky enough to escape radiation sickness they would probably be too weak from lack of gravity to do anything once they got there. It shows us that the idea of destinations is silly also. Much better to take research into a proper spaceship as a goal, before constructing it. In the mean time lets make it easy for commercial space to get started so launch prices can be brought down which should initiate the space boom we`ve all been waiting for.

Posted by Gary Warburton at 01/28/11 22:58:05

DC-X was NOT NASA. It was DoD. And it crashed after NASA took it over.

Posted by John at 01/28/11 23:36:20

"Won't you get some torque on the rest of the station? There's a giant gyroscope attached to one end ..."

Sorry, I was only thinking about the fact that the ring can be sped up or down with the thrusters on the rim and not by mechanical torque applied to the axle.

To counter the angular momentum of the centrifuge they have an "external 'dynamic' ring-flywheel" included in the hub. See, e.g., slide 9 in Holderman's presentation. (They mention that they could, in fact, use the centrifuge system to potentially work with the ISS control gyroscopes and "augment GN&C".)

WRT to off-balances, there is a brief item about "CG offset of Centrifuge centerline mitigated with internal ballast bladders [urine/waste fluids]" on slide 18. They also mention "flywheel torque off-set", presumably referring to using the flywheel also to help counter such imbalances.

I assume the centrifuge would include sensors to measure imbalances and issue warnings when mass distribution asymmetries were getting out of range of what could be handled.

- Clark

Posted by TopSpacer at 01/29/11 02:29:29

"Judging from the response to this article people are beginning to realize that a trip to Mars is going to take a long time to prepare. It is not like going to the moon."

While I've argued in the past that Mars is closer for travel and settlement than America was to Europe in the 14th-17th Centuries, that still is a huge logistical challenge and it certainly isn't going to be a duplicate mission to the Moon like the Apollo program was. I'm not sure there ever will be a "weekend trip" to the Moon... which is what you've got to admit the Apollo missions really were when they only spend at most three days actually on the Moon itself.

That is also why I think those who dismiss out of hand any lunar development are just simply being foolish as it is a body close at hand and accessible that should be developed for its own sake... going to Mars or the Moon does not have to be a zero sum game like Robert Zubrin keeps advocating for.

All this said, this proposal as outlined for the NAUTLIS system seems like something that can at least fall within reasonable technology envelopes for going to Mars, asteroids, or supply a long-term (multi-month) expedition to the Moon and really open up genuine exploration of the rest of the Solar System in a huge way. It also appears to be something that might just be affordable to NASA budgets and leverages developments in commercial spaceflight in a sound manner too.

I think this is the reason why this particular proposal is really hitting home here, and it certainly looks exciting. I just hope that somebody responsible for appropriations really takes this seriously as power point presentations like this are a dime a dozen.

Posted by Robert Horning at 01/29/11 09:16:57

Likely a bargain at 10x the price!

Posted by Eric S. at 01/29/11 09:24:23

"DC-X was NOT NASA. It was DoD. And it crashed after NASA took it over."

Correct that it began under DARPA (which canceled it, in spite of ongoing success), and it didn't crash *because* NASA took over. The same people were running it.

(Though landing it on a grating meant to minimize exhaust deflection on the vehicle, that ended up being *too* gentle and didn't trigger engine shutdown right away was perhaps a little *too* clever on NASA's part...but that's still not the loss of vehicle incident. And yes, the whole project might've taken 10x the money and at least 2x the time [if finished at all], had it *begun* under NASA.)

Using some discretionary money to keep DC-X alive a little while longer, was perhaps the smartest thing then-administrator Dan Goldin ever did...

Posted by Frank Glover at 01/29/11 11:29:57

Not DARPA, SDI.

Posted by Gary C Hudson at 01/29/11 12:30:46

So...instead of worrying whether it is too fantastic or that it is Battlestar Galatica or if it will end up looking exactly like it appears here; lets do it.
Lets show the world what the American spirite of innovation is all about and push this. Lets get the politicians to cancel the HLV and do this instead. What do you say? -Lets do this!

Posted by Gary Warburton at 01/29/11 19:07:03

Bigelow himself has stated from the very beginning, that cargo to LEO will have to cost $500 per pound or less, for his involvement to be sustainable.

Posted by Tony Rusi at 01/29/11 21:40:44

On balancing the centrifuge. If it is only used for sleep time, with a six person crew running 8 hour shifts two people would always enter at the same time, one on each side.

If only one person was in it would that 200 pounds really create that much of a problem with a 400 ton station? Can that weight cause so much of an imbalance that station keeping thrusters couldn't compensate?

With a 30' ring at two revolutions it would provide 0.0204 g's a 40' ring would be 0.0272 g's.

30' ring at three revolutions it would provide 0.046 g's and a 40' ring @ three revolutions would be 0.0613 g's
----

There is an alternative to all this... we could just do what Q says:

"Simple, just change the gravitation constant of the universe" - Q

Posted by Vladislaw at 01/30/11 16:24:24

Some one is a Star Trek fan.

Posted by Gary Warburton at 01/30/11 18:18:58

Speaking of constants
Listen to this item

Posted by Gary Warburton at 01/30/11 18:27:18

Gary .. did you try and post a link, because nothing showed up.

Posted by Vladislaw at 01/30/11 18:31:27

Yes I did I`ll try again.

Craving Constants

Dr Einstein might have been surprised...
The laws of physics that explain why atoms hold together, why stars burn, and why electricity flows in a wire, all depend on a range of special numbers - the constants of nature. These include things like the speed of light, the charge on an electron and the gravitational constant to name a few. The fact that these numbers don't change, no matter where or when you are in the universe, is one of the things that allows us to understand the universe and predict its future evolution. However, a small group of scientists, bolstered by a few tantalizing fragments of evidence, are considering a radical idea: what if the constants of nature aren't so constant? Quirks producer Jim Lebans takes a look at this cosmological conundrum, by talking with these scientists:

Dr. John Webb, an astrophysicist from the University of New South Wales in Australia, has looked into this idea by probing the chemistry of the distant universe - seeing how quasar light shines on distant gas and dust. He's found evidence that an important constant, the Fine Structure Constant, may be different in different parts of our universe.

The implications of changing constants are huge for physics, and would mean much of physics would have to be re-thought, according to Dr. João Magueijo, a cosmologist from Imperial College, London. Dr. Magueijo, however, thinks that if constants vary, it might also open physics to new ideas, including his own theory that a faster speed of light early in the Big Bang might explain the rapid expansion of the universe.

Dr. John Barrow, a cosmologist and mathematician from Cambridge University, suggests that constants might change, depending on how far we travel through space. This idea comes from the notion that the Big Bang created multi-verses, or "bubble universes," each with its own physical properties.

Related Links

Dr. John Webb

Dr. Webb's preprint paper on variation in the Fine Structure Constant
A non-technical article by Dr. Webb on varying constants (pdf)
Science Blog skeptical view of Dr. Webb's work
Another skeptical view by Dr. Sean Carroll
Paper by Dr. João Magueijo on Varying Speed of Light Theories
Dr. John Barrow
Dr. Barrow's upcoming book, The Book of Universes

Listen to this item (pop up player) or use this link to download an mp3.

Posted by Gary Warburton at 01/30/11 18:46:30

If anyone is interested go the CBC Quirks and Quarks and click on the last item of the program the first is also interesting.

Posted by Gary Warburton at 01/30/11 18:54:05

"40' ring @ three revolutions would be 0.0613 g's"

Tether guru Joe Carroll -
http://www.tetherapplicatio...
- has looked at partial g levels regarding the minimum at which you can more or less move about like you normally do. (I don't think he has written this up anywhere.) I remember him saying 6% g is the minimum such that, say, you don't shoot to the ceiling when you get up from the dinner table. Looks like that is achievable with the sort of system the Nautilus-X group is considering.

- Clark

Posted by TopSpacer at 01/30/11 19:15:42

I do not think it will be practical to do much actual standing up and walking around under these low g's in a small centrifuge. Although your feet are experiencing X amount of artifical gravity with a 30' module your head is moving within a 18' diameter one and will therefore be moving at a different speed than your feet.

I believe the main benefit will come from laying flat for 8 hours of sleep and an hour or two of exercise per day.

One complaint often voiced is the astronaut's head bobs around in 0g when sleeping, any g-force, no matter how small, should cure that and provide a mental benefit increasing their productivity and well being.

Bike A ------(0)------ Bike B

two bikes on an axle riding on the inner wall would create higher G forces the faster you rode.

If you used a recumbent bicycle to lower your head closer to the inner wall and riding at 10 miles per hour, plus the two rotations per minute base you could gain dual benefits. Reduced muscle loss from exercise and a lot higher artifical gravity at 0.64%.

It would be like the side show at the carnvial where the motorcycle rides around on the inside of a barrel. I believe a person could handle it as a short 'burst' exercise.
-----

(great post Gary)

Posted by Vladislaw at 01/30/11 20:15:24

"Although your feet are experiencing X amount of artifical gravity with a 30' module your head is moving within a 18' diameter one and will therefore be moving at a different speed than your feet."

I think you mean ~24' at the head but your point is well taken. [Wait, you're right. I was thinking radius.] However, I wouldn't underestimate the ability of people to adapt to such things. There is certainly a g differential from head to foot but the magnitude of the g is low to begin with so I doubt the differential would matter much.

One of the Skylab astronauts was able to run around the inner circumference of the Skylab. Doing that in zero g seems harder to me than doing it with a bit of g.
http://www.youtube.com/watc...

I agree, though, that much of the benefit would be for activities more less at a fixed theta position. As you say, exercise machines, sleeping, etc.

The point of the centrifuge is to investigate such things.

- Clark

Posted by TopSpacer at 01/30/11 20:40:21

@BRC:
"One idea would be to have a fluidic ballast distribution system. That is, they might consider using small water reservoirs, ringing the circumference of this torus, with the ability of piping water in varying quantities from one container to another (or maybe forgo containers altogether and just use the plumbing) to compensate for not only the various equipment installed within, but also the crew as they move all around the centrifuge. (Obviously they will also need to have extremely quick motion sensors to handle this.)"

My clothes washer has an adaptive balancer for the spin cycle. Seems to work pretty well. Why reinvent the wheel?

Posted by PKH at 01/31/11 09:24:38

"The point of the centrifuge is to investigate such things."

I agree, the minute I saw that Bigelow Aerospace was doing the BA 330 I was crunching the numbers because it had such a greater diameter than what they had at the ISS. I have long advocated for the clothes "dryer drum" type of small diameter centrifuge to start running comparative tests against free flight.

I believe if you slowly dial up the speed at the start of the sleep cycle, hit peak speed at 4 hours and then dial it down to the slow speed at the end of the 8 hour sleep cycle it will make a marked difference after 6 months on station.

Posted by Vladislaw at 01/31/11 12:21:55

It seems to me that Popular Science had a picture of an inflatable space station in 1962 or 1963? The Nautilus-X just seems right. It may need more ports for cargo & human capsules.

Posted by David B. Buck at 02/01/11 01:48:29

Finally, a for-real spaceship! Far better than firing tin cans at the moon, no disrespect to the tin can pilots, cos I hear Buzz Aldrin is handy with his fists...

Re: vomit
"At least the stuff will go in one safe direction (the FLOOR)!"Posted by BRC.
I think it would just carry on going where it's going, until it hits something/someone that's travelling with the outside of the centrifuge. Then it'll just sort of dribble down that something/someone until it gets to the floor. Then it'll run around the bottom of the centrifuge in endless circles. Sorry if you're reading this over lunch. .

"Likely a bargain at 10x the price!"
Posted by Eric S.
But when you've been to Mars you can use it again to go to.. Mercury? Jupiter? Do a PITT manoeuvere on a too-near Earth asteroid? Need only add or remove bits as needed. Look at how long the Shuttle's been going.

"My clothes washer has an adaptive balancer for the spin cycle. Seems to work pretty well. Why reinvent the wheel?"
Posted by PKH.
Your clothes washer probably has a bloody great concrete block bolted to the base, to stop it jumping around. This may or may not work for the ISS or Nautilus, but how much will shooting a concrete block up there cost? How about spinning 2 or 4 of these Bigelow modules around a common hub, that way any imbalance would only be more or less on one or two axis? Far easier to balance than a bloke moving randomly about a doughnut-shaped habitat.

Posted by Arch9enius at 02/08/11 22:56:25

The RPM limitation came out of medical studies throughout the 1960's and early '70's. They were correlated and combined into the supporting data that was used during the NASA/AMES Summer Studies.

http://settlement.arc.nasa....

Posted by Michael Antoniewicz II at 02/14/11 14:02:37

The problem is that CONgress is going to not just reign this in, but will push to build Ares V or this new Direct version throwing away years and billions. We did this back in the 90's, when the 1999 CONgress pushed against NASA doing anything BEO.
Regardless, NASA should continue to push back against the likes of Shelby, Hutchinson, Coffman, etc who are working hard to keep NASA as a large gov. jobs bill for themselves. Instead, NASA should continue to push for more COTS and private space, so that not just NASA, but private space can go BEO.

Posted by windbourne at 02/15/11 06:52:23

Why the push on VASIMR engines?

I used to like the idea, until I realized that Solar can not provide enough power (not for this craft), and large nuke power is not feasible either. The reason is that any reasonable nuke engine is a steam engine, so need a way to dump heat. On earth, we dump it in the environment (what a waste). But in space, it must be radiated away. As such, you will need a large amount of radiators for a small heat dump. Barring a clever design, That is going to weigh a great deal, which defeats the whole purpose.
Instead, it seems like we are going to need nuke engines, along with a small generator to provide power for the craft.
Until we solve the ability to get rid of waste heat effectively, we can not use VASIMR to push humans around, though it could be used with cargo, via solar cells (assuming that speeds is not critical).
Ultimately, the smart way is to develop a tug approach in which a berthing mechanism is used so that different engines can be plugged in upon development, demand,etc.

Posted by windbourne at 02/15/11 07:10:36

i fricking love it, love it love it!

this concept is what we need for Space exploration, anyother way is foolish. i think that 2 or more should be built. after all, columbus didnt head to mars on 1 boat.

Posted by anon at 02/15/11 11:53:53

It is a start. Best to use larger diameters for the centrifuge, like a hundred meters or so so small rpm's will impart larger gravitational values with less of a puke factor. Side benefit will be larger ship and more crew capacity. Also more cargo capacity for more flexible mission capabilities. No drag in space for the speeds our technological levels' capabilities will realistically achieve in the near future, but this may change with our drive tech as VASIMR/nuke power improves. Some may prattle and fret over heat wasting needs, but nothing need be truly wasted as we need to consider secondary recovery systems to direct what me might think of as waste into new constructive uses. We should not forget the Shawson Drive presently using photonic propulsion units for satellite station keeping, nor forget the solar sail concept recently validated by JAXA and the Planetary Society.

Posted by Yakov Lanskiy at 02/16/11 04:27:36

It will be amazing if NASA's first manned deep-space explorer could be powered by nuclear fusion.
http://tinyurl.com/nuclear-...

Posted by Robert at 02/18/11 12:08:50

The big mistake here was not sending China a similar design beforehand to introduce as their own. This would have increased the likelihood of Nautilus-X exponentially.

Posted by A.C. Heinlein at 02/18/11 15:15:14

Is NASA still measuring something in feets and fathoms? Or is this page compiled for assumed audience somewhere in Ghana?

Posted by sepi at 02/24/11 14:10:31

Regarding 99% of the above:
This is what happens when sci-fi fans believe their understanding of science and physics via this entertainment medium in any way mimics reality. In two words: It. Doesn't.

There's a reason why very, very few people become rocket scientists, astronomers and astrophysicists. Because it requires a level of education, intelligence and understanding that quite frankly none of us (including myself) possess.

First of all, many here assume that NASA actually has a mandate to do this. They do not.
For all intents and purposes, NASA, the space program agency - has been canceled.
NASA's last publicized gig was to provide "public awareness" for the "contributions to science that our Arabic friends have made over the centuries."
Awesome. just awesome.
Robocop, anyone? lol.

I'm not making this up. It was all over the major news cycles a couple months back.
They quickly rushed to say it was a misunderstanding - and. . .the last flight of the space shuttle program was today.
It's replacement is nonexistent.

Second, there has been open revolution between the NASA scientists and engineers and their administration regarding the next era of re-usable orbital vehicles.

NASA admin says no plans exist, no budget, etc., and then the engineers released documents of their own reusable design, that could be done for the fraction of what the shuttle cost. Oops. Layoff alert!

Lastly, and most importantly, NASA was conceived, financed, and given immense resources during it's heyday in the 1960's because the U.S. saw the Soviet space program as a direct threat to national security. We haven't had a President with the vision of John F. Kennedy, since - John F. Kennedy.

The truth is, NASA is an anachronism, withered, defunded, and largely ignored to a pathetic shadow of it's glorious past.

A new era is upon us. Private industry will be much better resuming space exploration - as they have viable commercial interest to do so.

The U.S. Government is bankrupt, and we can ill afford an agency that has long since outlived it's usefulness.

Respectfully,

Talesin

Posted by Talesin at 02/25/11 14:25:12

Actually, if you look back through the archives of this blog, 99% of the topics in your comment - NASA's budget, commercial launch services, NASA history, etc. - have been discussed here relentlessly for years. I often post items about such issues long, long before they enter "major news cycles".

NASA's spaceflight program is in no way canceled or defunded. At worst, NASA's funding will be cut back to 2008 or 2007 levels. The agency can still do a whole lot with $17-18B dollars.

There is no bigger fan of commercial spaceflight than me. I post about the latest developments every day. Yet, like every other transportation system that we have, commercial will develop more quickly and effectively if it works in cooperation with govt.

For access to LEO, NASA's most effective role is to act as a customer of competitive commercial launch providers. This will give incentives for new designs, economies of scale, etc.

For beyond earth orbit, the lower costs of getting to LEO will allow NASA to focus its resources on the frontier. That is where concepts like Nautilus-X come in.

Furthermore, by using commercial components like the expandable modules from Bigelow Aerospace, the cost of a system like Nautilus-X moves into the range of NASA's future limited budget.

There is no need for a "shuttle replacement". There is also no need for a heavy lift launch vehicle. By using in-space systems like fuel depots that are resupplied by current launchers, large and ambitious deeps space missions with a system like the Nautilus-X can be carried out and avoid the huge development and operational costs of a HLV.

Yes, a new era in space exploration and development is upon us but it will involved NASA working with commercial firms.

- Clark

Posted by TopSpacer at 02/26/11 15:19:01
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