Artificial Gravity Testbeds

[LMT]

No, we saw the VAST info, including their GNC job opening. 

Said job posting does not mention docking or berthing at all. So by your logic nobody, will be visiting the Vast station ever because no vehicles will ever dock or berth there.

To be explicitly clear: a job posting will not detail mission architecture, and it will not detail vehicle design. Trying to diving CONOPS from one is beyond tea-leaf reading and into examination of goat entrails.

$190k for GNC expertise... but no docking?   

Is the axial dock still invisible, edzieba?  Look closely...

Vast's notional renders are just that: notional.

[Coastal Ron]

Yes, stop quoting yourself as the only source of information. All that does is prove you don't have any proof.

Doubling down on nonsense there.  No, we saw the VAST info, including their GNC job opening.

See how easy it is to post a primary source of information, instead of quoting one (or more) of your own posts? That wasn't too hard, was it? 

But as edzieba said, that doesn't prove anything, other than VAST wants someone with GNC experience. And at the very least they may have decided that their station is too small for docking operations during rotation, so they plan to de-spin the station for cargo and crew transfers. That would require GNC just for the un-spun docking.

The VAST station is also the wrong configuration for a station that can allow docking at the center of rotation while the station is rotating. Some disagree, but regardless, VAST doesn't look like they are pursuing that - AND MANY OF US HAVE KNOWN THAT FOR A LONG TIME, SO NOT INFO YOU HAVE PROVIDED.

And we saw the job matches SOTA GNC docking methods, i.e., without counter-rotating hw.  We don't see "counter"-examples in the industry.

There is no "industry" for rotating space stations. Duh! 

You might start a new thread for "counter-rotating docks", specifically, where you can dismiss engineering that doesn't fit.

Sorry, I started this thread, and if you don't like the ideas that people provide, you don't have to comment. And how cargo and crew is transferred to a station is relevant to the station design itself, including testbed stations.

You are free to start a thread for "counter-rotating docks", so go do it if you feel it is necessary. 

[LMT]

Yes, stop quoting yourself as the only source of information. All that does is prove you don't have any proof.

Doubling down on nonsense there.  No, we saw the VAST info, including their GNC job opening.

See how easy it is to post a primary source of information, instead of quoting one (or more) of your own posts? That wasn't too hard, was it? 

But as edzieba said, that doesn't prove anything, other than VAST wants someone with GNC experience. And at the very least they may have decided that their station is too small for docking operations during rotation, so they plan to de-spin the station for cargo and crew transfers. That would require GNC just for the un-spun docking.

The VAST station is also the wrong configuration for a station that can allow docking at the center of rotation while the station is rotating. Some disagree, but regardless, VAST doesn't look like they are pursuing that - AND MANY OF US HAVE KNOWN THAT FOR A LONG TIME, SO NOT INFO YOU HAVE PROVIDED.

And we saw the job matches SOTA GNC docking methods, i.e., without counter-rotating hw.  We don't see "counter"-examples in the industry.

There is no "industry" for rotating space stations. Duh! 

You might start a new thread for "counter-rotating docks", specifically, where you can dismiss engineering that doesn't fit.

Sorry, I started this thread, and if you don't like the ideas that people provide, you don't have to comment. And how cargo and crew is transferred to a station is relevant to the station design itself, including testbed stations.

You are free to start a thread for "counter-rotating docks", so go do it if you feel it is necessary. 

So as we see:

-  yes, there is a VAST dock, and

-  no, it doesn't counterrotate, and

-  yes, GNC skillset is consistent, and

-  no, there's no counterrotation roadmap. 

Who caught the new confirmation in the video above?  What's docked there?

[Twark_Main]

Yes, stop quoting yourself as the only source of information. All that does is prove you don't have any proof.

Doubling down on nonsense there.  No, we saw the VAST info, including their GNC job opening.

See how easy it is to post a primary source of information, instead of quoting one (or more) of your own posts? That wasn't too hard, was it? 

But as edzieba said, that doesn't prove anything, other than VAST wants someone with GNC experience. And at the very least they may have decided that their station is too small for docking operations during rotation, so they plan to de-spin the station for cargo and crew transfers. That would require GNC just for the un-spun docking.

The VAST station is also the wrong configuration for a station that can allow docking at the center of rotation while the station is rotating. Some disagree, but regardless, VAST doesn't look like they are pursuing that - AND MANY OF US HAVE KNOWN THAT FOR A LONG TIME, SO NOT INFO YOU HAVE PROVIDED.

And we saw the job matches SOTA GNC docking methods, i.e., without counter-rotating hw.  We don't see "counter"-examples in the industry.

There is no "industry" for rotating space stations. Duh! 

You might start a new thread for "counter-rotating docks", specifically, where you can dismiss engineering that doesn't fit.

Sorry, I started this thread, and if you don't like the ideas that people provide, you don't have to comment. And how cargo and crew is transferred to a station is relevant to the station design itself, including testbed stations.

You are free to start a thread for "counter-rotating docks", so go do it if you feel it is necessary. 

So as we see:

-  yes, there is a VAST dock, and

-  no, it doesn't counterrotate, and

-  yes, GNC skillset is consistent, and

-  no, there's no counterrotation roadmap. 

Who caught the new confirmation in the video above?  What's docked there?

I love how, as if to make up for accidentally posting a direct link to a primary source, you put in two links to the same post of yours instead of just linking to the YouTube video. 



Is there anything in particular in this video you believe supports your point? Can you give a timestamp, perhaps?  Because the docking animation shown @2:00 very clearly depicts Haven-1, not their rotating stick concept.

[Coastal Ron]

So as we see:

-  yes, there is a VAST dock

There has to be some way to get cargo and crew onto a space station, so duh!

-  no, it doesn't counterrotate

I don't really care what VAST does, and whatever they do is one data point, not a trend.

-  yes, GNC skillset is consistent

Guidance, Navigation, and Control (GN&C) for both a space station and a visiting vehicle would be needed regardless if a dock rotates or not. Not sure if you understand that...

-  no, there's no counterrotation roadmap. 

What? Are you saying that the only entity in the world that can determine how visiting vehicles dock to rotating space stations is VAST? For the rest of time?

Do you realize how dumb that sounds? Sorry, but you really sound like you are trying to manage the conversations on this thread, which I created, and I won't have that.

Who caught the new confirmation in the video above?  What's docked there?

Sorry yet again, because you referenced your own post again, and I don't read references to your own posts anymore.

More to the point, STOP trying to use VAST as the reason why future rotating space stations can't use some form of rotating dock.

This argument is over, and I'll be happy to report you to a moderator if you keep dragging this thread off topic... 

[edzieba]

No, we saw the VAST info, including their GNC job opening. 

Said job posting does not mention docking or berthing at all. So by your logic nobody, will be visiting the Vast station ever because no vehicles will ever dock or berth there.

To be explicitly clear: a job posting will not detail mission architecture, and it will not detail vehicle design. Trying to diving CONOPS from one is beyond tea-leaf reading and into examination of goat entrails.

$190k for GNC expertise... but no docking?   

Is the axial dock still invisible, edzieba?  Look closely...

Vast's notional renders are just that: notional.

You may wish to go and visit Vast's website to find out what they are actually doing, rather than your imaginary version of what they are doing. The station depicted in that video is not their rotating station, but the nonrotating demonstrator mission.

[JohnFornaro]

We saw the VAST info...

I chatted with one of the VAST team a while back, asking for their price structure.  They wouldn't respond.  If you have to ask how much, you can't afford it, I guess.  Anyhow, they're making more progress than I am!

[JohnFornaro]

One thing that does push you above a certain minimum radii, is being able to dock 2+ starships to the station in a way that both 1) allows them to approach and dock without interfering with each other, and 2) also doesn't significantly upset the rotational balance of the station (we want 2+ visiting vehicles if there are to be crewed handovers, which is a priority for the CLD program).

My station provides for berthing up to four StarShips in the current configuration; two of SS version 2 and one SS version 3.  On my envelope, I've sketched out V2 and V3 as being doubled in size.  [See Section D-D on SK-203 whre V1,2, &3 are illustrated] This colony of 1M people on Mars will require quite the number of additional launches; a much larger SS will be required, as I see it.

In addition to that would be the UDH suggestion of mine [Unpressurized Deployable Hanger], first suggested by me in 2011, pre-dating Strickland's virtual copy thereof.  An EML to Mars orbit tug would pull several of these UDH's, which are currently sized to fit a Falcon, and would be launched from Earth; assembled in space, LEO perhaps, and stay in space. I need to make an animation.

[LMT]

What's docked there?

[Twark_Main]

My station provides...

Cool.

Also not a "AG Testbed," so off-topic in this thread. 

[Solarsail]

Looks like a Dragon capsule on the right side of both images;  Right monitor shows the abort motors and trunk, with its solar panels and fins.  Left monitor shows the shape of the overall dragon.

Left side of the left image seems to be...  The Hubble telescope 

Not clear what it is that they're docked to.  Extra regular-size modules?  There's also a frame of some kind around them.  If those are >8m across, I have no idea how they'd be delivered / built.  On the flip side, if a Dragon capsule stays docked during rotation, then this would produce a clear intermediate axis of rotation.  Not sure if the Dragon can handle enough tensile force on its docking port to hang down like that.

Edit:  Was responding to LMT.

[Twark_Main]

We saw the VAST info...

I chatted with one of the VAST team a while back, asking for their price structure.  They wouldn't respond.  If you have to ask how much, you can't afford it, I guess.

Don't throw shade. Bad form

Rather, it's quite silly of you to expect "firm fixed price" at this early point in development. You, of all people, should know better!

[JohnFornaro]

Also not a "AG Testbed," so off-topic in this thread. 

Huh.  When is a test bed not a testbed.  The point of my station, such as it is, is to "test" my hypothesis?

[JohnFornaro]

(1) If you have to ask how much, you can't afford it, I guess.

Bad form
(2)Rather, it's quite silly of you to expect "firm fixed price"

(1) My guess is that it's proprietary info.  Plus, my name didn't start with an "M" and end with a "k".  No harm, no foul, no shade.

(2) Specifically asked for ballpark amount.

[JohnFornaro]

What's docked there?

Um, where's "there"? and what's "what"?

I'm not getting your question.

[KelvinZero]

Hi! My two cents:

Re questions about basic stability, after proof with computer modelling, how about a demo with a cubesat experiment? In particular, the problems of a single tether approach might be solvable. I know there are problems, but there might also be solutions, including active stabilisation/damping.

Does the Dragon 2 provide enough room to stand upright standing on a treadmill? I think there is a bit more headroom with that glass viewing dome. Im also a fan of VR. You could have a crew of two, where only one is in the VR treadmill rig at a time, and the other is sitting or sleeping.

If a single tether is not solvable, there might be other lowish weight solutions. For example what about a rolled up tube that when inflated, becomes a rigid triangle or some other flat geometric shape? The dragon could be at one corner and some smaller weights could be at the other corners. To balance the dragon, they would be further from the COM.

If anything goes wrong, the dragon would instantly disconnect and the experiment aborted.

[Coastal Ron]

...the problems of a single tether approach might be solvable.

I am of the opinion that two bodies connected by a tether of some kind, might not be able to provide enough test time. But such a setup is probably the lowest cost option for creating artificial gravity.

I know there are problems, but there might also be solutions, including active stabilisation/damping.

Yep, the problem, and potential solutions, comes up from time to time. I have my own ideas for my Mars station, and also for a testbed station design I've been working on.

Does the Dragon 2 provide enough room to stand upright standing on a treadmill?

The plus for this approach is that most of the hardware exists, but with such a small volume for human occupation I would question the science return.

[KelvinZero]

The plus for this approach is that most of the hardware exists, but with such a small volume for human occupation I would question the science return.

I think that you would get the necessary scientific return if combined with something like this 2d VR treadmill, which I think could fit in a Dragon 2.
https://www.virtuix.com/

Just look at all those motions the player is doing. The walking, crouching, throwing. All these could be tailored by the environment, and if the gameplay was linear, it would be easy to repeat on earth and in space giving exactly the workout and exactly the feedback sought.

With two people, each could have up to 12 hours in the rig, 8 hours sleep, 4 hours daily stuff. It would also be interesting to run this experiment here on earth, which would of course happen before committing to the in-space version.

(I edited this way down to keep on topic)

[Coastal Ron]

The plus for this approach is that most of the hardware exists, but with such a small volume for human occupation I would question the science return.

Im a big fan of VR for long trips...

I'm sure AR and VR will be part of the inventory of information and entertainment systems on long term voyages.

However VR is not really related to the topic of artificial gravity, since VR can also be used in zero gravity situations, and VR does not really mitigate the negative physical effects of reduced or zero gravity.

[KelvinZero]

..However VR is not really related to the topic of artificial gravity, since VR can also be used in zero gravity situations, and VR does not really mitigate the negative physical effects of reduced or zero gravity.

I suspect I drowned my point in my enthusiasm. I edited my post down to make sure I was only responding to how an AR treadmill would be applied to the problem of this thread, which I understand to be primarily about answering human unknowns like gravity needed for bone mass, tolerance to small radii etc.

I think Im on to something. The volume of a Dragon 2 is enough. You could do it in two F9R launches, and only a single launch for following missions.

One launch would be the Dragon 2 of course. The other launch would be the counterweight flywheel+tether (or extending arm if we cant solve tethers) that stays in orbit. So the tether system could also be spun up and down without propellant, and perhaps you could fit larger habs than a Dragon 2 in the future.

Or maybe using thrust to spin up and down is easier. Im not sure. Flywheels are pretty well understood.

erm.. I might need a diagram. What I am describing might sound a bit too much like a yo-yo