Nasa Deploys inflatable modules to ISS

[wbnc]

We've had discussions about ideas like this..I think NASA was ahead of us a bit....
http://www.iflscience.com/space/groundbreaking-inflatable-module-be-launched-iss-next-week

It takes up 1/4 the space when stored as it does when deployed, the module is just being tested at this point but the idea seems like it's viable.

 

[Tenacious-Techhunter]

I think NASA was ahead of us a bit...

Some of us, maybe. They’ve been talking about it for 20 years or so, but development of space is slow. I’m sure the subject of inflatable modules has been brought up before, and was laughed out of the room, either because of ignorance, or because the guys with the “retro-future” pathology ganged up on them.

Frankly, anything that makes it to Atomic Rockets should just plain be in the game, at its appropriate TL.

 

[wbnc]

I think NASA was ahead of us a bit...

Some of us, maybe. They’ve been talking about it for 20 years or so, but development of space is slow. I’m sure the subject of inflatable modules has been brought up before, and was laughed out of the room, either because of ignorance, or because the guys with the “retro-future” pathology ganged up on them.

Frankly, anything that makes it to Atomic Rockets should just plain be in the game, at its appropriate TL.

I have to support the Atomic Rockets policy 110% they are a great resource for realistic style sci-fi ships

I am sure part of the laughter was based on the concept of a fabric capable of surviving the environment. But with the introduction of modern fibers, and advances in carbon fiber materials, that issue is one I think needs to be set aside. a flexible construct, with a a series of internal mesh to maintain form, when inflated is now about as practical as a solid metal structure.

with this model the space savings is extreme, the module is only 1.4 the size deflated as inflated It doesn't mention the mass of the module but the smaller deflated size will allow larger modules than can be fitted onto a booster. Initially the size of a module was limited by the cargo bay of the shuttle, or the maximum diameter of a launch vehicle. Which resulted in modules that are rather cramped for long term habitation.

Plus there is something to be said about an object that can flex under impact, a small diameter impact permanently deforms a metal plate, which can result in broken seams, and ruptured seals....but if not holed a fabric structure resumes it's shape after an impact, internal pressure automatically forces it back into it's original shape.

 

[Condottiere]

You could layer the fabric in air stratas, so that each layer could self seal as a hole gets punctured through.

My main interest would be if it would survive a weekly bath in hydrogen in another dimension.

 

[Tenacious-Techhunter]

They've already covered the impact issues fairly well. Give them a look.

Consistent pressure from outside would likely be a problem; these were specifically not designed for an outside pressure much greater than 0. So the matter of the gas being hydrogen is not so much the issue as there being any gas at all. The occasional bump and bang is fine, but consistent pressure, that would be a problem.

 

[wbnc]

If you took one into Jump deployed you would be facing the rigors of an atmosphere inside the bubble...all that hydrogen you pumped into it would be agitated, and fairly unruly bouncing around beteen the hll and the inner boundry of the bubble.

you would have to engineer the module to be able to resist the outside pressure by some means. a ring of individual inflatable cells, or tubes might serve as a skeleton for the module, but it would be easier to simply go with the policy they have to be collapsed for jump travel. ( it's the simplest rule to put in place)

this would be a good option for scouts, and other ships that spend a lot of time in normal space, allowing workshops and other facilities to be deployed in normal cruise and quickly packed up for jump increasing the effective size of the ship for use by the crew. from the article it looks like the module offers a 75% reduction in volume during transport so you add 25% of it's volume to the ship to account for storage during jump,with the other 75% being useful volume while in normal cruise mode.

 

[Jame Rowe]

This is what I imagine the civilian drop tanks to be, from Classic Traveller and The Traveller Adventure.

 

[Tenacious-Techhunter]

These are designed to be habitable. Therefore, there’s a lot of unnecessary engineering in place to make that possible that makes it a wasteful design for drop-tanks. In particular, there’s this big, strong, sturdy, central space-frame column where it attaches to the station that is completely unnecessary for a disposable fuel-cell. Don’t get me wrong, there’s probably a bit of crossover, but there might, for instance, be more crossover with, say, the lithobraking airbags of the Mars Rovers.

 

[Tenacious-Techhunter]

If you took one into Jump deployed you would be facing the rigors of an atmosphere inside the bubble...all that hydrogen you pumped into it would be agitated, and fairly unruly bouncing around between the hull and the inner boundary of the bubble.

Not built to take the turbulence of the jump bubble. Not even built to take the pull of any thrust at all. Not it’s intended purpose at all. While it’s not impossible to have inflatable modules endure the rigors of maneuvering, per se, this design does not accomplish that. It will probably be 2 or 3 TLs before such a design would reasonably withstand Thrust 2, with maybe an additional level of Thrust tolerance per additional TL after that.

you would have to engineer the module to be able to resist the outside pressure by some means. a ring of individual inflatable cells, or tubes might serve as a skeleton for the module, but it would be easier to simply go with the policy they have to be collapsed for jump travel. ( it's the simplest rule to put in place)

This version of the tech would require you deflate it before any sort of maneuvering thrust or jumping. Treat it like the expansion rooms on a modern RV... you would be a threat to yourself and others if you drove down the highway that way, because it was never built to do that.

this would be a good option for scouts, and other ships that spend a lot of time in normal space, allowing workshops and other facilities to be deployed in normal cruise and quickly packed up for jump increasing the effective size of the ship for use by the crew. from the article it looks like the module offers a 75% reduction in volume during transport so you add 25% of it's volume to the ship to account for storage during jump,with the other 75% being useful volume while in normal cruise mode.

I’m not feeling the Scout thing... they tend to need to book at the slightest notice, and they would be required to forcibly eject the inflatable module in order to safely run like hell.

But what it would work for though... Lab Ships! You can’t do any meaningful science in Jump Space anyway, so all the labs would be inflatable. Inflate the labs, swing the equipment out of the central column, and you’ve got 4.5-6 dTons of lab in half a dTon of payload!

Another idea for unrelated inflatable tech: Shipyard Crew Scaffolding

 

[Jame Rowe]

These are designed to be habitable. Therefore, there’s a lot of unnecessary engineering in place to make that possible that makes it a wasteful design for drop-tanks. In particular, there’s this big, strong, sturdy, central space-frame column where it attaches to the station that is completely unnecessary for a disposable fuel-cell. Don’t get me wrong, there’s probably a bit of crossover, but there might, for instance, be more crossover with, say, the lithobraking airbags of the Mars Rovers.

Yes, I do consider the "drop" tanks to be resuable.

 

[Askold]

So something like a spaceship version of this: https://www.youtube.com/watch?v=GIG9P0lB1iA&spfreload=10

I like the science-vessel idea although some experiments can be done during a Jump but I suppose that could be the time when they let the computers run through simulations and let the researchers have some R&R.

Another thing that came in my mind was a mining ship that could have massive cargo containers that can be collapsed. This would mean that they can't transport full cargo while making a Jump but it still lets them do mining in a system and transport more ores/whatever than they normally could to a drop off point within the same system. ...The drop off point may be a mobile refinery and designated cargo ships move the products.

 

[Rick]

Now that's extreme camping - putting up a tent in orbit!

 

[Tenacious-Techhunter]

Yes, that motorhome example is exactly right; same niche, but in space.

 

[Tenacious-Techhunter]

Yes, I do consider the "drop" tanks to be resuable.

O.K., you mistook what I meant by "disposable". If a micrometeoroid hits your fuel tank and puts a hole in it, your tank's sealing mechanisms kick in, and seal the hole before you lose significant fuel. You might have to run on low power for a bit through jump-space to save fuel before your next stop in order to make your deadline, but it's no big loss; the fuel drop-tank can afford to be holed a few times over its lifetime. But an inflatable hab module cannot afford to be holed, ever; nor is it built for being thrashed around in space, because humans have to not die in it. The design requirements for a hab module are well beyond those of a mere drop-tank with regards to stationary service, and well below those of a drop-tank with regards to service under thrust. Therefore, this module doesn't serve as a good example for that particular application, even if it may serve as proof that using similar technology for that application is plausible.

 

[Epicenter]

If you took one into Jump deployed you would be facing the rigors of an atmosphere inside the bubble...all that hydrogen you pumped into it would be agitated, and fairly unruly bouncing around beteen the hll and the inner boundry of the bubble.

you would have to engineer the module to be able to resist the outside pressure by some means. a ring of individual inflatable cells, or tubes might serve as a skeleton for the module, but it would be easier to simply go with the policy they have to be collapsed for jump travel. ( it's the simplest rule to put in place)

this would be a good option for scouts, and other ships that spend a lot of time in normal space, allowing workshops and other facilities to be deployed in normal cruise and quickly packed up for jump increasing the effective size of the ship for use by the crew. from the article it looks like the module offers a 75% reduction in volume during transport so you add 25% of it's volume to the ship to account for storage during jump,with the other 75% being useful volume while in normal cruise mode.

It's funny you say this because I'd imagine the biggest use for inflatable habitats on Traveller would be during Jump.

Is it stated anywhere the Hydrogen bubble around a starship is at 1 ATM or greater? If the hydrogen bubble is significantly less, it could remain "inflatable." Otherwise, some sort of stiffening structure could be erected. Finding some sort of material that'd resist Hydrogen infiltration wouldn't be hard, most certainly by TL12 and beyond. Everyone would have long experience with it due to the whole "Hydrogen bubble around the hull" thing. By TL12, I'd imagine that even providing the modules artificial gravity might not be hard - like "flip out" grav plates under the modules if they need to be monolithic, if not they might be "woven" into the module.

Beyond that, Jumpspace is pretty ideal for inflatibles. There's apparently little in the way of radiation that might harm people inside, no micrometeors (or meteors for that matter). The extra room could be handy for that one-week period - I've always imagined that ships actually do a lot of routine maintenance on the outside of the ship - particularly outside the ship - during that period. This would be done because besides this sort of hokey "Jump space drives you crazy to look at it" thing, it's safer than "real" space. Work could be conducted using of opaque "tent" stretched over parts of the ship you want to work on. Similarly, inflatable modules could be used for various purposes to just make a starship less cramped and for private space.

If you think about it, most Traveller starships spend most of their time in Jumpspace - so inflatable modules might be part of the "standard" interior space of the ship and the "folded" space would just for take-off and transit to the jump point (and back again); assuming that for most ships it does not take a day to get to 100 diameters, the "folded" space would just be for transit to and from Jumpspace. A ship with its inflatable volume folded might be considered much like today where you have to wear seatbelts on a plane during takeoff and landing but are otherwise free to move around the cabin. The modules might actually contain spaces we'd considered quite valuable to the ship. For instance, on a merchant vessel that basically doesn't really dally about - it spends most of its time in Jump space or on the ground / docked to a highport, the quarters and cabins might actually be in the inflatable part with the Stewards and crew "turning down the beds" in the modules for passengers (and themselves) once they're in jump space. Dining halls, exercise rooms, and similar areas would definitely be inflatable.

 

[Tenacious-Techhunter]

The existing inflatable technology *is not designed* for the sort of stresses you are describing; it’s like the difference between a parachute designed to work on Earth and a parachute designed to work on Mars; just because they’re both parachutes, and both designed to do a similar job, that doesn’t mean they are remotely alike in terms of construction. Any inflatable designed to operate in Jump Space would have *considerable differences* to the current inflatable ISS module, as well as the ones to come. You can consider the ISS module as a proof-of-concept that could be expanded upon, but you would have to *engineer from scratch* a solution appropriate to the Traveller setting, rather than simply *implementing* something like the ISS version.

With regards to Traveller physics, what you are describing ignores the fundamental issues of *changing your displacement while in Jump-Space*, and *requiring additional Jump Bubble to compensate*. Such an experiment would undoubtedly result in a *catastrophic jump failure*. Additionally, I do not recall *anything* saying that Jump-Space is *at all safe*. I seem to recall lots of stuff about burning Jump-Bubble plasma.

That’s not to say I don’t like your idea, I do... just that it would be limited to strictly *your* Traveller Universe, on account of the break with canon Traveller Physics, or require some other RPG altogether.

 

[wbnc]

Reading through these posts there are some good ideas for applications of the technology. I am leaning toward using it in low stress, low hazard, applications where the design could be kept fairly simple, and inexpensive.

I am also leaning to not using it in jump space. I a just not sure that the interior of a jump bubble would be a good place for it. and as it was pointed out above changing the volume of a ship after entering jump might cause issues.

perhaps the best use of the concept would be as a modifier for various ships facilities. Such as staterooms, labs, or workshops. when stowed they take up 25% of the normal space and are counted as cargo. the fittings fold up and form part of the 25% stowed volume. wouldn't apply any cost increase to the module since you are trading extra capacity, for the facility being unusable during jum travel, and other factors such as not being able to reinforce or armor it.That trade off should be enough to provide balance within the context of the rules.

 

[Epicenter]

You can consider the ISS module as a proof-of-concept that could be expanded upon, but you would have to *engineer from scratch* a solution appropriate to the Traveller setting, rather than simply *implementing* something like the ISS version.

I don't think anyone has suggested that this technology be directly applied using early 21st century materials science in the far-future of Traveller. The discussion is more the application of the concept of having an expandable interior volume (and possibly collapsible interior volume) and what kind of uses it can be put to and how that might change things.

With regards to Traveller physics, what you are describing ignores the fundamental issues of *changing your displacement while in Jump-Space*, and *requiring additional Jump Bubble to compensate*. Such an experiment would undoubtedly result in a *catastrophic jump failure*.

I do have to wonder what you mean by "Traveller physics" in this case. Has there been a canon supplement detailing exactly how Jump space works that I'm unaware of? I've been looking for one for a while to answer those nitpicky questions that come up in games.

I've never read anything about required minimum gas density of the Jump bubble, how it is prevented from dissipating into Jump Space, limits on how far it can be projected from the hull, and so on. What is known is that it is one of the possible explanations for the amounts of hydrogen necessary for every Jump. I doubt there's really been that much more detail about these kinds of things; for most players its in the realm of Too Much Information. In the absence of canon information, players can only speculate; my guess is as good as yours.

How the Jump bubble of Hydrogen gas is projected appears to still be up to some speculation. A common idea (I'm not sure if it is actually in any canon materials of any edition) is that the bubble is projected from the Jump Grid (the Lanthanum grid that is built into the hulls of Traveller ships); how far this bubble extends is something I've never read any references to - it'd seem like it must be extensible to quite a distance otherwise various smaller protrusions like the various slender fins, sensor dishes, and so on are unlikely to be part of the Lanthanum grid and you wouldn't want them sticking out. Some projections are no doubt retractable into the hull, but I somehow doubt they all would be. Similarly ships like Reformation Coalition clipper, which has attachable modules to a central spine creating this not-always-consistent volume between jumps, would suggest the bubble can be projected out a ways from the ship.

Further, the mass of the ship when it goes into jump space remains constant even with extensible modules. It's the volume that changes.

The expanded volume of the ship after the modules have been deployed is known before Jumping. The bubble containment field is projected to compensate for this additional volume by calculating it before the Jump is made. A hypothetical ship might be 10m x 10m x 10m. With extended modules, the ship might be 10m x 12m x 10m. If the bubble is already projected to cover the 10m x 12m x 10m when the ship goes into Jumpspace, I don't see the issues you're putting so helpfully into asterisks.

Additionally, I do not recall *anything* saying that Jump-Space is *at all safe*. I seem to recall lots of stuff about burning Jump-Bubble plasma.

Please provide the reference if you have it; if it's a change they added in since MongTrav I'd like to know it (since I run in MongTrav).

In my decades of playing Traveller, I've never encountered anything that suggests that Jump Space is anything but calm and unexciting for the most part (mostly because of the absence of anything saying it is turbulent and hazardous in routine Jump).

A TNE scenario in Challenge #75 (player-written so the "canon status" of it is up to considerable doubt) describes various bad things happening to a ship when the Jump gear starts to fail and the Hydrogen bubble / jump field starts to have integrity issues.

I think it was in T4 (that's when I recall a big deal being made of it - the concept may have been introduced much ealier) that the idea staring into Jumpspace was hazardous to your mental health was introduced.

Those are the only two references to Jump space being hazardous I've read - obviously you don't want to drift outside of the bubble and so on, but that's another story.

Of course, my knowledge of Traveller does have significant holes in it - I haven't followed T5 at all, I haven't read Miller's story "Agent of the Imperium", and some of the MongTrav supplements aren't in my collection yet.

 

[Tenacious-Techhunter]

I don't think anyone has suggested that this technology be directly applied using early 21st century materials science in the far-future of Traveller. The discussion is more the application of the concept of having an expandable interior volume (and possibly collapsible interior volume) and what kind of uses it can be put to and how that might change things.

No, you’re quite incorrect; if you look, you will see that discussion so far has been centered primarily around limitations of the existing module, and by extension, what limits modules of similar design and construction would have. It is not about inflatable design in general, because the ISS module is not a “general purpose” design; it’s specifically for non-thrusting applications in an environment with no outside pressure. If this discussion were about inflatable design, I would have brought up collapsible fuel bladders, which would eliminate the need for there being any distinction between fuel and cargo space. But as great an idea as that is, it has no place in this discussion, because the two designs have nothing to do with one another, besides a merely coincidental connotation of being “inflatable”.

With regards to Traveller physics, what you are describing ignores the fundamental issues of *changing your displacement while in Jump-Space*, and *requiring additional Jump Bubble to compensate*. Such an experiment would undoubtedly result in a *catastrophic jump failure*.

I do have to wonder what you mean by "Traveller physics" in this case. Has there been a canon supplement detailing exactly how Jump space works that I'm unaware of? I've been looking for one for a while to answer those nitpicky questions that come up in games.

...

Further, the mass of the ship when it goes into jump space remains constant even with extensible modules. It's the volume that changes.

The expanded volume of the ship after the modules have been deployed is known before Jumping. The bubble containment field is projected to compensate for this additional volume by calculating it before the Jump is made. A hypothetical ship might be 10m x 10m x 10m. With extended modules, the ship might be 10m x 12m x 10m. If the bubble is already projected to cover the 10m x 12m x 10m when the ship goes into Jumpspace, I don't see the issues you're putting so helpfully into asterisks.

The information you’re neglecting is found starting on page 106 with “The Engineering Section”, and page 141 with “Jump Travel”.

1. The use of Jump Space involve thousands of detailed calculations that require a computer
2a. The Jump Fuel required is a function of displacement (volume), not of mass; changing this variable mid-jump without accounting for it would cause a misjump... a catastrophic one, if you were unlucky
2b. The Jump Drive required is a function of displacement (volume), not of mass; changing this variable mid-jump without accounting for it would cause a misjump... a catastrophic one, if you were unlucky
3. While accounting for this variable change pre-jump is certainly possible, if the modules failed to expand completely and on-time, the math would be faulty, and it would cause a misjump... a catastrophic one, if you were unlucky; this puts it well-outside the range of “responsible travel-liner” territory and well-into “dangerously reckless idiot” territory... which, admittedly, some pirates might fall into

Additionally, I do not recall *anything* saying that Jump-Space is *at all safe*. I seem to recall lots of stuff about burning Jump-Bubble plasma.

Please provide the reference if you have it; if it's a change they added in since MongTrav I'd like to know it (since I run in MongTrav).

In my decades of playing Traveller, I've never encountered anything that suggests that Jump Space is anything but calm and unexciting for the most part (mostly because of the absence of anything saying it is turbulent and hazardous in routine Jump).

A TNE scenario in Challenge #75 (player-written so the "canon status" of it is up to considerable doubt) describes various bad things happening to a ship when the Jump gear starts to fail and the Hydrogen bubble / jump field starts to have integrity issues.

It’s calm and unexciting to the ship and the people in it; outside the ship, the as-hot-as-possible hydrogen used as power system coolant is just going to collect. The ship’s hull can take it because it was built for emergency reentry. While Mongoose Traveller may have gone into poor detail on this, it’s still Traveller canon.

 

[Condottiere]

Could be a rigid construction, like the Hindenburg.