Is a Wet Workshop a practical solution for interplanetary travel and space stations?

[fredinno]

This is a poll.

For those who don't know, a wet workshop would have used a spent rocket fuel stage to construct a living space in space. This contrasts from a dry workshop, which would have been constructed from a empty fuel tank on the ground, then sent into orbit. This was studied in the Apollo Applications Program, and was the prime contender for Skylab's construction before using a dry workshop instead.

What do you think guys?

This is also a "wet workshop" discussion forum, so discuss away!

[Kibble]

The problem with wet workshops is the same as the problem with inflatable habitats - you have to launch it empty. That means a multitude of launches to get it to useful working order, including at least one piloted labor-intensive mission. It's worse for wet workshops because it can't even be immediately used for just a big empty space (unlike inflatables). The tank interior has to be made sure its completely safe for occupation after launch.

[Rakaydos]

The problem with wet workshops is the same as the problem with inflatable habitats - you have to launch it empty. That means a multitude of launches to get it to useful working order, including at least one piloted labor-intensive mission. It's worse for wet workshops because it can't even be immediately used for just a big empty space (unlike inflatables). The tank interior has to be made sure its completely safe for occupation after launch.

Do you happen to know what the hazards of occupying a spent LOX stage might be?

[Kibble]

Do you happen to know what the hazards of occupying a spent LOX stage might be?

The same as the hazards of occupying any structure in space, plus the fact that it is a flown rocket stage that went thru all the rigors of launch before being depressurized and repressurized again.

[tater]

^^^yep. They also need hatch systems that are fuel/oxidizer tight in the first place, presumably.

[Rakaydos]

The same as the hazards of occupying any structure in space, plus the fact that it is a flown rocket stage that went thru all the rigors of launch before being depressurized and repressurized again.

So, other than cuting into propellant load, what's the reason yo cant build a workshop into the tank walls before filling and launching the tank?

[fredinno]

The same as the hazards of occupying any structure in space, plus the fact that it is a flown rocket stage that went thru all the rigors of launch before being depressurized and repressurized again.

But wouldn't that mean the wet workshop station would also be pretty strong and micrometeorite resistant at the same time?

So, other than cuting into propellant load, what's the reason yo cant build a workshop into the tank walls before filling and launching the tank?

It would almost certainly ruin the equipment.

I think wet workshop is better than inflatables simply because it allows you to multitask with each launch- Say, you launch a Falcon 9- the 2nd stage could be used as a space station part rather than landing it on the Earth for reuse. It would allow space stations to be built quickly for little extra cost, as you would only need to fill it up with equipment (which can be done with another Falcon 9 launch, or, in the case of the Falcon Heavy, just use the extra payload space not taken up by a crewed Dragon to haul up all the goodies needed it it.)

[Nibb31]

The idea was abandoned for a number of good reasons. The outfitting work in orbit is tremendous and extremely complex (think of all the walls, the wiring and piping and ventilation systems that need to be installed), and the extra fixtures and hatches add a whole lot of weight to the stage.

[fredinno]

The idea was abandoned for a number of good reasons. The outfitting work in orbit is tremendous and extremely complex (think of all the walls, the wiring and piping and ventilation systems that need to be installed), and the extra fixtures and hatches add a whole lot of weight to the stage.

Inflatable modules have the same problem, and yet, nobody has abandoned that idea. Hell, Bigelow has bet their money on it. Aside from cleaning up the remaining fuel, what would be so much harder with a empty tank than an inflatable?

[Nibb31]

No, inflatables can have a central core with all the plumbing without wasting weight for propellant. Cleaning up the remaining fuel is not a trivial task in microgravity.

[Bill Phil]

The idea was abandoned for a number of good reasons. The outfitting work in orbit is tremendous and extremely complex (think of all the walls, the wiring and piping and ventilation systems that need to be installed), and the extra fixtures and hatches add a whole lot of weight to the stage.

Actually, the main reason the wet workshop concept was not used was that they had an extra Saturn V. Skylab was ultimately more capable as a dry workshop, so I'm not complaining.

The concept is a good one. You have a pressure hull already there, it's an object in space. Might as well use it...

Yes there is going to be a lot of set up, but ultimately you wouldn't need a giant launch vehicle. I'd say it is viable if you're already going to be building it in space anyways...

[Ralathon]

Regarding fuel contamination of the equipment and the difficulties of installation inside a wet workshop, wouldn't it be possible to preinstall all the essential wiring and sockets. Then you put a bladder inside the station filled with propellant. As the bladder empties itself you keep releasing air into the station to maintain constant pressure. By the time the stage is burned out the bladder has completely crumpled.

This way the inside of the station is never in direct contact with the fuel and never exposed to a complete vacuum. All the astronauts would need to do is folding away the bladder and screw some racks in place. All in a comfortable shirt sleeve environment.

[Fel]

Regarding fuel contamination of the equipment and the difficulties of installation inside a wet workshop, wouldn't it be possible to preinstall all the essential wiring and sockets. Then you put a bladder inside the station filled with propellant. As the bladder empties itself you keep releasing air into the station to maintain constant pressure. By the time the stage is burned out the bladder has completely crumpled.

This way the inside of the station is never in direct contact with the fuel and never exposed to a complete vacuum. All the astronauts would need to do is folding away the bladder and screw some racks in place. All in a comfortable shirt sleeve environment.

This is precisely what I was thinking while reading through this thread.

Though, the biggest issue I think might be getting a (uncertain of the correct term so) "elastic like" substance that can withstand the sub-zero temperatures of the fuel.

[fredinno]

Regarding fuel contamination of the equipment and the difficulties of installation inside a wet workshop, wouldn't it be possible to preinstall all the essential wiring and sockets. Then you put a bladder inside the station filled with propellant. As the bladder empties itself you keep releasing air into the station to maintain constant pressure. By the time the stage is burned out the bladder has completely crumpled.

This way the inside of the station is never in direct contact with the fuel and never exposed to a complete vacuum. All the astronauts would need to do is folding away the bladder and screw some racks in place. All in a comfortable shirt sleeve environment.

Someone give this man a beer. Now the main problem we have is interior walling. It probably be made of thin sheets of aluminum with bolts on each end, so that it could be made in pieces. I'm wondering if this would be exceedingly weak or heavy to do.

I think the Wet worshop idea is best tried out in LEO, as a "side project" between (big rocket) launches. That way, when we replace the ISS, we have an easy solution.

[frizzank]

I think we should do it, at the very least be a good exercise/experiment in orbital construction. We would learn a lot from the enterprise even if it was not the most practical application.

[xenomorph555]

A wet workshop in my opinion is a terrible idea. Too complex and delicate to do something like that in space;

Complex plumbing

Fuel contamination

You need to construct the inside in orbit

And a tonne of other problems

There are so many much better ideas then this 1950's showerthought.

[Rakaydos]

Wet labs would be an interesting way to supplement spaced based manufacturing.

If every upper stage you launch has a functional airlock on the o2 tank and systems to bleed the excess pressure (once the liquid o2 becomes gas o2), then once in orbit you can 3d print basic habitation equipment inside the tank.

Bonus points if the insulation on the tank is made of salvagable 3d printable materrial.

[magnemoe]

The problem with wet workshops is the same as the problem with inflatable habitats - you have to launch it empty. That means a multitude of launches to get it to useful working order, including at least one piloted labor-intensive mission. It's worse for wet workshops because it can't even be immediately used for just a big empty space (unlike inflatables). The tank interior has to be made sure its completely safe for occupation after launch.

An inflatable habitate who is mostly designed as living space would not be an major issue, put stuff who has to be fixed in the center, then add dividing walls afterwards, this is not an major undertaking, mostly like assemble Ikea furniture

An wet workshop would be far harder, I would not recommend doing it during an interplanetary flight. Might be more practical as part of an spacestation.

[Bill Phil]

A wet workshop in my opinion is a terrible idea. Too complex and delicate to do something like that in space;

Complex plumbing

Fuel contamination

You need to construct the inside in orbit

And a tonne of other problems

There are so many much better ideas then this 1950's showerthought.

You do know the ISS has had interior furnishing after launching, right?

Fuel contamination is only present in the H2 tank, if Lox is used. If you want, you can let it all boil off.

Btw, this is more of a 60s idea...

[fredinno]

Wet labs would be an interesting way to supplement spaced based manufacturing.

If every upper stage you launch has a functional airlock on the o2 tank and systems to bleed the excess pressure (once the liquid o2 becomes gas o2), then once in orbit you can 3d print basic habitation equipment inside the tank.

Bonus points if the insulation on the tank is made of salvagable 3d printable materrial.

Why would you want to remove the insulation on the outside of the tank? It would weaken the internal structure of the wet lab significantly enough to run the risk of depressurisation.

[xenomorph555]

You do know the ISS has had interior furnishing after launching, right?

Fuel contamination is only present in the H2 tank, if Lox is used. If you want, you can let it all boil off.

Btw, this is more of a 60s idea...

1.The scale of this "refurbishment would be much greater and complex then the functional space station.

2.That's if your using hydrogen, not everyone uses hydrogen.

3.Eh 50's/60's, still came from the guy who wanted to build this...

[Ralathon]

This is precisely what I was thinking while reading through this thread.

Though, the biggest issue I think might be getting a (uncertain of the correct term so) "elastic like" substance that can withstand the sub-zero temperatures of the fuel.

Doesn't have to be elastic. The atmosphere inside the station provides pressure to the bladder, compressing it. Depending on your fuel choice it doesn't have to be sub zero either. Hydrogen tanks would obviously give you the most internal space, but a RP-1 tank is still very large.

[fredinno]

1. Not too much more different than inflatables though.

2. Even if you don't use Hydrogen, wouldn't venting off the fuel tank into space simply get rid of all the remaining fuel (via diffusion?) I'm thinking it would be effective, since space is a (near) vacuum.

[Orionkermin]

What about combing concepts from both a wet workshop and inflatable module? would it be feasible to design a stage in which the innards could be jettisoned and then the remaining outer structure could be used as a protective housing for an inflatable module?

You would still have to build out the inside of the habitat, but you wouldn't need to clean up remaining fuel or worry as much about micro debris. Would the advantages be worth the effort?

[Fuzzy Dunlop]

How much of a problem is remaining fuel, don't you just open the throttles and it will all evapourate and vent into space? If you need to you can leave it exposed to vaccum for a week or two, nothing much is going to be left.