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

[Wesreidau]

1. The scale is greater, sure. But that doesn't mean the cost is greater. Astronauts can bolt, brace or glue all the guts into the tank they need without the enormous launch cost of sending the thing pre-built. Not to mention you can get a much larger station this way.

2. Okay, worst case scenario. Your fuel is hypergolic K-stoff and C-stoff. Open the airlocks and wait a month.

3. Pff, those silly 50's / 60's people, trying to land on the moon.

[xenomorph555]

1. The scale is greater, sure. But that doesn't mean the cost is greater. Astronauts can bolt, brace or glue all the guts into the tank they need without the enormous launch cost of sending the thing pre-built. Not to mention you can get a much larger station this way.

2. Okay, worst case scenario. Your fuel is hypergolic K-stoff and C-stoff. Open the airlocks and wait a month.

3. Pff, those silly 50's / 60's people, trying to land on the moon.

1. Gotta carry all that stuff with you, if your on a Mars trip then it ain't ideal.

2.If your on a Mars trip you might not have a month, you might need that tank-hab in a week max.

[sojourner]

2.If your on a Mars trip you might not have a month, you might need that tank-hab in a week max.

Not that I am a fan of wet workshops, but this is a silly point. That's a planning issue, not an issue with the concept.

[Rakaydos]

1. Gotta carry all that stuff with you, if your on a Mars trip then it ain't ideal.

2.If your on a Mars trip you might not have a month, you might need that tank-hab in a week max.

I dont see a mars trip being launched straint into MTO, without a lengthy assembly period on earth orbit. We arnt taking about living in the transfer engine's fuel tank, just in the equivilant to the Shuttle's External tank boosted into orbit and modified into a livable pressre vessel.

[Kibble]

I dont see a mars trip being launched straint into MTO

Well there's your problem! Since a piloted Mars expedition means a huge IMLEO, you pretty much have to use high-energy fuel to get it to TMI. And high-energy fuel hates rendezvous and docking events. If the rendezvous doesn't go completely smoothly, there's a week of orbiting to sap all the hydrogen from your tank, and BOOM you got a whole extra super-heavy-lift launch, and the mission is delayed a few more months, while the astronauts twiddle their thumbs in the transfer habitat. If you use storable fuels you get the new problem of having to design a huge hypergolic rocket stage, and a ridiculously massive rocket to launch it.

[Wesreidau]

Ammonia, NTR, 600 seconds ISP. Next question.

[Kibble]

Ammonia, NTR, 600 seconds ISP. Next question.

This makes the assumption that we will fly nuclear-thermal rocket engines, and the further assumption that we will fly nuclear thermal rocket engines as the primary propulsion on a piloted spacecraft.

EDIT: Explanation

It would be a long time of a nightmare of political negotiations trying to get it to happen, decades most likely. Meanwhile solar-electric propulsion is matured and developed, as nuclear-thermal technology falls further and further behind. By the time you might have flown the first test nuclear-thermal rocket engine, a solar-electric rocket engine will be superior in all ways, especially cost.

Edited May 20, 2015 by Kibble

[sojourner]

And yet, solar power is only efficient up to a certain point. Go out further than mars and you really need something more.

[Wesreidau]

People are making a lot of assumptions, but I'm not predicting the future of technological development. Why should nuclear rocketry 'lag behind' solar-electric? Any improvement solar-electric sees, nuclear-electric can mimic with far more wattage while nuclear-thermal continues to out-thrust. What is so dangerous politically? A test ban treaty merely interpreted to include non-radioactive reactor exhaust? Throw a Russian into the crew or otherwise renegotiate it, if its even a relevant document. Just call it an open-cycle cooled reactor and fire it in a high orbit while wagging this at the press http://fas.org/nuke/space/consensus.pdf . What is so dangerous for manned flight? Radiation from the reactor? Reduced mission times equal reduced radiation exposure.

But all that isn't related to wet workshop re-configuring. I'll say this; learning how to fabricate, assemble and modify structures in space is a lesson which must be learned. Everything can't be inflated or pre-fab for the rest of time.

[Kibble]

Everything can't be inflated or pre-fab for the rest of time.

There is no reason to force ourselves to learn complicated procedures that we don't need yet, when there is a simpler solution that works. When we first invented boats, they were simple canoes. We used canoes for a long time, even though canoes can't travel across oceans, and we would eventually have to cross oceans.

[sojourner]

I'll say this; learning how to fabricate, assemble and modify structures in space is a lesson which must be learned. Everything can't be inflated or pre-fab for the rest of time.

Nope, inflatables and wet workshops are merely the answer to two current issues: lifting capacity and full on construction in space. Remove one or both of those current technological hurdles and neither inflatables nor wet workshops will be needed.

[Wesreidau]

There was no reason to force ourselves to learn how to go to the moon, and we did it in a tin foil Jiffy-Pop bag because we couldn't wave our hands at the engineering problems.

"Moar Boosters" is something of a cop-out. And how are we going to learn to conduct 'full on construction in space' if we do not learn how to 'fabricate, assemble and modify structures in space'? Fast forward a thousand years. Will the Ceres Propellant Company have to open up a Sears-Roebuck catalog to get a new pre-fab office rocketed up because they can't imagine re-purposing an old hydrogen tank? Will the ability to launch a thousand tons to the Moon for a dollar a kilogram change that you can get more square footage a kilogram with inflatables than with pre-fab, hollow steel cans? Or for that matter, convert your hollow steel cans from some super-lifter into

I don't see this argument going anywhere. "Remove a technological hurdle" begs a big question. People need to stop waving their hands at the very real problems that are the reason for the proposal in the first place, otherwise we can't have a productive discussion on a common frame of reference.

[hugix]

Wet workshops are quite the engineering challenge, and I dont know if the pro's outweigh the cons. But I do know that it would be a perfect idea for new KSP parts.

[sojourner]

I don't see this argument going anywhere. "Remove a technological hurdle" begs a big question. People need to stop waving their hands at the very real problems that are the reason for the proposal in the first place, otherwise we can't have a productive discussion on a common frame of reference.

Re-read my post. We're both saying that inflatables and wet workshops are not required technology.