Re: DIY space transport

"George William Herbert" <gherbert@xxxxxxxxx> wrote in message
news:11e5nc563vds8b5@xxxxxxxxxxxxxxxxxxxxx
> Pete Lynn <pete@xxxxxxxxxxxxxxxxxx> wrote:
> > Even this seems to assume an inflexible pre-furnished
> > module approach, not a bare shell approach that one
> > then moves furnishings into. Kind of like buying a fully
> > furnished caravan and then trying to attach it as one unit
> > onto the side of a house, instead of buying a shell of a
> > room and then adding light weight furnishings to taste.
>
> The issue here is that the shell, structure, and hatches are
> a small fraction of the total weight. Most of the weight is
> systems and payload.
>
> Even if we do reduce the cost of astronaut-hours in space,
> we need to make their time usage as efficient as possible.
> It is not cost effective, considering nearterm likely
> orbital manpower costs, to fit out modules on orbit. You
> still have to fly the systems to orbit in a pressurized
> container, for many of them, and once you do that you
> might as well make that container the module, and not
> have to spend time moving stuff around and plugging it in
> and debugging the wiring harness and cooling water
> plumbing once you're up in zero-G.

Assuming a space transport able to carry people, pressurised cargo
carrying would hopefully not be a significant issue.

Looking around my house at the few computers, etcetera, I suspect the ad
hock wiring harness within the rooms is significantly greater than that
within the walls. There was not a lot of debugging required. If one
took a similar approach, which is also possible for plumbing and air
conditioning, I would think furnishing need only take a few hours.
Obviously plumbing and air conditioning systems can be designed in a
standardised fashion suitable to such plug and play installation.
Somehow I would expect the extra flexibility gained, (including easier
maintenance access and replacement), would more than cover the perhaps
few extra hours of set-up time.

Furnishing a room on Earth need only take a few hours - I have seen it
on TV. I do not immediately see why with appropriate design, this need
take much longer in space. Without significant gravity, duck tapping
cables to walls and ceilings would be much easier.

> If a magic vehicle appeared tomorrow with $100/lb
> launch costs for payload inside its reusable shell, with a
> payload of 250 kg or 500 kg, that cost tradeoff might be
> different. But that's not nearterm credible.

I am not expecting another space station until after significant inroads
have been made towards CATS, though not to this degree.

I wonder if Henry's orbital assembly argument is applicable. Habitat
modules will grow beyond the payload size of space transports. We will
eventually have to furnish habitat modules in space, so it is perhaps
better to bite the bullet and start developing fast and cheap
sustainable systems for doing so now. Instead of continuing to spend
development money on dead end Apollo style habitat modules. - Is the
Apollo comparison too harsh?

I suppose the interesting thing for me is that even within current
orbital assembly practises, (no EVA), habitat modules could be
constructed in a relatively straight forward fashion from quite small
payloads. Optimal payload size for a space transport does not seem
immediately determined by habitat launch requirements. A space
transport designed to launch people, can with a little effort, probably
also launch most everything else.

Pete.




.

Relevant Pages

  • Re: DIY space transport
    ... Kind of like buying a fully furnished caravan and then trying to attach it as one unit onto the side of a house, instead of buying a shell of a room and then adding light weight furnishings to taste. ... Not shell, structure, hatches, systems, and payload. ... It is not cost effective, considering nearterm likely orbital manpower costs, to fit out modules on orbit. ...
    (sci.space.policy)
  • Re: DIY space transport
    ... >>>not a bare shell approach that one then moves furnishings into. ... >>>one unit onto the side of a house, instead of buying a shell of a room ... >> systems and payload. ...
    (sci.space.policy)
  • Re: DIY space transport
    ... > ago that argued that only large module space stations are ... not a bare shell approach that one then moves furnishings into. ... Why is furnishing a bare habitat shell in space such an onerous task ...
    (sci.space.policy)
  • Re: DIY space transport
    ... >not a bare shell approach that one then moves furnishings into. ... >one unit onto the side of a house, instead of buying a shell of a room ... Even if we do reduce the cost of astronaut-hours in space, ...
    (sci.space.policy)