Talk-Polywell.org

just thought i'd pop a thread up, since i didnt see one.

http://www.spacedaily.com/dragonspace.html

all a hive of most industrious and ernest activity as usual...

how about a spray-on concrete space station, made out of moon-cement.

chine number 1 space agency

rcain wrote:just thought i'd pop a thread up, since i didnt see one.

http://www.spacedaily.com/dragonspace.html

all a hive of most industrious and ernest activity as usual...

how about a spray-on concrete space station, made out of moon-cement.

chine number 1 space agency

How about making a rocket body out of sprayed cement?

djolds1 wrote:

rcain wrote:just thought i'd pop a thread up, since i didnt see one.

http://www.spacedaily.com/dragonspace.html

all a hive of most industrious and ernest activity as usual...

how about a spray-on concrete space station, made out of moon-cement.

chine number 1 space agency

How about making a rocket body out of sprayed cement?

i thought about that, but it would be quite heavy - lousy acceleration and difficult to stop/steer.

also i fear it would get heavily graffitti'd by space-vandals.

but for sitting at a lagrange point somewhere and spinning round, why not?

rcain wrote:

djolds1 wrote:How about making a rocket body out of sprayed cement?

i thought about that, but it would be quite heavy - lousy acceleration and difficult to stop/steer.

also i fear it would get heavily graffitti'd by space-vandals.

For a BDB? WGAS? Get to LEO and you're halfway to anywhere.

Space exploration can be divided into three areas:

Surface to orbit, and orbital activities

Outer orbits, and interplanetary work

extrasolar exploration, and things of that sort

Only surface-to-orbit is really sensitive to mass. The rest can deal with it much easier, since they're not fighting their way out of a gravity well. Surface-to-orbit would also be the only one to have to worry about being manufactured on a planet's surface. If you're building a ship that will be loaded by shuttles in Earth orbit, then drop cargo in shuttles from Mars orbit, you don't need to worry about 90% of the stuff you need for that last step, you're really only worried about thrust ratios.

Using cement of some sort made from non-metal asteroids would make sense in this case. You'd need a lot less metal, and I think the less dense material might work better for the cosmic ray shielding that stuff like lead doesn't work well for. You'd also be saving the metal for things it'd be nice to use it for, like selling things planetside.

kunkmiester wrote:Space exploration can be divided into three areas:

Surface to orbit, and orbital activities

Outer orbits, and interplanetary work

extrasolar exploration, and things of that sort

Only surface-to-orbit is really sensitive to mass. The rest can deal with it much easier, since they're not fighting their way out of a gravity well. Surface-to-orbit would also be the only one to have to worry about being manufactured on a planet's surface. If you're building a ship that will be loaded by shuttles in Earth orbit, then drop cargo in shuttles from Mars orbit, you don't need to worry about 90% of the stuff you need for that last step, you're really only worried about thrust ratios.

Using cement of some sort made from non-metal asteroids would make sense in this case. You'd need a lot less metal, and I think the less dense material might work better for the cosmic ray shielding that stuff like lead doesn't work well for. You'd also be saving the metal for things it'd be nice to use it for, like selling things planetside.

Cement requires water for curing. That means if you are building the stone rocket on the moon it will need to be done in a hangar.

Or plastic wrap. I'm sure there's a number of epoxies or other such materials that could be concocted from materials found in space.

kunkmiester wrote:Space exploration can be divided into three areas:

Surface to orbit, and orbital activities

Outer orbits, and interplanetary work

extrasolar exploration, and things of that sort

Absent a GUT breakthrough, extrasolar won't matter much for the next 1-3 centuries.

kunkmiester wrote:Only surface-to-orbit is really sensitive to mass. The rest can deal with it much easier, since they're not fighting their way out of a gravity well. Surface-to-orbit would also be the only one to have to worry about being manufactured on a planet's surface.

This was studied back in the '60s under the "Sea Dragon" design study. Actually, mass isn't important, tho NASA would like you to think it is. Its cost per kilo to LEO that is important. If you're willing to build big and crude, costs can be very, very LOW. The philosophy is called alternatively LCLV (Low Cost Launch Vehicle), and BDB (Big Dumb Booster).

THe other missions are less sensitive to scaling laws. Saturn V was cheaper per mass than the shuttle. Actually cheaper than most lifters, IIRC. But with small, low power thrusters, it's easier to get a good cost ratio to transfer to Mars orbit than to get up to orbit. Even better if you can put your time frame in years.

kunkmiester wrote:THe other missions are less sensitive to scaling laws. Saturn V was cheaper per mass than the shuttle. Actually cheaper than most lifters, IIRC. But with small, low power thrusters, it's easier to get a good cost ratio to transfer to Mars orbit than to get up to orbit. Even better if you can put your time frame in years.

And if you don't get to LEO, everything else is vaporware. Bussard QED/ARCs would be very sweet, but we shouldn't bet the farm on them.

djolds1 wrote:

kunkmiester wrote:THe other missions are less sensitive to scaling laws. Saturn V was cheaper per mass than the shuttle. Actually cheaper than most lifters, IIRC. But with small, low power thrusters, it's easier to get a good cost ratio to transfer to Mars orbit than to get up to orbit. Even better if you can put your time frame in years.

And if you don't get to LEO, everything else is vaporware. Bussard QED/ARCs would be very sweet, but we shouldn't bet the farm on them.

How about a garden plot?

MSimon wrote:

djolds1 wrote:Bussard QED/ARCs would be very sweet, but we shouldn't bet the farm on them.

How about a garden plot?

I was thinking at least one full field. But other options are worth considering, and I seriously like the "cheap, crude & effective" philosophy over and above the "uber efficient gold plated one off gigadollar toy" philosophy.

Just spraying shotcrete onto an airfoam core to create 90%+ of a rocket's structure seems... sweet. Very Russian, yes, but the Russians have created the most effective booster in human history (R-7 family).