Redesign Star Wars

[kitnut617]

Can you imagine if Elon Musk got really ambitious, build a really super size tank big enough to group nine (or more) Falcon Heavies around it ---- you could have a decent size spin habitat that way fairly quickly  -----

Have you seen his BFR? https://en.wikipedia.org/wiki/BFR_%28rocket%29#Starship_prototypes

One thing you can't criticise him for is lack of ambition... 

Yep, seen and read about that, but it's still too small for long term living in. You need something really big for that ---
Reminds me of a holiday in Kauai I had, we were there just over a week, we'd seen everything in that time, I can't imagine living there full time ---

[Weaver]

Can you imagine if Elon Musk got really ambitious, build a really super size tank big enough to group nine (or more) Falcon Heavies around it ---- you could have a decent size spin habitat that way fairly quickly  -----

Have you seen his BFR? https://en.wikipedia.org/wiki/BFR_%28rocket%29#Starship_prototypes

One thing you can't criticise him for is lack of ambition... 

Yep, seen and read about that, but it's still too small for long term living in. You need something really big for that ---
Reminds me of a holiday in Kauai I had, we were there just over a week, we'd seen everything in that time, I can't imagine living there full time ---

Yes, but how many launches would it take to put a really BIG station into Earth orbit using that thing, and how much time could you save by exploiting the large payload diameter to make sections self-deploying instead of needing endless spacewalks to put them together?

Imagine combining that launch capability with Bigelow Aerospace's inflatable habitat technology: https://en.wikipedia.org/wiki/Bigelow_Aerospace 

[kitnut617]

Never heard of that project Harold, mind you, one of the reasons Musk switched to stainless steel on his Starhopper was his concern of foreign objects penetrating the carbon fiber design when in space.  I wonder if that is why that Bigelow project hasn't gone anywhere.

[kitnut617]

Yes, but how many launches would it take to put a really BIG station into Earth orbit using that thing, and how much time could you save by exploiting the large payload diameter to make sections self-deploying instead of needing endless spacewalks to put them together?

say 20 launches 

Can you imagine 27 first stages all returning at the same time  ------

[Mossie]

Here's a difference in character between the inside of something like the ISS and a spin-habitat ship/station though:

On the ISS they have zero-G everywhere, so they can, very efficiently, pack stuff on the 'floor', 'walls' and 'ceiling' because you move around the station by floating in the middle of those surfaces. However on a spin habitat, the whole point is that you have a more or less conventional floor, that you have to walk on, and on which you can't put things that you don't want to tread on, and an equally conventional ceiling, where you can't put things that you don't want to fall on you. Also, the entire point of a spin hab is to provide space for conventional living, which includes walking around and exercising, so cluttering it with storage kinda defeats the object.

IIRC, Hermes' supplies arrive in resupply modules which dock to the spine of the ship, so moving bulk cargo 'downwards' from there into the spin hab is going to be a pointless PITA. Better to stow it in the zero-G spine and only take it to the spin-hab if and when you need it to be there.

The shuttle is pretty cluttered too.  That still needs a roof and floor, if only for part of it's mission.  But the main point is it's interior is enormous!

[scooter]

Never heard of that project Harold, mind you, one of the reasons Musk switched to stainless steel on his Starhopper was his concern of foreign objects penetrating the carbon fiber design when in space.  I wonder if that is why that Bigelow project hasn't gone anywhere.

As far as I can tell, the BEAM is still attached to the ISS.  Granted, the last bit of news is from 2 years ago: https://www.nasa.gov/feature/nasa-may-extend-beam-s-time-on-the-international-space-station

[Weaver]

Never heard of that project Harold, mind you, one of the reasons Musk switched to stainless steel on his Starhopper was his concern of foreign objects penetrating the carbon fiber design when in space.  I wonder if that is why that Bigelow project hasn't gone anywhere.

The reason for the switch is that stainless steel is lighter than carbon fibre for the range of temperatures required, i.e. from the intense cold of cryogenic propellants to the heat of re-entry. Stainless steel can be thinner than carbon-fibre and doesn't need any insulation on the leeward side of the craft during re-entry, and it can deal with the heat on the underside by being double-skinned with active cooling by fuel and evaporative cooling by water, which works out lighter than carbon-fiblre plus ceramic heat tiles.

The Bigelow project has achieved quite a lot: they've launched two unmanned habs to test the long-term durability (both still in orbit) and they've had their BEAM module attached to the ISS since mid-2016. BEAM was originally supposed to be a 2-year programme with year-by-year extensions: NASA has granted one so far and looks likely to grant more. The ISS crew use it for storing empty containers awaiting the arrival of a cargo vessel to take them back.

The main reason why Bigelow haven't launched a private space station yet is that development of commercial crew launchers has been slower than anticipated. Basically, as soon as SpaceX, ULA or Blue Origin start selling seats to low-Earth orbit, Bigelow will start trying to give them somewhere to go.

Bigelow's modules have actually demonstrated better micro-meteroid resistance than simulated ISS ones. The flexibility takes considerable force out of the impact: projectiles that penetrated the rigid ISS mockup hull only got halfway through the Bigelow hull.

[Weaver]

One thing that's occured to me is that, if you wanted a really durable space station, you could send up a Bigelow module with a big 'cargo' docking hatch on one end, then send up a 'tin can' cargo module containing rigid panels. You dock the cargo module to the inflatable one, then, in a pressurised, shirt-sleeve environment (i.e. MUCH safer than a spacewalk), you use the panels to build a rigid, pressure-tight hull inside the inflatable one. Cover those panels with built-in attachement points and you're free to use the space any way you want to, instead of only having rigid stuff attached to the core. Also, you've now got the cargo module, which can have things like solar panels and experiments attached to the outside of it.

[zenrat]

Or, you could find a suitable rock out there between Mars and Jupiter, move it into Earth orbit, hollow it out, spin it up and then move in.

[Weaver]

Or, you could find a suitable rock out there between Mars and Jupiter, move it into Earth orbit, hollow it out, spin it up and then move in.

Here's a Scotsman to tell you that "ye cannae change tha laws o'physics!" : https://www.youtube.com/watch?v=gU9dCWY7G2M

Hmm, now where have I heard that before.....

[Steel Penguin]

traveller asteroid hull 
ive mentioned it in the past, also used as a hull form in the starstormers novels for kids by ( I think) Nicholas Fisk  ( after a quick visit to wiki, yes I am correct)

[Weaver]

traveller asteroid hull 
ive mentioned it in the past, also used as a hull form in the starstormers novels for kids by ( I think) Nicholas Fisk  ( after a quick visit to wiki, yes I am correct)

Going back to the original point of this thread, that would have been another way to do the Death Star wouldn't it?

[zenrat]

If you found a rock with the required mix of metals you could mine it, refine it and build your "death star" around the dwindling central remains.  Harvest any missing minerals from the surrounding asteroids.
If the first things you built were engines and weapons you could even be in action while still building it (might have a few issues with the Construction unions though).

[Weaver]

Another approach to the Planet Killer (probably wouldn't call it the 'Death Star' in this case) would be to make it a really, REALLY big 'gun', so big that the spaceship bits around it don't cover it, but are built onto it, a bit like engine pods and gondolas on an airship. It might look a little like the Cygnus from The Black Hole.

[Mossie]

(might have a few issues with the Construction unions though).

Vader can find new ways to motivate them....