Page 1 of 1

#1 "Hard-SF" Ship Design

Posted: Wed Apr 18, 2007 7:47 pm
by Ra
This here's a preliminary design for a "hard sci-fi" spacecraft. It has no FTL, no artificial gravity plates/iniertial compensators/SIF grids, no petaton weaponry (actually, it has no weapons at all :razz:), and no magickal power sources. It's a bit ugly, but it works.

Image

As one can see, the decks run perpendicular to the ship's length, so that as the ship accelerates (her plasma engines constantly accelerate at around 1 g for long-distance jaunts) it produces normal gravity for the crew. The half-sphere on the bow is an armored debris shield. The ship's control room is inside the shield, while the windowed areas serve as crew quarters. IRL, the windows would likely not be that big, it just served for scaling purposes.

Power is supplied by a thorium fission reactor; not quite as far-fetched as hot fusion, but safer than a normal nuke. The panel things are heat radiators for the reactor core, and other heat-producing systems.

Like a traditional spacecraft, this baby is broke down into modules; 1. Habitation, 2. Mission Equipment (surveyors, mining drones, etc.), 3. Support (fuel and life support systems), and 4. power and propulsion.

Thoughts?

#2

Posted: Wed Apr 18, 2007 7:51 pm
by Hotfoot
If you're going to be really hardcore about the numbers here, I'd rethink the need for constant 1g accelleration, as in how much fuel would be needed for such an expenditure. Remember you'll spend half your time burning one way and the other half burning the other, with obvious pauses to switch.

#3

Posted: Wed Apr 18, 2007 8:05 pm
by frigidmagi
How do you turn?

#4

Posted: Wed Apr 18, 2007 9:19 pm
by Destructionator XV
Is most the lower portion of the rocket is for storing propellant?

#5

Posted: Thu Apr 19, 2007 6:33 am
by Ra
Well, it was a worthy attempt; but designing a spacecraft that doesn't rely upon handwavium is extremely difficult. The concept I had in mind was of a ship several centuries from now, designed to go interplanetary distances at extreme speed. Yeah, fuelwise it probably couldn't manage more than an Earth-Mars journey, which would be likely be hideously brief.

Adam: the propellent is stored in the series of gray tanks; the Support Module I indicated. Though even with liquid or supercondensed hydrogen, however, I doubt it fixes the fuel problem...

Frigid: The ship only turns midway, to have the engines facing "forward" to decelerate for the rest of the trip. Though I didn't draw them, it would have RCS or perhaps (if it's technically feasable) thrust vectoring with the main engines.

I had heard the idea floated around that VASIMR-type plasma drives could be vectored, but I have no sources or proof it would actually work.

Anyway, further pondering Hotfoot's point, I suppose the actual thrust could be closer to half a g, producing enough gravity to keep the crew from experiencing low/zero-g related health problems but cutting fuel consumption down by a fair amount.

Thanks for the input, guys, as always.

#6

Posted: Thu Apr 19, 2007 7:38 am
by Hotfoot
Well in furtherance of the point, it doesn't need constant acceleration. The human body can handle micrograv for extended periods with proper amounts of exercise. Burning at 1g for a while and then coasting before burning again close to the destination is perhaps a better way of travel. Keeping the engines going for such a long period of time, even at reduced thrust, is only going to drive up maintenance costs.