Saturday, July 23, 2011
Here's a couple shots of the little shuttle ship that I posted last time, docking with the larger craft. Note the funky "bi" shape of its mouth on either end of the shuttle, for docking with the larger ship or with other shuttles, or with other shuttles already docked to the big ship. The large ship is not shown in its fully finished form, because I haven't finished that yet.
If you look carefully you can see black sketch lines where tunnels connecting the core of the big ship to the rim might eventually be. Also the rim of black circles represents locations for rocket engines, which would provide acceleration and also maintain consistent rotation. The large ship is meant to rotate continuously to simulate gravity in the rim section of the larger ship. I worked this out once... the big ship is about 240 feet in diameter, spins at like something around 50 Mph (on the rim) or so to create 1 G on the main level. A funky effect would be that since the radius at the main floor is 100 feet, and each floor is 10 feet above the previous floor, it means that every time you climb a set of stair to the next higher floor your weight would decrease 10%. If I'm 200 lbs on the main floor, I'm only 180 when I go upstairs. 160 or so above that. 10 stories 'up' would put you into the center of the ship where zero gravity lives.
The funky mouth shape is to facilitate docking. Do you remember in Apollo 13 (the movie) when they show the LEM docking with the CM? There's a smooth female funnel shape to the LEM side of the port, to make it hard for the Command Module pilot to miss. The shape I am showing is intended to one up that design. In the Apollo moon missions every move, every docking, etc could be planned out in minute detail on Earth, and the vehicles maximized and specialized for their tasks. Little flexibility was needed because the missions were only a week long or so. Visiting Mars will be about a 2.5-3 YEAR commitment and it makes sense for the vehicles to be much more versatile. That means everything ought to be able to dock with everything. Hence, male/female docking systems are a potential problem.
I show a double set of freely rotating bearings between the main body of each craft and its docking ports. Since the ... sigh... MOTHER SHIPs (what else should I call them?!) are always rotating these bearings are important because they will serve as a sort of rotational shock absorber as two ships rotating at different speeds make contact. The shape of the duck mouth ports, I think, will create a self guidance sort of effect during rendezvous. (big word). I imagine a two step docking process: a physical docking that locks the two ships together with the quadruple (two on each ship) series of bearings allowing a smooth, non ripping each other apart, exchange of rotational inertia, and then a second internal docking- a connecting and sharing of air pressure- after the two ships are stabilized relative to each other.