Partial G Space Station

Radial rotation

One initial idea is to use Bigelow Aerospace inflatable space stations for partial gravity research, because these stations have a much larger diameter than anything that fits in a payload fairing. A large diameter station can simulate artificial gravity by rotating along its axis.

I have not been able to find the dimensions of the largest Bigelow module, but judging from [1] the BA 330 appears to have around twice the diameter of the Galaxy, so 8 meters across. TODO: calculate how fast it needs to spin for various G levels.

The basic idea is to assemble a rigid "Ikea style" floor inside the inflatable walls, so the force of supporting equipment and astronauts does not hit the inflatable walls. There can be a ramp and/or ladder up to the airlock, which is on the rotational axis.

Pros:

• Uses an off the shelf space station component.
• The air lock is on the rotational axis, so craft can be docked without spinning down the station.
• Can probably be launched in one go. The only on-orbit assembly will happen inside the already pressurized station.
• There is a lot of living space inside a BA 330, possibly as much as 100 square meters of partial gravity floor.

Cons:

• An "ikea style" floor would need to be installed inside the walls.
• The gravity level at the floor would be higher than at head height, by about 40% for a 1.70 meter astronaut.
• Matching the rotation of crew capsules to that of the station will complicate docking and supply stowage.

Tethered/dumbell configuration

Another proposal is to attach two components to each other with a tether or truss and rotate them around each other. This has the advantage that it can be done entirely using solid space station components.

Pros:

• Uses off the shelf space station components, except for the tether or truss.
• Uses all solid compartments.
• Has been done before briefly, on a Gemini mission.

Cons:

• Less living and laboratory space.
• The station needs to be "spun down" before crew capsules can dock and undock. Does this have "life boat" safety implications?