Another spinning space station question

[drcathyc]

Hi all,

I'm a science fiction writer working on a scene in which a character in EVA, approaching a cylindrical, spinning space station. He fires a grapple and attaches to the side of the station. What would he experience? Is this so unrealistic that no editor would ever buy the story?

Thanks for the help.

Cathy Chance

 

[LURCH]

Before attempting an answer, let me ask; is the cylinder spinning around its longitudinal axis (like a pencil ruling across a desktop), or is it spinning end-over-end, like a tossed cabre?

Having watched the movie "Mission to Mars" I am convinced that editors will buy anything.

 

[drcathyc]

The station is spinning around it's longitudinal axis. The grapple used does have a line, so could be attached away from the station, the character essentially reeling himself to the station.

Hollywood is less demanding on getting the science right than are good, major publishers!

Cathy

 

[pallidin]

Well, the first thing that would happen is that he would be pushed backwards as the "gun" fires forward.

Depending on the force and it's relationship to his body mass, it could be a simple, stable jolt, or it could result in a spin potential.

Either way, that aspect would, to me, be interesting and entertaining!

 

[drcathyc]

Okay, I'll have to deal with that. Now,what will he experience when the grapple attaches to the side of the spinning space station?

 

[rbj]

why not fire the damn thing at the axis of the cylinder?

 

[Danger]

That depends upon the participant being aligned with either pole. Presumably, that's not part of the set-up.

 

[drcathyc]

Okay, I understand about having him go for the poles, but that isn't how I've set this up. I would assume that it would be better for him to attach to the station close in. Would that be the best idea given an approach from the side? How would he experience the centrifugal force?

I'm assuming the station has a diameter of at least 200 meters and thus would revolve at a rate of about 20-30 seconds per revolution (to get about 1 g). He's about 6', massing 190 lbs.

 

[LURCH]

If I were in your character's situation, I imagine it would fire the graple at the edge of the station, the "horizon," so to speak. I would not fire at the edge that is moving toward me, but the opposite edge. That way, as my grapple made contact with the surface, it would start out in a motion almost directly away from me, with very little sideways motion. As the grapple disappears over the horizon, all of the "pulling" force that I experience would come from that horizon; the exact point where the cable makes contact with the side of the station.

Now, if I had any choice, I would latch on to the side of the station the instant I came within reach of it. Then, I would experience the same 1g as someone standing against the hull on the inside of the station. However, I would experience it in the opposite direction, as though I were hanging from a ceiling with the "bottomless drop" of outerspace beneath me. This would be a terribly uncomfortable situation, and I would want some sort of hook or clamping mechanism so that I could attach myself to the hull (rather than trying to hang on with my own strength).

To add to the drama, if your character misses his opportunity to attach to the bulkhead on the first Pass, he will overshoot and be flung back out into space. Once he passes the edge of the station which once represented its horizon to him, his cable will begin to pull with an angular motion. He would be flung out to the full length of the cable (much like a tetherball with its rope unwinding). Once at the end of the cable, he would "hang" from it while experiencing a centrifugal force of significantly more than 1 g. The amount of this force would depend on the length of the cable; as your hero gets further from the center of rotation, but the period of rotation remains constant, the centrifugal force increases.

 

[drcathyc]

Thanks, Lurch. I think this will give me what I need to make sense and give the reader a sense of being there.

I do like your idea for increasing the drama, but probably won't use it here. Perhaps another story.

 

[Danger]

If you get this published, or even just put it on-line, let us know. I'd love to read it.

 

[LURCH]

I'm with Danger; I'm dying to know why the peson is on the outside of the station and trying to attach to it along the rotating surface.

 

[drcathyc]

Okay, it's a space opera with a team of Special Forces guys. They're investigating this space station and are sneaking aboard. They're going to use a maintenance hatch. The working title is "Orders".

When (notice the confidence!) it get's published, I'll be sure to post a message to this board. This isn't the first time you guys have helped me with a technical problem in the story.

Thanks again.

Cathy Chance