Good writing weekend!

[seawasp]

This weekend was a good one for writing; Kathleen and company were able to avoid major kid disasters or blowups, so I ended up with both Saturday and Sunday clear. I was in a Jason Wood mood on Saturday and wrote nearly 5,000 words in the first new Morgantown story since I finished Digital Knight back in early 2003; title is "Shadow of Fear". On Sunday, I went over 15,000 words on Threshold, the sequel to Boundary. Effectively I think this is over 20,000, as there's quite a few additions I expect from Eric.

Threshold is probably going to be the hardest of the three Boundary-universe books to write; we're developing the political, social, and personal universe equally in Threshold, and it's COMPLICATED. I was able to sort of fake out all of the stuff in Boundary, even though Eric seriously modified things; I can't pull that off on some of these, though. Eric will have to write those sections and, for once, I'll have to edit/smooth out his stuff to make it fit with mine. There's also a LOT of new science-related stuff I'm having to do -- people on Baen's Bar are seeing some of that, with me asking questions about nuclear reactors and superconductors and orbital calculations -- which isn't easy, even though I can (as an SF writer) decide to occasionally handwave away practical difficulties. Once Threshold is done, I'll have a good enough grasp of the entire universe to just write the next one, at least as a rough first draft. But Threshold itself is going to "be a pure bitch", as Maddie would say.

Comments

Re: Yeah...

[kengr]

Both the slow down and speed up gravity assists tend to involve craft that are *not* yet in orbit around the body, but in a solar orbit.

The difference is whether you pass "ahead" or "behind" the planet as it orbits. It basically tries to "pull you along". Which produces a velocity change on the order of the differencer in velocities.

The *details* are the killer.

And it's not good for a *quick* velocity change.

But here's a thought. Given Jupiter's magnetic field, you might be able to deploy a mag-sail and use *that* for braking. That would avoid the problems with aerobraking, and help with radiation shielding.

Re: Yeah...

[seawasp]

The magbraking I thought of, and would be very interesting, but I can't find anything like sufficient detail on the magnetic field of the planets to determine whether it's actually practical to do, or whether you'll get no noticeable slowdown from the magnetic field until you're already IN the planet's atmosphere.

Re: Yeah...

[kengr]

Given that magsails are normally proposed to use the trapped filed in the solar wind, I think Jupiter's field is strong enough. :-)

Besides, you aim for a close pass, not straight at the planet!

Re: Yeah...

[james-nicoll.livejournal.com]

The forces that apply to magsails are minute, though. This means lots of time and space. I don't think you can halt a space ship at Jupiter this way (Annoying, I know I was in a thread about this but I cannot find it).

Re: Yeah...

[james-nicoll.livejournal.com]

Of course, you could exploit Jupiter's field in a different way: hang a conductive cable off Metis, then trade Metis' potential energy for power. You should be able to get 100,000+ terrawatt-years out of Metis before it deorbits and you could then apply the power to incoming space vessels, directly or otherwise.

Re: Yeah...

[seawasp]

Now that's fun. But it would seem perhaps somewhat difficult to pull off as a sort of improvised method unless one had thousands of miles of conductive cable just hanging around in the closet.

Re: Yeah...

[seawasp]

I rather thought not. Deploying a large magsail or equivalent while cutting through Jupiter's field would have SOME effect, but unless I can find a way to calculate it accurately I'm going to have to assume "not really very much".