Simple Space

As promised, this is a follow-up to last week's article titled Complex Space. To briefly recap, I'm planning to write a novel (once my current one is sufficiently done that I'm calling it "finished" and circulating it for publication) that involves an object passing through our solar system and the desire of certain humans to send manned spacecraft out to it.

Writing this novel will pose a multitude of challenges for me in terms of stuff I don't know - I'll need to brush up on (or simply invent) information about international politics, aerospace engineering, rocketry, extra-planar propulsion and navigation, astrophysics, ephemerides, astronomy and a host of other topics.

One subject that was really bothering me had to do with planetary movement within our solar system. As the object moved through one "side" of our celestial neighborhood, its passage would bring it nearer to or further from different planets at certain points in time. This would affect everything from its course (as different gravity wells applied force against the object to speed it up, slow it down, or pull it from side to side) to the launch windows for Earth-based spacecraft. It was something I could have just invented, but I felt compelled (for some reason I can't really explain) to make at least a cursory attempt to get it right. It's been bugging me for a good two months or more, and I finally couldn't stand it any more. I posted an article about it here on Virtual Vellum, and simultaneously posted the same plea for info on a message board that I've been a member of for over five years. Naturally, since the message board gets more traffic from a wide array of knowledgeable folks (some of whom work at NASA and others who simply have an interest in this subject), it got somewhat more attention there, including some very worthwhile information. I thought I would share it here for folks who may regularly read or just happen upon this blog and find this information of value.

First off, one site that I found all by myself (well, surely someone pointed me to it from somewhere at some point in the past, but I have no idea whom or when), is Atomic Rocket. It's a site dedicated to the mathematics of sci-fi rocket ships of the sort written by Robert Heinlein and Arthur C. Clarke. It's more related to the other topics I'll need to handle for the novel, but it's in the ballpark of useful and relevant sites, so I include it here.

Next, one fellow suggested that I look up the topics of Orbital Mechanics and Legrangian Points on Wikipedia, which rather goes without saying (as a writer I practically live on Wikipedia and am very unclear as to how anyone got meaningfully accurate - or even vaguely accurate - writing done without it. I sure wouldn't want to have to run down to the library and flip through the card catalog every time I had some niggling little point in my book that needed a little info to properly do its job.) but it's still good advice so I include it here.

That same fine fellow suggested a comic at the often-brilliant (and all-too-often over my head) XKCD webcomic, where the cartoonist compares the gravity wells of different planets and moons in the solar system. I'm not sure I need to know this info (it would only be relevant if the object were to come within a certain distance of these bodies, which I hadn't planned to have happen in the story), but I can see where it might well be helpful depending on what decisions I make regarding the story.


In addition, he recommended two articles at discovery magazine, here and here. They're good reads and, combined with the wiki articles probably contain more than I ever really wanted to know on the subject. It's not a passion of mine, just some raw info that I need to write my book. I'm trying to avoid doing graduate-level work in celestial movement in order to tell a story.

His final recommendation seemed to hold a lot of promise. The Geometry in Space Project: Orbital Mechanics: From Earth to Mars appeared at first to have some calculators and simulators on it (or linked from it) that might do what I needed. Sadly, none of them quite did - the closest, a java app showing the planetary positions - only worked to provide info for yesterday, today or tomorrow. I need one that will show the planets 5-10 years from now.

Another helpful chap recommended a piece of free software called Celestia. It's a tool that allows you to simulate the solar system (lots of solar systems, actually) and take a tour through it. It's definitely in line with what I'm looking for, though it has a rather steep learning curve and in an hour of fiddling with it I was unable to make it obey me. Definitely a step in the right direction, however.

Sort of like a spacecraft on final approach to an extra-planetary body, the mission kept spiraling closer and closer to success. Then a dude who I think works for NASA or the JPL posted a link to the NASA Solar System Simulator. Woo hoo! as Homer would say. The resulting graphics it generates are kind of hard to read, particularly the inner planets (which tend to get all smushed together in the middle), but it's totally adequate for my needs.

So, yeah - jackpot! There were some other helpful links to info on near-Earth asteroids and the recently-completed Hayabusa mission from Japan, too, but that solar system simulator is just the thing I needed.

Mission accomplished - thanks to the power of the Internet to bring people together. It'll be quite some time before I actually need any of this information, but just knowing I've got it has really removed some anxiety that I had for that novel. Thanks, everybody, for the enthusiastic support!