Complex Space

This is not so much a blog article as a cry for help. I'm hopeful that at some point, somebody will read this who knows a lot more about large bodies in our solar system than I do.

I have an idea in mind for my second novel (to be begun some months from now when the first one is finished), but one aspect of it has me concerned. I neither have the innate knowledge to handle it myself, nor have I had any luck finding the information online (though I hope it's there and I'm just failing to use the right search terms). My wife tells me I should just use creative license to make it all up, and I may end up doing that, but I'd like to at least attempt to get it correct (or nearly so) first.

Here's the problem - in the novel, there is a small object (about one or two city blocks cubed) moving at a more-or-less constant speed (no propulsion) through our solar system some time in the relatively near future (as early as 2015, probably more like 2020). People (ie. governments) on Earth are highly motivated to send manned crews to rendezvous with the object, and will find themselves competing to do so. Yes, I realize that it's implausible, given current or projected technologies, for Earth vessels to reach something like that unless it comes very close, or at tremendous expense, or both. I'll deal with that issue.

Anyway, my problem is one of astrophysics (at least, I think it is. This is far enough outside my experience that I'm not even positive I understand the terminology). I've got various heavenly bodies (planets, moons, etc.) that are all whizzing around the sun at various speeds and, at any given point in time, will be at very different places relative to other objects - most notably the Sun, the Earth, each other, and the "object." This is important for several reasons:

1. If the Sun is between the Earth and the object, it's probably not practical to launch a spacecraft to try to rendezvous with it at that time. Or, more precisely, if the Sun is between the Earth and where the object WILL BE at the point in time when a rendezvous would be attempted (since there's a very lengthy travel time from Earth to the object even at their nearest point).

2. One method of achieving the rendezvous (I'm postulating) would be to slingshot around another body and come up on the object from behind. To do so, I'd need to know where those suitable bodies would be at particular points in time.

3. As the object travels through our solar system, travel times would change dramatically. In fact, depending on the applicable calculations (which I'm unqualified to do without some sort of template), some governments might delay their launch and just let the Earth and the object travel a bit closer on their own.

I suspect I can probably figure out how fast the Earth moves through space and decide on a suitable speed for the Object on my own (assuming I can find figures for how fast comets and such move). I think I probably can also make up suitable speed numbers for the earth spacecraft (though I'm less sure of that). What I'm mostly concerned about, though, is being able to chart the position of the Earth and other major bodies in our solar system at various points in the novel. Where's Titan in December of 2017 relative to Earth and the Sun? As the author, I can just say "Sure it is, if I want it to be!" knowing that 98% of my prospective readers probably wouldn't know the difference. But if there's some guy at NASA who decides my book looks appealing, I don't want him throwing it away in disgust because I screwed up all the planets' orbits.

So with that long-winded explanation, can anybody point me to some layman's tools suitable for figuring this stuff out? One of my main goals is to avoid having to teach myself astrophysics in order to write this book. It's something I'd like to get correct if possible, but the storyline would survive if I had to fudge these numbers, so there's a point of diminishing returns on effort invested in this level of accuracy. Alternately, if anybody knows of an engineer or professor who's well-versed in this subject and might be interested in babbling on endlessly about this stuff to a very attentive audience (me!), I'd be interested in that, too.

So this is it - the dark underbelly of the writer's life, desperately clawing at forbidden knowledge in a vain attempt to understand foreign concepts well enough to use them intelligently. On the plus side, my vision for this new novel totally kicks ass and I'm looking forward to writing it.