james_davis_nicoll | Witness the power of this fully armed and operational battle station

I've been playing around with sbcalc again, a orbital calculator available from www.jaqar.com (1). If I have not misused it, it seems to me that even rather modest rockets, on the order of nuclear fission thermal or laser thermal, can put the gas giants closer than one might think, thanks to the fact that we can steal Ek from planets with the Oberth and the fly by methods (2). In fact, I _think_ you could put a payload around Saturn in under 18 months.

Of course, this requires a close pass by Saturn, closer than the rings, much as
Cassini did during Saturn Orbital Insertion (SOI) last year. It seems to me that the ships are most vulnerable during this close enough: material put in the way will do great damage and if the ship is jinking to avoid being targeted by lasers (if the math doesn't work out so that jinking is useless) it may miss its window for SOI. This suggests a ring of defenses -close- to Saturn to defend its moons from invasion (Not from bombardment, because that can be done as the other side's ships zip by)

Since the location of such a battle station (or really, at least three of them) would be known, because stealth is next to impossible in space, either there are lots of disposable stations or a few heavily armoured one or some combination. I point out the moon Prometheus as a possible source of cladding. Prometheus unsurprisingly orbits in the plane of the rings and I am not sure how much of an impediment that would present. Perhaps the defenses could be put into inclined orbits (in which case there will probably be losses as they pass through the plane of the rings twice per orbit) or maybe the best idea is to ignore Prometheus and take material from the innermost rings.

1: I'm always in the market for something better, though.

2: Note how I structured that to avoid having to pluralize "fly by".