LaCroix wrote:Nitpick: It's only 16.1 years for the chemical drive, you added a 0.
That's a VASIMR-like plasma drive, not a chemical rocket.
Good catch though. Thankfully it is a minor mistake.
It'd easily be able to stop if it was orbit to orbit, so it didn't have to pay the Earth launch penalty.
I linked other probes whose course was designed to do just that without requiring engines but just aerobrakings. Voyager's course was designed to launch it in deep space. Period.
If it wanted to brake once at Neptune, it had to be carrying a decent engine and 17 km/s of delta-v (more or less a Saturn V worth of fuel). It's already a few billion dollars wasted just to make the braking stage.
Earth departure Delta-v is 3.22 km/s, so that would have needed a orbit departure stage massing... ummmm that's a 3000 ton payload.... let's assume 3 SSME engines... say
4000 tons?
It's going to be easy with chemical rockets. Sure.
Assuming the ship itself is a sunk cost, if rocket fuel is cheaper than $5 / pound, there's profit to be made shipping it.
Yeah, let's also assume also that Santa Claus payed the development cost for all your equipment, that you found the money to invest in your enterprise under a tree, that there are no insurances for anything, no payer wages for the people checking your craft between each voyage (critical for reliability), no cost overruns due to random problems, and that your spacecraft isn't a chemical rocket that must discard stages to go anywhere (forcing you to pay again for a new vehicle for each new voyage).
I think you're handwaving a little too much.
Chemical rocket fuel is less than $1 / pound.
On Earth. In orbit, without any other fuel supply, it is worth a few millions per ton. (proton rocket, cost 85 millions, payload 22 tons to LEO --> 85/22 = 3.8 million dollars per ton). It is a payload just like any other.
And frankly, assuming fuel coming from the moon will be as cheap as the one produced on Earth is... very optimistic. (although it's likely to be still cheaper than lifted fuel from Earth)
Seriously, what's your point?
You said that thrust is irrelevant, then pulled out of your ass some numbers to demonstrate it.
I showed that what you say is true, but only for
engines that are already torches, like the ones with acceleration and fuel endurance in your example.
While for realistic engines with manageable power levels, thrust is an important factor in overall performance. Like I said.
Formless wrote:And for the same reason that defensive maneuver is going to cost you time and fuel because it will mean diverting from your planned flight path.
Nah, that's a tiny difference, barely noticeable, and the fuel needed is tiny, since you just have to give a tiny kick when you spot the guy homing on you. When you spot him it's going to be days before it actually reaches point-blank. In a day you're making a lot of space with inertia alone.
Even if you expend a puny 10 m/s of delta-v, after a day you made 864'000 meters.
Also you are still assuming civilians are going to be allowed to arm their spacecraft, which is not a given.
It may not be a given, but I don't see why a "Space Safety Solutions" section of Blackwater cannot be hired to provide protection with its space escorts (that are basically cargo ships loaded with KKVs), if pirates become a problem.
Lasers (being lightspeed weapons) cannot be dodged
Lasers have a limited penetration, since they are cones of (phased) light focused on a spot to vaporize material, not flashy beams doing BZZZZ in a vacuum.
For modern laser cutters that's 50:1, hole_depth:spot_size. For weapon-grade lasers, that don't cut stuff so close to their focusing array that ratio becomes around 20:1. Any laser with half-realistic power levels is going to have spot sizes between millimeters and centimeters.
Place a whipple shield more than half a meter "thick" and they have to waste hours to bypass it.
a pirate gang or political group might send one up to blind sensor platforms in preparation for future attacks or warfare
Sensors can be made with relatively dispersed arrays of mirrors pointing on the actual detector, it is relatively easy to make one with enough space between the mirrors so that any wide-spot laser cone passing by doesn't transfer enough energy in the the detector to blind it.
If you are shooting a small-spot laser cone to actually destroy the satellite, it will take a while since you will have to kill each single mirror, while the detector or its actual power source can be armored. This buys it enough time to return fire before you kill it.
Frankly, it's much more effective to crash your vessel on it than trying to destroy it with a laser.
So additonally, smugglers can't just make ballistic boxes that can be dropped off in orbit or outright survive re-entry and float in the oceans for pickup.
Depends from the procedures. If all incoming cargo traffic is forced to stay in a high orbit, where it will be guarded, the first isn't an option.
The second... reentring things tend to be obvious on any scanner on the same hemisphere, and an orgy for heat seekers.
As a general rule, any interplanetary vessel with a decent performance has either a nuclear reactor or has a radioactive engine (even fusion ones, although it's a radioactivity that dies off within a couple centuries). Also, they have dangerous exhaust, and unshielded reactors (the rad shield protects only the ship, for mass-saving reasons). They aren't going to dock with anything else than shielded (or robotic) cargo handlers and people ferries anyway, and nuclear-phobes will also scream if they get too close.
Anyway, please note that I'm not saying IT WON'T HAPPEN NEVER NEVER NEVER.
I'm just saying that if there are reasons to do so, most holes can be plugged without ludicrous expenses. So after the first pirates make money, their job will become more and more difficult.
Connor MacLeod wrote:What if it's not a ship that becomes a pirate, but a habitat?
Given the habitat minimum size (a few hundred people?), it's needs will be relatively big. This will very likely prompt other neighboring habitats to give it substantial aid like Europe does with its own component nations at risk of toppling (to keep it from becoming pirate), an evacuation, its destruction after they annoyed everyone.
It's not particularly complex to "accidentally" slam on them with a couple second-hand space transports full of (relatively cheap but not so suspicios) lunar fuel, since the damn thing cannot out maneuver even a comm satellite.
Its engines are unable to carry it anywhere out of Earth Orbit, if they were designed only for reboosting.
Another one is that you have some planet or installation that basically fails, and the military/police/space forces that are there decide to go rogue or go warlord. You might have a whole horde of pirates that crop up from that situation.
This makes more sense. Although most military installations aren't going to be full of people. Most stuff is going to be robotic, especially the "warships".
First off, would you need a human crew neccesarily to do in-system shipping iwth the kinds of performances we seem to be talking about?
No. Modern computers are more than up to the task for any kind of engine performance. (I thought I said it in the first post above)
What if they use solar sails or some sort of laser-assisted reaction drive? Maybe the pirates use lasers of their own to divert or capture the cargo ship.
Such engines require very big laser installations to work. If your pirates have the money to make one, then they probably don't need pirating to live. It can be fun if 2-3 of these laser installations are owned by different nations, that happen to be in war....
I don't think you need to kill witnesses to prevent them from knowing much about you or your destinatio,
If they had sensor logs of you getting close, they know how much delta-v you have in your tanks. If your engines are more or less realistic, this is enough to weed down the possible routes to a handful. If you have torch drives, not so much (although then it becomes complex to hide your exhaust from Space Traffic Control telescopes).