Formless wrote:the ship could be experiencing a malfunction (edit: or miscalculation),
Even in the unlikely event that something like that occurs, a simple tiny thrust from your own engines (little more than a fart) is sufficient to have such "malfunctioning" craft miss you by tens of thousands of km.
If you see that it corrects the course to home on your ass, then you can start to power up weapons.
Unless you know ahead of time what their flight plan was, you would be a complete idiot to assume hostility in such an environment.
The decision to open fire depends on how much pirates already used this same modus operandi in the past, and on the Ground Control's answer (since they should know any flight plan for the sake of safety, just like with aircraft traffic control).
Of course, if it's the first time and Ground Control lies/is jammed/your comms are fucked, you may fall prey of such a scheme. After 10 or 100 times... not so much.
Even with torch drives, not every ship will be using them due to cost efficiency
You may be right. Just remember that a torch drive can push a small ship very fast, or a VERY BIG ship not so fast. Depending on the torch drive in question, may be worth it to use the same engine due to ludicrously huge payload you are moving.
A pirate gang might launch several such drones at the start of a year, keeping thrust to a minimum and otherwise mimicking whatever other kinds of vessels that don't require high thrust and short travel times. When these drones come in contact with potential targets
Dunno, I see it much more like Ocean's Eleven. Any space flight is going to be scheduled somehow (it's not like they will launch with a moment's notice, there are checks and stuff to do before). Knowing the mass of the vehicle and its performance a navigator with a navicomputer can give you its possible courses.
Given the relatively constrained launch windows, it's not a lot of courses. If you have torch drives, it's harder, but still doable.
So your pirate gang launches stuff specifically designed to intercept that specific cargo on specifically computed courses. Although your prey can easily "think like a pirate" and try to choose the courses with less possibilities of being pirated.
Having an insider tell you their flight plan makes this game slightly easier, so to speak.
It's a plan to get your hands on a specific cargo IN SPAACE!!!, not a "let's set up traps and hope a prey falls into them" kind of scenario.
Eh, that depends on how highly saturated with orbital habitats the setting is.
I thought you were talking of interplanetary space. Cis-lunar space is likely going to be thick as soup, and such things are going to be much more common (although still not overtly easy to pull off).
Smugglers are going to be using official ports now?
Spaceports aren't that easy to make. Unless you have rogue nations with pirate-friendly ports (almost a given unless you have planet-wide nations), they will have to use your ports.
And for "spaceport" I mean some kind of orbital station, that controls the traffic of its own landers that bring down/up your stuff. Or a space elevator for more advanced settings.
I tend to think that landing your main vessel to unload it has the same verisimilitude than pulling ashore a mid-sized oceanic vessel to unload it, due to various reasons.
Also, what about searches for weapons?
Depends on what weapons you want to stop. Technically, any craft can dump anything while at the max speed (depending on the course, it's more than 10 km/s usually), and those will impact (anything in orbit and then the planet, although the planet isn't going to feel them) at very high speed. To defend from any kind of such thrown crap (that can happen even accidentally, mind me), it's relatively cheaper to place sensor stations to detect the thrown crap and intercept it with anything else, to exploit its own kinetic energy to destroy it.
If you want to defend from bombs (with reasonable yelds), then you just have to keep them in a very high (guarded) orbit while you search them. Not even the best nukes can do anything at something more than 1000 km distant, in space. And 1000 km is pretty close to nothing in space.
Lasers aren't an issue. They are easy to defend against for the time needed to scramble swarms of kkvs on the shooter. Unless there is an entire battle-ready fleet, but it is going to be somewhat obvious.
Other weapons may change this scenario, but these are the only realistic threats I can think of.
Also, we're back to requiring a third party authority watching the skies and all the tricks I mentioned for evading their watch.
Yup. Most tricks of yours still work fine with minor modifications. It's just that I think it's very likely some kind of such authority will exist in a setting where spaceflight is consistent, so their presence has to be taken into consideration for would-be space pirates.
Its not like shooting it out with the pirates is going to stop pirate attacks in such a scenario
Of course not. It becomes an arms race. The cheaper pirates will have to either bail out or use more trickery. It becomes harder, but there is still cost-effectiveness in the equation. The bigger companies will likely prefer to lose more shipments to pirates than paying for more defenses on loads of shipments, if it proves economically advantageous to do so. Smaller companies get fucked as always.
you can guarantee not just anyone will be allowed by the law to put guns on their spacecraft.
Meh, as I said above, the entire spacecraft can become a kinetic weapon, or if we are talking of engines with any kind of performance, the engine itself can incinerate anything (although with a relatively short range).
Placing a few KKVs won't hurt anyone.
Anyway, I don't see why Security Firms, like
Blackwater shouldn't be legally hired to defend the convoys. Hey, they are a fucking private military already.
Remember, unlike aircraft spacecraft are up there as long as you need them to be.
Mh, if you are talking of cis-lunar space that is more or less correct, with spacecraft in interplanetary space it becomes harder, since those drones will have a precise course. In Interplanetary space it would be more like a patrol: they get to a destination, they refuel, the get back home.
With torch drives this is much easier to pull off.
Destructionator XIII wrote:Please. Voyager didn't even take a full ten years to get all the way to Uranus, and that's taking the scenic route. Uphill.
My ass. Voyager wasn't designed to get in stable orbit of a damn thing, but just to slingshot in deep space after relatively quick flyby of various planets. If I may say, it is a route good for a kinetic impactor, not for a cargo ship.
Galileo is one you should be looking at. 3 tons and 6 or so years to get in Jupiter orbit.
MESSENGER is another, 7 years to get to a stable Mercury orbit (more or less anyway).
For our two most closes neighbors (Mars and Venus),
Venera 7 the first Venus lander (it's from Soviet Russia, btw), took 3 months or so to deliver half a ton. And
Viking 1 mars orbiter and lander, 10 months for slightly less than a ton of vehicle.
See? Rockets can bring us to Venus in no-time!!!!!! Let's hurry up or they will end the supply of green babes.
Mars is still doable for bots, anything farther than that isn't particularly cost-effective even for bots.
Let's consider a flat space trip, going 0.5 AU, no starting or stopping speed, no fancy effects. Call it an ideal Mars line.
Suppose we have an outrageously high performance rocket with 100 km/s delta v that has infinite thrust.
First, above I said "higher thrust with the same Isp", not just higher thrust. If you want to carry more at the same performance, you need higher thrust with the same Isp. You cannot just add more engines (doing that degrades your Isp), you need a more powerful engine design to do that.
Second, even 0.001 g is an outrageous acceleration for this fuel endurance, deign of being called "torch drive".
Of course you think higher thrust won't change a thing. You're
already playing with an Orion (BOOM BOOM) Drive, what can do better than that?
It's very simple, really. And I'll show you.
I'll run the
Atomic Rocket's, Thrust Power formula (total kinetic energy of the exhaust, scroll down a little from the link)
Fp = (F * Ve ) / 2.
F is thrust and Ve is exhaust velocity.
I need to get Ve and F, but both are more or less linked to the vehicle mass, so....
Let's assume that the craft masses 1000 tons and that 2/3 of it is fuel/propellant (an honest mass ratio of 3). This leaves us with 333 tons of dry vehicle, say half of that is structure and engine, and half is payload. A 150 ton payload. If you scale this up by say multiplying everything by 10, be sure to multiply the thrust power below for the same number.
Knowing the delta-v and the mass ratio, the exhaust speed is going to be at least: Ve=Delta_v/ln[mass_ratio] (by tweaking the
delta-v formula).
So, we have a Ve of (100 km/s) / (ln[3]) = 91 km/s, plus some spare change.
Now we need to calculate the thrust of this baby.
By F=ma, we can say that:
1 gee (9.81 m/s) acceleration * 1'000'000kg of mass = 9'810'000 Newtons
0.01 gee = 98'100 Newtons
0.001 gee = 9'810 Newtons
0.000001 gee = 9.810 Newtons
We have all the data we need now, let's run the thrust power formula Fp = (F * Ve ) / 2. (F is thrust and Ve is exhaust velocity)
Remember, this is the minimum energy this engine must give to its exhaust to do its work. Since nothing is 100% efficient (and most isn't even 50'% efficient), your actual engine power levels will likely be more than that.
One gee = (9'810'000 newtons * 91000 m/s)/2 = 446'355'000'000 watts --> Around 450 GW <--- eeeeeeek!
0.01 gee = 4.5 GW <--- slightly less ludicrous
0.001 gee = 450 MW <--- more or less the thrust power and performance I saw around on fusion concepts
0.000001 gee = 450 KW <--- around twice the power sucked by a FX200 VASIMR engine. also comparable thrust to two such engines. (although their Ve is around half, so the delta-v will be less, and I'm assuming a 100% efficiency one, while they have only 70% or so)
Now, if your engine isn't self-powered (self-powered = the fuel contains enough energy to do accelerate itself), from where does all this energy come from?
The puniest one can be nuclear or solar-powered (wasting 70 tons or so for power plant and heat rejection mass), but the others require simply too much energy (and will have too much wasted heat) to be doable.
For comparison, one SSME (the rocket engine most close to the chemcal rocket maximum performance) gives 5 or so GW. Not that it means a damn thing anyway. Chemical rockets without staging reach 5 km/s of delta-v, and with staging can reach up to 20 km/s of delta-v (with a Saturn V's worth of staging) so the overall speed is much lower than these ballpark examples anyway (not that going to Mars requires so huge Delta-v budgets).
The puniest engine needs: 50000 m/s / 0.00000981 m/ss = 5096839959,22528 seconds = 161
years to reach the same speed of your example torchships. Big deal. That's where a higher thrust would have been better.
Now, let's calculate the actual transit times for 0.5 AU of distance if we don't try to make it reach a specific speed, T = 2 * sqrt[ D/A ]
* T = transit time (seconds)
* D = distance (meters)
* A = acceleration (m/s2)
* sqrt[x] = square root of x
0.5 AU is 74'799'000'000 meters.
0,00000981
so, 2*sqrt[ 74'799'000'000 meters/ 0.00000981 m/ss] = 174639865.3481139 seconds ---> 5.67
years. (vs a few months for Venus and a year or so for Mars)
Chemical rockets do
much better for Mars and Venus. And don't need annoyingly huge power plants and waste rejection systems for the feat.
Let's try it for outer system, Jupiter, at a medium distance of 778 million km + spare change. 778'000'000'000 m
2*sqrt[ 778000000000 meters/ 0.00000981 m/ss] = 563229366.29954 seconds ---> 17.85
years. (vs 7 or so years for Galileo)
Ehm. I'm afraid it sucks balls for outer system too.
Also, the Sun's gravitational pull at Earth is 1.6 milligees, anything with double that acceleration can be safely called torch drive, since it can take brachistochrone courses (where the "flat space" approximation is pretty much close to reality). Anything less and you are stuck doing looooooong spirals to reach anywhere.
A chemical rocket can launch payloads of virtually any size, especially if it is orbit to orbit.
Sure, but it's going to become big-honking huge very fast.
Although with the moon producing the fuel, and in-orbit assembly the cost is surely going to become somewhat acceptable.
We are still talking of a Saturn V-sized thing
in Earth orbit to carry 100 or so tons to Mars, to give an eyeballed size estimate.