What's the difference between a spaceship and a missile once you remove the human passengers and pilots?
A missile is likely to be more efficient and cheaper, by a massive margin. Otherwise, none.
What future space combat would really look like
61–70 of 235 posts
Re: What future space combat would really look like
#62Earlier quoted context omitted.
The fighting methods in that essay still require ships (to sneak up into e.g. Kuiper's Belt). In any case, a big, dumb projectile can have its course changed with much less energy than required to fire it. The bigger it is, the earlier it will be detected; and the faster it goes, the smaller the angular deflection needed to miss its target.
While it is true that it should be easy to deflect, it is only easy to deflect if you can detect it. The essay assumes that the projectiles would be pushed to a significant fraction of the speed of light. At that speed there is no time to launch any type of deflection.
The energy required to accelerate a big object to even half the speed of light is prohibitive. Even if the process was feasible, it would be a vast cosmic event bound to emit some radiation, which would still arrive much sooner than the object itself.
Re: What future space combat would really look like
#63There are three fundamental problems I see here:
1) Why put humans on warships at all? Algorithms are probably better at it. Computers would obviously do the heavy lifting anyway (calculating burn times). An algorithm knows no fear, shows no mercy, and does not flee or surrender unless programmed to do so. The only thing left is target selection, and it doesn't seem worth bringing a human along just for that.
2) If you don't need to put humans on warships, then you quickly realize you don't need a warship at all. Just send a bunch of missiles from wherever the warship would have launched. It's harder to take them all out at once with a "mine" or something. You also get to build more missiles if you don't need to build the warship. Sure, you might attach a collective nuclear rocket "booster" to many missiles to build that initial velocity. There's no need for that rocket to be anything more than an engine temporarily attached to the missiles. It's also not really required to begin with.
3) If you're sending lots of missiles, there's no reason for them to be any larger than the smallest size permitted by design and manufacturing practicalities. For something that amounts to a liquid-fueled rocket, that smallest size is preposterously small. A liquid-fueled rocket can be fit into an object the size of a soda can with current technology. This makes the notion of point defense completely laughable: divert ten thousand missiles out of one hundred thousand, and you've reduced the incoming energy by 10%.
Re: What future space combat would really look like
#64Earlier quoted context omitted.
> Any combatant with the necessary wealth and technology to develop any space-combat capability is going to have significant terrestrial interests Imagine a colony that long ago severed its ties with Earth (or whatever other terrestrial body they started from). Living off comets and asteroids seems entirely feasible and it's a much harder to attack/easier to defend set up.
Complete economic isolation from the earth seems very unlikely, at the very least because it wouldn't actually benefit anyone.
If the outer solar system dwellers become self-sufficient, they would have no need to go down the gravity well of the Sun to have commerce with earthlings. The further out those colonies are, the lesser their contact with Earth will be. If they live off the Oort cloud, the would be about one light year away from Earth and it's very hard to imagine a shared culture with such a communication lag.
Re: What future space combat would really look like
#65Earlier quoted context omitted.
The fighting methods in that essay still require ships (to sneak up into e.g. Kuiper's Belt). In any case, a big, dumb projectile can have its course changed with much less energy than required to fire it. The bigger it is, the earlier it will be detected; and the faster it goes, the smaller the angular deflection needed to miss its target.
He addresses that in the next paragraph: If that’s not bad enough, one could envision flinging appropriate small moons or large asteroids from other solar systems. Why not? Boosting a large body to fractional c velocities and aiming it at a far away planet isn’t inherently any more absurd than building a ship and boosting it to fractional c. The motion of stellar bodies is famously predictable out for many centuries.…
One of my favorite "ohh, that's interesting" facts about space combat, is that a kinetic kill weapon (ie, .9c rock) being shot at you. By the time you see it, it's already 9/10s the way to you...
Re: What future space combat would really look like
#66Earlier quoted context omitted.
While it is true that it should be easy to deflect, it is only easy to deflect if you can detect it. The essay assumes that the projectiles would be pushed to a significant fraction of the speed of light. At that speed there is no time to launch any type of deflection.
The energy required to accelerate a big object to even half the speed of light is prohibitive. Even if the process was feasible, it would be a vast cosmic event bound to emit some radiation, which would still arrive much sooner than the object itself.
Well you don't have to accelerate it all at once. Remember, this is space war, and we're playing for keeps. Spending a millennium to accelerate a rock up to .5c might be worth the trouble.
Re: What future space combat would really look like
#67What if you launch a surprise attack by launching a missile at relativistic speeds?
Re: What future space combat would really look like
#68There are three fundamental problems I see here: 1) Why put humans on warships at all? Algorithms are probably better at it. Computers would obviously do the heavy lifting anyway (calculating burn times). An algorithm knows no fear, shows no mercy, and does not flee or surrender unless programmed to do so. The only thing left is target selection, and it doesn't seem worth bringing a human along just for that. 2) If y…
On the same idea of not having humans I have been wondering when when we will see a war type video game where you play drones be it land air or sea rather than soldiers on the ground or flying a plane. The cost of sending humans is so high just around our little planet that I can't see how anyone would want to inject humans into any space attacking where the costs as mentioned in the article are so much higher.
Re: What future space combat would really look like
#69Earlier quoted context omitted.
It's two things basically: -You can do a full survey in about 5 hours with one telescope these days. -Ships are very bright, don't look anything like stars and CCDs are very sensitive. http://www.projectrho.com/rocket/spacewardetect.php has a good break down.
I've been trying to get a sense of how effective these scans are. Asteroid 2005 YU55 was discovered 28 December 2005. It's about 400m in width, which is the length of the biggest vessel we have. When it was discovered, it was 0.8AU from the Earth, and its orbit is inside that of Mars. This tells me that 6 years ago we did not know all of the +300m asteroids within the orbit of Mars. How much better are we now? I read…
Asteroids don't pump out waste heat. Things get a lot more obvious when heat differentials are big.
Re: What future space combat would really look like
#70Earlier quoted context omitted.
I don't think you would try to slow down approaching meteorites to zero speed, only deflect them a little so that they miss the planet. The further away you catch it, the less energy it takes (I assume, didn't do the maths).
It depends on the momentum of the asteroid. If I've accelerated an asteroid up to .5 c , then even if you discover the attack years ahead of time you might still not have the energy to deflect the asteroid by enough to save your planet. You also have to remember that the attacker can launch multiple simultaneous asteroids. You might have enough nukes to deflect one asteroid. Do you have enough to deflect ten? A hundr…
If you can accelerate an asteroid up to .5c, you have harnessed energy resources to power the earth for a gazillion years. You would be so rich that you dont need to be a warlord. You could become ... a banker.
Actually, at .5c from the Kuiper belt, the warning time is only 30 hours or so and the momentum is such that deflection is impossible. I'm too lazy to do the math but the collision would be spectacular.