GI joe retaliation zeus weapon

[Vaebn]

You know... with a really good electromagnetic launcher, the satellite could de-orbit the rod merely by tossing it really really fast no?

Of course that would accelerate the satellite the other direction, but technically you'd save on the weight of having to give the rods separate engines. The satellite then (who probably already has a nuclear reactor on board and tons of capacitors for said launcher ) could use a much more efficient way, like ion engines, to fix its orbit.

See! It all makes sense.

[Thaniel]

Ok, so I watched the Scott Manley video about celestial telephonepoles, and he touches on most of the problems with that kind of delivery system pretty nicely. To deorbit the poles, he uses a small engine assembly to lower it´s periapsis into the lower atmosphere, to cross through the intended target.

The shape and density i.e. momentum of the projectile will help in limiting the effect of drag, but as seen here, even for the high speeds experienced here, there is still a significant loss of speed.

Something wich he mentions he limits a bit by entering at a steeper angle.

About the energy in an 8 tonn projectile moving av mach 10, = 46 648 900 000 kJ = 11.14 KT, yeah, it seems I got that right in the other example

Note to self, I gotta try something like that in KSP myself, but try to counter the orbital speed completely. See if that makes any difference on impact speed in KSP.

[1of6Billion]

Well, it's a step forward from the sinking ice sheets in the first movie

[Brabbit1987]

Ya, I watched this movie recently. When I first heard them say "drop", I was like "What!? That wouldn't work at all! >.>". Then they said "nuclear", and I face palmed.

You know, I sometimes think ignorance seriously would be bliss in situations like this. It really ruins the whole fun of the movie when you know what they are claiming wouldn't actually work. Seriously, if the same situation happened in real life, I would probably wet myself from laughing so hard at the villains stupidity. I would be like "OK .... h .. here .. push the button right now and shoot it ..." Villain pushes button "5 minutes pass and nothing happens as I am rolling on the floor laughing as the villain looks embarrassed as hell.

[Thaniel]

I did a few tests yesterday with some simple contraptions in KSP, just to see how efficient gravity could be. When I brought enough fuel to cancel my orbital speed from orbit, and drop straight down, I did build up a significant speed. I never tried it from the correct altitude, will do that tonight I guess.

As far as I can see, the only ways to make this idea work, you either have to do it like von Braun suggested, carefull deorbiting a nuclear warhead that can steer itself towards the target, wich will hit when it is allmost on the oposite of the orbit of when it was released, or carry enough fuel to cancel orbital speed at the time of "drop". It would still take a while to hit the surface.

Edited August 13, 2013 by Thaniel

[randomness5555]

Basically like has been said it would stay in orbit if simply dropped. HOWEVER if it dropped out of orbit (through losing speed for whatever reason, rockets, ion thrusters ect.) it would turn into a weapon. It would hit the ground far faster than a bullet (providing it survived re-entry) hitting the ground hard enough for it to drive itself many meters into the ground with bunker busting force. However, it would not explode. While it's a great idea for a weapon it wouldn't work like the film had it working.

[Nibb31]

It would pretty much hit the ground at terminal velocity, which would depend on the mass and drag of the rod.

I would imagine that deorbiting it would be inefficient because you would actually need to reduce the energy that you imparted into the object by sending it to orbit.

Wouldn't it be better to accelerate your projectile into a high apogee/high energy parabolic trajectory, so that it reenters on a near-vertical trajectory with even more energy? Of course, in that case you lose the "rapid response" capability of the weapon, which wasn't great anyway... and there wouldn't be much point in launching it from orbit in the first place, as it would basically just be an ICBM with a telephone pole on top.

Edited January 17, 2014 by Nibb31

[Ralathon]

It'd still be an impressive sight though. If you make the projectile sufficiently aerodynamic it would go so fast it plasmises the air. So you'd see a white streak descent like a thunderstrike followed by a sonic boom. I can see why they called it "Zeus"

[Skyler4856]

Oh that's rich XD

Who did they hire as a physics consultant.

[Kermunist]

I imagine such a ting would look like this

That is 8 re-entry vehicles from an american ICBM test, without warheads.

(Though with fast moving objects, the camera catches them differently from the human eye. The naked eye would probably see downwards movement, not lines.)

Edited January 18, 2014 by Kermunist

[Wahgineer]

Since the rods are 'only' the size of telephone poles, a sufficiently powerful retro package, combined with a drop from a very high polar orbit, could allow the rod to drop more or less straight down. Since it's dense and moving at Mach 10+, the Rod will spend a very short time traveling through the atmosphere. It might be able to cause an Earthquake if several of them were directed at a fault line simultaneously.