theHassan

Still, the main problems remain. ISS is a microgravity research station (among other things), and the vibrations of the centrifuge would upset it. Also, do not forget acclimation. Now, an astronaut goes up, gets through "space adaptation syndrome", which is the accepted expression to describe vomiting all around the place, and lives happily ever after. Then they comes down, gets through gravity readaptation, and that is it. With one part of the station having artificial gravity and the rest weightless, one would need to readapt several times a day. And just once forget where you are and drop something. It is better this way, I think. Being an astronaut carries a significant occupational health risk. Take it or leave it.

Rockets come in many different varieties. A bipropellant chemical rocket burns a fuel (liquid hidrogen, kerosene, ethanol, hydrazine...) with an oxidizer (liquid oxigen, fluorine, nitric acid...) to produce hot gases to eject. There are also solid fuels, like black gunpowder and various plastic-metal mixes. These are the biggest rocket motors, which carry (carried) the Soyuz, the Apollo, the Shuttle and many more space vehicles up to there. There are monopropellant chemical rockets, much smaller things, where hydrazine is reacted in a catalytic chamber to generate the gases. Here nothing is burned, the chemistry is different. Even smaller rockets use pressurized gas (nitrogen usually), and just release the amount of gas as needed. These smaller rocket motors are used to orient the spacecraft, that is, to turn it around to look wherever it needs to look to do its job. Ion engines are also rockets, but they use electric fields to accelerate ionized gas, which is ejected from the engine. However you produce the mass flow out from the rocket motor, it always comes down to the principles already described.

Gyro would be one problem, vibration another one. All the vibrations propagating through the whole structure would mess up all the microgravity works on the station. Power and bearing lifespan comes to mind also.

The real problems are throughput and polar coverage. High-throughput satellites (geostationary) do not cover the polar region, and airtime is expensive anyway. Now with Iridium Certus (Iridium NEXT) coming on, the situation might change. In my opinion, it would be best to have ICAO laungh dedicated satellites for this very purpose and do not rely on commercial satellites. I leave the legal and financial details to someone else more conversant with international politics, however.

In military terminology, Kinetic Energy (KE) is most often (I even risk, only) used to describe solid anti-armor projectiles, like APFSDS (sometimes with a -T added for tracer). Check out https://www.globalsecurity.org/military/systems/munitions/m829a1.htm for an example, there are many like that (and not only uranium ones). The terminology is used to differentiate KE armor-piercing rounds from Chemical Energy anti-armor rounds or warheads, which contain high explosives, and therefore most often called HEAT. Example at the link: https://fas.org/man/dod-101/sys/land/m830a1.htm Origonal Poster really should clarify...

Dear MigL, Please allow me to correct You a little. What You described as "passive" is actually called semi-active. As there is an active part in it, the illuminator. Which can be radar (Sparrow air-to-air missile is my example) or laser. Passive guidance relies on the emissions of the target itself, like IR/UV emissions of a fighter jet engine to be homed on by a SAM (Stinger, for example) or a Sidewinder-like air-to-air missile, home-on-jamming missiles to take out jammer aircraft, antiradiation (antiradar) missiles to target air-defence radars (HARM) or imaging sensors in air-ground weapons like in some versions of Maverick.