Notes from the road yesterday

Notes for my next post the asteroid that nasa proposes to capture weighs 500 tons.

If 30 percent of it is water this will yield 300000 pounds. In order to supply three astronauts, you will need ten times as much for a trip to Mars and back.

Therefore you will need 10 missions of that type, are ten times less supplies.

Another note is that I want to tell the difference between pounds feet and foot pounds.  Pound feet is for thrust.  Okay, that looks dumb, but it does confuse me.

Update:

Part 4 of a series.  The series is about using Hunter gas guns as propulsion to and from asteroids in order to exploit them for their resources.  Part 3 was here.

I am wondering if a small nuclear reactor is placed on board to heat the hydrogen for the gas gun.

Instead of using gas as propellant, use a solid.  Maybe water.  Don't like to use water, but it's advantage is that it will vaporize in space.  Don't want solid projectiles whizzing around in space that may become a hazard.

As I recall, you don't need a lot of heat to the hydrogen in order to get some decent velocity out of it.  Hunter said room temperature could get escape velocity from the moon, for christ's sake.

Maybe you can compress the hydrogen without heating it.  Then use it to propel an object like a small piece of ice.

Heating a gas for propulsion is very energy intensive.  Also very inefficient to an extreme.  By using a compressed gas to propel ice, the energy consumption and mass consumption can be much more efficient.