[amsat-bb] BY70-1

[Phil Karn]

On 3/1/17 14:57, Howie DeFelice wrote:
> "You'd collect both protons and
> electrons and accelerate the protons rearward and the electrons forward
> to maintain charge balance. The protons, being much more massive, would
> result in a net forward thrust"
> 
> 
> sort of like the atomic equivalent of electrolysis 😊 So unlike current
> ion thrusters, you wouldn't need to carry a medium to ionize.

Right.

The Holy Grail of space travel seems to be propulsion with energy but no
propellant mass, at least propellant mass you have to carry with you.

You can make as much energy as you want from solar panels if you're
patient. Or use a nuclear reactor if you're less than patient, but
ultimately energy in space is nearly unlimited.

Mass is the big problem, because by definition space contains very
little of it (if any). So if there *is* any mass around you, however,
small, you should try to figure out a way to use it.

I also think about all the mass that's sent to the ISS only to be
wasted: upper stages of launch vehicles, complete cargo vessels, etc.
This waste won't get us to the planets. Everything sent into space
should be (re)used as many times as possible. Cargo ships and even spent
rocket stages should become permanent additions to the station, for
storage if nothing else.

Even trash could be used as reaction mass to reboost the station's orbit
if you can figure out how to accelerate it. A big electromagnetic
slingshot running the length of the station, for example.

Phil