FEEP (Field Emission Electric Propulsion) can be a more efficient technique
(higher Isp) than many other techniques. it doesn't use xenon and may even
use cesium or other liquid metal.
https://en.wikipedia.org/wiki/Field-emission_electric_propulsion
-----Original Message-----
From: David Weinshenker
Sent: Saturday, February 6, 2016 1:35 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] practical electric thruster propellant and power?
I've been contemplating the "multiple miniaturized asteroid probes"
mission concept mentioned here a while back, in which context the
question of electric propulsion was raised. I note that many of the
systems use xenon as a propellant - isn't that hideously rare and
hence expensive? Aren't there other atoms that would work as well?
As far as powering the system, how feasible would it be to progressively
deploy a lightweight reflective concentrator so as to maintain steady
solar illumination with increasing distance? (It wouldn't take much
structural mass to hold some metalized film in the appropriate
reflective shape; the loads would be small under the gentle
acceleration of an electric thruster.)
-dave w
