If the Prometheus project is intended to develop a VASIMR nuclear-powered
plasma-propulsion system, why settle for Mars? Why not Jupiter? Specifically one of its outer-Galilean moons,
like Ganymede or Callisto?
The radiation levels [at their equatorial regions] shouldn't be that bad.

Two-months to Mars by VASIMR?
Well then...It should be little difficulty in using a VASIMR propulsion system to send you on a parabolic
trajectory [42km/sec at one a.u.]
to that giant planet...The trip there
will take you eleven months using a parabolic trajectory...Aerobrake into orbit when you get there... go into orbit around one of those two moons
for a month and land a LEM-type spacecraft on its surface.
Did you know that the surface-gravity on those two moons is almost 1/6th that of Earth [remarkable 'coincidence']?
Oh yes! Somebody will mention that it
will take 1.5 - 2.O years to return
to Earth.
Let's see! Eleven months on the way to Jupiter, a month in orbit, and 24 months
to return here....That's a three-year round-trip.
How many of you recall NASA's plans
during the 1980's for a three-year round-trip to Mars?

Jacob

on eithoer of those two moons by a