But why just visit two worlds?
Yes, I'd love to see those close-up images of Ceres
and Vesta from Dawn orbiting those two worlds.
But why stop there?
Surely that spacecraft will have a surplus of ion-propellant fuel
and cold-gas thruster fuel available at the end of the primary mission?
Why couldn't it then depart to "flyby" perhaps five or ten more asteroids
over one or two additional decades?
There is precedence!...The Galileo spacecraft was launched in
1989, and was still functioning in 2003.
The Voyager's were launched in 1977, and are still functioning today.
Jacob