QUOTE (JRehling @ Oct 30 2006, 06:52 AM)
The ideal time to arrive at Uranus would be near equinox. One is happening about now, and it's obviously too late for that.
The next one is in 42 years. Put some pennies in the piggybank for a 2035ish launch.
A next-best arrival time might be when the anti-Voyager 2 hemispheres are in the light (to "finish" the coverage)...
the next such solstice is in 20 some years (with lots of leeway for off-goal-but-OK illumination conditions).
That's not going to happen (with NH2 being a dead possibility), and the next one after that is in 66 or so years. ....
That'll be probably the reason why we won't see a launch of a Uranus-orbiter-mission in say the next 40 to 45 years.
New inventions in propulsion systems will hopefully offer us a variety of capabilities to send and maintain an orbiter at Uranus then.
Maybe there could be 5 landers for the large moons on a platform or 2 corresponding missions -
one with such landers and another with a long surviving (21 years) orbiter.
Neptune and of course Triton for me seem to be the more rational targets.
There's no illumination problem like in the Uranian system - I'm still aware of Triton's 'chaotic' retrograde orbit!
But Neptun could be reached roughly every 12 years by a Jupiter swing-by with a launch window of 1-2 years.
Mission goals are clearly fixed - observation of Neptune itself and full cartography/remote sensing of Triton over years -
maybe for 1-3 decades, depending on the RTGs.
'Neptuneshine' should help on imaging Triton's dark hemisphere.
A Triton lander should be on board if manageable at this cold temperatures!
The rest few percent of the mission should aim at 340 km small Nereide (maybe like Phoebe at the begin of the mission)
and the other small satellites, most interesting here is 440×416×404 km large Proteus.Bye.