Uranus Orbiter, The other proposed ice-giant mission Options

[Rob Pinnegar]

Since the Neptune Orbiter thread has started to veer into talking about a Uranus orbiter as well, it seemed like a good idea to start a topic for Uranus.

[PhilHorzempa]

Time to re-start this thread. Thanks to Cassini, we now have a better idea
of the diversity of all of the non-Titan moons of Saturn. This makes me feel that
an Uranus Orbiter should be flown before a Neptune Orbiter. Uranus is "only"
2 billion miles away, instead of Neptune's 3 billion. No matter which method one takes
to get there, the travel time will always be shorter to Uranus.

Also, for the meteorologists, the atmospheres of Uranus and Neptune are very
similar, except that Uranus is easier to get to.

Triton has always been thrown in as an extra Neptune bonus. It is a fascinating moon, I
must admit. However, as mentioned above, Cassini has shown us that even the smaller
icy moons of Saturn show complexity, perhaps even including zones of liquid water, e.g.,
Enceladus.

Uranus has 5 mid-size icy moons, with interesting possibilities for several of them.
We all know of Miranda's strange surface (Miranda is about the size of Enceladus)
The other 4 moons are in the size range of Dione and Rhea, which Cassini has shown are
more complex than Voyager led us to believe.
In fact, take a look at an image of Ariel and you will be reminded of recent views of
Dione's cracked and fractured surface.


My vote is for an Uranus Orbiter first.

Another Phil

[JRehling]

Also, for the meteorologists, the atmospheres of Uranus and Neptune are very
similar, except that Uranus is easier to get to.

They're made of the same stuff, and their gross dynamics are similar, but Neptune shows those huge cyclones which Uranus never has.

http://lasp.colorado.edu/~bagenal/3720/CLA...ntPlanets3.html

I agree that Uranus's larger satellites are made more interesting by forming a class with Saturn's midsize satellites. It would be interesting to see them upclose and from all angles.

Triton, though, is an understated "star". It has geysers being blown in the wind. Only Venus and Titan might match that doubly-impressive dynamism.

I don't think the gravity assist factor is all that important. Seeing what impressive results came from the single Voyager 2 trajectory, which was constrained by the need to get to Neptune, I think even a random orbit through the small Uranian system would produce some pretty good imaging of all of the satellites in time. The early tour could accomplish the satellite flybys, then a propulsive manuever at apoapsis could tilt the orbit to get some looks at the rings and the Uranian poles.