Frogwatch wrote:
So, say we want to explore Titan completely from the air, we drop a
Pluto style ramjet into the atmosphere of Titan where it flies around
for months sending back data. At the end of its life, we could simply
allow it to crash OR we could use onboard solid rockets to accelerate
it to escape velocity from Titan and allow it to either go in orbit
about Saturn or to drop into Saturns atmosphere.


You might run into a really unexpected problem with that...Titan has a
very thick atmosphere, which could generate a lot of drag and heating on
the ramjet if it tried to fly at multi-Mach velocities like SLAM/Pluto*
was supposed to.
On the other hand, Titan's high atmospheric density combined with its
low gravity might make a propeller driven aircraft using a electric
motor powered by a small reactor or RTG feasible. This could cruise
along at quite a low velocity giving its sensors time to examine the
surface under it. One other problem is that the atmosphere of Titan has
a lot of turbulence in it according to the latest findings, so anything
you fly around in it has to be pretty tough.

Such a flying machine might be just what we need to explore Venus
too. The dense atmosphere would allow for fairly low speed flight
there.


Can't get it too slow if you want a ramjet (nuclear or otherwise) to
work...start-up speed for one is around 300 mph, at least in Earth's
atmosphere.

* _S_upersonic _L_ow _A_ltitude _M_issile...SLAM was the missile proper,
Pluto was the code name for the project to develop it, TORY was the code
name for the reactor-driven ramjet engine:
http://www.designation-systems.net/dusrm/app4/slam.html

Pat