One of the posters over on Scott Lowther's blog linked to this website
which has a load of cover artwork from books aimed at children about
space exploration from the years 1883-1974:
http://dreamsofspace.nfshost.com/
There are a lot of really off-the-wall spacecraft designs in it, like
sending a X-15 to Mars for instance:
http://dreamsofspace.nfshost.com/rockets.htm
This one is interesting - using backpack helicopter units to explore
Titan: http://dreamsofspace.nfshost.com/195...paceannual.htm
Which, given its low gravity and thick atmosphere, might actually work.

Pat