QUOTE (TheAnt @ Feb 9 2017, 05:14 AM)
I really like the Dragonfly proposal,......
I'm glad you like it, it has been a lot of fun to work on.
I'm not going to get into a to-and-fro on a competitive proposal, but your metallurgy risk comment is not well-founded. Engineering systems operate in Titan-like
conditions all the time in the liquefied natural gas industry (and in launch vehicles with cryogenic propellants like liquid oxygen) The relevant materials are well-understood - Huygens didn't smash into pieces.
As for rotors, they don't need gearboxes so the lubrication is a much simpler problem than for rovers, for example.
Of course, all these and other technical challenges will receive close scrutiny during the review process, which I am not going to prejudice with further discussion in this forum.
Over the years I have formulated an aphorism of planetary vehicle design :
"It is possible to contrive a pathological planetary scenario that will defeat any finite-cost space system".
So reductio ad absurdam, to avoid risk altogether, you stay at home. I hope that is not NASA's posture.