T
thalion
Guest
Great topic; this has been close to my heart for a long time.<br /><br />Lift:<br />For a balloon, the answer is simple, elaborated in Clarke's classic novella "A Meeting with Medusa": hot hydrogen. Actually, I'm willing to bet that hot atmosphere period would be sufficient for good lift.<br /><br />Power: I'm guessing an RTG would be good...however, there are some problems, IMO:<br /><br />1.) Weight on a platform on which every ounce means considerably more gas.<br /><br />2.) We shouldn't send an RTG-powered balloon to Jupiter without a precursor mission, IMO, to show that survival in the atmosphere for more than a few hours or days is feasible. For instance, we have little idea how turbulent Jupiter's atmosphere is at the balloon level; IIRC, Galileo probe data suggested it was a bumpy ride.<br /><br />For this precursor mission, I suggest solar power, or better yet, a battery that can last at least a week or two.<br /><br />Radiation:<br />I doubt this would be a problem in Jupiter's atmosphere proper, but getting there would be something else.<br /><br />In sum, the biggest obstacles we face in deploying a balloon probe to Jupiter are:<br /><br />1.) Little knowledge about the atmospheric environment.<br /><br />2.) How make an instrument platform that will last.<br /><br />3.) How to make a probe with all the "trimming" that can survive however many years in space, Jupiter's radiation belts, and the extreme deceleration required to deploy it. With Galileo, there were few moving parts aside from the probe and its shield. With a much more complex balloon probe, there will be that much more that can go wrong.<br /><br />4.) And, last but not least, the cost of launching the required mass to Jupiter.<br /><br /><br />