Good-news, bad-news; 10th planet, protomoon or dead Earth

Paul F. Dietz wrote:

Cardman wrote:


When you mine the atmosphere you are subject to drag. And I am sure
that it is true to say that He3 extraction is not exactly a small and
easy operation.

And so you would be hanging about in a decaying orbit, that you would
need to support through regular boosts, where at the end of all this
you still have to climb out of that large gravity well.


You certainly would have to get back to space, but you wouldn't
be mining from orbit. You'd use a bouyant vessel down around
the 10 bar level, probably a nuclear hot air balloon.

The point is you'd be boosting four or five orders of magnitude
less mass up to orbital speed vs. your scheme.

I thought it was supposed to be a combination of the two. You
have a hot air (well Uranian atmosphere, can we really call that
air) balloon mining 3He and preparing packets for the scoop.
The scoop only pickups 3He. The scoop only serves as a way
to avoid having an 18.7 km/s delta vee rocket carrying the mined
3He from Uranus. A few *technical details* need to be worked
out before doing this :-)

Alain Fournier

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