Doc O'Leary wrote on Mon, 11 Jun
2018 03:16:38 -0000 (UTC):

For your reference, records indicate that
Jeff Findley wrote:

High altitude balloon launch is a tad risky and only gains you a bit of
altitude and zero velocity. Not worth the complexity and cost, IMHO.


Like I said, it might not *currently* be viable, but as an alternative
technology it brings new sets of trade-offs to the table such that a few
tweaks here and there might make it viable for certain kinds of launches
(e.g., “bulky” items that are hard to make aerodynamically efficient
benefit from starting at the highest possible altitude).


And just what such items do we send to space?



BFR/BFS is planned to be "zero waste" from the very beginning. Fully
reusable TSTO with "gas and go" like operations.


But that’s not the true “zero waste” I was talking about. Any resources
that you’re sending up *and* down, along with any fuels you burn to do it
safely, is a waste. It may be a necessary waste for the current launch
technologies, so it’s good to minimize it, but I still say it’s a good
idea to think about ways to shoot stuff into space that doesn’t involve a
lot of heavy stuff coming back to Earth.


Well, let us know if you think of one that doesn't require unobtainium
or payloads to take tens of thousands of gravities on launch.



Also don't count out Blue Origin. They're off to a slow start, but have
a very reliable funding source in Jeff Bezos ($1 billion a year).


I’m not counting them out, but when the topic is cost/efficiency, the
basic question is still how much energy is being expended to get each
kg into orbit. So long as the idea is still to send a lot of
supporting (non-fuel) heavy stuff up only to have most of it come back
down, there are wastes that a new technology can come in and improve
upon.


We're constrained by the real world. Magic materials are right out.



Besides, how you going to get those space elevator bits into orbit?
That's right, conventional (hopefully reusable) launch vehicles.


Hope for bigger things. I fully believe that, for a society to be
advanced enough to make a space elevator project realistic, it’s value
would be more incremental than revolutionary. Rockets are the best we
have right now, but we’re stuffed if that’s the best we can do.


Just why are we 'stuffed'? Be specific.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn