posted on Jun, 15 2013 @ 06:12 AM
reply to post by pez1975
I f Google is using the high-pressure balloon design developed by NASA for long-term research, each balloon should be able to stay aloft for several
weeks, at least; possibly even several months.
Since these balloons will not be manned, there is really no reason why they would need to use helium as the lifting gas; hydrogen would be far more
efficient, cheaper, and there is no shortage of hydrogen.
Permeability of the gas envelope would be the only real limiting factor; the hydrogen atom is so much smaller than the helium atom it can make
long-term leakage through
the lifting-cell envelope material a real problem for flight duration.
As far as flight-path control is concerned, I'd strongly recommend that Google contact the folks at JP Aerospace
high-altitude, automomous airship designs with full aerodynamic station-keeping capabilities.
The JPA Tandem
airship has already flight-proven many of the capabilities Google is seeking.