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To: killermosquito

Gravity doesn’t drop off that fast as air does.

An Airplane at 35K feet isn’t hovering on engine power, It’s using differential air pressure on the wings to stay up... which takes a lot less energy than direct thrust.

Above 25K feet, there isn’t enough air to breathe. Above 60K ft there is barely enough air to generate lift... and you still have 50 more miles to get to lower “space”.

Airplanes need air to fly. Planes that fly above 80K feet need to go Mach 2 to hit enough air molecules to generate enough lift to stay up. To fly much above 100K ft in a steady state, the plane would likely need to go Mach 5 and its still a long way from space.

A rocket going straight up can go slower in the atmosphere (and not pay such a big drag penalty) and speed up outside of the atmosphere (where drag is much less).

This is the reason we don’t have “aerospace planes” yet. Rockets are much easier/cheaper.


53 posted on 10/31/2014 2:00:17 PM PDT by UNGN (I've been here since '98 but had nothing to say until now)
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To: UNGN

“It’s using differential air pressure on the wings to stay up..”

Actually, lift is generated by the deflection of the air molecules.


65 posted on 10/31/2014 5:00:14 PM PDT by TexasGator
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