if a human could fly, will he be able to exit the earth's atmosphere, flying slowly, without hurting himself ?

Question

And can re-enter not not wearing any kind of special suit.

Answer 1

No. Neither can birds or airplanes. Flying that way depends on the air, and there is no air in outer space. Space flight is all ballistic and not aerodynamic. That means it is like a rock being thrown and not a feather drifting on the air.

Answer 2

How do you define flying? If you are talking about bird-like flying, you need air to push and pull yourself against. Once out of the atmosphere, there's no air and thus you cannot fly. There is a "service ceiling" where there's just enough air to keep your altitude, without the ability to go any higher. This service ceiling is nowhere near the end of our atmosphere.

Then there's rocket-like flying. If a human being could somehow generate enough trust, without relying on the surrounding air (for oxygen), and with unlimited power (fuel), you can go higher than the service ceiling in my previous paragraph. As long as the trust is high enough to counter earth's gravity plus a bit more, you will move away from earth. The further away you get, the less gravity you will have to counter.

Forget the story about escape velocity. This is only true for an unpropelled ("ballistic") flight.

Human skin is not able to protect the body against cosmic radiation, extreme heat, extreme cold, and thus you need a space suit for these reasons. But I guess you were talking about burning up due to friction: Yes, if you apply just enough trust to *almost* balance earth's gravity, you will be able to enter the atmosphere very slowly and without any recognizable friction. It will take a long time to descent but you could get a constant rate of descent, for instance one meter per second, by applying just enough trust.

Of course all this is pure theory. Humans will never be able to fly by themselves, and even rocket-like propulsion (be it rockets, or anti gravity, or whatever else we come up with) will not be possible soon.

Answer 3

Aside from not being able to fly fast enough to reach escape velocity, what would this human be BREATHING once he left the atmosphere? And without an atmosphere to push against how would he fly? There are just too many things wrong with this question.

Answer 4

"Flying" implies an interaction with the air. It is the flow of air along wings that creates the lift needed to stay in flight and to move around.

No atmosphere = no flight.

Also, some kind of suit would be needed to keep the flying human alive once she or he is above the atmosphere (breathing, protection from heat or cold, protection from vacuum and from strong radiations like UV rays...).

Answer 5

All the above are true, but you can get close. Back in the earliest days of the space program, people ascended to about 35 kilometers in high-altitude ballons (above almost all of the earth's atmosphere), and returned to earth by sky-diving with a parachute. They had pressure suits and oxygen tanks, of course. Falling down from that height took about an hour.

Answer 6

Above 10,000 feet there is not enough oxygen to sustain you (although some can adapt and survive up to 15,000 feet). But definitely when you hit 20,000 feet and above you would pass out.

Commercial aircraft are pressurized with air, so that's why you go so high yet don't pass out.

The escape velocity was already mentioned, but there is a technology which will allow us in the future to go into space more easily- the space elevator. See the link in the reference below.

Answer 7

No. Earth's escape velocity is over 11 km/sec.

Answer 8

An airplane will climb continually but it"s gets slower and slower the higher it goes.
Eventually it will run out of air.