I was talking to a friend and we were discussing the earth's
atomsphere, does a rocket need a special trajectory to leave earth's
atomsphere? I know it needs one to come back. How many miles are we
from space, (in miles) from the earth's surface.

muser wrote:
I was talking to a friend and we were discussing the earth's
atomsphere, does a rocket need a special trajectory to leave earth's
atomsphere? I know it needs one to come back. How many miles are we
from space, (in miles) from the earth's surface.

"Space" is often conventionally defined to begin at 50 miles above
sea level. But however it's defined, rockets do follow strategically
chosen paths as they travel through the atmosphere.

The quickest way to get through as much of Earth's air as possible
is to shoot straight up. As the air becomes progressively thinner, it's
then possible to concurrently bend the flight path gradually towards
the horizontal. The thinner the air, the closer to horizontal it can
afford to be without suffering much from drag. This path is called a
"synergic" curve, and it optimises fuel consumption vs drag.

-Mark Martin

muser wrote:
I was talking to a friend and we were discussing the earth's
atomsphere, does a rocket need a special trajectory to leave earth's
atomsphere? I know it needs one to come back. How many miles are we
from space, (in miles) from the earth's surface.



Escape Velocity
http://scienceworld.wolfram.com/phys...eVelocity.html

Certain trajectories can help achieve the desired velocity.

"muser" wrote in message
oups.com...
|I was talking to a friend and we were discussing the earth's
| atomsphere, does a rocket need a special trajectory to leave earth's
| atomsphere? I know it needs one to come back. How many miles are we
| from space, (in miles) from the earth's surface.

Err...I dunno what the atomsphere is, perhaps you mean atmosphere.
To win the $10,000,000 X-prize, SpaceShipOne had to go beyond
the atmosphere.
http://www.scaled.com/projects/tierone/
$10,000,000 said that we are a 328,000 ft, or 62.12...miles from
space.
Straight up is a fairly good trajectory, although if you want to orbit
it's best to
curve over and accelerate to about 17,000 mph.
Androcles.

Sam Wormley wrote:
muser wrote:

I was talking to a friend and we were discussing the earth's
atomsphere, does a rocket need a special trajectory to leave earth's
atomsphere? I know it needs one to come back. How many miles are we
from space, (in miles) from the earth's surface.



Escape Velocity
http://scienceworld.wolfram.com/phys...eVelocity.html

Certain trajectories can help achieve the desired velocity.

You may not want to escape, but just go into orbit
http://scienceworld.wolfram.com/physics/Orbit.html

muser wrote:
I was talking to a friend and we were discussing the earth's
atomsphere, does a rocket need a special trajectory to leave earth's
atomsphere? I know it needs one to come back. How many miles are we
from space, (in miles) from the earth's surface.


Even though the optimal trajectory, might be considered "rocket
science" to some, you can learn a lot from

Trajectory
http://scienceworld.wolfram.com/physics/Trajectory.html

Androcles you are so clever and witty, do many people tell you that, or
do they just call you a w*nker.

muser wrote:
I was talking to a friend and we were discussing the earth's
atomsphere, does a rocket need a special trajectory to leave earth's
atomsphere? I know it needs one to come back. How many miles are we
from space, (in miles) from the earth's surface.



Even though the optimal trajectory, might be considered "rocket
science" to some, you can learn a lot from

Trajectory
http://scienceworld.wolfram.com/physics/Trajectory.html

"muser" wrote in message
oups.com...
| Androcles you are so clever and witty, do many people tell you that,
or
| do they just call you a w*nker.

Thank you, I am, aren't I?
Actually I don't that many complements, nor tolerate stupid ****ing
****s like you.
*plonk*
Androcles.
"If you pick up a starving dog and make him prosperous, he will not bite
you. This is the principal difference between a dog and a man."--Mark
Twain

muser wrote:

I was talking to a friend and we were discussing the earth's
atomsphere, does a rocket need a special trajectory to leave earth's
atomsphere? I know it needs one to come back. How many miles are we
from space, (in miles) from the earth's surface.

Up to leave, over to orbit. Look at a Space Scuttle Launch (OK, look
at tapes, at the launches that worked). Coming back is easy.
Surviving it is something else. Didn't you ever wonder why sci-fi
rocket ships came back butt first? Re-entry frictional heating is
higher in temp than rocket exhaust. The flame is coolant. One then
has an obvious alternative.

Florida launches equatorial orbits eastward for the obvious reason.
Vandenberg lauches polar orbits (surveillance).

Space Officially starts at 50 miles above sea level.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf