The 21st century may never top this and it's only 2015.

[fromderinside]

The only definition of edge of space that even remotely mentioned orbiting is:

from: http://www.ask.com/science/far-edge-space-earth-e3f3ef46b7bdb91f

The Kármán Line, which was first proposed by scientist Theodore von Kármán in the 1950s, lies within the thermosphere, the layer of the atmosphere where the International Space Station orbits. The United States Air Force defines the edge of space as 50 miles above mean sea level, and international law does not specify an exact boundary but uses the lowest perigee of an orbiting space vehicle to define the boundary.

and

The edge of space is generally recognized internationally to be at the Kármán Line, which is 62 miles from the surface of Earth. While the exact boundary of space is open to interpretation, this is the definition recognized by the Federation Aeronautique Internationale and National Aeronautics and Space Administration

The reason orbiting is mention is it is at that altitude of orbit perigee where atmosphere does not cause significant degradation of orbit (maintainable orbit). It is considered an altitude and it really has little to do with how fast the object passing it is traveling beyond sufficient for the vehicle to achieve that altitude. Its obviously not required to be orbiting velocity since suborbital and below escape velocity speed craft have achieved that altitude in suborbital flight.

https://en.wikipedia.org/wiki/Kármán_line

We agree. My point is that any object that achieves 62 m above earth has entered space including those craft which travel nowhere near orbital velocity. The thing we hadn't discussed was necessity in the actual experience of a particular craft.

 

[Loren Pechtel]

The only definition of edge of space that even remotely mentioned orbiting is:

from: http://www.ask.com/science/far-edge-space-earth-e3f3ef46b7bdb91f

The Kármán Line, which was first proposed by scientist Theodore von Kármán in the 1950s, lies within the thermosphere, the layer of the atmosphere where the International Space Station orbits. The United States Air Force defines the edge of space as 50 miles above mean sea level, and international law does not specify an exact boundary but uses the lowest perigee of an orbiting space vehicle to define the boundary.

and

The edge of space is generally recognized internationally to be at the Kármán Line, which is 62 miles from the surface of Earth. While the exact boundary of space is open to interpretation, this is the definition recognized by the Federation Aeronautique Internationale and National Aeronautics and Space Administration

The reason orbiting is mention is it is at that altitude of orbit perigee where atmosphere does not cause significant degradation of orbit (maintainable orbit). It is considered an altitude and it really has little to do with how fast the object passing it is traveling beyond sufficient for the vehicle to achieve that altitude. Its obviously not required to be orbiting velocity since suborbital and below escape velocity speed craft have achieved that altitude in suborbital flight.

https://en.wikipedia.org/wiki/Kármán_line

We agree. My point is that any object that achieves 62 m above earth has entered space including those craft which travel nowhere near orbital velocity. The thing we hadn't discussed was necessity in the actual experience of a particular craft.

The point of my link was that flight is useless above that altitude.

 

[fromderinside]

The only definition of edge of space that even remotely mentioned orbiting is:

from: http://www.ask.com/science/far-edge-space-earth-e3f3ef46b7bdb91f

The Kármán Line, which was first proposed by scientist Theodore von Kármán in the 1950s, lies within the thermosphere, the layer of the atmosphere where the International Space Station orbits. The United States Air Force defines the edge of space as 50 miles above mean sea level, and international law does not specify an exact boundary but uses the lowest perigee of an orbiting space vehicle to define the boundary.

and

The edge of space is generally recognized internationally to be at the Kármán Line, which is 62 miles from the surface of Earth. While the exact boundary of space is open to interpretation, this is the definition recognized by the Federation Aeronautique Internationale and National Aeronautics and Space Administration

The reason orbiting is mention is it is at that altitude of orbit perigee where atmosphere does not cause significant degradation of orbit (maintainable orbit). It is considered an altitude and it really has little to do with how fast the object passing it is traveling beyond sufficient for the vehicle to achieve that altitude. Its obviously not required to be orbiting velocity since suborbital and below escape velocity speed craft have achieved that altitude in suborbital flight.

https://en.wikipedia.org/wiki/Kármán_line

We agree. My point is that any object that achieves 62 m above earth has entered space including those craft which travel nowhere near orbital velocity. The thing we hadn't discussed was necessity in the actual experience of a particular craft.

The point of my link was that flight is useless above that altitude.

I'm not so sure. Is it true that the amount of atmosphere (number of molecules per cubic meter) is the same for minimum practical keeping of orbit and practical minimum for user in propulsion? Even at the minimum orbits decay and platforms finally crash. Perhaps a minimum there are enough molecules of oxygen for exploitation by fuels and for additional lift. I even expect that satellites built with lift elements might stay in orbit longer than those that don't include such features both of which suggest flying is still a potential benefit.

 

[skepticalbip]

I'm not so sure. Is it true that the amount of atmosphere (number of molecules per cubic meter) is the same for minimum practical keeping of orbit and practical minimum for user in propulsion? Even at the minimum orbits decay and platforms finally crash. Perhaps a minimum there are enough molecules of oxygen for exploitation by fuels and for additional lift. I even expect that satellites built with lift elements might stay in orbit longer than those that don't include such features both of which suggest flying is still a potential benefit.

I think what Loren is saying is that at 62 miles there isn't sufficient air density for wings to give sufficient lift to support the aircraft at speeds below orbital velocity (not even worrying that there isn't enough oxygen to keep the engines going). An aircraft at this altitude would either be on a ballistic trajectory having gained enough momentum at lower altitudes to throw itself there (following an arc like an artillery shell) or rocket powered and standing on its tail till the fuel runs out.

And yes, satellites at this altitude would have a decaying orbit because there is still a thin atmosphere sufficient to slow its velocity to below orbital velocity given a little time.

62 miles is the "edge of space", not enough atmosphere to fly and too much atmosphere to maintain a stable orbit.

 

[Loren Pechtel]

I think what Loren is saying is that at 62 miles there isn't sufficient air density for wings to give sufficient lift to support the aircraft at speeds below orbital velocity (not even worrying that there isn't enough oxygen to keep the engines going).

Exactly. I'm not discussing whether an air-burner engine is possible, but whether wings work.

I don't believe an air-burner engine could work, either--you'll get the same problem you have with a Bussard ramjet. Gathering the material costs you energy, there's only a certain amount of energy to be had from the material you gather, the ratio between these sets a maximum velocity that can be attained. (In the case of the Bussard ramjet it's about 12% of lightspeed IIRC.)

 

[fromderinside]

I'm not disagreeing with you Loren Pechtel. I am just suggesting that "state of the art" is a moving target. NASA didn't bother with recoverable, by self landing, fuel units because the technology wasn't yet there. Now that batteries are both powerful enough and provide sufficient range electric cars are becoming a reality.

I just got the sense that some considered all research relevant to space launch had been done, the book was closed. Its not.

Obviously much of what I thought was possible isn't so thats bad on me. Closing doors with a stuffy shirt even when it is justified requires that everybody keep an open mind.

 

[Loren Pechtel]

I'm not disagreeing with you Loren Pechtel. I am just suggesting that "state of the art" is a moving target. NASA didn't bother with recoverable, by self landing, fuel units because the technology wasn't yet there. Now that batteries are both powerful enough and provide sufficient range electric cars are becoming a reality.

I just got the sense that some considered all research relevant to space launch had been done, the book was closed. Its not.

Obviously much of what I thought was possible isn't so thats bad on me. Closing doors with a stuffy shirt even when it is justified requires that everybody keep an open mind.

The thing is "can't" comes in two radically different flavors.

There's the "can't" of not having any idea whatsoever of how to accomplish it and thus decreeing it impossible. This is generally the statement of an older scientist and is probably wrong.

There's also the "can't" of it violates physical laws (which almost always is right--you can't get around this one other than by finding new physical laws) or it demands more than is possible (which normally is right).

 

[barbos]

Well, latest attempt failed

 

[Loren Pechtel]

Well, latest attempt failed

"Break a leg" isn't supposed to be taken literally!

 

[barbos]

Well, latest attempt failed

"Break a leg" isn't supposed to be taken literally!

Yeah, someone must have broken that leg before the start.

 

[Loren Pechtel]

"Break a leg" isn't supposed to be taken literally!

Yeah, someone must have broken that leg before the start.

Actually they are thinking that it might not have been broken, but rather that ice jammed up the mechanism and it didn't lock.