wardialer
Topic Author
Posts: 1184
Joined: Fri Sep 14, 2001 1:08 pm

### What Is The Edge Of Space (Altitude In Feet)

At about what altitude does actual space begin in feet? I heard it was something like 350,000 feet. But I just want to make sure.

bragi
Posts: 212
Joined: Sun May 27, 2001 5:17 am

### RE: What Is The Edge Of Space (Altitude In Feet)

Hi,
The atmosphere is divided into; the troposphere (approx. 36.000 feet, where most of the flying takes place), the stratosphere (approx. 164.000 feet), the Mesosphere (approx. 262.000 feet) and the ionosphere, which is divided into four layers and extends to about 700 kilometers. That´s approx. 2296700 Feet.

When you leave the ionosphere, you´re out of the atmosphere!
Muhammad Ali: "Superman don’t need no seat belt." Flight Attendant: "Superman don’t need no airplane, either."

sllevin
Posts: 3314
Joined: Wed Jan 30, 2002 1:57 pm

### RE: What Is The Edge Of Space (Altitude In Feet)

For what's it's worth, the USAF and NASA consider a person to be an astronaut if they've flown higher than 264,000 feet (50 miles). This was most relevant to people flying the X-15, which was capable of getting above that altitude.

Steve

jhooper
Posts: 5561
Joined: Thu Dec 13, 2001 8:27 pm

### RE: What Is The Edge Of Space (Altitude In Feet)

While there might be various definitions, I don't believe that there is an exact point where atmosphere stops and space starts. The further away from earth you get, the less air molecules you will encounter, but it's a gradual transition. Perhaps someone can answer at what altitude does the sky lose it's blueness and turn black? That's where I tend to define "space".
Last year 1,944 New Yorkers saw something and said something.

sllevin
Posts: 3314
Joined: Wed Jan 30, 2002 1:57 pm

### RE: What Is The Edge Of Space (Altitude In Feet)

Seeing "black" and the curvature of the earth happens while one is still well within what I think we'd define as 'atmosphere' -- somewhere around 60,000 feet or so. Concorde sees it, and the XB-70 and SR-71 pilots saw it as well in the 70,000 foot range. But there's still plenty of atmosphere at that point -- enough to heat their airframes to nearly 1000 degrees Fahrenheit in the case of the SR-71!

But yes, even at 50 miles it would be tough to maintain an orbital profile, but the decay would be in tens of hours, though. The shuttle routinely operates in at the 150mile arc, though.

Steve

ThirtyEcho
Posts: 1411
Joined: Tue Jan 01, 2002 1:21 am

### RE: What Is The Edge Of Space (Altitude In Feet)

Physiological "space" is what counts. That is where, without a pressure suit and pressurized oxygen helmet, your blood would boil instantly in a depressurization and you would be immediately dead. Depending on atmospherics, that altitude is around 60,000 feet. Virtually all of the atmosphere is below you at 60,000.

Have fun suiting up for your trip on Concorde, heh-heh.

prebennorholm
Posts: 6609
Joined: Tue Mar 21, 2000 6:25 am

### RE: What Is The Edge Of Space (Altitude In Feet)

The 50 miles border is in fact a "political" one. Some 40 years ago the USA and the Soviet Union agreed upon recognizing the 50 miles border (or rather 80 km which is approximately 49.7 miles).

I think that that border was later somehow recognized by the UN too.

It means that an unarmed vehicle (e.g. a spy satellite) cruising above that border shall be considered a "legal" vehicle anywhere, while below....

Regards, Preben Norholm
Always keep your number of landings equal to your number of take-offs

GDB
Posts: 12888
Joined: Wed May 23, 2001 6:25 pm

### RE: What Is The Edge Of Space (Altitude In Feet)

Liquids boil at 63,000ft.
Concorde routinely reaches 58,000ft at the top of the cruise/climb.
At 58,000, the sky is a dark blue, with the curvature of the Earth visible in clear conditions, (distortion through camera lenses and windows does tend to exaggerate this in pics taken by pax though).

Guest

### RE: What Is The Edge Of Space (Altitude In Feet)

GDB - which liquid - ??? water or mercury, or beer...
xxx
Blood boils at 63,000 feet, at its temperature of 98 F or 37 C...
Reason why pressure suit required to fly at high levels...
xxx
My blood boils too, in view of numerous incorrect statements, at sea level...
(s) Skipper

prebennorholm
Posts: 6609
Joined: Tue Mar 21, 2000 6:25 am

### RE: What Is The Edge Of Space (Altitude In Feet)

Lukewarm beer starts boiling off the alcohol slightly above 50,000 ft. So if you want to get blasted on a Concorde trip, then better keep that cabin pressure up or keep your beer cold.

On an unpressurised Concorde I'd recommend whisky on the rocks rather than hot tea.

PS: Only one slight problem - when the alcohol goes into your blood, then how do you keep it cold?
Always keep your number of landings equal to your number of take-offs

Guest

### RE: What Is The Edge Of Space (Altitude In Feet)

If this helps... On average, at 100,000ft, 99% of the atmosphere's molecules are below you. But there is still a whole heck of a lot of distance above you too!

Cameron

GDB
Posts: 12888
Joined: Wed May 23, 2001 6:25 pm

### RE: What Is The Edge Of Space (Altitude In Feet)

I was obviously referring to the previous post, which specified blood, but it was late!
Concorde's cabin pressure is some 6000ft.

### Who is online

Users browsing this forum: fortytwoeyes, Horstroad, paracetamol and 20 guests

### Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos