This month marks the 75th anniversary of Charles Lindbergh's historic flight across the Atlantic. It also marks the 50th anniversary of the first commercial jet flight, and it has already been 45 years (this October) since Sputnik was launched. Coming up next year is the 100 year anniversary of the Wrights Brother's first "powered-flight" at Kitty Hawk, North Carolina. So, there's quite a bit to celebrate in terms of aviation history. Even before we were roaring through the sky on winged aircraft, balloons enabled us to have a perspective of what the Earth looks like from above. In fact, during the Civil War, the Union Army used balloons for reconnaissance in an effort to deploy troops.

While low-flying planes and balloons are useful for surveying battlefields or looking at storm damage, for example, they don't allow you to get high enough to examine much of the Earth. For this, you need more altitude than propeller-driven aircraft can provide. The higher you go, the more of the Earth you're able to observe. Of course, in order to go high, not only was a powerful propulsion system needed to lift heavy objects into off the ground, but a suitable aerodynamic design was also required.

Space rockets are narrow and long to reduce air resistance. Because they're inherently supersonic (orbital velocity is 24-25 times the speed of sound), they don't use wings during ascent. Wings only help at low speeds and just create more air resistance at higher speeds. Additionally, rockets have sharp noses, which produce the weakest wave shocks - the greater the shock the greater the resistance.

Once the rocket breaks the surly confines of our atmosphere, their shapes can be a bit more variable. For instance, spacecraft can spin or not, some are drum-shaped (those usually spin), some have solar panels that stick out. However, if the spacecraft is to reenter the atmosphere safely, a tremendous amount of energy must be dissipated. A blunt front creates a strong shock wave and much of this energy goes to heating the air in the shock wave, rather than the spacecraft. Still, the heating of the front of the spacecraft is strong enough to require protection. In the case of the Space Shuttle, ceramic tiles are used to help absorb re-entry heat.

The Concorde is the world’s only supersonic commercial aircraft. It cruises at more than twice the speed of sound at around 1,350 mph and at an altitude of up to 60,000 ft (over 11 miles high). A typical trans-Atlantic crossing (Paris to New York) takes less than three and a half hours. Concorde's fastest Atlantic crossing occurred on February 7, 1996, when it completed the New York to London flight in 2 hours and 53 minutes. Because of the 5 hour difference in time between the east coast of the US and western Europe (4 hours during daylight savings time), when travelling westwards, the Concorde actually arrives before it has departed - local time at least. Although the first flight of the prototype Concorde aircraft took place on April 9 1969, the supersonic commercial era was inaugurated on January 21, 1976, with trips from London to Bahrain and from Paris to Rio de Janeiro.

The Concorde measures 204 ft in length, however because of heating that takes place during flight, the air frame stretches between 6 and 10 inches. Although its signature nose droop looks aerodynamic, it was designed to improve pilots' visibility, especially during take off and landing. The Concorde's four engines have been specially modified to produce more than 38,000 lbs of thrust, with the injection and combustion of additional fuel, and this permits the final stage of the engine "burn" to generate the extra power required for take-off and the transition to supersonic flight. Concorde takes off at higher speeds than do subsonic aircraft, 220 knots compared to 165 knots, and landing speeds are also higher. In flight, however, the Concorde handles similarly to other commercial jets.

An advantage for the aircraft at flying high is that travelling at Mach 2 and at 60,000 feet effectively removes any moisture that may have collected on its frame while on the ground - this helps prevent corrosion. While the windows of a subsonic commercial jet feel cool, the Concorde's windows are warm to the touch, due to the heating of the frame that occurs in flight. In addition, at full altitude, encounters with clear air turbulence aren't a concern. Again, you're well above most of the atmosphere and hence most weather that could cause turbulent conditions.

In regards to the main thrust (sorry) of the question, the Concorde is the closest that you or I will likely ever come to leaving the Earth's atmosphere. Heights of 60,000 ft or about 11 miles or so put you well into the stratosphere. Still, that's several hundred miles shy of the altitude required to orbit our planet. Nevertheless, it's high enough to see things that aren't possible from a commercial jet, which rarely fly above about 40,000 feet.

The take off of the Concorde is rather brisk. Just 15 minutes into the flight, you're already traveling faster than any subsonic airliner is able to, and a mere 30 minutes after heading down the runway, you're cruising at 48,000 feet and at a speed of Mach 2 (1,350 mph). About an hour into flight, a view of the curvature of the Earth is possible - too bad the windows can't be bigger. Other than astronauts and test pilots, passengers on the Concorde are the only ones to ever see this sight. if you look up, away from the Earth's surface, you might notice that the sky doesn't have much of a blue color. You're basically above the air molecules which preferentially cause blue light to be scattered toward the Earth's surface. Consequentially, the sky may look more black than blue.

Although departure schedules don't always allow you to see this, because of the Concorde's speed, it is indeed possible to see the Sun rise in London, and then on arrival in New York, see it rise once again. Traveling eastward, twilight is very brief on the Concorde. You basically go from daylight to darkness in a matter of minutes. If the cabin lights are turned down, the stars or the glow of aurora can be breathtaking - not because you're closer but simply because there's less atmosphere to content with.

Of course, flying high and fast doesn't come cheap. Instead of a round trip fare on a normal subsonic flight of approximately $500 between New York and London, a typical one way ticket on the Concorde would cost more than 12 times this amount - more than $1 per mile! Even with this hefty fare, the on-board amenities aren't particularly noticeable at first. For instance, since the Concorde is smaller than other commercial jets, the seats are slightly smaller. By the way, what I'm writing here certainly doesn't come from personal experience - I've never been in the Concorde. On occasion, I used to see it, or hear it, when Washington's Dulles Airport was a Concorde destination (it only flies into New York now).

Compared to other jet airlines, there's a definite ambiance associated with the Concorde. For example, Dom Perignon is served throughout the flight, and Maine lobster, served on white china dishes, may be on the menu. I guess it goes without saying that if you're forking over 6000 clams for a ticket, you expect something more than a soda and peanuts.

For more about rocket flight and similar questions see;
http://www-spof.gsfc.nasa.gov/stargaze/Sintro.htm
For more about the Concorde see http://www.concorde-jet.com/
and the Washington Post article in the Style section on January 27, 2002.