Permanent Human Settlement of the Earth, Space and Ocean Frontiers

Friday, April 10, 2009

Now We Know - The Final Frontier Begins At 73 Miles

If one is venturing to the final frontier, it would be nice to know where it actually begins. Space has a definition – it is that point where the earth’s atmosphere officially ends and the vacuum of space officially begins. In aerodynamic terms, it is that point where there is no longer any lift on aerodynamic structures – such as the wings of aircraft.

NASA has a true need to know where this is for the purposes of piloting the Space Shuttle – and their equations define the boundary layer at 62 miles and the shuttle’s performance is plenty good with this definition.

However, scientists at the University of Calgary applied instrumentation to this question by a rocket launch to this boundary, too high for balloons and too low for satellites. The space boundary instrument was carried by the JOULE-II rocket on Jan. 19, 2007. It traveled to an altitude of about 124 miles (200 kilometers) above sea level and collected data for the five minutes it was moving through the "edge of space."

According to this study, the precise boundary of space is exactly 73 miles above the surface of the earth.

This has a fairly important meaning. NASA defines an ‘astronaut’ as anyone traveling to an altitude of more than 50 vertical miles. For the most part nearly all NASA astronauts fly well above that – but there are some interesting exceptions.

For example: The X-Prize was awarded in 2004 to Scaled Composites as the first private flight into space. But, Spaceship One, according to telemetry, never actually made up what the Calgary definition now defines as 73 miles. Spaceship One only made it to 367,422 feet, nearly three and a half miles short of the boundary. They were significantly above the “astronaut’ definition of 50 miles and just above the space shuttle boundary – but just short of the new definition.

And – there are eight X-15 pilots who have earned “Astronaut Wings” who have flown above 50 miles but still short of 73.

It is, of course, so much trivia and much ado about literally nothing – but – in the future when many millions of dollars are on the line – the precise definition and bragging rights will eventually come into play. This scientist and engineer predicts that the boundary between 50 and 73 miles will be a true no-man’s-territory that no one will want to settle who desire to be called a 'real astronaut'. For after all - who will pay all those hundreds of thousands of dollars and still fly just short of the newly defined boundary? After all - the whole private spaceflight venture is all about and only about bragging rights, period.

PS. If I may be allowed an afterthought – Spaceship Two, is currently designed to carry fairly large numbers of people into that no-man’s-boundary with an advertised max altitude of 68 miles – an agonizing five miles short of the newly defined Calgary limit. I strongly suspect there is going to be an inevitable political argument over this finding!