Will the rich and famous that might travel on the Virgin Galactic flight to the sub orbital region be called astronauts?
Well that depends on our definition of where atmosphere ends and space begins. If you ask me where is outer space, I will point my finger up. No one actually knows where air space ends and outer space begins. The question looks trivial to us but with the present interest and exploration of space by many countries it becomes important as it can become a clash point between countries.
The present status on space is that it is free for use and exploration by all, but the sovereign airspace above a country is a different thing. Here each country has its rights and domination. If space is defined to start at 55 miles above earth then it is ok to fly a satellite at 60 miles above Russia. But if Russia defines the edge of space at 60 miles then it can take that satellite as hostile object. Therefore it becomes crucial.
Experts of this field are of opinion that space starts where the orbital dynamic forces become more important than that of aerodynamic forces. That is at sub orbital speed the atmosphere alone cannot support the aircraft.
Theodore Von Karman a Hungarian physicist defined it first at 50 miles or 80 kms above sea level, but now the accepted line is 62 miles or 100 kms above sea level. This imaginary boundary is called the Karman line. NASA places the line at 76 miles and US Air Force and NATO at 50 miles.
There is no clear demarcation as earth’s atmosphere thins over about 600 miles. The International Space Station orbits at about 240 miles so actually it is not at a space zone as some atmosphere is there.
For the powerful countries it has civil and military overtones. Satellite communication is the backbone of strategic missile systems and GPS and ground maps, weather maps. All satellite systems; both commercial and military have 3 components, the satellite, the ground support and the link connecting the two.
The third component, the links are most vulnerable. There can be up link jamming and down link jamming. Up link jamming target the radio receivers and require high power transmitters. Its effect is over a larger area if its customers are located around the world. Down link jamming can affect communication links and navigational links signals and its effect is localized.
Then there are anti satellite weapon systems which can actually bring down a satellite. Four nations have successfully tested them USA, Russia, China and India.
As the countries rush towards space exploration and militarization, it becomes imperative to frame laws governing it. In future the ‘near outer space’ is of keen interest of both large commercial establishments as well as the military. In our endeavor t fulfill the political and commercial ambition of countries we should not make it a flash point of conflict in future.
Thanks Telesfor sir