Space travel is back in the news. The adventures of Richard Branson and Jeff Bezos have made it possible for an average person like me dream again of travelling in space.
The last time I had that feeling was in the late 60’s after moon walks. We believed then that space travel would become common place and we would all be making journeys to the moon, if not Mars. Remember 2001: A Space Odyssey? Well, 2001 came and went, and 20 years later, we are still no closer to travelling to moon. Now, I am getting too old, but thanks to Virgin Galactic and Blue Origin, there is some hope that my dream will be fulfilled.
For many people, this is just a stunt by very rich people and they could have used their money elsewhere. Well, yes, and I am not endorsing Bezos or Branson. They are showmen and have accumulated enormous wealth, some of it on the backs of people who work for them. They are also human beings with faults.
But that does not take away from the fact that they demonstrated at their own risk two different systems for commercializing space travel. These are still baby steps but now there is a price attached to make any individual an astronaut. It is still expensive, but the price will come down. Also, this is just one of many possibilities opening up…consider the SpaceX system for example. They have announced an all-civilian crew for an orbital flight later this year.
Regarding spending money elsewhere, I have heard that argument many times, for example, when NASA was launching manned flights or when the Indians Space Research Organization was testing rockets in the 60s. If you go with that attitude, there will be no discoveries, no adventures, no excitement.
Now a few explanations and clarifications.
In US, if you go above 50 miles (80 km), you become an astronaut. Another organization (FAI) requires the altitude to be 62 miles (100 km). This is when you cross what is called Kármán Line, and the atmosphere is so thin, you require centrifugal force to remain afloat for a long time. That is how satellites or space station stays afloat.
The space-flight of Bezos or Branson was not quite sustainable. They went up above the 50-mile limit and came down making them (and their fellow travelers) astronauts. In the past, a rocket powered experimental aircraft, X-15, went up high enough to make its pilots astronauts in 1959, long time before Virgin Galactic.
They did experience weightlessness. Weightlessness does not mean zero gravity. Gravity is always around — -you experience weightlessness when you do not resist its force by being in a free fall. After reaching its maximum altitude, Blue Origin crew experienced weightlessness because they were in a free fall inside their spacecraft which was also in a freefall. Hence the sensation of floating around in their vehicle.
Now if you add horizontal speed to the vehicle, free fall will not be straight down but a parabola. This is what an airplane designed to simulate weightlessness does…it executes parabolas starting from high altitude. It is nicknamed vomit comet because of what it does to many people experiencing weightlessness.
If you keep increasing the horizontal speed the vehicle will fall further and further away until at one speed, it will not fall and start going round and round earth. This is when it will be in orbit.
Another, easier way to understand weightlessness while in orbit is to observe two forces: gravity (very much present) and centrifugal force. They balance each other out. Also, both the vehicle and the astronauts are in the same force balance situation and so they can float around.
Oh, how I would love to participate these emerging possibilities!
I realize that at this stage it is a competition between my physical ability to undertake such a journey and its financial affordability.
Who will win?