What are the billionaires waiting for their turn and suborbital tourist trip? For some, the satisfaction of a child’s illusion, which may border on obsession. For others, it’s a question of ego. But everyone shares the dream: “Boldly go where no one has ever gone,” as stated in the introduction to each chapter. Star Trek. Space society Jeff Bezos has posted on his YouTube channel a complete record of the flight that caused his baptized mannequin capsule Skywalker as the only crew member. The whole trip takes 11 minutes. It’s worth a look to get an idea of what the first four Blue Origin passengers will see.
But where does the universe begin? The generally accepted border is the Karman line, one hundred kilometers above the ground. Anyone who exceeds this limit, even for a few minutes, has the right to be called an astronaut. This is certainly the main motivation of space tourists.
Although the border was not always there. For many years, the US Air Force set it a little lower: about 80 kilometers. This allowed several X-15 pilots (experimental aircraft and missile hybrid) to obtain this title. Neil Armstrong, who flew seven times in the X-15, never exceeded this limit; he would have to wait for his incorporation into NASA to get through it.
The level of 100 kilometers – more kilometers, less kilometers – is not arbitrary. It is the height at which the air is so thin that a conventional aircraft would have to fly at enormous speeds for its wings to develop enough lift to keep it in flight. Almost eight kilometers per second, that is, orbital speed: 24 Mach.
No aircraft reached this speed. Spy plane SR-71 Blackbird reached its mark at speeds of just over 3,500 km / h or around one kilometer per second; and X-15 more than doubled (equivalent to Mach 6’7). Both were disqualified for many years.
But these are only theoretical considerations that do not make sense in practice. After curving the Earth at almost eight kilometers per second, the sheer centrifugal force compensates for the weight of the spacecraft, so it remains in flight without the need for wings: artificial satellite.
At such speeds and only 100 kilometers high, of course, the friction of the air, however slight, makes it impossible to maintain orbit. The braking effect is so intense that the surface of the capsule is incandescent and – if not sufficiently protected – is destroyed within a few moments.
The flights that Blue Origin advertises are simple vertical jumps, almost like going up and down in a very high lift.
The satellite rarely flies below 180 kilometers and even this level is very critical. He holds the world record Tsubame, a small Japanese vehicle that lasted a week and descended less than 168 kilometers to take high – resolution photos. Some military satellites also occasionally descend to these levels, but it’s a momentary maneuver to track very specific targets and then ascend again to safer heights.
All of these factors explain why the flights announced by Blue Origin are simple vertical jumps, almost like going up and down in a very high elevator. The speeds achieved are relatively modest. There is no re-entry maneuver, which is always the most dangerous part of the mission, and no acceleration over the short three “ges”; just falling from a height of 100 kilometers, stopped at the last minute by parachutes.
Rafael Clemente He is an industrial engineer and was the founder and first director of the Museum of in Barcelona (now CosmoCaixa). He is the author of the book The Little Step for [un] man (Dome Books).