CNN
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Blue Origin will carry on Monday a crew full of stars composed of six passengers to the edge of space in one of the most followed suborbital space tourism missions in years.
The flight will last about 10 minutes, will take the group more than 100 kilometers (62 miles) high and offer them a few minutes of ungravation before descending.
But when of the flight the singer Katy Perry, the journalist Gayle King and her travel companions will arrive at the “space”?
Is it when they look out the window and the blue glow of the sky darkens? Is it when they reach an altitude that satellites can orbit? Or is it when the atmosphere becomes so thin that it no longer plays a determining role in the physics of the flight?
In the community flight community, there is no strict definition.
The space can be defined in several ways and the usefulness of the criteria to determine its starting point may depend on the stage. Therefore, various organizations from all over the world use different altitudes to mark that invisible threshold for registration purposes.
And in the case of suborbital space tourism, disputes over definitions can come life of their own.
For example, it is known that Blue Origin and Virgin Galactic have publicly discussed this matter, mainly due to a specific means of defining the space: the Kármán line.
The Kárman line, perhaps the best known and controversial space demarcation, is 100 kilometers (62 miles) above sea level.
Blue Shepard’s suborbital flights from Blue Origin travel just beyond that altitude.
But the company’s main competitor, Virgin Galactic, does not. Its flights to date have reached a distance of approximately 88.5 kilometers (55 miles), which still exceeds the 81 -kilometer (50 miles) barrier that the US government has used for a long time to define the space.
Even so, Blue Origin has pointed out the Kárman line to affirm that its trips are a more legitimate route to obtain the status of “astronaut”, saying in a publication in social networks of 2021 that “none of our astronautas has an asterisk next to its name”, an indirect subtle to Virgin Galactic.
However, defining an astronaut is a completely different matter. In the beginning of space flights, the US government established the definition of 81 kilometers (50 miles) as a basis for granting astronaut badges to military and NASA pilots.
The Federal Aviation Administration (FAA) originally granted commercial astronaut wings to the adventurers of the private sector who would reach altitudes greater than 81 kilometers (50 miles). However, in 2021, the agency decided to almost completely eliminate this program, choosing to publish the list of participants on its website instead of delivering physical badges to private aviators.
Spacex has also granted its own silver set to non -governmental passengers that fly in their Crew Dragon orbital capsule.
So, in practice, deciding who it is and who is not astronaut is the task of the records.
NASA Terry Virts exastronaut told National Geographic in 2018 that it was not too worried about restricting the use of the designation of “astronaut.”
“If you get your back to a rocket, I think it is worth it,” Virts told National Geographic in 2018 when asked about the subject. “When I was a F-16 pilot, I was not envious to call Cessna pilots. I think everyone will know if you paid to be a passenger on a five-minute suborbital flight or if you are the commander of an interplanetary space vehicle. They are two different things.”
However, in the public imagination, the idea of an astronaut often evokes images of a person floating in anxiety, surrounded by the black cosmic extension.
But experiencing the ungravation has little to do with altitude (at least not in the relatively low orbits in which Blue Origin and Virgin Galactic fly).
The gravitational attraction of the Earth will continue to exert pressure on the Blue Origin capsule when it reaches the apogee drinking, the term on space flights to refer to the highest point of the flight career.
But astronauts will not have weight because the energy that the rocket and the capsule accumulated after takeoff will be canceled by the severity of the earth, which will give them a version of a few minutes of the sensation that people experience when they reach the top of a large roller mountain.
On the contrary, astronauts at the International Space Station remain without weight for months because they are in orbit around the earth, which requires speeds much greater than those of the suborbital flights of New Shepard.
However, those in charge of the records have not stipulated that a person must travel to the orbit to be considered astronaut.
The civil and military pilots who commanded X-15 aircraft of altitudes of more than 81 kilometers (50 miles) during a test campaign in the 1960s, for example, were given Alas de Astronaut.
The US government uses the 81 -kilometer (50 miles) brand to define space for many of the same reasons that other organizations use the Kármán line. It is possible that the latter simply calculate the phenomenon differently.
Theodore von Kármán, Hungarian-American engineer and physical and co-founder of the NASA jet propulsion laboratory, was one of the first to try to describe the altitude to which aeronautics becomes astronautical.
But even the initial attempts of Kárman in the 1950s were inaccurate.
“The atmosphere is, in effect, dynamic and its density fluctuates, which makes any delimitation imprecise,” according to a 2014 study on the definition of space. Thus, “the line of Kárman fluctuates between 84 kilometers (52 miles) and 100 kilometers (62 miles).
It should be noted that 100 kilometers is the number defined by the Kárman line La Fédération Aéronautique Internationale, or World Federation of Air Sports, based in Switzerland.
“It has been so since the 60s,” Scott Neumann, president of the Astronautical Registries Commission of the Federation, Icare, told CNN.
The Federation suggested in 2018 that it could reduce its altitude of definition in response to a new research on the Kárman line, but the organization finally did not take such a measure after analyzing the figures.
“You have this beautiful maximum point, which we call ‘maximum equilibrium speed altitude’, and you can point it out in a graph and say: ‘This is where you are starting to look more like a spacecraft and less to a plane,” said Neumann.
The “maximum equilibrium speed altitude” refers to the altitude to which the atmosphere becomes so thin that a ship can no longer depend on the flight dynamics of airplanes.
Instead, the vehicle will need the type of speed provided by rocket engines.
Although the International Aeronautical Federation decided to maintain its definition of 100 kilometers, other researchers and institutions of the space industry do not share the same opinion.
Spence Wise, senior vice president of space missions of the Aerospace Manufacturing Company Redwire Space, told CNN that he believes that a more precise altitude is closer to the 88 kilometers (55 miles).
Wise explained that this definition derives from the behavior of vehicles – mostly discarded propeller rockets – that have returned from space after being dragged out of orbit by atmospheric friction. To contextualize, space emptiness is not always empty. The Earth’s atmosphere, in fact, is reduced along thousands of kilometers.
“But what can be observed consistently is that, at some point between 90 and 88 kilometers, these rocket bodies, when re -entering (to the atmosphere), stop acting as if they were floating in space, driven by a behavior similar to that of the Keplerian orbit,” said Wise, referring to the principles of the planetary movement described by Johannes Kepler in the seventeenth century. “And they simply begin to fall from heaven.”
Satellites and spacecraft can also briefly approach the earth during their orbits – until 80 or 90 kilometers high (50 to 56 miles) – without being dragged down immediately. In aerospace language, these low -flight spacecraft are known as very low terrestrial orbit satellites (buckle).
Atmospheric resistance becomes more noticeable at lower orbital altitudes, And that is a key consideration when designing a vehicle.
“The orbits can really be reduced, perhaps up to 150 kilometers (93 miles), but there is a cost that is paid for it. … Something is probably being designed all the time trying to stay in orbit,” Wise said.
In a nutshell: when it comes to defining space, calculations and considerations change depending on the spatial object in question.
“Some experts have pointed out that the function and purpose could lead to more appropriate distinctions between aircraft and spacecraft than the altitude,” reads the 2014 article.
And distinctions can become increasingly diffuse as technology evolves and new types of vehicles can achieve different types of flight.
So do these definitions really matter?
“It’s curious to think about it,” Wise said. “Is Everest still scaing? We need these standards or definitions agreed for this arduous and epic feat. So, particularly in the context of commercial trips to space, I think the Kárman line is an excellent option.”
