Sir Richard Branson (L) of Virgin Galactic and Jeff Bezos, Founders of Blue Origin.

Getty Images

Richard Branson and Jeff Bezos will only launch a few weeks apart, but the exact limit and experience of their space travel has become a point of contention.

Branson’s Virgin Galactic flies 80 kilometers (or about 262.00 feet), which is the altitude the US recognizes as the limit of outer space, while Bezos’ Blue Origin flies 100 kilometers (or about 328,000 feet), which is well known than the Kármán line.

After Branson said he plans to take off from Bezos just nine days before the previously announced space flight, Bob Smith, CEO of Blue Origin, condemned Virgin Galactic’s approach as “an entirely different experience,” as “they don’t have the Kármán- Line fly “.

Virgin Galactic CEO Michael Colglazier replied simply, “We are going beyond the astronaut frontier,” adding that it is “the only commercial company to have flown private astronauts to date.”

On Sunday, Branson plans to launch Virgin Galactic’s fourth space test to date. He founded the company 17 years ago and is now trying to complete development tests this year so it can start flying passengers for space tourism in early 2022. Bezos’ Blue Origin has goals beyond tourism, but the billionaire also wants to fly to the sidelines when the company first launched with a crew on July 20.

At the heart of the two billionaires’ dispute is that the limit at which space begins is not a generally accepted altitude, a fact that astrophysicist Jonathan McDowell pointed out in an interview with CNBC.

“It’s not that the US is one way and everyone else is the other … there is no real international agreement,” McDowell said.

There are a variety of reasons McDowell argues that 80 kilometers is the clearest boundary of space, such as the scientific measure of Earth’s atmosphere, gravitational physics, and historical precedent – including the fact that the original line of Hungarian-American engineer Theodore von Kármán was closer to 80 than 100.

McDowell is an astrophysicist at the Harvard-Smithsonian Center for Astrophysics who published an article in 2018 with more detailed information on the debate on the proposed limit of space. The little planet (4589) McDowell is named after him.

The spaceship

VSS Unity will be released from the carrier aircraft VMS Eve during the launch of its third space flight on May 22, 2021.

Virgo galactic

The key to understanding the dispute is the differences between the company’s spacecraft. Primarily, neither Blue Origin nor Virgin Galactic fly into orbit – both spaceships are defined as suborbital and can take passengers to the edge of space to hover in weightlessness for a few minutes at most. An orbital flight, such as Elon Musk’s SpaceX, costs tens of millions of dollars and typically spends several days or weeks in space.

Blue Origin’s New Shepard missile launches vertically from the ground, with a six-passenger capsule separating from the rocket booster near the top of the flight. After that, the capsule returns to Earth under the control of a series of parachutes, with the booster returning to landing separately so that it can be launched again.

Virgin Galactic’s SpaceShipTwo system is released into midair by a carrier aircraft before igniting its rocket motor and arching upward in a climb. After a slow backflip in weightlessness, the spacecraft returns to earth for a runway landing in gliding flight.

A New Shepard missile takes off on a test flight.

Blue origin

The difference in elevation that each spacecraft reaches is about 15 kilometers, or 50,000 feet. This difference, according to McDowell, is about “20% higher” and “perhaps noticeable” for the passengers, “but not dramatic”.

“I think experience shows that it will be pretty similar,” said McDowell. “Important is: [The difference] is a bit arbitrary. “

100 km instead of 80 km

In the debate between heights of 100 or 80 kilometers, McDowell emphasized that “it is actually incorrect to say that the rest of the world knows 100 kilometers”. He said the Fédération Aéronautique Internationale (FAI) was “the only official place” adhering to 100 kilometers and reiterated that “it is not an international law”.

Even so, Blue Origin doubled the view of the Kármán line in a tweet on Friday.

“For 96% of the world’s population, space begins at 100 km,” said the company.

The US recognizes 80 kilometers for a number of reasons, including space weapons regulations and the historical precedent of early military astronauts. In the 1960s, the Air Force gave pilots their X-15 rocket-powered aircraft astronaut wings after flying 50 miles.

On the weapons side, McDowell stressed that “the US has opposed an international agreement” on the boundaries of space “because it does not want space to be defined too clearly”.

“Because then it becomes apparent that their missiles are flying through space and may be subject to space law,” said McDowell. “The general idea is that the US [military] has more freedom of action if it is not defined. “

On a scientific basis, McDowell provided physics-based reasoning for 80 kilometers, based on the density of the upper atmosphere. Through modeling, his research showed that the edge of the atmosphere “doesn’t swing around as much” and is fairly consistent in its effect on spaceships.

“If you look at satellites with elliptical orbits, you find that they can survive when their point of orbit with Earth is in the mid-50s. But when it plunges in the mid-1970s, they just burn and” can’t orbiting more, “said McDowell.

Finally, McDowell says that Theodore von Kármán himself “did not originally choose 100 kilometers as the edge of space”. His approach is also “a physics-based idea” and “something” in the middle 80 kilometers. But over time, McDowell said that people working on Kármán’s research decided not to specify it that much and instead decided to just round it up to 100.

“The Kármán line has become synonymous with 100 kilometers, but that wasn’t the original definition of the Kármán line,” said McDowell.

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