Tuesday , April 20 2021

Limit of space is reconsidered as a Virgin Galactic test program advances



WASHINGTON – As Virgin Galactic approaches its first suborbited flights into space, a potential change in terminology could facilitate the company's reach of this landmark.

In an interview with CNN released on November 30, Virgin Galactic's founder, Richard Branson, said the company was within weeks flying its space space SpaceShipTwo suborbital in space. This vehicle, called VSS Unity, was a manufacturing series of powered test flights, most recently on July 26.

"Space is difficult," said Branson in response to a question that mentioned non-critical critics that did not believe that the company could reach space with SpaceShipTwo. "Obviously, we would love to prove our critics incorrectly and it's reasonable for us to do that before Christmas."

Branson suggested in October an interview with CNBC that SpaceShipTwo's first space space space would come in "weeks, not months." The Company's correspondents have declined to comment on this schedule, with a long-term policy leaving Branson's schedule and timetables, although they have indicated that they have planned to perform at least one more powerful test flight before the end of the year.

George Whitesides, a general executive of Virgin Galactic, did not give a specific schedule in the 27th speech at the SpaceCom Expo in Houston, but suggested that more and more test flights will come soon. "The next flights will be even more exciting" than the July flight, which reached a maximum height of 52 kilometers, he said. "We'll see some of them soon."

This July flight involved a 42-second burn from SpaceShipTwo's hybrid rocket engine, which is designed for fire for about 60 seconds on a typical flight. "We're in the place where we will add a lot of stress, if we continue to burn the rocket," Whitesides said during a dinner at the Summit Space Championship. 2 in Los Angeles.

One question is how high SpaceShipTwo will need to reach to consider getting space. While there is no formal limit of space in treaties or law, the industry has often used the height of 100 kilometers, known as Karman Line after the late aeronautics engineer Theodore von Kármán. This definition gained prominence during the Ansari-X competition competition for commercial suborbital vehicles, won by SpaceShipOne in 2004 when it flew over that height twice within two weeks, and during a test flight three months earlier.

However, the industry speculation that SpaceShipTwo will not be able to reach this altitude in its current configuration with full load of space participants or experiments on board. Whitesides, asked about altitudes in his Angelized speech, referenced instead of lower altitude used by the US government.

"For Virgin Galactic, the most important milestone we perceive is the height when NASA and the Air Force receive their astronaut wings, which is 50 miles," he said. "For us and our customers, I think we will focus 50 miles, at least at the beginning."

International organizations now review the Karman line definition. On November 30, the Aeronautical International Federation (FAI), the world-wide aerial sports federation, which adheres advertisements for aviation and space light, has announced it will work with the International Astronautics Federation (IAF) to review, What highway is the boundary of space for its conservation?

"Recently published analyzes present a convincing scientific case for a reduction in this height of 100 km to 80 km," the FAI said its statement. Eight kilometers are about 50 miles. FAI said it had offered to IAF that "an international workshop will take place in 2019 to fully explore this issue with input and participation in the astronomy and astronomy community."

The FAI statement did not mention the specific analyzes that led it to reconsider the Karman Line height. One such paper, however, was released recently in the newspaper Actor Astronautics by Jonathan McDowell, astronomer and spaceflight historian at the Harvard Smithsonian Center for Astrophysics, who recommended lowering the Karman Line at 80 kilometers.

This paper, besides examining the historical record, featured extensive mathematical analysis, modeling forces on a spaceship traveling through the upper atmosphere. It concluded that for most satellites, gravity surpassed aerodynamic forces at altitudes of 70 to 90 kilometers. "Based on these physical, technological and historical arguments, I suggest that a value of 80 km is a more suitable choice to use as the canonical inferior edge of space and in circumstances where such an internal gap between the atmosphere and space is desired, "the paper finished.

Whitesides addressed this paper in their comments last month. "If you look back to the space history, not quite clear that Karmar really thought that 100 [kilometers] It was really the right place, "he said." It's a kind of pretty round number ".

This sharing line was not a matter for the other company pursuing a business human suborbital of space light. Blue Origin's New Shepard exceeded 100 kilometers on several of its ticket flights, including the latest one July 18, where the ship's crew reached a maximum height of about 119 kilometers thanks to the use of its abortion motor shortly after separation of the propulsion module.


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