Amazon founder Jeff Bezos was ready to grab headlines by taking a trip to space later this month. He will be a part of the first crewed mission for his company, Blue Origin, when it launches its New Shepard rocket later this month on July 20. However, Bezos recently got scooped by Virgin Galactic founder Richard Branson, who made a surprise announcement that he will be riding aboard his company’s VSS Unity craft tomorrow, July 11.
This seems to have sparked some animosity between the two companies based on who will make it to space first. But Blue Origin has recently made the argument that Virgin Galactic’s plans don’t technically count as a trip to space, in a tweet posted yesterday, Friday, July 9.
The issue at stake is how high each company plans to fly its craft, and where the official boundary for space lies. Most of the world uses the Kármán line as the designated end of Earth’s atmosphere and the beginning of space, which is 100 kilometers above the average sea level. However, organizations in the U.S. such as the Air Force consider the start of space to be 50 miles above average sea level, which is around 80 km.
Virgin Galactic’s VSS Unity has flown to a maximum altitude of 90 km, which is above the start of space as defined by the U.S. Air Force, but below the Kármán line. Therefore, some people argue that those who fly in the VSS Unity have been to space, while others say that it is in fact a sub-orbital flight.
On the other side of the equation, Blue Origin’s New Shepard vehicle has reached over 100 km altitude, so it has undeniably been to space. And the company also made other arguments that its vehicle is superior to the VSS Unity in an infographic shared on Twitter:
From the beginning, New Shepard was designed to fly above the Kármán line so none of our astronauts have an asterisk next to their name. For 96% of the world’s population, space begins 100 km up at the internationally recognized Kármán line. pic.twitter.com/QRoufBIrUJ
— Blue Origin (@blueorigin) July 9, 2021
Something to remember is that the definition of what altitude counts as “space” is arbitrary. There is no clear point at which the atmosphere stops and space begins.
Both the crews of the VSS Unity and the New Shepard will be taken to a high altitude, experience a few minutes of weightlessness, and then be returned to the ground. Neither craft will go into orbit, and neither Branson nor Bezos will be performing any kind of scientific or technical work.
However, there are some key differences between the two vehicles which are helpful to remember. The New Shepard is essentially a type of sounding rocket, a well-developed and well-understood piece of technology that agencies like NASA have used for decades. The VSS Unity is a spaceplane, which is a more complex piece of technology that can maneuver in the atmosphere. The landings are also different, with the VSS Unity gliding back to Earth to land on a runway, while the New Shepard will fall back to Earth with its descent slowed by parachutes.