Are Virgin Galactic and Blue Origin only good for billionaire joyrides?

Billionaire entrepreneur Richard Branson and his team successfully flew to the “edge of space” on the Unity 22 mission aboard a Virgin Galactic plane on July 12. The event was hailed as the start of space tourism, narrowly beating the planned launch on 20 July by fellow billionaire business magnate Jeff Bezos and his firm Blue Origin.

But does the 85km (53 miles), the altitude of the recent Virgin Galactic flight, actually count as space? And what are these companies likely to achieve going forward?

The definition of where space begins is very subjective. The Kármán line is a distance of 100km (62 miles), determined in 1957. This line has been adopted by the Swiss Air Sports Federation (Fédération Aéronautique Internationale) to determine if an activity is aeronautical or astronautical.

Alternatively, the US Air Force and Nasa determine their boundary as 80km (50 miles), which is where military personnel get their “astronaut wings”. This altitude has been reached by a number of specialist planes including the X-15 and notably the privately funded SpaceShipOne, reaching 112km (70 miles) – well above VSS Unity’s current achievement. The Blue Origin launch is aiming for 106km (66 miles).

While this altitude allows some excellent views of the Earth, it is not an orbit. To be orbiting at this altitude you need to be traveling at a minimum speed of 7.85km/s (17,500mph) in a horizontal direction. Unity was just an acceleration straight up and then a controlled drop back down. This is relatively simple to do, but it’s significantly more difficult, both in terms of energy and engineering, to turn this into an orbit.

The definition of the edge of space is not trivial. Space is not where you feel weightless, as this can be achieved for short periods of time in specialist drop chambers or on parabolic flights. And despite the tweet from Virgin Galactic stating the crew were in zero-gravity, the gravitational pull was roughly 9.5 meters per square second – about 97% of that on the surface. The weightlessness experienced is purely due to an extended free fall.

Future outlook

The first billionaire in space has excited some, feeling that they too may one day see the Earth from 85km if they can afford US$250,000 for a one-hour trip. However, public opinion has not been unanimous, with many highlighting that the cost of the venture could be used to eradicate poverty or assist with the current pandemic response.

There’s also the environmental impact. According to Virgin Galactic, a single flight on Unity results in carbon emission of 1.2 tonnes – equivalent to a passenger in business class on a return trip from London to New York. Compared to aviation, this is small, but the more regular these flights become the more carbon will be added. Blue Origin’s engines, on the other hand, are powered by liquid hydrogen. While the emissions are therefore minimal, the generation of liquid hydrogen and carbon cost of transporting materials is still an issue.