There is no sign saying “Welcome to Outer Space” when a ship such as Virgin Galactic’s SpaceShipTwo arrives at its edge, as it reportedly did on Thursday. The atmosphere doesn’t abruptly end, but thins out gradually. The craft’s maximum altitude of 51.4 miles was lower than the 100 kilometer (62-mile) limit set by the Ansari X prize back in 2004. (This was won by SpaceShipOne, then of Mojave Aerospace Ventures, which maxed out at 69.7 miles.)
Is it OK to lower the bar on the edge of space? Who gets to decide where space begins? Virgin Galactic and its competitors in the space tourism trade would like to make it low enough to say their customers are getting there. (Though moving the line won’t affect Elon Musk if he pulls off his promised trek around the moon.)
