A Closer Look at Human Spaceflight Statistics

Credit: Bryce Space Tech

Virgin Galactic likes to talk about how it’s going to more than double the number of people who have flown into space with its SpaceShipTwo vehicle. Using the most generous definition of space (50 miles/80.5 km), that number now stands at 567, according to statistics compiled by the worldspaceflight.com website.

It’s a worthy goal. But, counting the number of individuals who have been to space tells only part of the story.

It doesn’t account for people who have flown to space multiple times. For example, retired NASA astronauts Franklin Chang-Diaz and Jerry Ross share the record for having flown to orbit seven times apiece. Seven others have flown six times each.

As the Bryce Space Tech graphic above shows, a total of 1,319 occupants have launched into orbit as of Dec. 3, 2018 on 318 flights since Yuri Gagarin flew in 1961.

The International Space Station (ISS), which has been permanently occupied since November 2000, has hosted 233 total visitors who have flown on 98 separate flights. The Soviet/Russian space station Mir hosted 137 visitors who flew aboard 39 spacecraft. And five U.S. space shuttles launched 852 passengers.

Worldspaceflight.com estimates that astronauts have spent in excess of 145.5 person years in orbit. That equals a total of more than 1,746 months or 53,144 days in orbit.

By comparison, passengers aboard SpaceShipTwo will experience about three or four minutes of microgravity apiece during their flights depending upon how the altitude the vehicle reaches. Thus, the roughly 600 passengers who have signed up for flights will experience between 30 and 40 hours of weightlessness. (The estimate doesn’t include the two pilots on each flight.)

In May 1963, Gordon Cooper flew 22 orbits around the Earth in his Mercury Faith 7 capsule. The entire flight from launch to landing lasted 34 hours and 19 minutes.