Boldly Going Where 14 Men Have Gone Before

Congratulations to Aleksey Ovchinin, who just became the 553rd human ever to reach outer space. #Soyuz pic.twitter.com/v0M4s3Mu7e

— Virgin Galactic (@virgingalactic) March 18, 2016

For nearly a dozen years, Virgin Galactic has used the number of individuals who have flown into space as a target to shoot for once the company began suborbital space tourism service. Virgin promised to double the number, which was around 500 when the company launched in 2004, within the first year of operation. That year was originally targeted for 2007 in the confident days after the success of SpaceShipOne.

That goal has long since faded away, and it’s unlikely Virgin will double the number of space travelers during the first year. In any event, the number of space travelers cited by Virgin has always been a bit misleading. The company’s well heeled customers, who are paying upwards of $250,000 per flight, will actually be joining a much more elite group on their suborbital flights.

Of the 553 individuals who have visited space through last month, only 14 of them (2.5 percent) have  boldly (and briefly) gone to suborbital space; the other 439 have traveled to orbit. And that’s using the most generous definition of where space begins.

The table below shows human spaceflights above 50 miles (80 km), which is the U.S. Air Force’s definition of the boundary of space. The international boundary, known as the Karman line, is set at 62 miles (100 km).

Thirteen of the 19 flights were made by the air-launched X-15 rocket plane during the 1960’s. Eleven of those flights made it above 50 miles (80 km) but below 62 miles (100 km). Joseph A. Walker flew the vehicle above the Karman line twice in 1963, setting an altitude record of 67 miles (107.8 km) that would stand for 41 years.

Walker’s record was broken by Brian Binnie in the final flight of SpaceShipOne on Oct. 4, 2004. Binnie reached 69.6 miles (112 km) during a flight that won the $10 million Ansari X Prize for a team led by Burt Rutan and Paul Allen.

The prize had required to flights by a privately built spacecraft above the Karman line within a two-week period. Mike Melvill had flown the first prize flight five days earlier.

In all, SpaceShipOne flew to space three times. Melvill piloted the first flight in June 2004, barely exceeding the Karman line along the way. For that achievement, SpaceShipOne is now displayed in the National Air & Space Museum in Washington, D.C.

The other three suborbital flights were conducted via ballistic missiles. Alan Shepard became the first American in space during a 16-minute flight aboard Freedom 7 in May 1961. Two months later, Gus Grissom repeated the feat two months later in Libery Bell 7.

The only other manned suborbital flight occurred by accident in 1975. After the Soyuz 18.a spacecraft failed to separate from its booster, Vasili Lazarev and Oleg Makarov endured a harrowing descent into Siberia during which they were subjected to 21.3 g’s. The capsule rolled down a hill after landing, stopping just short of a steep cliff.

The table below shows the pilots who have flown on suborbital flights along with the number of missions they flew.

In all, 14 individuals have flown suborbital flights, four of them multiple times, for a total of 19 flights. Eight of the flights went above 62 miles (100 km), with the remain 11 missions reaching above 50 miles (80 km) but below the Karman line.

One of the flights was fatal. Michael J. Adams died after he lost control of his X-15 rocket plane during re-entry, causing it to break up. He was unable to eject.

Suborbital pilots faced other dangers. During the Soyuz 18.a abort, Lazarev suffered internal injuries so severe that he never flew in space again. Grissom nearly drowned after the hatch of his spacecraft was blown prematurely, causing Liberty Bell 7 to fill with water and sink.

Grissom would later die in the Apollo 1 fire. Walker died three years after his record mission when his F-104 fighter collided with an XB-70 bomber during a promotional flight. McKay passed away in 1975 after suffering for 12 years from injuries suffered in the crash of an X-15.

Although they won’t be going to orbit, future suborbital space tourists flying aboard SpaceShipTwo, Lynx, New Shepard or some other vehicle can rest assured that they will be joining a truly elite group of brave men in performing a feat that involves significant risks to life and limb. That will involve a lot of courage.