This is a list of space travellers by first flight. The table is listed in chronological order from the date of first flight. The table adheres to a common definition of a space traveller; the Fédération Aéronautique Internationale criterion of achieving an altitude higher than 100 km (62 mi; 330,000 ft), thereby crossing the FAI-defined Kármán line. The criteria for determining who has achieved human spaceflight vary. Personnel who qualify only for the United States Astronaut Badge, awarded to those who achieve an altitude of 50 mi (80 km; 264,000 ft), are listed at the X-15's highest flights and the VSS Unity test flights.