The height a human can "fly" depends entirely on the technology used, as the human body cannot survive unassisted at high altitudes. In an unpressurized environment, a human can typically only fly up to about 15,000 to 20,000 feet before losing consciousness due to hypoxia (lack of oxygen). Using a pressurized suit and balloon, the current record for the highest "flight" is held by Alan Eustace, who reached 135,890 feet (about 25 miles) in 2014 before parachuting back to Earth. For traditional aircraft, commercial pilots usually cruise at 35,000 to 40,000 feet, while specialized military jets like the SR-71 Blackbird could fly at over 85,000 feet. If you define "flying" as traveling in a spacecraft, the record is held by the crew of Apollo 13, who reached an altitude of 248,655 miles from Earth as they swung around the far side of the Moon. In 2026, the edge of space is increasingly accessible through private companies like Virgin Galactic, which take "citizen astronauts" to an altitude of about 50 miles (264,000 feet) to experience weightlessness.