Video: 'Rare COLOR footage of first spacewalk, Alexei Leonov, March 18, 1965'

(Friday, March 18, 1965, 08:34:51-08:47:00 UTC; during the Space Race) — Soviet cosmonaut Alexei Leonov became the first person to walk in space today, spending 12 minutes and 9 seconds floating outside his spacecraft in a daring feat that marked another milestone in the space race.

The Voskhod 2 spacecraft launched at 1:00 p.m. local time from Baikonur (10:00 a.m. Moscow time, 3:00 a.m. in Washington) and entered orbit. Approximately 90 minutes later, as the capsule passed over the Soviet Union, Leonov exited the airlock while 307.5 miles (494.9 km) above Earth—the highest altitude any human had reached at the time.

Secured by a 16-foot (5-meter) tether and equipped with an oxygen supply, Leonov floated freely in the vacuum of space for 12 minutes. His crewmate, Colonel Pavel Belyayev, remained inside the capsule to monitor the mission.

The historic moment, however, was not without peril. Upon attempting to re-enter the spacecraft, Leonov encountered a life-threatening challenge: his pressurized suit had stiffened in the vacuum, making it nearly impossible to bend and fit through the narrow airlock.

With his pulse racing to 168 beats per minute and his oxygen supply dwindling, Leonov made the critical decision to reduce the suit’s pressure from 400 hPa to 270.

“With the urgent desperation of a doomed man,” one account described, Leonov fought his way back into the airlock, narrowly avoiding catastrophe.

The successful spacewalk solidified the Soviet Union’s lead in the space race, following earlier achievements such as launching the first satellite, Sputnik, and sending the first human, Yuri Gagarin, into orbit.

NASA, which had been preparing for its own extravehicular activity, was once again outpaced by its Cold War rival.