The Deadly First Spacewalk: Alexei Leonov's Near-Disastrous EVA on Voskhod 2

Introduction:

The dawn of human spaceflight was fraught with peril, and no event exemplifies this more than Alexei Leonov's first spacewalk on March 18, 1965, aboard the Soviet Voskhod 2 spacecraft a 12-minute venture into the void that nearly became a tragedy. At 30 years old, Leonov became the first person to float untethered in space, tethered only by a 5.35-meter umbilical cord, but his Berkut spacesuit ballooned due to the vacuum, stiffening and overheating, forcing desperate measures to survive. This EVA, conducted 335 km above Earth, lasted 23 minutes total but tested the limits of human physiology, with Leonov battling fatigue, oxygen depletion, and suit rigidity in temperatures swinging from -150°C to 120°C.

Voskhod 2, commanded by Pavel Belyayev, was the Soviet Union's audacious response to NASA's Gemini program, aiming to outpace the Americans in the Space Race. Leonov's walk, filmed by a chest-mounted camera, symbolized Soviet ingenuity but exposed the raw dangers of extravehicular activity (EVA). Why does this matter? Leonov's ordeal shaped EVA protocols for decades, influencing NASA's Apollo moonwalks and the ISS era, reminding us that space exploration's glories come at the edge of catastrophe. This article recounts the mission's harrowing details, technical failures, heroic improvisation, historical context, legacy, and modern reflections, drawing from Leonov's memoirs, NASA archives, and Smithsonian accounts as of September 2025.

The Mission: Voskhod 2's Audacious EVA

Voskhod 2 launched from Baikonur Cosmodrome on March 18, 1965, at 10:00 Moscow Time, carrying Leonov and Belyayev in a cramped capsule designed for three but modified for the airlock. The Soviet program, under Sergei Korolev, prioritized milestones over safety, skipping animal tests for the EVA. At 15:29 UTC, Leonov squeezed through the 90 cm airlock, emerging into space at 327 km altitude.

For 12 minutes and 9 seconds, he maneuvered using handrails, testing a color TV camera and photographing Earth humanity's first untethered steps. However, the Berkut suit, pressurized at 0.4 atmospheres, expanded in vacuum, ballooning by 20-30% and locking joints, per Leonov's 2004 book The First Spacewalk. Sweat poured, visibility fogged, and heart rate soared to 140 bpm as he struggled to re-enter.

Technical Failures: What Went Deadly Wrong

The EVA's peril stemmed from unforeseen suit dynamics:

• Suit Ballooning: Without gravity, the nylon and rubber Berkut inflated, increasing size by 22% and stiffness, making arm/leg movement impossible Leonov described it as "a balloon."
• Overheating: No cooling system led to 1.8°C core temperature rise, nearing heatstroke; sweat obscured his visor.
• Oxygen Crisis: Rigid suit restricted breathing, dropping oxygen to critical levels; manual valve adjustments were futile.
• Re-Entry Panic: Planned feet-first entry impossible; Leonov twisted headfirst, scraping through the airlock, damaging the suit.

These issues, untested in full vacuum, highlighted EVA's hazards, contrasting NASA's safer Gemini 4 walk by Ed White on June 3, 1965.

Heroic Improvisation: Leonov's Life-Saving Decisions

Leonov's ingenuity saved the day:

• Pressure Reduction: From 0.38 to 0.27 atmospheres, shrinking the suit enough to bend limbs risking decompression sickness (the "bends").
• Headfirst Re-Entry: Defying protocol, he contorted through the airlock, heart pounding at 160 bpm, emerging battered but alive.
• Manual Landing: Post-re-entry, attitude thrusters failed; Belyayev used manual controls for a snowy Ural Mountains landing 400 km off-course, rescued by helicopter.

Leonov later admitted nearly cutting the tether in panic, but composure prevailed, per his 2004 memoir.

Historical Context: Space Race's High Stakes

The EVA was the Soviet's bid to eclipse NASA's Project Gemini:

• Voskhod 1 (1964): First multi-person flight.
• Gemini 3 (1965): U.S. two-man debut.
• Leonov's Walk: March 18, 1965, first EVA.
• White's Walk: June 3, 1965, first U.S. EVA.

Korolev's aggressive timeline, amid Cold War pressure, prioritized glory over safety, leading to tragedies like Soyuz 1 (1967).

Legacy and Modern Reflections: Shaping EVA Protocols

Leonov's walk influenced:

• Suit Designs: NASA's Gemini and Apollo suits added mobility joints; modern EMUs have pressure valves.
• Training: Underwater simulations now standard, per NASA.
• Over 500 EVAs: ISS record 340+ hours by one astronaut.

In 2025, as SpaceX's Polaris Dawn plans the first private EVA, Leonov's story warns of risks, per Smithsonian.

Statistics: EVA Milestones

• Duration: 12 min 9 sec (first EVA).
• Altitude: 335 km.
• Soviet EVAs: 36 by 1984.
• Total EVAs: 570+ (NASA/ISS).
• Longest: 8h 56m (Jerry Ross, 1993).

Expert Opinions: Reflections on Leonov's Feat

James Oberg (Space Historian): "Leonov's improvisation saved the program; a turning point." NASA’s Kathy Leveille: "His walk pioneered EVA safety." Leonov (2004): "I saw the Earth worth every risk." Consensus: Heroic amid peril.

Potential Impacts: On Future Spacewalks

Leonov's legacy informs private EVAs like Polaris Dawn (2025), emphasizing suit flexibility. It underscores risks in commercial space, urging regulations.

Conclusion: A Walk That Changed History

Alexei Leonov's March 18, 1965, spacewalk, though deadly close, opened the cosmos to humanity. His courage shaped EVAs forever. As 2025 marks 60 years, it inspires explore more on nuvexic.com.

FAQ

1.When was the first spacewalk?
March 18, 1965, by Alexei Leonov on Voskhod 2. This historic event lasted 12 minutes and 9 seconds, making Leonov the first human to float in space, tethered to the spacecraft at an altitude of 335 km, a feat that pushed the boundaries of Soviet engineering during the height of the Space Race and set the stage for future lunar missions by demonstrating the feasibility of extravehicular activity despite the immense risks involved.

2.What made Leonov's spacewalk deadly?
His Berkut spacesuit ballooned in the vacuum, stiffening and overheating, raising his core temperature by 1.8°C and restricting movement, forcing him to reduce pressure to 0.27 atmospheres and re-enter headfirst, nearly causing decompression sickness and oxygen depletion in the 23-minute ordeal that highlighted the untested dangers of early EVA technology.

3.How did Leonov survive the spacewalk?
Leonov improvised by bleeding air from his suit to shrink it enough to maneuver, enduring exhaustion and fogged visor from sweat, then contorting headfirst through the airlock, a decision that saved his life but violated protocol and led to a tense manual re-entry landing in the snowy Urals, rescued after hours.

4.What was the impact on future spacewalks?
Leonov's near-disaster informed NASA’s Gemini and Apollo suit designs, adding mobility joints and cooling systems, and established EVA training protocols like underwater simulations, enabling over 570 spacewalks since, including Apollo moonwalks and ISS maintenance, while underscoring the need for redundancy in life-support systems.

5.How does Leonov's walk compare to modern EVAs?
Unlike Leonov's 12-minute tethered walk in a rigid suit, modern EVAs last 6-8 hours with untethered jetpacks and advanced EMUs, but risks persist, as seen in 2025's Polaris Dawn private spacewalk, where full-crew exposure echoes his challenges, though improved materials and AI monitoring have reduced fatality odds from 50% in 1965 to under 1%.