What Happens if an Astronaut Floats Off in Space (Explained)

Floating off into space is a terrifying yet fascinating concept, begging the question of what happens if an astronaut floats off in space.

With movies like Gravity exploring this scenario, it’s natural to wonder – what would really happen if an astronaut became detached from their spacecraft?

This article dives into the science behind spacewalking accidents to uncover the physiological effects and survival chances.

What Happens Physically if an Astronaut Floats off in Space?

atronaut floating in space with attachments
Photo By Rick Partington

If an astronaut became detached from their tether during a spacewalk, they would float away with no way to get back. Initially, with their spacesuit on, they would be able to survive for a few hours. However, once their oxygen ran out, they would lose consciousness within 15 seconds.

Without air pressure, gases in their body would expand, but their skin and tissues are strong enough to keep from exploding. Ultimately, death would come within a couple of minutes from asphyxiation and ebullism. Though a tragic outcome, their body would remain largely intact, slowly drifting through space.

How Long Can an Astronaut Survive After Floating Off?

10 Ways You Could Die in Space
Photo By Eddie Toro

What happens if an astronaut floats off in space; well after floating off into space, an astronaut could potentially survive for up to 10 hours if their spacesuit remains intact. Modern spacesuits carry about 7 hours worth of oxygen, which could be stretched to last a bit longer. However, the lack of air pressure and extreme temperatures of space would ultimately prove fatal before their oxygen ran out completely.

Without a tether, there would be no way for the astronaut to get back to the safety of the spacecraft. So despite having some temporary life support from their suit, an astronaut detached from their ship would sadly not survive more than 10 hours at most.

What Safety Measures Prevent Astronauts From Floating Off?

astronaut tethered
Photo By NASA

NASA takes every precaution to avoid astronauts becoming detached during spacewalks. All astronauts must be tethered at all times to the spacecraft with a braided steel cable. This umbilical cord provides oxygen, power, cooling, and a strong anchor. Spacesuits also have an independent oxygen supply as a backup.

Astronauts use handrails and foot restraints to stay attached and do “buddy checks” of each other’s gear. Mission control monitors everything closely too. Though not impossible, NASA’s safety measures make it extremely unlikely an astronaut could float away accidentally. Proper precautions allow astronauts to focus on their missions, not on the dangers of the void.

Can a Floating Astronaut Be Rescued?

astronaut trying to save someone detached from the space walk
Photo By Jonathan Knowles

While highly unlikely, NASA does have contingency plans if an astronaut becomes detached. The lost astronaut could use their SAFER jetpack to navigate back to the spacecraft. Mission control could also command the spacecraft to move toward the astronaut. As a last resort, another astronaut could do a spacewalk to retrieve them.

There are many options to rescue a floating astronaut before their oxygen runs out. With proper tethering and safety checks, this scenario is extremely remote. But NASA prepares detailed procedures for every possible crisis. Their quick response and ingenuity make astronaut rescue achievable if ever needed. Space exploration has risks, but NASA’s diligence keeps astronauts as safe as possible.

What Is the Orbital Trajectory of a Floating Astronaut?

astronaut floating away from the space station
Photo By Labroots

If an astronaut becomes detached from their spacecraft while on a spacewalk, their trajectory depends on several factors. Initially, they will continue moving alongside the spacecraft due to momentum. However, without thrusters, they will gradually drift off into a different orbit. The new orbit depends on the astronaut’s velocity when detached and the gravitational effects of nearby celestial bodies.

On ISS spacewalks, the astronaut’s orbit likely changes slightly but stays relatively close to the station’s orbit. With a SAFER jetpack, the astronaut can maneuver themselves back quickly. Otherwise, the new orbit may be calculated and rendezvous planned. While an uncontrolled trajectory is dangerous, space agencies can still locate and recover a floating astronaut.

Historical Context: Has This Happened Before?

michael collins
Photo By NY Times

Throughout space exploration history, several astronauts have become detached from their spacecraft during spacewalks. Firstly, in 1966, astronaut Michael Collins drifted away from the Gemini 10 capsule. Fortunately, he managed to use his thruster to return safely. Then, in 1984, Bruce McCandless became the first untethered spacewalker when he tested the MMU jetpack. Moreover, in 2005, Stephen Robinson faced a scare when his tether unexpectedly retracted during an ISS spacewalk.

Thankfully, he swiftly grabbed onto the station. Although these incidents were perilous, they showcased that with the right equipment and training, it’s possible to rescue a drifting astronaut. To prevent such uncontrolled drifting, innovations like the SAFER jetpack and rigorous tether procedures have been introduced. Due to these proactive safety measures, no astronaut has ever been left stranded in space.

The Psychological Impact of Floating off Into Space

astronauts talking with each other
Photo By Sciworthy

Drifting off into the void of space is a nightmare scenario for any astronaut. The immense solitude and helplessness would be psychologically traumatic. While training helps astronauts stay calm in emergencies, the thought of floating endlessly with limited oxygen and resources would be harrowing. The view of the receding spacecraft could lead to despondence.

Panic or errors in judgment could hasten doom. However, space travelers are highly resilient people. Their will to survive may counteract despair. Drawing on their training, they might meditate, conserve resources, and signal for help. Just knowing that ground control is doing everything possible to recover them could provide hope. The human spirit can overcome remarkable adversity. Even facing the abyss, an astray astronaut may yet prevail through rational thinking and faith.


Has an astronaut ever floated off in space?

No, an astronaut has never floated off into space. They are always securely tethered to the spacecraft when on spacewalks.

What would happen if you floated into space?

If an astronaut became untethered and floated off into space without a spacesuit, they would lose consciousness within 15 seconds due to lack of oxygen. Death would follow shortly after due to asphyxiation and exposure to the vacuum of space.

What happens if an astronaut falls from the space station?

It is nearly impossible for an astronaut to fall from the space station. They are always attached to tethers during spacewalks. In the unlikely event this did happen, they would float endlessly through space unless rescued quickly by another spacecraft.


During spacewalks, astronauts always tether themselves securely, making floating off into space highly unlikely. Yet, if an astronaut ever floated away or found themselves exposed to space without a suit, they would lose consciousness in seconds and die within minutes from oxygen deprivation and the harsh conditions of space. Proper safety procedures and advanced spacesuit technology ensure such incidents don’t occur.

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