NASA astronauts were forced to shelter in their spacecraft and prepare for potential evacuation on Friday due to an escalating air crisis on the International Space Station.
The extraordinary precaution came as US and Russian officials clashed over how to tackle a growing air leak aboard the orbiting laboratory.
In a dramatic attempt to reach the source, Russian cosmonauts used a saw to cut into a section of the station where they believed the leak was hiding.
The four astronauts of NASA’s Crew-12 mission, two Americans, a French astronaut and a Russian cosmonaut, were instructed to enter their docked SpaceX Dragon spacecraft and put on spacesuits while Russian crews attempted repairs.
But roughly 90 minutes later, NASA ended the safe-haven procedures after Russia’s space agency, Roscosmos, paused the repair operation to gather additional data and measurements.
The dispute had been brewing for months, with NASA and Roscosmos unable to agree on either the source of the persistent air leaks or the best way to stop them.
While the leaks have plagued the station on and off for years, Reuters reported that the rate of air loss recently doubled from about one pound per day to two.
The decision by Russian cosmonauts to use a saw heightened concerns aboard the orbiting laboratory, prompting NASA to place astronauts into safe-haven procedures as a precaution.
NASA ordered astronauts aboard the International Space Station (ISS) to take shelter over ‘worsening air leaks’
Bethany Stevens, NASA press secretary, said in a statement on X: ‘Roscosmos has paused Friday’s structural repair efforts inside the Zvezda service module transfer tunnel, known as PrK, as more measurements and data are assessed.
‘Given this development, NASA has instructed the crew members inside the Dragon spacecraft to end the safe haven procedures and return to planned operations aboard the International Space Station.’
The Zvezda service module transfer tunnel is a pressurized cylindrical passageway in the rear of the Russian part of the station.
Its function is to connect the Zvezda’s main living quarters with the docking port where cargo is brought aboard the ISS.
While the module arrived in space in 2020, some parts of this section were constructed in the 1980s and have been a site of worsening leaks for years.
A leak has been ongoing since 2019, when air began escaping from the module’s transfer tunnel.
NASA has a plan in place for an emergency evacuation of the ISS, and it could be used amid cracks and leaks on the ship
Bethany Stevens, NASA press secretary, said that the astronauts have now been told to ‘return to planned operations’ after Roscosmos called off their attempted repairs at the last minute
These leaks rapidly accelerated as the repair attempts failed to stem the flow, leaking 1.68 kg (3.7 lbs) of precious air into space every day by 2024.
The issue has become so serious that NASA has reportedly ranked it among the highest-risk challenges facing the station, with the possibility of a ‘catastrophic failure’ discussed during internal meetings.
This new leak, detected on May 1, initially allowed roughly one pound of air to escape into space each day – about the weight of a loaf of bread.
However, this rate doubled, a senior NASA official told Reuters on condition of anonymity, prompting the space agencies to act.
In the past, Roscosmos astronauts have used sealants to attempt to plug the hole and prevent more air from escaping.
However, the Russian agency’s planned repairs carried a higher risk, and the remaining astronauts were ordered to take shelter as a precaution.
The astronauts are currently taking shelter inside the SpaceX Crew Dragon spacecraft in preparation for an emergency evacuation
Stevens said in a statement: ‘The Zvezda service module transfer tunnel, known as PrK, has suffered from cracks and leaks for some time, and has been mitigated by Roscosmos as much as possible to date.’
‘Following new leaks, Roscosmos has elected to proceed with a more extensive repair operation on Friday, June 5,’ she added.
‘Out of an abundance of caution, NASA has directed all four of the agency’s SpaceX Crew-12 members and NASA astronaut Chris Williams to assume an elevated safety posture in the Dragon spacecraft while the repair is underway.’
‘The cracks have always been a concern that NASA watches very closely. NASA and Roscosmos have been working to determine the root cause of the cracks, and Roscosmos manages the issue through operational mitigation measures and periodic partial-repair efforts’
NASA has a plan in place to evacuate the space station in case of an emergency, and had been ready to put that into action until Roscosmos called off the risky repair.
The moment Houston gave the signal, astronauts moved to their assigned spacecraft to shelter in place in case the station lost pressure.
The four astronauts of NASA’s Crew-12 mission (pictured before launch) on the station – two U.S. astronauts, a French astronaut and a Russian cosmonaut – donned their space suits in preparation for an emergency evacuation
The capsules have been stocked with emergency suits, allowing the crew to quickly put on the proper gear as they flee the orbiting laboratory, saving valuable time.
It can take up to 30 minutes to get inside a spacesuit, according to NASA, which makes early preparation vital.
If the station became unsafe and NASA was forced to call for a full evacuation, the crew would launch their SpaceX Crew Dragon capsule and return to Earth.
NASA’s Commercial Crew Program Manager Steve Stich has previously said that in the event of an emergency, SpaceX’s Dragon could be powered up within minutes.
This comes amid growing concern that the ageing space station needs to be retired before disaster strikes.
Since 1998, when construction began on the first modules, the ISS has hosted more than 250 visitors from 20 different countries and produced over 400 research papers.
But after roughly 146,000 orbits, the systems and hardware installed on the ISS are beginning to show their age.
The ISS was only intended to stay in orbit until 2015 and has now been in orbit for more than a decade longer than planned.
NASA is tracking 50 ‘areas of concern’ related to a leak in the Russian Zvezda Service Module, Transfer Tunnel (labelled), which sprang a leak in 2019
This is not the first time the ISS has sprung a leak. In 2018, astronauts rushed to fix a hole (pictured) which had appeared in the outer wall of the Soyuz capsule on the orbiting laboratory.
ESA astronaut Tim Peake took this photo from inside Cupola in 2016, showing a 7 mm-diameter circular chip gouged out by the impact from a tiny piece of space debris
In September last year, NASA’s Office of the Inspector General (OIG) identified 588 replacement parts that were operating beyond their operational lifetimes.
This has come with a risk of worsening leaks and damage from impacts with micrometeorites and space junk, especially in the oldest Russian modules.
In 2018, astronauts rushed to fix a hole that had appeared in the outer wall of the Soyuz capsule on the orbiting laboratory
Weighing 400 tonnes (880,000 lbs), equivalent to more than 400 elephants, the ISS is so large that it can’t actually stay in such a low-Earth orbit unassisted.
This means that the station’s thrusters need to be regularly fired in order to keep it in a stable orbit of around 250 miles (400km) above Earth.
If these thrusters failed, the station would gradually fall out of orbit and crash uncontrollably to Earth.
To bring the football-pitch laboratory down to Earth safely, NASA will need to deliberately push the station out of orbit.
NASA currently plans to bring the ISS down to Earth in 2030, bringing an end to three decades of international collaboration in Earth’s orbit.
NASA estimates it will cost $1bn (£800m) to convert a Dragon capsule (pictured) into a vehicle capable of pushing the ISS out of orbit
Starting from the end of this year, the station will be allowed to fall naturally under the effects of atmospheric drag until it reaches an altitude of around 200 miles (320km).
At this point, the last ISS crew will depart the station, taking with them any equipment or items that are deemed historically important.
Once the last crew has gone, the station will continue to fall over several months until it reaches the ‘point of no return’ at an altitude of 175 miles (280 km).
To deliver the finishing blow, NASA has commissioned a ‘space tug’ which will launch from Earth, dock with the ISS, and then push the station out of orbit.
The space agency plans to use a modified SpaceX Dragon capsule, which will dock with the station before pushing it into the atmosphere at an estimated cost of $1bn (£800m).
EXPLAINED: THE $100 BILLION INTERNATIONAL SPACE STATION SITS 250 MILES ABOVE THE EARTH
The International Space Station (ISS) is a $100 billion (£80 billion) science and engineering laboratory that orbits 250 miles (400 km) above Earth.
It has been permanently staffed by rotating crews of astronauts and cosmonauts since November 2000.
Crews have come mainly from the US and Russia, but the Japanese space agency JAXA and European space agency ESA have also sent astronauts.
The International Space Station has been continuously occupied for more than 20 years and has been expended with multiple new modules added and upgrades to systems
Research conducted aboard the ISS often requires one or more of the unusual conditions present in low Earth orbit, such as low-gravity or oxygen.
ISS studies have investigated human research, space medicine, life sciences, physical sciences, astronomy and meteorology.
The US space agency, NASA, spends about $3 billion (£2.4 billion) a year on the space station program, with the remaining funding coming from international partners, including Europe, Russia and Japan.
So far 244 individuals from 19 countries have visited the station, and among them eight private citizens who spent up to $50 million for their visit.
There is an ongoing debate about the future of the station beyond 2025, when it is thought some of the original structure will reach ‘end of life’.
Russia, a major partner in the station, plans to launch its own orbital platform around then, with Axiom Space, a private firm, planning to send its own modules for purely commercial use to the station at the same time.
NASA, ESA, JAXA and the Canadian Space Agency (CSA) are working together to build a space station in orbit around the moon, and Russia and China are working on a similar project, that would also include a base on the surface.
