NASA Astronauts Lost A Crucial ISS Shield On A Spacewalk, And It's Now Orbiting The Earth

NASA¡¯s astronauts aboard the International Space Station were on another scheduled space walk on Thursday, when they accidentally lost a crucial fabric shield essential to their work.

Images courtesy: NASA

Astronauts Peggy Whitson, who on Thursday set the record for most spacewalks by a woman with eight in total, and Shane Kimbrough were working on one area of the ISS¡¯ exterior, reconnecting a docking module that had been transported there recently. While going about their work, one of four large cloth panels used to cover the docking port access point unhitched itself and drifted away into space.

Whitson¡¯s frustration was noticeable as she reported the incident to Mission Control, audible on the livestream of the space walk being broadcast at the time. According to NASA spokesman Dan Huot, everything had been going smoothly for the previous 3.5 hours of the mission, and it¡¯s unclear why exactly the fabric shield was lost.

¡°The team will go back and look at what the chain of events were, but essentially it was untethered,¡± Huot told the media.

A piece of cloth may seem like a paltry thing to obsess over, but it had a crucial use during the maintenance process. Before the docking module could be attached, the fabric shields were being used to protect the exposed port from micro-meteoroids or orbital debris (MMOD) ¡ª miniscule particles of asteroid debris or space junk that could damage the crucial hardware and jam the module. In addition, the shields were also providing a barrier from extreme temperature changes.

Meanwhile, at Mission Control, scientists gathered around a simulation of the ISS, scrambling to think of a backup plan to protect the quarter of the docking port left exposed by the accident. Astronauts are limited to only what supplies may be on board the station, and so scientists on Earth have to take this into consideration when looking at backup plans. They eventually settled on using a spare sheet of cloth and makeshift wire ties to replace the lost fabric shield.

Spacewalk support personnel at Mission Control pondering a hasty solution to the accident

¡°It was spur of the moment, completely unplanned,¡± Huot said. ¡°They got presented with a problem and the ingenuity kicked in.¡±

To be clear, these fabric shields aren¡¯t like the average king size bedsheet you might imagine. Each one is a little over 5 feet long, 2 feet wide, and almost 3 inches thick, and weighs approximately 8 kg.

It¡¯s the first time NASA has lost a fabric shield during a spacewalk, though other parts have made their escape into the abyss before. ¡°Sometimes bolts will go,¡± Huot said. ¡°There was one spacewalk where we lost an entire bag of tools.¡±

Eventually, the gigantic sheet of cloth will degrade, then burn up when it reenters Earth¡¯s atmosphere. However, there¡¯s no gravity or friction to stop floating objects in space, so any item lost during a spacewalk runs the potential risk of making a full orbit of the Earth, and then damaging the ISS on its return. If you¡¯ve seen the movie Gravity, it¡¯s the same as when the debris from the damaged space station makes another circuit. Thankfully, Mission Control¡¯s obsessive monitoring of the cloth tracked its circuit and determined it wouldn¡¯t be a problem in the future.

The rest of the spacewalk blessedly went of without a hitch, clocking in at seven hours and four minutes, with Whitson accumulating a total of 53 hours 22 minutes in space, the most amount of spacewalk time ever by a female astronaut. The record she broke was that of Sunita Williams, at 50 hours and 40 minutes.

(L-R) Thomas Pesquet, Peggy Whitson and Shane Kimbrough aboard the ISS