In footage beamed from high above, it looks more like ballet than anything resembling what humans describe as walking on terra firma. But all the same it is called a spacewalk and remains arguably the best way till date of experiencing space first hand and grabbing the best views of the Earth below. As two Chinese taikonauts completed only the second spacewalk for the country, here’s all you need to know about stepping into the void.
Why Is The Chinese Spacewalk a Big Deal?
People from only a handful of countries have had the extremely rare privilege of taking a walk in space. The US and Russia dominate the spacewalk list and most of the others that can check off this item from their bucket lists accomplished their space walks aboard a vessel made by either of these two countries. Therefore, when Liu Boming and Tang Hongbo stepped out of the Tianhe core module of its upcoming space station, it marked another feather in the cap for the country’s space programme.
It was, however, not the first time that a taikonaut had gone on a spacewalk. In 2008, Boming was part of the crew that had pulled off the China’s first spacewalk. He had then got a small taste of space as he primarily assisted another crew member who spent about 20 minutes outside the Shenzhou-7 spacecraft. This time around, Boming and Tanh Hongbo, who is on his first space mission, spent about seven hours outside the station to set up cameras and other equipment using a 50-foot-long robotic arm.
The Chinese trio — Nie Haisheng is the third taikonaut — who have journeyed to Tianhe are tasked with facilitating the setting up of the Chinese space station, called Tiangong, which is expected to be ready by end-2022. ‘Taikonaut’ is just the Chinese word for a space traveller and combines the Chinese term for ‘space’ with the Greek term for ‘sailor’.
China has planned a total of 11 space missions through which it will move the components and finalise the setting up of its space station. The taikonauts’s mission is the third in the series. For the first two missions, the Tianhe core module was sent into orbit on April 29 this year followed by the Tianzhou-2 cargo spacecraft that was launched on May 29, to dock with Tianhe. Tianhe means ‘Heavenly Harmony’ in Chinese.
What Happens On A Spacewalk?
According to US space agency Nasa, a spacewalk is not really a pleasure trip but an activity that lets astronauts carry out key tasks like conducting experiments, executing repairs and testing equipment. For example, the Chinese taikonauts are actually putting in place the components that are essential for the functioning of their future space station.
Given that it’s a tight manoeuvre, an astronaut out on a spacewalk needs a lot of help from his fellow travellers.
To actually get out into space, astronauts exit the spacecraft through a special door called an airlock, which is actually two doors, the first is locked behind them and keeps the spacecraft airtight while the second door is the one that opens out into space. To get back in, the astronauts execute this process in reverse. First, tightly shutting the second door behind before opening the door into the pressurised spacecraft.
What Does One Need For A Spacewalk?
First and foremost, a proper suit. Nasa says that the spacesuit not only keeps the astronauts safe, they also provide them with water to drink and oxygen to breathe. Some might say, too much oxygen. You see, after donning their spacewalk suit, the astronauts “breathe pure oxygen for a few hours". That helps them rid their body of all the nitrogen, for unless they do that “astronauts might get gas bubbles in their body" as they walk in space. These gas bubbles can cause pain in shoulders, elbows, etc. and is described as getting “the bends" as it affects the places where the body bends. Scuba divers, who wear pressurised suits for diving deep into water, are also known to experience the bends.
The National Geographic magazine quotes astronauts who say that the suit can prove to be itchy but that one can try and shuffle around to take care of that.
How Safe Is It To Walk In Space?
It is very important for an astronaut to remember the tether as they head for a walk in space. The tether is like a rope that ties the astronaut to the spacecraft. If not for this tether, an astronaut will float away into space as there is no gravity up there like on Earth to keep you glued to an object. Nasa says that even astronauts’ tools need to be tethered and are hence attached to their spacesuits.
But there have been instances of ‘untethered’ spacewalks, with the first of them coming in 1984 and executed by the US astronaut Bruce McCandless. Reports say there have been only seven untethered spacewalks, all done by US astronauts. The first six, all of them in 1984, used something called the Manned Manoeuvring Unit, while the last one in 1994 used what is known as ‘SAFER’, short for Simplified Aid for EVA Rescue. EVA here stands for extra-vehicular activity, the technical term for spacewalks.
One thing to look out for is flying space debris, astronauts say, as the remnants of a wrecked satellite or some space object, however small, can hit an astronauts spacesuit and make it leak oxygen.