How Do Astronauts Conduct a Space Walk in Space?
Astronauts conduct a space walk to fix or install a new instrument at the space station. Since the robotic arms of the space station are not designed to do the entire job outside of the space station, the crew onboard often have to leave their cabin for such tasks.
However, before going for any spacewalk, the participating astronauts will have to prepare ahead of time for the success of the extravehicular activity (EVA). So how do astronauts participate in a space walk? You will discover how astronauts move out of their spacecraft to perform spacewalks in orbit.
What is a Space Walk?
A space walk is an extravehicular activity (EVA) in which astronauts leave their vehicle to perform a specific task outside their spacecraft or space station. This specific task could be to either install new equipment, repair damaged equipment, or for maintenance purposes.
On March 18, 1965, Alexi Leonov, a Russian Cosmonaut became the first human to ever perform a spacewalk outside his spacecraft. That first spacewalk only lasted for about 10 minutes. But it reminded the entire world about the possibilities of going outside the spacecraft in a highly protected spacesuit to perform a task on the exterior part of the space vehicle.
After the success of the first spacewalk, Americans were fascinated and began to work on performing a spacewalk too in orbit. On June 3, 1964, NASA astronaut Ed White became the first American to go for a spacewalk during the Gemini 4 mission and it lasted for about 23 minutes.
The success of these first two spacewalks proved that astronauts could survive outside their spacecraft if they deployed proper measures to stay alive. Currently, astronauts aboard the International Space Station and Tiangong space station usually go on spacewalks outside the station.
But unlike the first spacewalks that lasted for only a few minutes in the 1960s, these modern spacewalks last between five and eight hours depending on the tasks the astronauts have to accomplish outside the station. Russian cosmonaut Anatoly Solovyev held the world record for the most spacewalks in orbit. During his career, Solovyev participated in 16 spacewalks which equals more than 82 hours outside the space station.
Why do Astronauts go for Spacewalks?
Astronauts don’t just participate in spacewalks for the fun of the Extra Vehicular Activity. Hence, there must be crucial reasons before any space agency will allow their astronauts to perform a spacewalk in orbit. Firstly, scientists are always curious to test several science experiments during a space walk.
Hence, astronauts can go for a spacewalk to conduct these experiments. From the outcome of these outside the space station research, scientists usually learn a lot. They use the knowledge acquired to determine how space affects the astronauts outside their stations.
Astronauts also conduct spacewalks to test new equipment, repair satellites, or install new instruments. Returning the spacecraft of part of the spacecraft to Earth for proper maintenance and repair could cost any space agency billions of dollars. Hence, it is always safer and cheaper for astronauts to conduct spacewalks in space to fix any damages.
How Do Astronauts Train for A Space Walk?
Astronauts don’t have to wait until they arrive in the weightless environment of space before they begin to train for spacewalks. In fact, training for spacewalks commences even before the astronauts travel to space. Any space agency hoping to send its astronauts for a spacewalk must train them in underwater pools first. Hence, astronauts train for spacewalks by going for a swim.
Scientists have realized that floating in space is similar to floating in water. Hence, astronauts train for spacewalks in underwater large swimming pools. NASA’s massive swimming pool for this training is called the Neutral Buoyancy Laboratory (NBL) and it is located near NASA’s Johnson Space Center in Houston, Texas.
The American Space Agency built this pool to hold up to 6.2 million gallons of water. Astronauts usually train for about seven hours in the pool for every hour they spend participating in a spacewalk in space. Astronauts also train for a spacewalk by using virtual reality.
The virtual reality is like playing a video game and the astronauts often put on a helmet with the video screen embedded inside. The crew also wears a special glove for proper assistance during the virtual reality training. Once the astronaut moves, the special gloves often allow the movements to be displayed on the video. The virtual reality simulation makes the astronauts feel like the spacewalk is real in space.
How Do Astronauts Go on Spacewalks?
Before astronauts leave the space station for a spacewalk, they usually wear spacesuits to keep them safe. The inside spacesuits do contain enough oxygen and drinking water to sustain the astronauts throughout the duration of the spacewalk. Astronauts participating in the spacewalk usually put on their spacesuits several hours before the EVA commences, according to safety protocol of most agencies.
The suits are pressurized as they are filled with oxygen. Since the suit is too complex to be worn by a single person, other astronauts aboard the station often assist the participating astronauts in wearing the spacesuit properly.
Once the astronauts have dressed in their suits, they will have to breathe pure oxygen for a few hours to get rid of all the nitrogen in their bodies. If the participating astronauts ignore getting rid of the nitrogen, they might get gas bubbles in their bodies during the spacewalk.
Scientists revealed that these gas bubbles can make astronauts suffer pain in their shoulders, knees, elbows, and wrists. Astronauts identify these pains as the bends as they most affect joints where the body bends. After spending a few hours in the airlock region, the astronauts will leave through the airlock door and commence with the spacewalk.
The airlock has two doors. Once the astronauts are inside the space vehicle, the airlock is airtight to prevent air from leaving the spacecraft. Hence, the astronauts usually leave for the spacewalk through the first door and lock it tight behind them.
They can then proceed to open the second airlock door without allowing air to get out of the spacecraft. Once they complete the spacewalk, the astronauts can return to the spacecraft through the airlock
How Do Astronauts Stay Safe During A Space Walk?
During spacewalks, space agencies mandate their astronauts to use safety tethers to stay closer to their spacecraft and avoid floating away in space. Tethers used in space are like ropes and one end of it is hooked to the astronauts while the other end is connected to the space vehicle.
Aside from protecting astronauts from floating away in space, the tethers also help the astronauts keep their tools intact and prevent them from floating away. However, astronauts have to tether their tools to their spacesuits. The spacewalkers also stay safe in space by putting on SAFER. SAFER stands for Simplified Aid for EVA Rescue and astronauts usually wear it like a backpack.
This technology takes advantage of small jet thrusters to move astronauts around in space. Hence, if an astronaut eventually becomes untethered and floats away in space, the SAFER would help the person to fly back to the space vehicle. Astronauts often train to regulate the SAFER with a small joystick. This implies that they will control the space vehicle like they were playing a video game.
What Happens After the Space walk?
Once astronauts complete their spacewalks, they return to the space vehicle through the airlock chamber. They will remove their spacesuits and join the rest of the crew for other activities.
Conducting spacewalks in space requires lots of planning and effort from space agencies. So far, many astronauts have participated in spacewalks to prove that it is safe for humans to do so. We should be expecting more spacewalks in space in the future.
