How Are Astronauts Sent To International Space Station
Selection Of The Best Candidates
The first part of sending astronauts to space is selecting them. More than hundred people are tested for this job. And belive me when I tell you that the people that are selected are the best people in the *world!*
These astronauts have reached this point with nothing but hardwork. They are the veterans that are ignored. And even when you read this, there are some of these veterans, doing all kinds of things in space.
Only the fittest and the finest are selected. They don't only have to be fit physically, but also mentally. Just the thought of living six months in the claustrophobic space station scares most of the people, but these astronauts are prepared to face it.
It is very difficult to get selected for a mission, and only those who shine are given the chance.
After the astronauts are ready, they board the space craft that would take them to the space station. After the US Space Shuttle Program ended, the Russian Soyuz is the only means of getting people to space (SpaceX and China are also working towards manned missions.)
After all the pre-flight checks, the engines are started and the astronauts are launched towards space. During this ride, the space craft experiences extreme atmospheric resistance, and the space craft shudders violently almost all the time.
But, when the atmosphere starts getting thinner, the air resistance also decreses, and things start getting calmer. If everything goes as planned, the launch is considered a success.
Getting To The Space Station
After the launch, the next step is to reach the space station. The rocket starts accelerating towards it. The launch is timed very precisely, so that the least amount of distance is covered, and fuel consumption is low.
As the manned capsule reaches the ISS, the engines are burned retrograde (opposite to the velocity vector), so that the speed of the space craft equals that of the space station. This matches the orbit of the space craft to the station.
Soon, the station and capsule are moving side to side. Then, the next step starts.
Now, the most difficult part comes. Docking. Docking means joining the two ships, so that the exchange of crew can take place. This happens almost every month. For crew, or for supplies.
When both the ships are moving side by side, the experience of a pilot comes into play. If the docking is for supplies, then someone on the space station remotely pilots that supply craft, or if it is a manned mission, the pilot in the capsule does the docking.
Docking requires such precision that the main engines cannot be used. So, for this purpose, RCS thrusters are used. They are small puffs of thrust that help control the craft very precisely.
Using these RCS thrusters, the capsule slowly starts moving towards the docking port on the space station. This requires so much experience and precision, that even a single mistake can be the end of both the people in the capsule, and for the people aboard the station.
When the two ships are docked, there is generally a few hours gap for equalizing pressure before the docking ports are opened and the crew exchange handshakes.
So, this was the whole process in a nutshell. Hope you enjoyed it. Thanks for reading!!