Image: Astronaut Matthias Maurer training for EVA

ESA astronaut Matthias Maurer practices Space Station repairs in the Neutral Buoyancy Lab at NASA's Johnson Space Center in Houston, USA.

The giant pool is over 12 metres deep and features a full-scale mock-up of the International Space Station. It is used to train astronauts in the very precise and difficult task of making repairs or installing new equipment in the vacuum of space.

To simulate microgravity underwater, astronauts are weighted down to minimise the buoyant force that would otherwise have them bobbing back up to the surface. They must also work very slowly to compensate for the drag caused by water.

It's about as fun as falling in water fully dressed and pulling out your laptop to start working. But someone has got to do it.

Extravehicular activity or EVA training is standard across the astronaut experience, beginning at the candidate level and continuing before and after a spaceflight.

Additionally, astronauts take on a slew of other hands on activities and simulations. Matthias is in Bordeaux, France, today for the latest parabolic flight campaign. From medical training to orbital mechanics and computer engineering, astronauts have a busy schedule.

Becoming an astronaut involves a cutthroat selection process for an exciting job. But it's not without its risks. Human spaceflight today has evolved into a standard and safe job, thanks to the sacrifice of courageous individuals over the years. Without their contributions, humans would not be the space faring species we have become today.

In celebration the beginning of the space era, the UN has designated 12 April as International Day of Human Spaceflight, more popularly known as Yuri's Night. Cosmonaut Yuri Gagarin was the first human to fly to space on 12 April 1961, a historic event in human history.

Events are held across the globe in celebration of Yuri's Night. Find one near you and join the world's largest space party celebrating human achievement beyond Earth's atmosphere.

And if you happen to meet an astronaut, show them some love. They don't always have it easy.