The 20 most amazing moments of the ISS

The International Space Station (ISS) has welcomed more than 230 people from 18 countries in the past two decades, not bad for a science lab floating in space!

Astronauts from all over the world have lived on the space station. They conduct experiments and make new scientific discoveries as they orbit the Earth, 200 miles above our heads.

The ISS started as three basic 'modules' or rooms and has now grown into a massive research centre with five bedrooms, a gym, two bathrooms and even a 360-degree window where astronauts can look down at the Earth below.

Earth viewed from a window on the ISS

According to Nasa the ISS has 'paved the way for visitors from countries around the world who conduct science in the name of benefitting humankind'.

So let's take a look at the most memorable moments and achievements of the astronauts who have made the ISS their home over the past 20 years.

• November 1998: Construction of the ISS began in orbit, eventually ready for its first guests after 11 years being carefully constructed in space. The parts were produced across the globe and sent up in 42 separate assembly flights. It took the cooperation of 15 nations to make the ISS in space.

• 2 November 2000: The first crew arrived. Nasa astronaut William 'Shep' Shepard left Earth for the ISS on 31 October and was its first ever commander alongside Russian cosmonauts Yuri Gidzenko and Sergei Krikalev.

From left: Cosmonaut Yuri Gidzenkosoyuz, astronaut William Shepherd and cosmonaut Sergei Krikalev

• March 2001: The longest ever spacewalk was conducted by Susan Helms and James Voss, it took eight hours and 56 minutes.

• April 2001: Umberto Guidoni, an astronaut from Italy, became the first European astronaut to board the ISS.

• April 2001: US multimillionaire Dennis Tito paid $20 million for a six day stay on board the space station, becoming the first private citizen to be sent into space. That's a pricey break!

• April 2007: Sunita 'Suni' Williams ran the Boston Marathon in space, as the station circled Earth at least twice. She was strapped into place on the treadmill so she didn't float off in zero gravity.

• November 2008: The European Space Agency (ESA) sent the Declaration of Human Rights into space to stay on display in a laboratory on the ISS.

• December 2009: First ever Monarch butterflies were taken up to space, they emerged from their cocoons on the ISS, allowing students to study the effects of zero gravity life on the insects.

• January 2010: The first tweet was sent from space by astronaut Timothy Creamer.

The first tweet from space!

• May 2013: Canadian astronaut Chris Hadfield made the whole world his stage as he played David Bowie's 'Space Oddity' on the ISS.

• November 2013: The Olympic torch made it to the ISS and was handed between two Russian cosmonauts, Oleg Kotov and Sergy Ryazanskiy, before the flame was lit in Sochi, Russia for the 2014 Games.

Cosmonaut Fyodor Yurchikhin with the 2014 Sochi winter Olympic Games torch after landing.

• December 2015: British Astronaut Tim Peake became the first person from the UK to join colleagues on the ISS. He conducted research into how seeds that have been in space grow back on Earth, compared to ones that haven't been.

• March 2016: The first whole year mission is completed by Scott Kelly and Mikhail Kornienko. However this isn't the longest time anyone has spent in space, that record belongs to Valery Polyakov who completed 437 days aboard the station this year.

• March 2016: Tim Peake and Scott Kelly played a unique game of space invaders using VR headsets and their fingers as fire canons.

• April 2016: Tim Peake ran the London marathon in space in three hours and 35 mins achieving a Guinness World Record for the fastest ever marathon run in space.

• April 2016: Tim Peake also carried out a repair on the ISS and made history as the first ever British astronaut to complete a space walk.

Tim Peake on his space walk

• October 2019: The first ever all-female spacewalk took place with US astronauts Christina Koch and Jessica Meir who went outside the ISS to fix a battery unit.

• February 2020: Christina Koch broke the previous record for the longest single spaceflight by a women, she was on the ISS for 328 days.

• May 2020: Elon Musk's Space X became the first private company to send humans into space, US astronauts Robert Behnken and Douglas Hurley arrived at the ISS. The first stage in SpaceX's plans to ultimately send astronauts to Mars.

• October 2020: After six years of development and costing $23 million, Nasa's latest unisex toilet design arrived at the ISS. It is much smaller than older versions and is able to recycle urine into usable water for astronauts the next day.

So next time you spot the ISS orbiting the Earth, don't forget to wave hello to the astronauts who are calling the space station home right now.