German, US astronauts return from 7-hour ISS spacewalk

Germany's Matthias Maurer and Raja Chari of the United States returned to the International Space Station (ISS) after a seven-hour spacewalk mission, reported dpa.

Live footage shared by US space agency NASA showed the two men re-entering the ISS via an airlock on Wednesday evening.

The two astronauts had left the ISS to attach new tubes to a cooling system, replace a camera, and attach an electricity and data connection on the external European research platform "Bartolomeo."

Spacewalks are physically very demanding and require very detailed planning.

The mission was 52-year-old Maurer's first extravehicular mission more than 400 kilometres above the Earth's surface. He is the 12th German in space and the fourth on the ISS.

Maurer's inaugural spacewalk went very well. After he returned to the space station, however, some water was spotted that had built up inside his helmet.

However, the astronaut was "in good health" and NASA's ground control said there was "no danger" to Maurer.

"Though some water has been identified in @astro_matthias's helmet, our spacewalkers are fit, healthy & happily exhausted. Congratulations @astro_matthias & @Astro_Raja on a spacewalk well done," the European Space Agency (ESA) tweeted.

Maurer already had to deal with a few minor problems. First, a loose camera on his helmet, which was then provisionally fixed with wire, temporarily delayed the work.

After that, he became tangled in his tethers, but was able to free himself with the help of instructions from the control centre.

Nevertheless, Maurer and Chari had completed their most important tasks, according to NASA.

The pair deferred a few secondary tasks to a future spacewalk.