After spending almost six months in space, three astronauts are all set to return to earth from the International Space Station (ISS).

The commander of Expedition 43, Terry Virts, and his crewmates Anton Shkaplerov and Samantha Cristoforetti are among the three astronauts set to return to earth.

The trio spent six months at the ISS carrying out scientific research and technology demonstrations.

Ms. Cristoforetti has set the record for spending the longest time in space on a single mission by a woman. The three have been at the ISS since November 2014.

Three of them climbed into their Soyuz space capsule to make the three-and-a-half hour descent later on June 11. They will land in Kazakhstan just before 3pm UK time.

The crew faced a number of challenges including one of January, when the astronaut crew had to be evacuated from one part of the space station after a suspected gas leak.

In April, a resupply spacecraft - Progress M-27M - suffered a major malfunction, spinning out of control shortly after launch and eventually ending up crashing.

Following the incident, Roscosmos decided to delay any manned missions to the ISS while they tried to understand what happened to Progress, leaving back the astronauts stuck at ISS.

Just before their departure this week, an engine malfunction on one of the docked Soyuz rockets unexpectedly shunted the Space Station, but Russian space agency Roscosmos said that it didn't put astronauts in any danger.

Cristoforetti was able to set the record for the longest time ever spent by any woman in space because of the unexpected delay of the trio's return.