Merry Christmas, NASA astronauts say from space

The stockings are out, the tree is up and Christmas celebrations are on in the zero-gravity nest of astronauts in space.

As astronauts continue advanced space research to benefit life on the Earth and in space, the team including Italian astronaut Samantha Cristoforetti is in the holiday spirit. The International Space Station (ISS) is decorated with stockings for each crew member and a tree in the Christmas week.

A wide array of research work took place this week on the space station with scientists on the ground, working in conjunction with the astronaut lab assistants, exploring different fields.

The behavioural testing for neuromapping study assessed changes in a crew member's perception, motor control, memory and attention during a six-month space mission.

The results will help physicians to understand brain structure and function changes in space and how a crew member adapts to returning to the Earth and develop effective countermeasures.

Another study is observing why human skin ages at a quicker rate in space than on the the Earth.

The experiment will provide scientists a model to study the ageing of other human organs and help future crew members prepare for long-term missions beyond low-earth orbit, the US space agency said in a statement.