UK astronaut Tim Peake is set to complete a spacewalk next week – he will be the first Brit ever to float in outer space, with just a spacesuit between him and the vacuum outside. He and NASA’s Tim Kopra will repair a power unit located on the outside of the International Space Station (ISS). Astronauts call a spacewalk an Extra-Vehicular Activity.
The two astronauts, referred to as the ‘Two Tims’ by the European Space Agency, will carry out the repair on 15th January. They will work closely together for about six hours to replace the faulty unit.
Major Peake explained:
“Our primary task will be to replace a failed Solar Shunt Unit, which transfers electrical power generated by the solar panels.”
Major Tim Peake in a spacesuit during training at NASA’s Johnson Space Center in Houston. Donning the suit and safety equipment is a major operation that takes a few hours. (Image: www.esa.int)
A fairly straightforward procedure
The procedure is fairly straightforward, says the European Space Agency (ESA). The unit is a simple box that is removed by undoing just one bolt.
Once the unit has been taken out, the spacewalkers will have to lay cables in advance of new docking ports and reinstall a valve that was taken out for the relocation of the Leonardo module last year.
Within ISS, the spacewalkers will be helped into and out of their suits by fellow crew member, Scott Kelly. ESA says this is a major operation in itself.
Measures to prevent getting ‘the bends’
Before leaving the station, the two Tims will breathe pure oxygen for two hours to purge their bodies of nitrogen. Air pressure in their spacesuits is lower than in ISS.
The drop in pressure could give them ‘the bends’ – decompression sickness, also known as divers’ disease or caisson disease – a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurisation. It is a risk scuba divers face if they rise too quickly to the sea surface.
NASA astronauts Tim Kopra and Scott Kelly getting ready for their spacewalk of 21 December 2015. Major Peake supported them from inside the Station and took this picture with the comment “Tim and Scott primed and ready for their spacewalk.” (Image: www.eas.int)
Putting on their spacesuits and attaching the safety equipment will take hours before they enter the airlock to reduce the air pressure until it is safe to open the exterior hatch.
Peake excited at prospect of spacewalk
Major Peake commented:
“I am thrilled at this opportunity for a spacewalk. Right now we are focusing on preparing the tools, equipment and procedures.”
Astronaut Tim Kopra in the Quest airlock during the 21 December 2015 spacewalk. Major Peake took this picture and added the following comment: “What a great day! Hard work getting Tim Kopra and Scott Kelly safely out and back but they were awesome.” (Image: www.esa.int)
“Maintaining the International Space Station from the outside requires intense operations – not just from the crew, but also from our ground support teams who are striving to make this spacewalk as safe and efficient as possible.”
ISS has eight shunt units to regulate power, but since November 2015, it has been operating with just seven.
Major Peake concluded:
“If the spacewalk is successful, this will restore the International Space Station to 100% of its operational capability.”
This is the 35th NASA-led spacewalk for ISS. Tim Peake is assigned as EV2. Tim Kopra is EV1 and will have red stripes on his spacesuit.
Scott Kelly during the 34th NASA spacewalk, on 21 December 2015, to free a stuck transporter on the outside of ISS. Major Peake took this picture and added the following comment: “My ringside-seat view of the spacewalk EVA 34 – taken from the cupola.” (Image: www.esa.int)
Major Peake’s six-month Principia mission will see him work on more than 30 experiments for the European Space Agency.
He is ESA’s first British astronaut, the 6th British-born person to visit the International Space Station, and the 7th British-born person in space. He started ESA’s intensive astronaut basic training course in September 2009, and graduated in November 2010.
Video – ESA astronaut Tim Peake spacewalk training
In this video, you can see some of Tim Peake’s spacewalk training in Houston, Texas. Astronauts train underwater on life-size mockups of the Space Station.