European Space Agency (ESA) astronaut Tim Peake has been busily preparing for Friday's spacewalk outside the International Space Station, a first for any British astronaut as a member of the ESA. Peake will be joined by NASA astronaut Tim Kopra for the extravehicular activity in low-Earth orbit. 

The primary task for the spacewalk will be the replacement of a voltage regulator near the solar arrays that failed in November. The Sequential Shunt Unit is one of eight that regulates power from the space station's solar arrays.  After the astronauts replace the Sequential Shunt Unit, they will deploy cables to be used in the installation of an International Docking Adapter. These adapters will be used to dock SpaceX and Boeing commercial crew spacecraft. A broken light from a camera located on the space station's structural backbone will also be collected during the spacewalk.

Peake completed a final spacesuit check on January 11. Ahead of Friday's spacewalk, the astsronaut has been conducting experiments aboard the space station. Peake and NASA astronaut Scott Kelly are setting up the Electrostatic Levitation Furnace inside the space station's Japanese Experiment Module.

Peake will also be involved in an experiment evaluating the effects of microgravity on gut bacteria. In addition, Peake is keeping track of his skin condition, as part of the Skin-B experiment, and any signs of headaches during his time in space. "Skin-B collects data on skin structure, oxygenation, hydration and elasticity. The goal is to develop a computer model of how skin ages. Results on Tim’s skin will improve the model and could contribute to protecting people’s skin on Earth as well as in space," ESA explained.

The astronauts will be working under the cover of darkness during Friday's spacewalk. Because of the location near the solar arrays, the sun would cause unsafe work conditions for the astronauts. Kelly will serve as an assistant during Friday's EVA.