[letmelogin]

From here.

For more than a week, astronauts on the station have been trying to figure out how to replace a malfunctioning Main Bus Switching Unit, which transfers power from the massive solar panels into the station, space.com reported.

Without the 100kg MBSU the station was unable to get power from two of its eight panels. Then on Saturday another malfunction put a third panel offline - making for a nervous time on the station as they conserved power to keep vital life support systems functioning.

Last week a marathon eight-hour spacewalk failed to fix the problem, as a pair of stubborn bolts thwarted their efforts to install a spare MBSU.
Space Station

Experts at NASA's Johnson Space Centre in Houston worked around the clock to figure out a solution, improvising a set of tools from existing supplies on the station that could help fix the stuck bolt. Their solution included an Allen wrench taped to a bolt, and a $3 toothbrush used to clear metal shavings from the threaded bolt hole. Would have been a nerve-wracking task, but a good one to look back on later in life and say you were involved.