The real question is: what ISN'T it???
Move over, duct tape, because it's toothbrush's time to shine! Astronauts Sunita Williams and Akihiko Hoshide were having a trouble getting a bolt repaired on the Main Bus Switching Unit (MBSU) of the International Space Station during an 8-hour spacewalk on August 30.
The MBSU is part of the station's framework designed to control the movement of external stowage platforms which house spare parts and equipment. Frustrated with the unit's lack of cooperation, the astronauts turned to a rather unconventional set of tools. As Space.com describes:
"One was a modified toothbrush that was used to lubricate the inside of the bolt's housing after debris and metal shavings from inside had been removed. Another improvised instrument included a cleaning tool that had been made from wires that were bent back to form a brush, explained Keith Johnson, lead spacewalk director at the Johnson Space Center."