R2 was designed as a prototype to be used on Earth but mission managers were impressed by R2 and chose to send it to the ISS. Various upgrades were made to qualify it for use inside the station. The outer skin materials were exchanged to meet the station's flammability requirements, shielding was added to reduce electromagnetic interference, processors were upgraded to increase the robot's radiation tolerance, the original fans were replaced with quieter ones to accommodate the station's noise requirements, and the power system was rewired to run on the station's direct current system rather than the alternating current used on the ground.