A joint project of NASA and the Agenzia Spaziale Italiana (ASI; Italian Space Agency) to demonstrate the use of long tethers in space. Tests have been conducted to show how satellites on tethers can be deployed and controlled, and how they can generate electrical power. The TSS-1 Italian satellite was launched aboard the space shuttle Atlantis on 31 July 1992. The satellite was connected to the shuttle by a conductive tether. The electric potential was created as the tether passed through the Earth's magnetic field, the satellite charging positively and the shuttle negatively. The two vehicles separated by 167 m, but the mission failed to achieve the full extension of 20 km. TSS-1R (the ‘R’ stands for ‘reflight’) was launched on Columbia on 22 February 1996 with the same goals. The satellite was lost when the tether broke, partly due to a protruding bolt, after being extended to more than 19 km.