The amateur radio satellite Tethersat is a 3U CubeSat that splits into two joined by a 1 km tether to test electrodynamic tether propulsion.
Both spacecraft will use 9600 bps AX25 GFSK packet downlinks on UHF.
A launch is planned on ORS-3 in July 2013 from the Wallops Flight Facility on Wallops Island, Va.
Electrodynamic tether propulsion propulsion has the potential to make space travel significantly cheaper. It is a simplified, very low-budget magnetic sail. It can be used either to accelerate or brake an orbiting spacecraft. When direct current is pumped through the tether, it exerts a Lorentz force against the magnetic field, and the tether accelerates the spacecraft.
Potentially this technique could be used to raise the orbit of a satellite from 600 to 1000 km using a Ward Spiral maneuver.
See the 2009 paper Tethered Satellite Dynamics, Mission Design and Applications by Chadwick Healy - http://ccar.colorado.edu/asen5050/projects/projects_2009/healy/
IARU Satellite Frequency Coordination Panel status - http://www.amsat.org.uk/iaru