FITSAT-1 led experiment on Christmas Eve.
The led experiment comprising a bank of high power LEDs that will be driven with 200W pulses to produce extremely bright flashes that may be visible to the unaided eye of observers on Earth.
The team aim to start testing the LEDs at the end of November and it is planned that a message will be flashed from space on Christmas Eve, December 24, 2012. Further information will be posted at http://www.fit.ac.jp/~tanaka/fitsat.shtml
[PE0SAT Thanks Amsat-UK for the above information]