Dawn was launched by NASA on the 27th of September 2007 with a final destination of the asteroid Ceres which it is currently in orbit around.
Key Dates during Dawn's mission:
Launch 27 September 2007
Mars gravity assist February 2009
Vesta arrival August 2011
Vesta departure May 2012
Ceres arrival February 2015
End of primary mission July 2015
Telecommunications summary:
Telecommunications block diagram:
It is recommended that the NASA book on Dawn is read, you can find it here Signal received from Dawn on the 7th May 2015:
The FFT corresponding to the above audio sample is shown below:
The FFT Image gallery below shows some of the signals received from the Dawn spacecraft over the years.