It looks as if ICESat has collected its last data. The following message was posted on the ICESat website recently.
As of October 11, 2009, Laser 2 of the Geoscience Laser Altimeter System (GLAS) onboard the ICESat satellite stopped emitting light pulses. Since this time, no new science data have been returned from the GLAS instrument.
Currently, a GLAS Anomaly Review Board has reviewed and assessed the situation and a series of attempts to restart Laser 2 has been initiated, to be followed by attempts on the other two lasers which stopped working earlier in the mission.
Please stay tuned for future ICESat Mission Updates.
Alternatively wait for ICESat-II.