NASA officials hope to launch as early as October 2015 the second Ice, Cloud and land Elevation Satellite (ICESat-2) as part of a $650 million project to measure changes in polar ice sheets and sea ice. The spacecraft’s predecessor, ICESat-1, stopped gathering data on Oct. 11, 2009, and ongoing efforts to restart the lasers have been unsuccessful, said Thomas Neumann, deputy ICESat project scientist at the NASA Goddard Space Flight Center.

ICESat-2 will carry an Advanced Topographic Laser Altimeter System, an instrument designed to measure sea ice thickness in spite of the challenges posed by sloping and rough terrain, as it travels along the same path followed by ICESat-1. The laser altimeter will be designed at Greenbelt, Md.-based Goddard with parts procured from external vendors. NASA has not yet selected a launch provider or a contractor to build the ICESat-2 spacecraft, Neumann said Dec. 15, 2009, during a meeting of the American Geophysical Union in San Francisco.

ICESat-1, launched in 2003, used a similar instrument, the Geoscience Laser Altimeter System (GLAS), to measure changes in ice sheet elevation and sea ice thickness, information used by scientists to predict how changing ice patterns affect global sea levels. Soon after it was launched, one of ICESat-1’s three GLAS lasers failed. When NASA officials realized that the same mechanical failure would probably shorten the life of all three lasers, they canceled plans for continuous data gathering and used the remaining lasers instead for one-month campaigns conducted twice each year.

NASA’s budget includes $15 million in 2010 and $80 million in 2011 for ICESat-2, Neumann said.