Earth's vital signs soon to go unmeasured as satellites fail

Lisa Palmer in Scientific American reports on a dreadful situation in space: Satellites aren't built to last forever, so it's not a big surprise that the third and last laser on NASA's Ice, Cloud and Land Elevation Satellite (ICESat) quit working on October 11, outlasting its designed mission length by three and a half years. Since its launch in 2003 ICESat has been a critical instrument for continuously monitoring how much ice sheets in Antarctica and Greenland are contributing to the rise of the world's oceans and how much the swath of sea ice in the Arctic Ocean is thinning—both of which are occurring faster than projected.

The loss of ICESat, however, is a signal of what the future holds for NASA's ailing Earth Observing System (EOS), which is dying just as it is most needed to inform decisions and policy on climate change. Today, 14 of the 15 satellites currently making climatic observations on Earth are far beyond their designed life-expectancies, with the exception being the Ocean Surface Topography Mission (OSTM):

* Landsat 7
* Tropical Rainfall Measuring Mission (TRMM)
* Quik Scatterometer (QuikSCAT)
* Terra
* Active Cavity Radiometer Irradiance Monitor Satellite (ACRIMSAT)
* Earth Observing 1
* Jason 1
* Aqua
* Ice, Cloud and land Elevation Satellite (ICESat)
* Gravity Recovery and Climate Experiment (GRACE)
* Solar Radiation and Climate Experiment (SORCE)
* Aura
* CloudSat
* Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)
* Ocean Surface Topography Mission (OSTM)

Several of these are expected to "go dark" in the next two years, robbing scientists of critical data needed for monitoring climate change and verifying international agreements, just as a critical mass of global players is agreeing that such agreements are essential to the future health of the world's people and economies.

…Planned replacements for Earth-observing satellites are inadequate, too. The various airplanes that carry the instruments for ICE Bridge, a stopgap measure until ICESat's successor is launched five years from now, have limited coverage. So, consecutive measurements for tracking global ice patterns will not resume until 2015, after ICESat 2 enters orbit….

An image of the Landsat 7 satellite from NASA