During the presidential campaign, Barack Obama said he would work to launch "without further delay" the Global Precipitation Measurement mission, "an international effort to improve climate, weather, and hydrological predictions through more accurate and more frequent precipitation measurements."
 
The launch isn't planned until 2013 -- which would be in Obama's second term, if he wins one -- but we've seen some progress.
 
First, some background on the mission. Scientists have a hard time studying rain, snow and ice because the amounts that fall vary widely even within small distances, and because weather events can emerge and disappear quickly.
 
"Reliable ground-based precipitation measurements are difficult to obtain over regional and global scales because most of the world is covered by water and many countries are not equipped with precision rain-measuring sensors," NASA says. "The only practical way to obtain useful regional and global scale precipitation measurements is from the vantage point of a space-based remote sensing instrument."
 
Thus the effort to launch Global Precipitation Mission. NASA is working with the Japan Aerospace Exploration Agency to launch the mission, which will feature a space-borne "Core Observatory" designed to help unify and advance measurements from a constellation of multinational research and operational satellites carrying microwave sensors. According to NASA, "GPM will provide uniformly calibrated precipitation measurements globally every 2-4 hours for scientific research and societal applications. The GPM Core Observatory sensor measurements will for the first time make quantitative observations of precipitation particle size distribution, which is key to improving the accuracy of precipitation estimates by microwave radiometers and radars."
 
On Dec. 2, 2009, NASA officially approved key elements of the mission, allowing the project to move forward. The review meeting was chaired by NASA's Associate Administrator Christopher Scolese.

The GPM Core Observatory is scheduled for launch in July 2013, so we can hardly call this a Promise Kept. But the Dec. 2 green-lighting is more than enough to move this promise to In the Works.