The Orbiting Carbon Observatory Was a satellite that was going to let us create a dynamic detailed map of carbon emissions and carbon sinks. We do have some ability to do this now, but nothing like what this would have helped us to do. Now we will be looking to Japan Gosat satellite to perform this function. Too bad.
Update: Bad Astronomy has more and will have update. Clearly its better to read about it there..... But I still beat him to the punch!