Today, the Global Precipitation Measurement mission Core Observatory successfully fired its thrusters for five seconds to check out the thruster performance. This type of maneuver, called a delta-V, changes the velocity of the spacecraft to adjust the altitude of its orbit. Today's delta-V resulted in only a very slight change in the orbit, but will help the GPM team assess and calibrate the thruster performance.

By contrast, yesterday the team pulsed each maneuvering thruster 3-6 times, but for only 100 milliseconds each time. This was long enough to make sure the thrusters were working, but not enough to calibrate them.