thrusters

The GPM spacecraft continues to perform normally. The GPM Microwave Imager and Dual-frequency Precipitation radar continue operations and calibration. The spacecraft performed two routine maneuvers. The first was a 180-degree yaw (left/right in the horizontal plane) turn. This is the second yaw turn that changes the orientation of the spacecraft; it is now flying forwards again. Yaw turns are performed approximately every 40 days for thermal control, as the angle between the spacecraft's orbit and the sun changes. This keeps the side of the spacecraft designed to remain cold from overheating

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

Following yesterday’s activities with the two science instruments associated with the Global Precipitation Measurement core observatory, the flight control team’s attention today is focused on the observatory’s onboard maneuvering thrusters. The satellite has a dozen thrusters: four forward and eight aft. The flight team is activating and initializing the thrusters over the course of today. A brief (5 second) propulsion burn to further calibrate the thrusters is planned for early this week. GPM’s propulsion system has two functions. First, to adjust its orbit and maintain altitude, and second