Astronaut Mike Massimino inside one of Hubble's instrument bays (left of center). Instrument Specialists, Michael Good (center) is standing on the Manipulator Foot Restraint, which is connected to the Shuttle Remote Manipulator System/Canadarm Latching End Effector. The Canadarm is white and extends from the upper right corner to the bottom center.

Hubble Hubble SM4: Gyroscope Swap

Astronaut Mike Massimino works to remove and replace Hubble’s Rate Sensor Units, which contain the telescope’s gyroscopes, during Servicing Mission 4 in 2009. All of Hubble’s gyroscopes were replaced during the mission.

Credits: NASA