Deploying a Satellite’s Reflectors: Ready for Service
It’s been two weeks since the launch of Intelsat 30. In this blog post, Mohinder Guru, Senior Program Manager, Space Systems Acquisition, describes the deployment of the satellite’s reflectors.
During launch, the four antenna reflectors were stowed against the East and West sides of the spacecraft, and the two DAPM SPT Modules (Dual-Axis Positioning Mechanism Stationary Plasma Thruster Modules – known as “DSMs”) were stowed against the North and South sides of the spacecraft.
With four successfully executed apogee motor firings, the satellite’s perigee was raised to the same altitude as the apogee, resulting in a circular orbit. Then the satellite performed a well-choreographed sequence to deploy the reflectors and DSMs.
Each reflector is pinned to the spacecraft body by three hold-downs, each of which has a tensioned rod. These rods are severed by the firing of pyrotechnic cutters in a defined command sequence initiated by ground, which releases the reflector. Each reflector also has a DAPM to drive it to its deployed position. The deployed reflector is then slewed by commanding the DAPM in pitch and roll to the final on-orbit position.
All four reflectors were released and successfully deployed into their final positions in readiness to receive and transmit signals from Earth.
Each DSM was held to the spacecraft body by two pyrotechnically-released hold-downs. With ground command, the two hold-downs were fired simultaneously, freeing the DSM to deploy. Deployment of the DSM release was verified by monitoring the position telemetry of the DAPM potentiometers, in addition to a response on the gyro rates in the roll and yaw axis.
The DSM is ready now to perform electric North/South Station Keeping Maneuvers.
Here is an animation of the IS-30 solar array and reflector deployments – enjoy!