Satellite communication system
A cubesat design includes selected subsystems for managing communications to other satellites and ground stations. In one embodiment, the subsystem includes a deployable antenna having compact size and low weight that reliably releases and detects an extended antenna after launch.
1. A cubesat communication system comprising:
a structure, in the cubesat communication system, including:
an antenna that has a coiled profile when the antenna is not deployed, and transforms from the coiled profile to a straight line profile when the antenna is deployed;
a storage slot defined in the structure for storing the antenna when the antenna is not deployed, and
a hinged door that has a closed position to close the storage slot, the door being releaseably held in the closed position by a meltable wire;
a control connector, in the cubesat communication system, for releasing said door from the closed position and deploying said antenna; and
a detector, in the cubesat communication system, for generating a signal that indicates a successful deployment of the antenna.
2. The cubesat communication system of claim 1 , wherein during the deployment of the antenna, the antenna exerts its spring force on the door to open the door.
3. The cubesat communication system of claim 1 , wherein when the door is in an open position, a circuit in connection with the door is closed and triggers a signal to the detector confirming that the door reaches the open position.
4. The cubesat communication system of claim 3 , wherein said circuit is closed when a contact arm in connection with the door contacts two metal screws.
5. The cubesat communication system of claim 1 , wherein the antenna is about two feet in length in a deployed linear position.
6. The cubesat communication system of claim 1 , wherein said wire is made of ultra-high-density-polyethylene and approximately 10 mm thick.
7. The cubesat communication system of claim 1 , wherein the structure includes a second storage slot to accommodate a second antenna, and the second antenna extends from a coiled profile to a straight line profile when the second antenna is deployed.
8. The cubesat communication system of claim 7 , wherein when the two antennae are deployed, they form a predetermined angle between them.
9. The cubesat communication system of claim 1 , wherein the wire has sufficient strength to hold the door in the closed position against spring force of the antenna.
10. The cubesat communication system of claim 1 , wherein the wire is in contact with two resistors.
11. The cubesat communication system of claim 10 , wherein the control connector releases the door from the closed position by sending a signal to apply a current across the resistors and cause the wire to melt.