Integrated antenna system for imaging microsatellites
Examples of imaging microsatellites are described that have an imaging system and antenna system disposed within the microsatellite body when the microsatellite is in a non-deployed state. The properties of the antenna system can be adjusted such that the antenna system does not impact, contact, or displace the imaging system when the microsatellite is in the non-deployed state. The properties of the antenna system can be adjusted such that the antenna system does not contact or impact the body of the microsatellite or any other structure when the microsatellite transitions to a deployed state. The antenna system can be configured to achieve a desired gain and/or data transmission rate by adjusting properties of the antenna system based on the radiation pattern of an antenna feed and geometric constraints imposed by the imaging system. Examples of methods for designing such imaging microsatellites are provided.
1. An imaging microsatellite comprising:
a movable door configured to:
cover a radiation entrance to the microsatellite when the door is in a closed position, and
uncover the radiation entrance to the microsatellite when the door is in an open position;
an imaging system disposed within the microsatellite, the imaging system configured to receive radiation entering through the radiation entrance when the door is in the open position, the imaging system comprising a primary mirror and a secondary mirror; and
an antenna system comprising an antenna feed, the antenna system coupled to an interior surface of the door, the interior surface facing the imaging system when the door is in the closed position,
wherein when the door is in the closed position, the antenna feed is disposed between the primary mirror and the secondary mirror, and
wherein while the door moves from the closed position to the open position, the antenna feed moves through the opening without contacting any portion of the imaging system or any portion of the imaging microsatellite.
2. The imaging microsatellite of claim 1 , wherein the microsatellite has a volume envelope less than or equal to about 125 cm by 125 cm by 175 cm.
3. The imaging microsatellite of claim 1 , wherein the microsatellite has a mass less than or equal to about 500 kg.
4. The imaging microsatellite of claim 1 , wherein the imaging microsatellite is configured to launch as a secondary payload on a launch vehicle configured to launch a primary payload.
5. The imaging microsatellite of claim 1 , wherein the imaging system comprises:
a primary baffle associated with the primary mirror; and
a secondary baffle associated with the secondary mirror,
wherein the antenna feed is disposed between the primary baffle and the secondary baffle when the door is in the closed position.
6. The imaging microsatellite of claim 1 , wherein the primary mirror and the secondary mirror are spaced apart by two or more support struts, the antenna feed is supported by a feed support, and the feed support extends between two adjacent support struts when the door is in the closed position.
7. The imaging microsatellite of claim 1 , wherein the antenna feed comprises one or more of a feed horn, a dipole driven element, a waveguide, an orthomode transducer, or a polarizer.
8. The imaging microsatellite of claim 1 , wherein the antenna system comprises an antenna reflector having a diameter d and focal length f, and a ratio f/d matches a radiation pattern of the antenna feed.
9. The imaging microsatellite of claim 1 , wherein the antenna system comprises an antenna reflector, and a ratio of a diameter of the antenna reflector to a width of the door is greater than about 50%.
10. The imaging microsatellite of claim 1 , further comprising a release mechanism configured to release the door and allow the door to move from the closed state to the open state.
11. The imaging microsatellite of claim 1 , wherein the antenna system is configured to provide a gain in a range from about 10 dBi to about 30 dBi.
12. The imaging microsatellite of claim 1 , wherein the antenna system is configured to provide a data transmission rate between about 1 Mbit/s and 100 Mbit/s.
13. The imaging microsatellite of claim 1 , wherein the antenna system is configured to transmit data across one or more communication channels within a band of frequencies between about 8.0 GHz and about &4 GHz.
14. The imaging microsatellite of claim 1 , wherein the antenna system is configured to transmit imaging data acquired by the imaging system when the door is in the open position.
15. The imaging microsatellite of claim 1 , further comprising one or more solar panels configured to provide power to electrical components in the microsatellite.