All commands reach MoonRanger from Earth, and MoonRanger’s exploration data is conveyed back to Earth after WiFi relay through its lander. This WiFi is absolutely essential to mission success. The capability is achieved by a custom circuit board developed around the CC3200 WiFi chip. The board has a pair of selectable antenna ports that selectively utilize either of MoonRanger’s two antennas to assure the strongest signal at any time.
A series of bench and field tests were undertaken to verify the design, build and performance of this board with its embedded software and antennas. These tests include Inspection (confirms solder pads and component connections), Continuity (checks resistance at specific pins of interest), Smoke (confirms no overheating or component damage), and Power (power draw while transferring 50,000 WiFi messages). The board passed these tests.
The functional tests evaluate the ability to transmit and receive data over a given range, as well as switching between its two omnidirectional antennas. Tests confirmed that the Wi-Fi board and antennas transmit and receive data at an impressive range of 160 meters with only a 30% performance drop from peak performance that is achieved at short range. Hence the rover’s range doubles the 80 meters of range that is guaranteed by the lander.
The flight version of this board will be tested in a similar manner when the time comes.
By: Sarah Abrams & Dream Vo