Cubesat Laser Infrared CrosslinK (CLICK) B/C Mission Development Status

Small satellite constellations for applications such as navigation and data collection can require high data rate communication and precision ranging between spacecraft. Free space optical communication can achieve both high data rates and precision ranging with less size, weight, and power (SWaP) than comparable radio frequency (RF) terminals. However, optical links will have more stringent pointing requirements than standard RF links. NASA's CubeSat Laser Infrared CrosslinK (CLICK) mission will demonstrate low-cost miniaturized optical transceiver technology in Low Earth Orbit (LEO) for downlink and crosslink. The mission consists of two phases: CLICK-A and CLICK-B/C. CLICK-A deployed in September 2022 and demonstrated six optical downlink experiments. CLICK-B/C will demonstrate full-duplex optical crosslink communication between two identical spacecraft, CLICK-B and CLICK-C, at $\geq$ 20 Mbps over 25 km to 580 km link ranges. CLICK-B/C will also demonstrate ranging precision of better than 50 cm and time transfer of at least 200 ps timing accuracy. CLICK-B/C is slated to launch in 2025, funded by NASA CubeSat Launch Initiative (CSLI) and deployed through Nanoracks. The CLICK-B/C satellites are currently in assembly and functional testing. This paper presents the current progress in integration and testing of the CLICK-B/C payloads including fine pointing, acquisition, and tracking (PAT) development and open loop characterization results, co-alignment, and divergence testing.