XW 4 (CAS 10, Macau Student Science 1, HO 119, Hope-OSCAR 119)

XW 4 (CAS 10) [CAMSAT]

The XW 4 or CAS 10 (Chinese Amateur Radio satellite 10), also known as Hope-4 and Macau Student Science 1, is an 8U (2×4U) CubeSat that will carry an Amateur Radio VHF to UHF linear transponder for SSB communications.

It is a follow on mission from CAS-9 and is an 8U CubeSat, approx 228 × 455 × 100 mm, with a mass of 12 kg.

The satellite carries:

• A VHF uplink and UHF downlink linear transponder with a bandwidth of 30kHz. This transponder will work all day during the life cycle of the satellite, and amateur radio enthusiasts around the globe can use it for two-way radio relay communications.
• A camera, and the pictures it takes are stored in the flash memory on the satellite, we have designed a simple remote control system based on DTMF, and amateur radio enthusiasts around the globe can send DTMF commands to download the camera photos.
• A CW beacon to send satellite telemetry data, which is also a feature that is widely welcomed by amateur radio enthusiasts.
• A AX.25 4.8k/9.6kbps GMSK telemetry downlink

It was launched in November 2022 from Hainan Launch Center onboard of Tianzhou 5 using a CZ-7 launch vehicle into a 400 km circular 42.9° inclination orbit. It was deployed from Tianzhou 5 while being docked at the CSS.