SSTL is currently manufacturing Lunar Pathfinder, a lunar communications spacecraft due to launch Q4 2024.
More about Lunar Pathfinder
We have previously supplied space engineering hardware for beyond Earth orbit missions:
Optics for the NIRSpec unit on the James Webb Space Telescope
A Momentum Wheel for the Philae lander on the Rosetta Mission
2 payload computer units for India's Chanrayaan-1 lunar mission