https://techcrunch.com/2019/09/02/3d-printers-on-the-final-frontier-made-in-space-is-building-satellites-that-build-themselves/

In a nondescript building near Moffett Field, still undistracted by any VC funding, an 80-person company named Made In Space is building tools for the next generation of satellites and space exploration, including most remarkably, the first self-manufacturing satellite, due for launch in three years’ time.

Building in space rather than on the ground, courtesy of 3D printers and automated assembly, comes with many advantages. You can save volume by sending dense feedstock for 3D printers rather than capacious constructed objects. More importantly, if you don’t have to build to survive the traumatic forces of launch, you can use more fragile designs, and hence less mass.