Companies like Nanoracks, Made In Space, and Bigelow Aerospace are developing and demonstrating in-orbit assembly technologies. These technologies include:

1. Robotic arms and grippers: These are used to manipulate and assemble components in space. Examples include the Canadarm2 on the ISS and the robotic ARM on NASA's Space Launch System (SLS) rocket.
2. In-orbit assembly machines: These are specialized machines that can print, assemble, or fabricate structures in space. Examples include the Made In Space's 3D printer and the Nanoracks M3.
3. Modular construction: This involves building structures in parts, which are then assembled in space using robotic arms or other tools.