Siderostat pointing: validation of an advanced line-of-sight pointing concept beyond LISA

We present a mechanism prototype for a previously proposed advanced pointing concept for a Laser Interferometer Space Antenna-like space-based gravitational wave observatory that enables an architecture with two bi-directional interferometric laser links per S/C referenced to a single active test mass. Compared to the baseline concept, this eliminates an optical backlink connecting two individual optical benches and a massive flexing harness, significantly reducing the drag-free control’s complexity and avoiding self-gravity effects due to large moving parts. An experimental validation of the pointing jitter and creep of the pointing mechanism is performed. The general design procedure can also find application in lithography or other scenarios requiring ultra-stable manipulation of one or more opto-mechanical degrees of freedom.