Milli-Newton Thrust Stand
The milli-newton thrust stand is an inverted-pendulum, null-displacement thrust stand based on the NASA-Glenn design. Thrust from the attached propulsion source attempts to displace the inverted pendulum. Thrust stand displacement is measured by a linear voltage displacement transducer (LVDT). This displacement is “nulled” by an onboard electromagnet which provides a restoring force, the current of which is directly proportional to the thrust.
The thrust stand is capable of resolving thrust as small as 1mN [Hopkins], with an estimated experimental uncertainty of ±5% [Massey]. The thrust stand is capable of being calibrated at vacuum to minimize thermal drift and temporal variation in output.