Using a device that is capable of measuring force at a single-digit micronewton level, a NASA team has measured approximately 30-50 micronewtons of thrust on a propellantless test item that was designed to experience force, but not as a result of interaction with the quantum vacuum. However, using the same measurement equipment, a nonzero force was also measured on a "null" test item that was not designed to experience any such force; White says that this hints at interaction with the quantum vacuum; this explanation both agrees with the Law of Conservation of Momentum and it also explains why the null device experienced a thrust. If White is correct, this would essentially be a proof-of-concept for quantum vacuum plasma thrusters. All measurements were performed at atmospheric pressure, presumably in contact with air.  The test device was created by US scientist Guido Fetta. British and Chinese scientists found similar results, adding credibility to NASA's experiment.