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. [1] The test device was created by US scientist Guido Fetta. British and Chinese scientists found similar results, adding credibility to NASA's experiment.[2]