 That December, Chen announced that CAST was conducting tests on a resonant cavity thruster in orbit, without specifying what design was used.In an interview on CCTV in September 2017, Chen Yue showed some testing of a flat cylindrical device corresponding to the patent describing stacked short cavities with internal diaphragms.The proposed theory for how the EmDrive works violates the conservation of momentum, which states any interaction cannot have a net force; a consequence of the conservation of momentum is Newton's third law, where for every action there is an equal and opposite reaction.