NASA has been testing an EM drive for a while. Although the initial results appeared positive, the scientific community was skeptical because these results would violate conservation of momentum. Much criticism was directed at the fact that thermal convection might be causing the results. However the more recent results were conducted in a vacuum.
What does this mean for the believability of this drive? Should we still be skeptical of the drive? If so, what explanations could there be now that convection currents have presumably been ruled out.