Positron Dynamics is still is undergoing a funding bridge for their test of a antimatter drive powered cubesat, supposedly next year. This is pretty significant, if they get the investment they need, as a successful test might lead to more advanced development. The team looks like it's a mix of former JPL, NASA, SpaceX and Blue Origin researchers. For fans of advanced propulsion systems this is REALLY becoming an interesting time. I'm reading interesting news from Ad Astra and their VASIMR engine too, lately. Seems like the solar system and beyond is going to open up this century, and sooner than later.