SPACE: Franklin Chang’s VASIMR plasma engine readies for key test. “Ad Astra’s Chief Operations Manager Juan Ignacio del Valle said the goal for this year is to maintain a plasma firing for about one hour. That would represents a mayor milestone for the VASIMR current prototype, known as VX-200SS. The device has only fired plasma discharges lasting a few seconds, he said. AdAstra has completed more than 10,000 firings of its prototypes since 2005.”