This is a record power level test firing in a series of experiments with the VASIMR VX-200 plasma rocket prototype. The rocket's 1st stage (a Helicon plasma source) was fired at 30 kW using a state-of-the-art solid state RF power supply, and the rocket's 2nd stage was fired at 149 kW using a second solid state RF power supply. Argon gas was used as the propellant, and gives a distinctive purple/blue/UV glow. The second half of the video is slowed down to 1/10 speed during the firing of the second stage. The plasma diagnostics that can be seen in this video are situated on an xy motion stage capable of moving side to side 200cm and in an out 500cm with 0.5mm precision. Because of the extreme temperatures and heating within the plasma exhaust, the diagnostics are all constructed out of refractory metals, high temperature ceramics, or graphite (or all three). The rocket and everything else seen in this video is located within a vacuum chamber, used to simulate the vacuum environment of space. The VX-200 is the precursor to the VF-200, a flight demonstration unit that is intended to fly on the International Space Station (ISS). www.nasa.gov www.adastrarocket.com