its hydrogen powered. how else are you supposed to move a 10000 KG hunk of metal through space... having the monstrous engine like this also requires safety equipment, such as an oscillating magnetic nozzle that prevents the charged stream of hydrogen ions from transferring that insane tungsten vaporising heat to the nozzle and frying the circuitry. Sudden bursts of energy are caused by some trapped ions building up and being burst out at critical velocity, thus increasing acceleration performance.
