The Korolev Hydrogen Drive is an improved form of spacecraft thruster with an extremely efficient fuel to thrust ratio. Utilizing high-density pellets of the hydrogen isotope Tritium, Korolev drives allow humanity to accelerate virtually any amount of mass to relativistic speeds.
As an example, it took fewer than a hundred thousand tons of Tritium for Lifeboat Leif Eriksson to travel 17 years at 1G acceleration. Most intra-system craft carry only a few thousand pounds of the radioactive pellets.
Korolev Drives produce an intense plume of super-heated plasma which can extend for kilometers behind a craft, and as such are extremely dangerous to use in close quarters maneuvering. Additionally, sophisticated sensing systems have enabled fingerprinting drive plumes at interplanetary distances and identifying the associated ship with a relatively high degree of accuracy.
The Mao-MacGregor Jump Drive, or M² Drive, has made the galaxy a much, much smaller place than it was before. Exploiting the emerging field of trans-dimensional physics, M² drives allow starships to “dive” out of three-dimensional space for a period of time. In this trans-dimensional space, inaccurately coined “Subspace” or “Jump Space” in popular media, time is a constant and distance is a variable of energy expenditure and the computations of sophisticated trans-dimensional navigation systems.
Due to these unique properties, every dive takes 168 hours±10%, regardless of distance travelled. Commercial M² drives are able to traverse roughly a parsec (3.27ly) in this time. Bleeding-edge military drives can double that.
While an M² drive requires no reaction mass on its own, they consume a staggering amount of power, so much so that many ships have a fusion plant dedicated solely to their drive. Conducting dive or surface operations create massive electromagnetic pulses that can be detected at interplanetary distances, and can be used to determine the relative mass of the ship conducting jump operations. Failures in the drive or the power supply while in a dive are catastrophic, and few ships suffering from such a loss are recovered.
The maintenance schedule for an M² drive prescribes roughly sixteen hours of maintenance tasks between jumps, as well as requiring a recharge of the drive’s dive capacitor, the duration of which is dependent upon how much power a ship’s reactors can put out – typically twenty-four hours or longer. It is possible, but highly ill-advised, to abbreviate any of these tasks.