Hyperdrive was a means of faster-than-light travel, easily discovered by simple experiments. For whatever reason, humans failed to make these rudimentary experiments and failed to discover it and the related contragrav. Instead, humans devoted their ingenuity to other scientific endeavors resulting in a technological society far in advance of any other species.
In 2039 Earth was invaded by the Roxolani, an alien race which, with the exception of hyperdrive and contragrav, were at a 17th century level of technology. The invasion was defeated with ease and humans learned of hyperdrive from the wreckage of the ships of the invaders. This led to a human expansion into space and the formation of the Terran Confederacy.
When a hyperdrive device is activated, it generates a field which takes the ship out of normal space and allows it to travel many times the speed of light. A side effect is that all information from normal space is blocked, that is, no electromagnetic signals may be sent or received. Navigation is done by dead reckoning. The ship is steered in a particular direction and travels at a known speed so that after a calculated time interval, the hyperdrive is deactivated and the ship returns to normal space near its destination. Normally, this occurs at a distance from the destination to prevent collisions with matter when the ship appears. The ship may then take further, shorter jumps to bring it close enough to proceed with contragrav to the desired planet.
While electromagnetic radiation is blocked in hyperdrive, other ships using it can be monitored and tracked due to their effects on the ship's field. When two hyperdrive fields touch, both collapse ejecting the ships into normal space.