The name hyperspace was given to a space with a non-Euclidean geometry coexisting with "normal" space. Traveling in hyperspace allowed for what was effectively faster-than-light travel relative to normal space.
Hyper space was organized into discrete bands, with each band corresponding to a lower point-to-point distance compared to normal space. This meant for a given velocity, higher hyper bands allow for higher velocity relative to normal space.
Transiting different bands did have drawbacks, as the boundaries between hyper bands were full of high energy surges which could destroy an unwary ship. The higher the band, the faster a vessel would travel. This was especially deadly in the early years of the Diaspora of Man. A less deadly drawback is that in order to break into a higher band, a certain percentage of relative speed was bled off. This speed could be made up after fully moving into the band. For early reaction drive ships, constantly re-accelerating after transitioning (assuming it survived the transition in the first place) proved too energy intensive. It was only after the development of the Warshawski sail that both of these drawbacks were negated.
The danger of dimensional shear was not present when ships translated down through the bands as far as hardware was concerned. Humans, on the other hand, experienced physical distress and nausea, which was stronger the faster the ship was going when it translated. Ships slowed to one fifth of their relative velocity each time they performed a translation down through the bands. Without renewed acceleration, this could mean that a ship's velocity could slow to a crawl if they translated down through many bands (a ship travelling at 90,000 km/s or approx .3 c would be reduced to 144 km/s if it went through four translations from the Delta band to n-space).
Naval crews were trained for crash translations, yet there was a limit to what training could do to offset the effects, so crash translations were avoided unless absolutely necessary. (HH6)
Hyperspace bands were labeled by Greek alphabet letter. While relative velocity in each band was low, apparent velocity increased, the "higher" you went within the band.
The main band for space travel was the Alpha band, which was the lowest of the bands. The band was at .3c, which if any vessel went higher, than the vessel's destruction would have been imminent. It took nearly two hundred years for that limitation to be accepted. In the beginning, only survey vessels went into the Alpha Band because of the high risk factors until the Hyper Log's accuracy was made better. (HH6)
Older Manticoran merchant ships could only manage to travel .5 c in the lower end of the Delta band, at a maximum apparent velocity of 912 c. (HH6)
The Zeta band was frequently used by warships, as it offered good speed and moderate safety. Faster freighters or some passenger liners could travel at .7 c in the Zeta band, attaining an apparent velocity of 2500 c. (HH6)
The Theta band was the highest band that had ever been used, and the most dangerous to travel. Courier ships frequently rode the edge of the Theta band, because it offered the fastest speed. Courier ships travelling the "ragged edge" of the Theta band gained an approximately 40% speed increase over frigates travelling in the Zeta band. (CS1)
Gravity affects hyper space such that it is impossible to travel inside a certain radius of any massive object, such as a star or the Tellerman wave. Attempting to do so would result in complete destruction of the transiting ship from gravimetric shear. (HH6)
- ↑ 32% faster than the average merchant ship