Technology to induce a state of deep hibernation in human beings was developed early in the course of Imperial history, having long been considered a practical necessity for long voyages.

Safety

As practised by modern space travellers, hibernation is safe and effective, with a low rate of complications and side effects. (The chance of a serious hibernation complication is less than one per million inductions, comparable to a flu shot.) Statistically speaking, hibernating crewmembers are also safer than the awake minimal crew on long voyages. The awake crew includes one or more hibernation medical technician who checks up on each hibernating person daily for the duration of the voyage, assisted by medical telemetry. Pre-hibernation physical exams are conducted to qualify crewmembers for hibernation, and are the most important aspect of a hibernation safety protocol.

Long Term Biological Effects

Hibernation has long-term biological effects, some of which are considered desirable. Most notably, the process of ageing is markedly reduced during hibernation. As a rule of thumb, forty days in hibernation are equivalent to one day of normal activity. Different ageing processes are affected to differing degrees by cumulative hibernation. People who have accumulated many years of hibernation show a different distribution of ageing-related illnesses and physiological changes than non-hibernating populations, but since most habitual hibernation-users are also frequent space travellers, the exact effects have been difficult to disentangle from the effects of the spacecraft environment. In any case, it is clear that hibernation markedly extends chronological lifespan and delays the onset of ageing-related debility.