In the future, space travelers might spend part of their journey in suspended animation. This is necessary because the costs for food, oxygen and carbon dioxide scrubbers would be too high.

The problem is that it’s quite difficult to achieve suspended animation. One solution would be to put the crew in cryogenic stasis, but body temperatures below 30 degrees might disturb the heart’s rhythm. The other solution would be for astronauts to breather hydrogen sulfide, the same substance that is produced by rotten eggs and swamp gas. Dr Warren Zapol from Harvard University’s Massachusetts General Hospital and his colleagues have shown how hydrogen sulfide slows mouse metabolism without cutting the blood flow to the brain.

This, before astronauts can be put into hibernation, further research has to be conducted. Still, this procedure could prove useful in cases of traumatic injury when a person’s life is in danger. Soldiers who are hurt in the field could be put into a hibernation state until they are transported to a hospital.

In the experiments conducted by Zapol, the consumption of oxygen and the production of carbon dioxide in the case of mice started dropping as soon as 10 minutes after inhaling hydrogen sulfide, and remained low as long as the gas was administered. The mice returned to normal metabolism within 30 minutes after receiving normal air flow. The animals’ heart rate dropped by 50% and respiration rates decreased, but there was no sign of risk of oxygen starvation.