Hibernation Method Tested for Space Travel

Researchers are studying hibernation methods to help space travelers endure long travels. Without hibernation, it would cost too much to keep them alive.

A flight to Mars would take three years and to support a manned flight, the expenses of carrying food, water, oxygen and carbon dioxide scrubbers would be very high. It would also cost too much to process urine and feces.

To deal with these challenges, researchers are looking at ways in which humans could spend part of the journey in hibernation. Scientists at the Harvard University’s Massachusetts General Hospital are trying to create harmless methods of hibernation that can be used in space and battlefields to treat soldiers.

One of the methods of hibernation includes cooling the crew cabin into a big chill. The problem with this method, however, is it cools body temperatures below 30 Celsius (86 degrees Fahrenheit), affecting the heart’s rhythm. Another proposed method includes astronauts breathing hydrogen sulfide (swamp gas).

Warran Zapol, the head of anesthesiology (one of the researchers in this study) plans to use the latter method and is testing it on mice. They will use hydrogen sulfide which slows the metabolism in mice without preventing increased blood flow to the brain.

Zapol told Discovery News:

The mice aren't asleep…If you pinch their tails, they respond.

In one of the experiments, researchers noticed the metabolic measurements of mice (such as their oxygen consumption and production of carbon dioxide) dropped immediately within 10 minutes of inhaling hydrogen sulfide. When the gas was continually administered the metabolic measurements of the mice remained low. After normal airflow was applied, the mice returned to normal state after about 30 minutes.

The researchers observed the following:

The animals' heart rate dropped nearly 50 percent while they were breathing the gas, with no significant change in blood pressure or the strength of the heart beat. Respiration rates decreased, but there were no changes in blood oxygen levels, suggesting that vital organs were not at risk of oxygen starvation

Zapol said it will take many years to study this behavior until it is used in space. However, researchers will find immediate applications in treating traumatic injuries in real life as well as on the battlefield.

Zapol added:

Sixty percent of people in war are dead right there on the field…They are instantly hurt, and because there is no blood and no fluids in the field, by the time they get to a hospital they are cold and dead and there is nothing to fix. During this early period after trauma, if we could freeze you down or shut you down, we could restart you after we fix the aorta, or whatever has been damaged,"

Emergency workers have tried cooling victims in the past, but they need plenty of cold water which is impractical on battlefields or in space.

This study will be published in this month’s Anesthesiology journal.

Zapol and his team will test the method again with larger mammals such as sheep before testing it on humans.