Credit: Adis Rimic from Pixabay
Despite what Star Trek AND Star Wars It may have taught you, the amount of time needed to travel between the stars is vast.
Consider Voyager 1. The space vehicle is traveling to 38,000 mph (61.155 km/h). If Voyager 1 were aimed at our nearest star, Proxima Centauri (which is not), it would take 73,000 years to reach his destination. What this means on a practical level is that any human spatial flight between the stars, even at speeds well beyond that of voyager, would employ, at least dozens of years at the age of hundreds.
A long -term response to the problem of the time required for the interstellar journey is human lethargy, sometimes indicated as “suspended animation”. If humans could drastically slow down their metabolic rate, they could potentially “sleep” for long periods of time and be awakened upon arrival at their destination. Human lethargy was used with great effectiveness in science fiction films (think about 1968 2001: a spatial odyssey o 1979 Aliento name only two), but it is Truly possible?
And would people even agree to do it?
Sandy Martin, emeritus professor of cellular and development biology at the University of Colorado, thinks like this: “I think there will always be some humans who would consider lethargy for a few months an acceptable, if not desirable compromise [on a long duration spaceflight] At all. “In addition to dealing with the psychological and social complications of such a journey, says Martin, the hibernation would also reduce the need for exercise, food, oxygen, water and waste removal, thus reducing the useful load and facilitating engineering problems. It will probably also reduce the risk of exposure to radiation.”
Hypothermia induced from a medical point of view
In order for humans to truly lethargan, many significant technical and medical problems should be solved. It is not clear whether we will never be able to make humans in the first place, but a possible option would be to reduce exogenous body temperature to slow down the metabolism of humans in hibernation, a practice known as induced hypothermia.
The hypothermia induced from a medical point of view is already used (with contrasting results) by doctors between patients with serious heart attacks or traumatic brain lesions in the hope of improving neurological recovery. The degree of hypothermia currently used in hospitals is relatively mild (the patient is cooled a few degrees below normal) and hypothermia is maintained only for a short period of time (from one to two days). Hypothermia reduces the demand for oxygen on a cellular level and, coupled with a reduction in the cardiac range at low temperatures, can allow the hibernation man for long periods of time. There are well -documented cases of people who completely recover from a deep hypothermia, usually after accidental immersion in extremely cold water, so there is some previous ones. If humans aboard an interstellar space vehicle can survive prolonged hypothermia and what effects this situation could have on heart, brain, skin, eyes, kidneys, blood vessels and other organs, it is largely unknown.
Torpor
Another possibility of exploring would be if humans could be placed in the type of hibernation that animals use to survive in hard winters or times of scarce resources. The animal lethargy, sometimes also indicated as a tower, can be seen in many species, including birds, mammals and piles. Hanging in animals can last for hours in days or months. The alaska bears have been known for lethargy for seven months, although they can wake up and move briefly if disturbed. Hanging animals abruptly lower body temperature and heart rate, break down internal energy reserves and do not eat or drink. Critically, unlike medical hypothermia (which is induced externally), the animals that naturally ibernally are able to induce and remain in this state alone without support or external intervention.
If humans aboard an interstellar profession could be induced in hibernation similar to what animals can do naturally, it could provide another path for humans to endure long -lasting space flights. Human beings do not naturally tolerate periods of metabolic depression: the physiological parameters (temperature, impulse, blood pressure, etc.) that humans must maintain to survive are very close. For example, a fever only a handful of degrees above the normal body temperature can be fatal. But scientists are studying the genetic and biochemical factors that allow animals to undergo a safe hibernation (and repeatedly). If this research brings fruits, it could potentially create treatments, such as gene therapy, which could also allow future humans to undergo a form of hibernation.
“I think the biggest obstacle is to understand exactly how lethargy works to reversiblely lowering the metabolic demand and protecting organ systems throughout the body in natural hibernators,” says Martin. Despite this, he says he believes he has technology – or soon – to better understand animal lethargy and imitate it in humans, “if sufficient resources are available to allow a reasonable and concerted effort”, he adds.
More challenges
Other key questions about human hybarnament remain unanswered. Who would monitor members of the hibernation crew? Some humans would be kept awake so that they (and potentially their offspring) could make sure that the asleep crew was safe? What if the custodian and/or hibernation humans get sick? Would an artificial intelligence be able to supervise the safety of humans in hibernation? If an artificial intelligence had been chosen, could we count to work reliablely for a long period of time? In the event of an emergency, how quickly could you awaken the members of the hibernation crew and how long after awakening would it take to work normally? Could the hibernation be induced safely in the same individual more than once?
Everyone will have to respond to everyone before humans can never use lethargy technology in real life. Since human space flights on Mars (and beyond) may not be so long for the arrival, the research on human hybarnament seems to be worthy of careful investigation.
