Designing a ship that is going to spend more than a year in space requires a lot more than a good propellant. Because not everything is reduced to reaching the destination in the shortest possible time. Thus, you cannot have crew members hand in hand with nothing to do and without providing them with any entertainment. What will the astronauts do with their days and nights, always the same? As romantic as space travel sounds, boredom and monotony is the worst of enemies . How will we keep astronauts safe from the dangers of cosmic radiation or the pernicious effect of microgravity on bone and muscle? How will we prevent them from running out of water and food? And once they reach their destination, how will they send messages to Earth? What to do with the psychological stress of living in space far from Earth?
Putting the bodies in suspended animation is the classic movie expedient . But that is something unthinkable in the short and medium term: the amount of science that is needed to prove if it is possible is far beyond our current reach, despite the fact that in 2006, at the Massachusetts General Hospital in Boston they slowed down metabolism and cardiovascular system of mice by administering small controlled doses of hydrogen sulfide, -that gas with the characteristic smell of rotten eggs-, and then they were able to reverse the process. And all without lowering your body temperature.
And the food? A different option to “astronaut food” is aeroponics, growing plants suspended in the air inside plastic bags instead of soil and fertilizers . It is a very good option, especially since the air weighs less than the mulch. But a human being cannot live on cauliflower alone, he also needs a source of protein. That is why since 2001 NASA has been investigating the controlled growth of turkey cells and in November 2009 Dutch scientists announced that they had succeeded in growing meat in the laboratory using cells from a live pig. Will this be the solution? Maybe, but it’s still a long way off.
Still, the worst problem astronauts will face will be the ubiquitous cosmic radiation ; it is so serious that until NASA’s Johnson Space Center has dissected the problem in sufficient detail, it will not be decided whether to send a manned mission to Mars. And it is that traveling to the red planet, which is just around the corner from the cosmic point of view, will cost 2.5 years, almost 6 times what astronauts spend on the space station. To realize what it means, the astronaut who has been up there the longest has been the Russian Valery Polyakov, who spent almost 438 days on Mir. The level of exposure to cosmic radiation is really worrying: at Brookhaven National Laboratory they bombarded mice with high-energy cosmic rays very similar to those that astronauts will encounter on a future trip to Mars and found that it takes them longer to get out of a labyrinth: somehow one of the effects of cosmic radiation is that it affects the cognitive system . What other effects does it contain? Of that, so far, we can only speculate.
“Unknown unknown”: the worst problem
This is what NASA biomedics are most concerned about, “the unknown unknowns”, those problems that were not raised, could not be foreseen, and appeared suddenly. For example, the one that appeared in the eyes of the doctor and astronaut Michael R. Barratt during his six-month mission on the International Space Station in 2009. One day he realized that he had problems seeing things very close . When mentioning it to his colleague -also a doctor- Robert B. Thirsk, he told him that the same thing happened to him. After examining each other’s eyes, they discovered that they were becoming farsighted. They also discovered signs of inflammation in their optic nerves and the appearance of spots on their retinas. Can we imagine what this would have meant in the middle of the trip to Mars? Now, the most important question of what happened is if this hyperopia is just that or a symptom of much more serious changes in the health of the astronauts.
It is not surprising that currently most space station missions are aimed at studying the slightest changes in astronauts’ health and determining the biological, physical, and psychological impact of long-duration space missions.
And the psychology of interstellar travel? Will astronauts be prepared to spend at least more than two years living in a tiny ship en route to Mars? And that in the simplest case. To shed light on this mystery, in June 2010, ESA and the Russian Institute of Biomedical Problems sent 6 men on a 520-day mission to Mars. Of course it was a false mission, but what interested the researchers was the effect of a long period of isolation and the stress that this entails. During the (fake) trip to Mars there were no problems, as they had many things to do and were eager for the new adventure that awaited them. The simulated walk on Mars went well too, but the ride home… That was another matter altogether. In short, the astronauts were bored as oysters, and the days seemed like weeks . And that they knew that on the other side of the door of their ship were the facilities of the Russian institute: what will happen when they know that on the other side there is only emptiness and darkness?
Harrison, A.A. (2002) Spacefaring: The Human Dimension, University of California Press