Going into space changed the bodies of the first American astronauts, but it was more related to the long time they spent wearing uncomfortable space suits than the time they spent in zero gravity, according to new research.
The United States sent humans into space for the first time during the Mercury Project, whose six flights ranged from 1961 to 1963. Before and after the flights, which ranged from 15 minutes to 34 hours, the astronauts underwent heart rate and activity tests. , body temperature and urination. , fluid intake and weight loss. Although almost all the research has been previously published, a report published today in the journal Nature is the first to analyze all that science in one place. He discovered that all astronauts had increases in heart rate and some weight loss after returning to Earth, and that these changes correlated more with the use of the space suit than with time in flight (real or simulated).
During the trip to Mercury, the suits in question were pressurized and weighed 20 pounds, with reinforcements in the joints and an outer layer covered with aluminum. Oxygen flowed through a hose connected to the waist. Even if the flights were short, the astronauts had to wear these suits for long periods of time. "The astronauts had to adapt early for several system controls, and then there was also a delay after each flight to retrieve the ocean capsule," study co-author Virginia Wotring, an associate professor at the Baylor Space Medicine Center. College of Medicine, writes in an email to The Verge.
For example, the first two Mercury missions were approximately 15 minutes in total, but although the time without weight for each was about 5 minutes, the appropriate time was more than five hours, says Wotring in the study. On longer missions, he adds, the times before and after the mission became proportionally smaller, because the actual flight times became longer.
So, why could changes be linked to demand? "Being in a space suit, particularly pressurized on a spacewalk, is a stressor," The Verge Dorit Donoviel, a space health expert at the Baylor College of Medicine, told E-mail in an email. (Donoviel did not participate in the study). For example, people avoided urinating in diapers because it is uncomfortable to sit in the urine. And, as a result, many shuttle astronauts decreased their fluid intake.
The results of this analysis show how dependent we are on the equipment during space flight, writes study co-author William Carpentier, a NASA flight surgeon who was then assigned to the Apollo 11 mission to the Moon. It is important to know that time in space, at least for short-term flights, is not the most important factor affecting health, because it helps us think of ways to improve the equipment. Today, there are still many technical and design challenges to create today's space suits, and there is no "one size fits all" solution.