Doctors have pushed and pushed NASA astronauts for years, and astronauts, as government employees, have largely fulfilled their role of test animals by studying how an alien environment – outer space – affects the human body.
But professional astronauts have historically been a small slice of humanity. Initially, they were chosen from the ranks of military test pilots who were white males and in good physical shape. Later, as NASA broadened its criteria, it still only chose astronauts who exceeded their physical thresholds.
But that could change as private spaceflight opens up space to a more diverse cross section of humanity.
For scientists, the change will create a wealth of new data on how the human body adapts to space.
The Inspiration4 mission, launched on Wednesday, shows how medical researchers can benefit from new commercial space travel. The crew of four, none of whom are professional astronauts, will spend a fair amount of time in orbit to help advance medical research.
One of the passengers, Hayley Arceneaux, illustrates these possibilities. At 29, she is younger than most space travelers, a cancer survivor, and will be the first person in space with a prosthesis – metal rods that were implanted after a tumor was removed of his left leg.
“We’re going to learn some very basic things,” said Dorit Donoviel, executive director of the Translational Research Institute for Space Health, or TRISH, at Baylor College of Medicine in Houston, which coordinates research during the Inspiration4 flight. .
Research to date has found that fluids move upward in the body in the absence of gravity – swollen heads, constricted legs. The lack of gravity also weakens the bones. Not only does radiation in space crash into DNA creating mutations, but the unusual conditions of weightlessness cause some genes to turn on and others to turn off. The biological repercussions of these alterations are not yet understood.
The Inspiration4 crew will pass 10 tests each day originally designed to assess the mental performance of NASA astronauts. The tests take about 20 minutes.
“It had to be brief, because astronauts hate doing these things,” said Dr. Mathias Basner, professor of psychiatry at the University of Pennsylvania who is the principal investigator of this experiment.
But in a dangerous environment like space, small mistakes can lead to disaster.
“So we need our astronauts to perform at their best all the time,” said Dr Basner. “Now the problem is that humans are particularly bad at self-evaluating their performance capabilities, especially in chronic exposure situations. If you sit in the same environment all the time, you think everything will be fine, but in fact you are not.
A test is simply a square that appears on a screen, and you have to press it. The square changes position and gradually becomes smaller. This measures reaction speed and hand-eye coordination.
Another measure is what is called psychomotor alertness. First, the subject looks at a box on the screen. A stopwatch suddenly appears in the box, counting down the milliseconds until the subject presses a button. “Which is extremely sensitive to sleep deprivation,” said Dr Basner.
Another test assesses a person’s ability to identify emotions in others.
The test displays 20 faces showing a variety of emotions – happy, sad, angry, fearful, or expressing no emotion. In a so-called bed rest study – lying down for long periods of time mimics many of the physical effects of weightlessness in space – subjects were still able to correctly identify most emotions. But they took longer to identify them, and their responses were skewed towards more negative expressions.
Mark J. Shelhamer, professor at Johns Hopkins Medicine, collects data on how spaceflight affects the vestibular system – the parts of the human body, especially the inner ear, that maintain balance.
Its research consists of two parts, to be carried out before launch and after returning to Earth. The postures of the crew members will be measured. “This is exactly what it sounds like,” Dr. Shelhamer said. “It’s the ability to stand up. And the ability to stand is not only based on muscle strength, but also coordination.
Inspiration4 crew members will hold a Windows tablet to their chest, put their feet together, and close their eyes. The tablet accelerators will measure their oscillation while standing.
“It’s not that hard to do on Earth,” Dr Shelhamer said. “But it can be difficult after spending time in space.”
Dr Shelhamer also designed a test using the tablet to determine if weightlessness causes eye misalignment. This could give clues as to how the brain might become confused, disrupting the sense of balance.
What the researchers want to learn is how to predict who gets sick in space. Surprisingly, there is no correlation between those who suffer from motion sickness on Earth – on a boat swaying back and forth, on a long road trip, even short episodes of fluttering when flying. parabolic planes – and those who get sick in orbit.
“We don’t understand this at all,” said Dr Shelhamer. “It’s an embarrassment, because we would like to think that these are the same basic mechanisms – the fact that the different sensory systems do not correspond.”
TRISH, the organization Dr Donoviel heads, created a database to store the study results that not only protects the privacy of private space travelers in accordance with the requirements of HIPAA, the Health Insurance Portability and Accountability Act, but will also allow researchers to compare data from different studies for the same individual.
For example, Dr Shelhamer might want to know if a person whose ability to stand upright without swaying decreased after space travel also encountered cognitive slowdowns when testing Dr Basner in space. This is often not possible with the way NASA reports the data it collects on its astronauts, he said.
Additionally, Inspiration4 crew members wear Apple Watches that will measure their heartbeats and oxygen levels. They will also test ultrasound devices that can track how the water in their body moves upward as they float in orbit. It could help solve the puzzle of crushing eyeballs and the resulting change in vision in some astronauts.
The research depends on how the Inspiration4 crew feels during their journey. Because there is no way to predict who gets sick in space, it is possible that they all are and then not be able to do much research during the three-day trip. .
“My concern is that they are not going to take advantage of their time in space,” said Dr Donoviel. “They might not be able to perform the experiments that we send to them. So it’s a risk I’m taking.