The saccule and utricle, two chambers of the inner ear, sense the direction of gravity and help the body balance. Without their influence, we quickly become lost and disoriented.
To prevent this confusion from happening to astronauts in space, scientists at Brandeis University Have proposed a new system that is surprisingly simple.
These are a series of small vibrating devices that stick to the skin and vibrate to signal one’s position in space, a sort of mechanical inner ear. Early research has shown that the devices help, but they must be combined with extensive training so that users follow their inputs automatically.
In a series of experiments, research subjects trusted the devices and understood how they worked, but that was not enough to overcome the confusion and disorientation they experienced in a simulated zero-gravity environment.
“Trust has to be at a deeper, almost subcognitive level,” Brandeis researcher Vivekanand Pandey Vimal said in a declaration. “To achieve this, specialized training will be necessary.”
How Brandeis Simulated Spacewalks
The small team of researchers brought together 30 different subjects in a multi-axis rotation device (MARS), which rotated a chair on two axes to emulate a spacewalk.
At first, the team kept the machine vertical, so the subjects could rely on their inner ears to orient themselves. Blindfolded and listening to white noise, subjects rotated to a predetermined “balanced” position.
The scientists then turned the people on their backs and instructed them to find the equilibrium position again, following the guidance of the vibrating devices. If the subjects turned too much to one side, they “crashed” and MARS reset.
Virtual astronauts later reported that they had struggled between misleading signals from their inner ears and signals from the devices.
Still, the latter seemed to have helped. The control group that received only MARS training spun more erratically and crashed 2.5 times more.
What are the dangers of long space missions?
Past studies have found that related devices reduce spatial disorientation in airplane and helicopter pilots, who sometimes become disoriented despite operating relatively close to Earth. Between 1993 and 2013, these disruptions led to the loss of 65 aircraft and 101 lives.
Could the same thing happen during the long planned manned missions to the Moon and Mars?
“Long-duration spaceflight will cause many physiological and psychological stressors that will make astronauts very susceptible to spatial disorientation,” Vimal said. “When an astronaut is disoriented he will no longer be able to rely on his own internal sensors that he has depended on his entire life.”
Read more: Why and how do astronauts get sick in space?