Monday, a An astronaut capsule resembling a giant orange sap was sprayed into the Atlantic Ocean, bringing its four-man crew back under the influence of Earth’s gravity. These astronauts spent six months in International Space Station, so the gravity pulling their bodies now would feel familiar to them, but strange.
This team, called SpaceX Crew-2, has spent most of the past half year in orbit doing science work in space, such as testing “tissue chipsSmall-scale analogues of human organs. But they also spent hours working as rats in the gym: six days a week, they had a 2.5-hour exercise block to minimize the damage living in space could do to the body. Space, as they say, it’s hard. But it is especially difficult for humans. radiation, zero gravity, and living in cramped spaces all have their costs.
Michael Stinger, elemental scientist at Human health countermeasures, the agency’s arm dedicated to understanding and mitigating how spaceflight affects physiology. One big problem is that living in orbit is physiologically similar to bed rest, even if you’ve been wandering around doing experiments all day. “Being in space is a lot like doing nothing,” he says.
When you don’t need to resist gravity, your muscles and bones lose their strength, because those parts of the anatomy adhere to a kind of “use it or lose it” philosophy. Muscles can fade away, the same way they would if the astronaut lay on the sofa while playing He falls The whole day. Bones can lose mass: both form and disintegrate based on the forces they encounter day in and day out, from gravity and muscle use. After six months in space, the femur near the tibia can flop 10 percent of its mass, requiring years of recovery back on Earth.
The space is also hard on your cardiovascular system, says Stinger: “Your heart no longer has to pump as hard to maintain blood pressure, so your heart becomes weaker.” During astronaut Scott Kelly’s year in space, the size of his heart has shrunk by more than a quarterIt adapts to its new conditions. Again under the influence of gravity, the heart can pump itself back to normal, apparently without long-term damage.
Scientists don’t do this completely understand why, but astronauts’ spines also grow longer in space, just a few inches in height. Travelers shrink back to their normal sizes on Earth, but after flight, astronauts are more likely to develop disc herniations, which may be related to these spinal shifts. Also, their suits and equipment must be designed according to their dimensions – and if those dimensions change, the design becomes complex, especially for a longer flight.
To keep astronauts’ guts fit for their missions in space and healthy once they return to Earth, human health countermeasures have attempted to correct these physiological errors—in part by using gym equipment designed for space. The advanced resistance exerciser is a type of space-based Bowflex: It uses deflated cylinders to create a few hundred pounds of resistance, and microgravity athletes can reconfigure it to do two-hour deadlifts, squats, or bench presses, including the time it takes It takes to reconfigure the device and do some recovery. The ISS is also equipped with a treadmill and a cycling machine, which the astronauts use for 30 minutes of interval training.