SpaceX’s flight made astronauts genetically younger. The most interesting thing is that it only lasted three days.

• The 2021 Inspiration4 mission was SpaceX’s first all-private commercial flight.

• The four crew members’ telomeres, chromosomal structures that shorten with age, lengthened.

In September 2021, SpaceX launched the first fully private space mission into orbit: Inspiration4. It lasted only 71 hours, but this was enough for four crew members to become genetically younger.

Four skin and blood samples. Inspiration4 had non-scientific goals. It was a commercial flight into low-Earth orbit on the Crew Dragon spacecraft, which billionaire Jared Isaacman funded for charitable purposes.

However, the crew, including Isaacman himself, became involved in science after Hayley Arsenault, a medical worker on board the ship, took skin and blood samples from her companions and herself. After their return to Earth, a series of tests on the samples continued to yield surprising results.

Fast and deep effect. A recent analysis of genetic changes in four space tourists found that their telomeres – the structures that protect the ends of their chromosomes and shorten as they age – lengthened significantly in space.

The results of the experiment, published in the journal Nature, indicate that the space environment has a rapid and profound effect on the human body. Within a few hours in orbit, the four Inspiration4 crew members noticed significant changes in biological markers in their blood.

Have but. Upon returning to Earth, the telomeres shrunk almost immediately, becoming even shorter than they were before the mission. They also experienced bone and muscle loss, as well as increased brain tension, which did not return to pre-flight levels for six months (slightly less in the case of the two women on the mission, Arsenault and geologist Sian Proctor).

“We don’t fully understand what causes such rapid changes, but we hope to learn the answer in the future,” said study leader Susan Bailey. The relativistic speed meant that the main characters of Interstellar did not age, but the results of this three-day flight remain a mystery.

The case of Scott Kelly. One of the most famous studies of the physiological changes that an astronaut undergoes in space comes from Scott Kelly, who spent a year on the International Space Station in 2015. Upon his return, he was compared to the evolution of his twin brother Mark Kelly.

Telomeres, which typically shorten over time and under stress, also lengthened in Kelly’s case. But a new study shows that just a few days in space is enough to see changes in the body, including astronauts’ proteins and gene expression.

Image | Hayley Arsenault (Inspiration4)

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