Human bodies are mostly recovered from space, the tourist mission shows

How bad is space travel for your health? The answer to this question will be crucial not only for astronauts who want to get to Mars, but also for the booming space tourism industry, which plans to launch anyone who can afford it into orbit.

In the most comprehensive look yet at the health effects of space, dozens of papers were published Tuesday using new data from four SpaceX tourists aboard the first fully civilian orbital flight in 2021.

Researchers from more than 100 institutions around the world sifted through data to show that human bodies change in different ways after reaching space – but most return to normal within months of returning to Earth.

Our bodies are subjected to tremendous stress in space, from radiation exposure to the disorienting effect of weightlessness.

By studying astronauts, scientists have known for decades that spaceflight can cause health problems such as bone loss, as well as heart, vision and kidney problems.

Fewer than 700 people have ever traveled to space, meaning the sample size is small—and governments can be reticent about sharing all their findings.

However, the four American tourists who spent three days in space during the Inspiration4 mission were happy to have their data published.

The first results, which were compared with 64 other astronauts, were published in Nature dailies on Tuesday.

When humans are in space, they undergo changes in blood, heart, skin, proteins, kidneys, genes, mitochondria, telomeres, cytokines and other health indicators, researchers have found.

But about 95 percent of their health markers returned to their previous levels within three months.

‘I love my space scar’

The “big take home” message is that people usually recover quickly after spaceflight, said one of the study’s lead authors, Christopher Mason of Weill Cornell Medicine.

Mason told reporters that he hopes the “deepest crew investigation we’ve ever done” will help scientists understand what drugs or precautions will be needed to protect people launching into space in the future.

Funded by its billionaire captain, Jared Isaacman, the Inspiration4 mission had the stated goal of showing that space is accessible to humans who haven’t spent years training for the feat.

For this, the four civilian astronauts underwent a huge number of medical tests.

“I love my space scar,” nurse Hayley Arceneaux said of the lingering skin biopsy mark. She was only 29 years old when she went into space.

One study found that telomeres—the shoelace-like caps that protect the ends of chromosomes from fraying—had lengthened dramatically in all four subjects when they reached space.

But all of their telomeres had shrunk to nearly their original length within months of returning to Earth.

Because telomeres also lengthen with age, finding a way to solve this problem could help “we mere mortals” in the never-ending battle against aging, said Susan Bailey of Colorado State University.

It could even lead to anti-aging products like “telomerase-infused face cream,” the study’s author speculated.

A safe mission to Mars?

Looking at the data so far, “there’s no reason why we can’t safely get to Mars and back,” Mason said.

“You probably wouldn’t do multiple trips because it’s a lot of radiation,” he added.

One study found that mice exposed to radiation equivalent to 2.5 years in space suffered permanent kidney damage.

“If we don’t develop new ways to protect the kidneys, I would say that even if an astronaut could get to Mars, they might need dialysis on the way back,” said study leader Keith Siew of the London Tubular Center. declaration.

But Mason emphasized that the research was “really mostly good news.”

“I think it’s a good sign for people who think: maybe I’ll be in space in six months,” he said.

While there wasn’t enough data to say definitively, female astronauts appeared to be more tolerant of the stress of spaceflight, he added.

“This may be due to the fact that women have to give birth,” which means their bodies are more used to big changes, Mason said.