Human bodies usually recover from space, as tourist missions show

How bad is space travel for your health? Answering this question will be crucial not only for astronauts looking to go to Mars, but also for a booming space tourism industry that plans to put anyone who can afford it into orbit.

In what is being billed as the most comprehensive look yet at the health effects of space, dozens of papers were published Tuesday with new data from four SpaceX tourists aboard the first all-civilian orbital flight of 2021.

Researchers from more than 100 institutions around the world reviewed the data to show that human bodies change in different ways once they reach space, but most return to normal within months of returning to Earth.

Our bodies are put under enormous strain in space, from radiation to the disorienting effect of weightlessness.

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

Fewer than 700 people have ever traveled into space, meaning the sample size is small – and governments can be reluctant to share all their findings.

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

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

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

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

‘I love my space scar’

The “big 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 he hoped the “most in-depth investigation we’ve ever had of a crew” would help scientists understand what drugs or measures will be needed in the future to protect people flying into space.

The Inspiration4 mission, funded by billionaire captain Jared Isaacman, aimed to demonstrate that space is accessible to people who have not spent years training for the feat.

To do this, the four civilian astronauts underwent numerous medical tests.

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

One study found that the telomeres — caps similar to those of shoelaces that protect the ends of chromosomes from fraying — of all four test subjects lengthened dramatically when they arrived in space.

But their telomeres all shrank back to nearly their original length within months of returning to Earth.

Because telomeres also lengthen as people age, finding a way to tackle this problem could help “us common Earthlings” 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 author speculated.

Safe mission to Mars?

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

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

One of the studies 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 while an astronaut could get to Mars, he might need dialysis on the way back,” lead researcher Keith Siew of the London Tubular Center said in an interview. rack.

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

“I think it bodes well for people who think, maybe in six months I’ll go to space,” he said.

Although there wasn’t enough data to say anything definitive, female astronauts seemed to be more tolerant of the stresses of spaceflight, he added.

“It could be caused by the fact that women have to give birth to a child,” which means their bodies are more accustomed to big changes, Mason said.