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Spinal Taps And Sleeping Sacks: Astronauts Try To Learn Why Vision Changes In Space

NASA’s latest research connects astronauts on the International Space Station, cancer patients on a roller coaster, plane flight and high-tech sleeping sacks.



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Astronaut Jeff Williams and Kate Rubins successfully installed the first of two international docking adapters (IDAs) during a spacewalk.

NASA's latest research connects astronauts on the International Space Station, cancer patients on a roller coaster, plane flight and high-tech sleeping sacks.

After spending six months on the International Space Station, Michael Barratt had a strange request when he finally stepped foot on Earth. He wanted a spinal tap.

"Yep, it ranked right up there with a hot shower," he said.

Barratt isn't a masochist; he's a NASA astronaut who while flying hundreds of miles above Earth in 2009, noticed his vision was changing. He was struggling to read checklists.

"I spent a lot of time on the Russian segment as well, when you're reading in Russian in small print in a dark place, and your visual acuity starts to tank, you notice it," he said with a laugh.

Barratt is also a curious physician, which brings us to his request for a spinal tap to check the pressure in his brain. He knew he wasn't the first astronaut whose vision had changed while in space, and he hoped sticking a needle into his back might provide a clue to his vision loss. The theory: microgravity raises pressure in the head and reshapes the eyeballs.

"This is a medical issue that affects a large percentage of people who fly in space and for which we are now making very expensive decisions, how we're going to go to Mars and what not, so the stakes are extremely high," Barratt said.

Scientists know that when people go into space, the fluid normally below their hearts goes into their heads. But is it creating enough pressure to damage the eyes – to flatten the eye and affect the optic nerve?

Dr. Benjamin Levine has been on his own mission to find out at UT Southwestern Medical Center and Texas Health Resources. Instead of sticking needles in astronauts' backs, he wanted to stick them inside people's brains

"Basically, and that's what we did. We didn't actually do the drilling but we found people who'd had holes put in their brain," he said.

Levine found eight healthy cancer survivors who already had ports in their heads, once used to deliver chemotherapy. Then, he convinced them to get on a plane, for a sort of extreme roller coaster ride to simulate zero gravity.

You know that feeling of weightlessness when you drop on a roller coaster? Well, these folks did that, except they plunged 8,000 feet in 30 seconds, dozens of times, all in the name of science.

Trent Barton, a lymphoma survivor from Dallas, went on the wild trip above the Texas-Mexico border.

"I enjoyed each and every rotation we did," he said during the car ride after the flight. "That was a lot of gadgets on me. Literally I had things hooked up to both arms, blood pressure on my finger literally tracking blood in and out of my finger."

Most importantly, he had a needle in that port in his head monitoring the pressure in the fluid surrounding his brain. Remember, they're testing the hypothesis that pressure inside the brain at zero gravity is so high it damages the eyes.

However Levine says it turns out that space flight doesn't cause pressure to be much higher than it is when you or I are standing up. But, it is a little higher.

"So we now think this mild, but persistent pressure may be the thing that's stimulating remodeling the eye and causing the visual impairment," he said.

See, unlike us earthlings, astronauts never get to rest their brains in lower pressure. When they're standing up, the fluid won't go to their feet. So, researchers like Levine are now trying to find a way to give these astronaut brains a rest.

"We've been working with UnderArmour, the garment company, to come up with a soft, but comfortable almost like a sleeping sack or pair of trousers, that you can put on at night, hook up to a vacuum cleaner, suck the blood and fluid into the feet and unload the heart and the brain while your sleeping," Levine said.

Astronaut and Doctor Mike Barratt says he'd be willing to try the sleeping sack, but he also wants to do more tests on the International Space Station to better understand intracranial pressure. Especially before we send astronauts deeper into space. As for his eyesight, six years post flight:

"It's my right eye that has apparently has been permanently remodeled...other than that I'm totally normal," he said.

Still the same curious doctor, he just sees things a bit differently since being back on Earth.