JACKSONVILLE, Fla. -

Hemorrhagic stroke is responsible for more than 30 percent of all stroke deaths. It happens when a weakened blood vessel ruptures and bleeds into the brain.

Its something Jon Galvan experienced five years ago when he almost died from a hemorrhagic stroke while at work.

"I was typing away and I felt a pop in my head," Galvan said.

He was able to recover, but Dr. Abba Zubair, medical director of transfusion medicine and stem cell therapy at Mayo Clinic, Florida, said not everyone is as fortunate.

"If it happens, you either recover completely or die," Zubair said. "Thats what killed my mother."

Zubair said he wants to send bone marrow derived stem cells to the international space station.

"Based on our experience with bone marrow transplant, you need about 200 to 500 million cells," Zubair said.

But conventionally grown stem cells take a month. Experiments on earth have shown that stem cells will grow faster in less gravity.

"Five to ten times faster, but it could be more," Zubair said.

Continued here:
Health Beat: Growing stem cells in space: Medicine's next big thing?