ARTICLE

December 2002

NASA Striving to Extend Human Endurance in Space

by Elizabeth Book

Faster space travel and extended human endurance are among the research priorities today at the National Aeronautics and Space Administration, said Sean O’Keefe, the agency’s administrator.

O’Keefe spoke last month at a breakfast meeting of the National Defense Industrial Association’s space committee.

“We are impeded, as a consequence of the laws of physics, that we can only go 17,500 miles per hour. That’s about the speed John Glenn flew at 40 years ago,” O’Keefe told the group.

“This translates into ‘you can’t get anywhere real quick’ in this solar system,” he said.

To get to the edge of our solar system, it would take about 16 years, O’Keefe said. “If we launch a mission by 2006, we will get there by 2018. We would have to hope that the cameras and film would still be good.”

The amount of time needed to travel to the edge of the solar system makes the trip an unlikely proposition, because of the challenge of human endurance. “The longest duration of human space flight is 196 days, and that was a record set over the last two years,” O’Keefe said.

A voyage of 196 days is not enough time to even complete the first leg of a trip to Mars, he said.

There are several unknown factors related to human endurance, such as the effects of radiation on astronauts. The Van Allen Belt emits as much radiation as “the equivalent of eight chest x-rays a day,” he said.

“The intensity of the exposure isn’t nearly as important as the duration for how long you’re exposed,” O’Keefe said.

Also, living in microgravity conditions long-term is a serious health concern for astronauts. The effects of microgravity on human physiology, “is really quite profound. Muscle mass loss is 20 to 30 percent on average, even after exercising, rather strenuously, for two to three hours a day. There is also a dramatic loss of bone content, easily on the order of 5 to 10 percent,” he said.

“If we could figure out how to arrest that loss—imagine the breakthrough achievement that could be applied here,” he said. “But the stark reality is that we can’t go much of anywhere, unless we overcome these challenges.”

O’Keefe said he hopes that NASA’s collaborative work with the Defense Department in the development of “enabling technologies,” such as nuclear propulsion systems, will help NASA reach some of its goals to move faster.

“We are leveraging with our colleagues in the national security community,” he said. “They have been very supportive in the sphere of power generation and nuclear propulsion capabilities.”

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