Spaceflight Now Home





Spaceflight Now +



Subscribe to Spaceflight Now Plus for access to our extensive video collections!
How do I sign up?
Video archive

STS-126: In review

The STS-126 crew narrates highlights from its mission that remodeled the interior of the space station.

 Play

Expedition 19 crew

The Russian commander and two American astronauts to serve aboard the space station during the Expedition 19 mission hold this pre-flight news briefing.

 Play

Delta 4-Heavy launch

The Delta 4-Heavy rocket launches a new intelligence-gathering satellite for the nation.

 Full coverage

STS-119: Shuttle on pad

Shuttle Discovery rolls to pad 39A for its February launch to the space station.

 Play

STS-119: The programs

In advance of shuttle Discovery's STS-119 mission to the station, managers from both programs discuss the flight.

 Play

STS-119: The mission

A detailed preview of Discovery's mission to deliver and activate the space station's final power truss is provided in this briefing.

 Play

STS-119: Spacewalks

Four spacewalks are planned during Discovery's STS-119 mission to the station.

 Play

STS-119: The Crew

The Discovery astronauts, led by commander Lee Archambault, meet the press in the traditional pre-flight news conference.

 Play

Station's new toilet

Space station commander Mike Fincke shows the new U.S. toilet installed aboard the complex. The astronauts are preparing the station for larger crews beginning in 2009.

 Play

Become a subscriber
More video




NewsAlert



Sign up for our NewsAlert service and have the latest news in astronomy and space e-mailed direct to your desktop.

Enter your e-mail address:

Privacy note: your e-mail address will not be used for any other purpose.



Astronauts on space station lose alarming amounts of hipbone strength
UNIVERSITY OF CALIFORNIA-IRVINE NEWS RELEASE
Posted: January 26, 2009

IRVINE, Calif. - Astronauts spending months in space lose significant bone strength, making them increasingly at risk for fractures later in life.

UC Irvine and UC San Francisco led a study evaluating 13 astronauts who spent four to six months on the International Space Station and found that, on average, astronauts' hipbone strength decreased 14 percent. Three astronauts experienced losses of 20 percent to 30 percent, rates comparable to those seen in older women with osteoporosis.

These results alarmed researchers because they revealed a greater rate of bone deterioration than previously measured using less powerful technologies.

"If preventive measures are not taken, some of our astronauts may be at increased risk for age-related fractures decades after their missions," said study leader Joyce Keyak, UCI orthopedic surgery and biomedical engineering professor.

For as long as there have been astronauts, researchers have studied why the microgravitational environment of space makes bones more fragile. While previous studies looked at bone mineral density, this study is the first to specifically evaluate bone strength.

Keyak and her colleagues used a novel computer program she developed over the past 20 years to identify hipbone fracture risk in people with osteoporosis. The study team used this program to analyze structurally the hipbone CT scans of one female and 12 male International Space Center crewmembers.

The decrease in bone strength measured between 0.6 percent and 5.0 percent for each month of service on the station, Keyak said, which was noticeably greater than monthly reductions in bone mineral density of 0.4 percent to 1.8 percent observed in previous studies on the same subjects.

Orthopedic researchers looking into the effects of long-duration spaceflight usually study the hipbone or spine. The hip experiences the greatest rate of bone loss in space, and a hip fracture almost always requires hospitalization and major surgery. It can impair a person's ability to walk unassisted and may cause prolonged or permanent disability or even death. Fractures of the vertebra also have serious consequences, including loss of height, severe back pain and deformity.

Along with Keyak, Alain K. Koyama, Ying Lu and Thomas F. Lang of UC San Francisco, and Adrian Leblanc of the Universities Space Research Association in Houston participated in the NASA-funded study. Study results appear in the online version of Bone.

About the University of California, Irvine: The University of California, Irvine is a top-ranked university dedicated to research, scholarship and community service. Founded in 1965, UCI is among the fastest-growing University of California campuses, with more than 27,000 undergraduate and graduate students. The top employer in dynamic Orange County, UCI contributes an annual economic impact of $4.2 billion.