CAPE CANAVERAL, Fla., Feb. 20 (UPI) -- U.S. space shuttle Atlantis and its seven crew members safely returned to Earth Wednesday under what were described as virtually ideal weather conditions.

Four landing opportunities were available for the astronauts, but none except the first was needed at the 3-mile-long Kennedy Space Center runway with Atlantis touching down as scheduled at 9:07 a.m. Wednesday on orbit 202, National Aeronautics and Space Administration controllers said. The uneventful touchdown ended a 13-day mission to the International Space Station.

The landing occurred on the 46th anniversary of John Glenn's becoming the first American to orbit the Earth. Glenn's Feb. 20, 1962, flight lasted 4 hours, 55 minutes and 23 seconds.

STS-122 arrived at the ISS Feb. 9, delivering the European Space Agency's Columbus laboratory. The shuttle and ISS crews installed Columbus Feb. 11 and conducted three spacewalks to prepare the laboratory for its scientific work. They also replaced an expended space station nitrogen tank.

STS-122 was the 121st shuttle mission and 24th mission to visit the space station, flying approximately 5.3 million miles. The next mission, STS-123, is expected to be launched in March.

New craniosynostosis surgery is effective

COLUMBIA, Mo., Feb. 20 (UPI) -- U.S. scientists have found a minimally invasive surgical technique to treat craniosynostosis -- the premature fusion of an infant's skull -- is effective.

Surgeons have used one of two procedures to correct the problem. One procedure was to make an incision from ear to ear, strip back the infant's scalp and reshape the skull by breaking the fused bones. The other procedure required a small incision near the point of the fused skull plates.

In the new study, University of Missouri School of Medicine researchers found the minimally invasive technique is just as effective and results in a quicker recovery time than the old technique.

With craniosynostosis, two or more of the skull plates fuse prematurely, restricting growth in the head for the brain.

"Instead of exposing the skull as surgeons do with the old technique, we are able to make two small incisions and remove a small strip of bone," said Assistant Professor Dr. Usiakimi Igbaseimokumo, who said the procedure is not only successful in correcting the problem but is also as effective than the older procedure in the long term.

Igbaseimokumo presented the findings during a recent meeting of the International Society of Pediatric Neurosurgeons.

Mysterious material found on Saturn moons

DENVER, Feb. 20 (UPI) -- U.S. space scientists are investigating an unidentified black material coating the surfaces of some of Saturn's moons.

Astronomers said there's mounting evidence some mechanism has spread the material found on several of the moons from one to another and the material might have a common cometary origin.

Roger Clark of the U.S. Geological Survey in Denver said the Cassini spacecraft found the same spectral signature on all the moons -- Phoebe, Iapetus, Hyperion, Epimetheus -- and Saturn's F-ring that have coatings of dark material.

But the scientists said they don't know where the material originated or what it is.

"It's a mystery, which makes it intriguing," said Clark. "The data keep getting better and better. We're ruling things out and figuring out pieces."

Cassini's next close study of a Saturn moon is a March 12 flyby of Enceladus at a distance of 31 miles at its point of closest approach.

The Cassini-Huygens mission is a cooperative project of the National Aeronautics and Space Administration, the European Space Agency and the Italian Space Agency.

A collection of 14 papers about Saturn's moons appears in the February issue of the journal Icarus.

A breath might soon foretell disease

BOULDER, Colo., Feb. 20 (UPI) -- U.S. scientists have created a technique that analyzes a person's breath to detect trace compounds that might provide early warning signs of disease.

A team led by Jun Ye, a physicist at JILA -- a joint facility of the National Institute of Standards and Technology and the University of Colorado at Boulder -- demonstrated the optical technique for simultaneously identifying tiny amounts of a broad range of molecules in the breath, potentially enabling a fast, low-cost screening tool for disease.

"It is exciting to imagine the potential of analyzing all major biomarkers in one's breath at once," said Ye. "For example, nitric oxide can indicate asthma but it also appears in breath with many other lung diseases, including chronic obstructive pulmonary disease, cystic fibrosis and bronchiectasis.

"However," he added, "if we simultaneously monitor nitric oxide, carbon monoxide, hydro-peroxide, nitrites, nitrates, pentane and ethane, all important biomarkers for asthma, we can be much more certain for a definitive diagnosis of this important disease."

The research is reported in the journal Optics Express.