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Hill-climbing Mars rover
The Mars Exploration Rover Spirit has reached the summit of Husband Hill, returning a spectacular panorama from the hilltop in the vast Gusev Crater. Scientists held a news conference Sept. 1 to reveal the panorama and give an update on the twin rover mission.

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Planes track Discovery
To gain a new perspective on space shuttle Discovery's ascent and gather additional imagery for the return to flight mission, NASA dispatched a pair of high-flying WB-57 aircraft equipped with sharp video cameras in their noses.

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Rocket booster cams
When space shuttle Discovery launched its two solid-fuel booster rockets were equipped with video cameras, providing dazzling footage of separation from the external fuel tank, their free fall and splashdown in the sea.

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Discovery ferried home
Mounted atop a modified Boeing 747, space shuttle Discovery was ferried across the country from Edwards Air Force Base, California, to Kennedy Space Center, Florida.

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Shuttle tank returned
Shuttle fuel tank ET-119 is loaded onto a barge at Kennedy Space Center for the trip back to Lockheed Martin's Michoud Assembly Facility in New Orleans. The tank will be used in the investigation to determine why foam peeled away from Discovery's tank on STS-114 in July.

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Delta 4 launch delayed
Launch of the GOES-N weather observatory aboard a Boeing Delta 4 rocket is postponed at Cape Canaveral, Florida.

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Mars probe leaves Earth
The Mars Reconnaissance Orbiter lifts off aboard a Lockheed Martin Atlas 5 rocket from Cape Canaveral's Complex 41.

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Launch pad demolition
Explosives topple the abandoned Complex 13 mobile service tower at Cape Canaveral Air Force Station. This video was shot from the blockhouse roof at neighboring Complex 14 where John Glenn was launched in 1962.

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Evidence says some comets may have become asteroids
Posted: September 5, 2005

Some asteroids that have comet-like orbits may actually be comets that have lost gases and other easily vaporized substances, according to a NASA research team.

The team will present its findings at the American Astronomical Society's Division for Planetary Sciences annual meeting in Cambridge, England, on Sept. 5.

"Several objects classified as asteroids have orbits that are dynamically similar to those of comets," said Dale Cruikshank, an astronomer at NASA Ames Research Center in California's Silicon Valley and a member of the research team. These asteroids may be comets that have lost gases and other materials by repeated passages through the inner solar system, according to Cruikshank.

The team studied infrared light from 55 asteroids using NASA's Spitzer Space Telescope to "better understand possible links between asteroids and comets," according to the authors. In addition to co-author Cruikshank, Joshua Emery who also works at NASA Ames and is an employee of the SETI Institute, Mountain View, Calif. is the principal author; and Jeffrey Van Cleve of Ball Aerospace, Boulder, Colo., is the other co-author.

"The suggestion that some asteroids originated as comets has been made before, but the new Spitzer Space Telescope observations provide the first chance to really test this suggestion," Emery noted. "Most of the objects observed in our program appear to be typical asteroids, but a few have surface compositions and textures that are more similar to comets," Emery added.

"The infrared light we are studying gives us information about the composition and surface textures of solid bodies in the solar system." Cruikshank said.

The research team reports that some of the asteroids have very fine-grained surfaces. "We think this fine-graininess is a characteristic of comets," Cruikshank explained.

The Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.