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Joining tank and SRBs
The space shuttle Discovery is hoisted high into the Vehicle Assembly Building and mated with its external fuel tank and solid rocket boosters.

 Hoisted | Attached

Discovery moves to VAB
Space shuttle Discovery makes an evening move October 31 from its processing hangar to the Vehicle Assembly Building for mating with an external fuel tank and twin solid rocket boosters in preparation for the STS-116 mission.


Final Hubble servicing
The objectives of the just-approved final Hubble Space Telescope servicing mission are detailed and the anticipated science from the new instruments to be installed are detailed in this briefing from Goddard Space Flight Center.

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Meet Hubble astronauts
The crew for the final Hubble Space Telescope servicing mission will be led by Scott Altman, with pilot Greg C. Johnson, robot arm operator Megan McArthur and spacewalkers Andrew Feustel, Mike Good, John Grunsfeld and Mike Massimino. The astronauts meet the press in this news briefing from Johnson Space Center.

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STEREO launch
The twin STEREO space observatories designed to change the way we view the sun launch from Cape Canaveral aboard a Boeing Delta 2 rocket.

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STS-48: Atmosphere research satellite
With launch of the Upper Atmosphere Research Satellite from space shuttle Discovery in September 1991, a new era in studying Earth's environment from space began. The crew of STS-48 describes the mission in this post-flight film, which includes an beautiful nighttime flyover of the United States.

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STS-40: Medical lab
Astronauts, rodents and jellyfish were the subjects during extensive medical tests performed aboard the first Spacelab Life Sciences mission launched in June 1991 aboard shuttle Columbia. A space laboratory module riding in the payload bay housed the experiment facilities. The crew of STS-40 explain the mission in this post-flight film.

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Exploration update
A progress report on development of the Orion crew exploration spacecraft and the Ares launch vehicle is given during this briefing held October 18 at the Glenn Research Center in Cleveland.


MRO early images
Some of the initial pictures and data from NASA's Mars Reconnaissance Orbiter since the craft entered its mapping orbit around the Red Planet are presented in this news briefing held October 16 from the Jet Propulsion Laboratory.


STS-39: Military maneuvers
Space shuttle Discovery's STS-39 flight, launched in April 1991, served as a research mission for the U.S. Department of Defense. An instrument-laden spacecraft for the Strategic Defense Initiative Organization was released to watch Discovery perform countless rocket firings and maneuvers, as well as canisters releasing clouds of gas. The crew tells the story of the mission in this post-flight film presentation.

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Moon's escaping gasses expose fresh surface
Posted: November 10, 2006

Conventional wisdom suggests that the Earth's moon has seen no widespread volcanic activity for at least the last 3 billion years. Now, a fresh look at existing data points to much more recent release of lunar gasses.

This false color composite image indicates age and composition of lunar surface features. Titanium basalts (blue) are exposed on the floor of Ina structure and in the Œfresh' impact crater. Less mature soils (based on spectral ratios) appear in green. Credit: NASA
The study, published in the journal Nature by geologists Peter Schulz and Carle Pieters of Brown University and Matthew Staid of the Planetary Science Institute, uses three distinct lines of evidence to support the assertion that volcanic gas has been released from the moon's surface within the last 1 to 10 million years. The researchers focus on a D-shaped area called the Ina structure that was first recognized in images from Apollo missions.

The unusual sharpness of the features first called Schultz's attention to the area. "Something that razor-sharp shouldn't stay around long. It ought to be destroyed within 50 million years," said Schulz. On Earth, wind and water quickly wear down freshly exposed surface features. On the airless moon, constant bombardment with tiny space debris accomplishes a similar result. By comparing the fine-scale surface features within the Ina structure to other areas on the moon with known ages, the team was able to place its age at closer to 2 million years.

The scarcity of asteroid impact craters on the surface within Ina provided a second line of evidence for the feature's relative youth. The researchers identified only two clear impact craters larger than 30 meters on the 8 square kilometers of the structure's floor. This frequency is about the same as at South Ray Crater, near the Apollo 16 landing site. The surface material ejected from South Ray Crater has long been used as a benchmark for dating other features on the moon's surface and most lunar scientists studying these rocks agree on a date of approximately 2 million years, based on cosmic ray exposure.

The third piece of support for the authors' hypothesis comes from comparing the spectral signatures of deposits in the Ina depression to those from very fresh craters. As lunar surface deposits weather, the wavelengths of light they reflect change in predictable ways. Overall reflectance, or albedo, gets less bright and the ratio of light at 1,000 nm wavelengths to 750 nm wavelengths increases. Based on these color ratios, the deposits on Ina's floor are exceptionally young - and possibly even newly exposed.

The appearance of the surface at Ina does not indicate an explosive release of magma, which would result in visible rays of ejecta surrounding a central crater. Rather, it suggests a rapid release of gasses, which would have blown off the surface deposits, exposing less weathered materials. This interpretation is particularly appealing because Ina is located at the intersection of two linear valleys or rilles - like many geologically active areas on Earth.

Ina also does not appear to be alone. The authors identify at least four similar features associated with the same system of rilles, as well as others in neighboring rille systems. Although several kinds of evidence support the authors' conclusion that the moon is more geologically active than previously thought, the only sure way to resolve the question would be to collect samples at such sites. "Ina and other similar features are great targets for future exploration, by people or robots," said G. Jeffrey Taylor, a lunar researcher at the University of Hawaii. "They might be the best place to get a good look at the interface between the powdery regolith and the consolidated rock beneath."

Over the years, says Schultz, amateur astronomers have seen puffs or flashes of light coming from the moon's surface. Although most professional observers have upheld the conclusion that the moon was inactive, such sightings have kept open a window of doubt. A coordinated observation campaign, including both professional and amateur astronomers, would be one way to build additional evidence for activity, says Schultz. A gas release itself would not be visible for more than a second or so, but the dust it kicked up might stay suspended for up to 30 seconds. With modern alert networks, that's long enough to move a professional telescope into position to see what's happening.

NASA's Planetary Geology and Geophysics Program supported this research. Peter Schultz and Carle Pieters are professors of geological science at Brown University. Matthew Staid is a research scientist at the Planetary Science Institute.