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Shuttle simulation
A long mission simulation is underway to rehearse the launch of space shuttle Discovery, the uncovering of impact damage and the decision-making process of the flight controllers and management team. (14min 31sec file)

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Space rendezvous
After a two-day journey from Baikonur Cosmodrome, the Russian Progress 17P mission and International Space Station rendezvous in Earth orbit. Cameras on both craft provide scenes in this highlights movie. (4min 02sec file)
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Station flyaround
The Progress vehicle performs an automated flyaround of the International Space Station to align with the docking port. (3min 42sec file)
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ISS cargo ship docking
The Russian Progress M-52 resupply ship docks to the International Space Station as seen by the nose-mounted camera on the delivery freighter. (1min 30sec file)
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Approach and docking
This extended length clip shows the Russian Progress cargo ship's final approach and docking to the International Space Station. (10min 00sec file)
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Shuttle tank mating
The external tank for the return-to-flight space shuttle mission is moved into position and mated with the twin solid rockets boosters at Kennedy Space Center. (4min 30sec file)
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Cassini update
Go inside the Cassini-Huygens mission to explore Saturn, its rings and moons with this lecture from NASA's Jet Propulsion Laboratory. (81min 05sec file)

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Shuttle testing
Testing to support the space shuttle return to flight is being performed at NASA's Ames Research Center. This footage shows wind tunnel testing using a shuttle mockup and thermal protection system tests in the arc jet facility. (5min 02sec file)
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Newly seen force may help gravity in star formation
Posted: March 7, 2005

Scientists have pierced through a dusty stellar nursery to capture the earliest and most detailed view of a collapsing gas cloud turning into a star, analogous to a baby's first ultrasound.

This image comes from the R Corona Australis star-forming region, about 500 light years from Earth. This image was created with the University of Hawaii 88-inch telescope in the "near" infrared waveband, which is slightly lower in energy than what is visible to our eyes. Many protostars (reddish) and young stars (bright white) are seen here. Credit: UH88/Nedachi et al.
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The observation, made primarily with the European Space Agency's XMM-Newton observatory, suggests that some unrealized, energetic process -- likely related to magnetic fields -- is superheating the surface of the cloud core, nudging the cloud ever closer to becoming a star.

The observation marks the first clear detection of X-rays from a cold precursor to a star, called a Class 0 protostar, far earlier in a star's evolution than most experts in this field thought possible. The surprise detection of X-rays from such a cold object reveals that matter is falling toward the protostar core 10 times faster than expected from gravity alone.

"We are seeing star formation at its embryonic stage," said Dr. Kenji Hamaguchi, a NASA-funded researcher at NASA Goddard Space Flight Center in Greenbelt, Md., lead author on a report in The Astrophysical Journal. "Previous observations have captured the shape of such gas clouds but have never been able to peer inside. The detection of X-rays this early indicates that gravity alone is not the only force shaping young stars."

Supporting data came from NASA's Chandra X-ray Observatory, Japan's Subaru telescope in Hawaii, and the University of Hawaii 88-inch telescope.

Hamaguchi's team discovered X-rays from a Class 0 protostar in the R Corona Australis star-forming region, about 500 light years from Earth.

Class 0 is the youngest class of protostellar object, about 10,000 to 100,000 years into the assimilation process. The cloud temperature is about 400 degrees below zero Fahrenheit (minus 240 Celsius). After a few million years, nuclear fusion ignites at the center of the collapsing protostellar cloud, and a new star is formed.

The team speculates that magnetic fields in the spinning protostar core accelerate infalling matter to high speeds, producing high temperatures and X-rays in the process. These X- rays can penetrate the dusty region to reveal the core.

"This is no gentle freefall of gas," said Dr. Michael Corcoran of NASA Goddard, a co-author on the report. "The X-ray emission shows that forces appear to be accelerating matter to high speeds, heating regions of this cold gas cloud to 100 million degrees Fahrenheit. The X-ray emission from the core gives us a window to probe the hidden processes by which cold gas clouds collapse to stars."

This is a slightly wider view of the R Corona Australis star-forming region, this time seen in X-ray energies captured by ESA's XMM-Newton observatory. The six blue sources are protostars, mostly corresponding to the reddish dots seen in figure 1. The Class 0 protostar that Kenji Hamaguchi's team observed in X rays is labeled IRS7B. Although not obviously visible in figure 1, this protostar would be just left of the bright central source in that image. Zooming in on the Class 0 protostar, we see it once more -- this time seen in an infrared waveband lower in energy than that in figure 1. Credit: ESA/XMM/Subaru/UH88
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Hamaguchi likened the generation of X-rays in the Class 0 protostar to what happens during solar flares on our Sun. The solar surface has lots of magnetic loops, which sometimes get tangled and release large amounts of energy. This energy can accelerate atoms to velocities of 7 million miles an hour. The particles smash against the solar surface and create X-rays. Similarly tangled magnetic fields might be responsible for X-rays observed by Hamaguchi and his collaborators.

The detection of magnetic fields from an extremely young Class 0 protostar provides a crucial link in understanding the star formation process, because magnetic field loops are believed to play a critical role in moderating the cloud collapse.

The team used XMM-Newton for its powerful light-collecting capability, necessary for this type of observation where so few X-rays penetrate the dusty region, and the exquisite resolving power of Chandra to pinpoint the X-ray source position. The team used the infrared Subaru telescope to determine the protostar's age.

"The age is based on a well-established chart of spectra, or characteristics of the infrared light, as the protostar evolves over the course of a million years," said Ko Nedachi, a doctoral student at the University of Tokyo who led the Subaru observation.

The science team also includes Drs. Rob Petre and Nicholas White of NASA Goddard, Dr. Beate Stelzer of the Astronomy Observatory in Palermo, Italy, and Dr. Naoto Kobayashi of University of Tokyo. Kenji Hamaguchi is funded through the National Research Council; Michael Corcoran is funded through Universities Space Research Association.