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Huygens science update
One week after the Huygens probe landed on Saturn's moon Titan, scientists hold a news conference to announce additional results and describe more pictures from the mission. (69min 02sec file)

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ISS spacewalk preview
The upcoming spacewalk by the International Space Station's Expedition 10 crew is previewed by NASA officials at the Johnson Space Center on Jan. 21. (25min 04sec file)

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Launch of Deep Impact!
A Boeing Delta 2 rocket blasts off from Cape Canaveral carrying NASA's comet-smashing probe called Deep Impact. This extended clip follows the mission through second stage ignition and jettison of the rocket's nose cone. (5min 37sec file)
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Press Site view
A camera located at Cape Canaveral's Press Site 1 location offers this view of the Delta rocket's ascent. (1min 24sec file)
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Cocoa Beach
A Boeing Delta 2 rocket blasts off from Cape Canaveral carrying NASA's comet-smashing probe called Deep Impact. This extended clip follows the mission through second stage ignition and jettison of the rocket's nose cone. (5min 37sec file)
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Playalinda Beach
A Boeing Delta 2 rocket blasts off from Cape Canaveral carrying NASA's comet-smashing probe called Deep Impact. This extended clip follows the mission through second stage ignition and jettison of the rocket's nose cone. (5min 37sec file)
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Tower rollback
The mobile service tower is rolled back from the Boeing Delta 2 rocket, exposing the vehicle at launch pad 17B just before daybreak. (3min 21sec file)
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Rocket preps
Assembly of the Boeing Delta 2 rocket at launch pad 17B and mating of the Deep Impact spacecraft is presented in this video package with expert narration. (6min 12sec file)
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Spacecraft campaign
The pre-launch campaign of Deep Impact at Cape Canaveral is presented in this video package with expert narration by a spacecraft team member. (5min 32sec file)
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Giant planetoid Sedna may have formed far beyond Pluto
SOUTHWEST RESEARCH INSTITUTE NEWS RELEASE
Posted: January 24, 2005

Recently, astronomers reported the surprising discovery of a very large diameter Kuiper Belt planetoid -- (90377) Sedna -- on a distant, 12,500-year-long, eccentric orbit centered approximately 500 astronomical units from the Sun. Sedna's estimated diameter is about 1,600 km, two-thirds that of Pluto. Initial studies of Sedna's origin have speculated that it might have been ejected from the giant planets region of our solar system far inside the orbit of Pluto, or perhaps was captured from a passing star's Kuiper Belt.


This artist's conception shows a large Kuiper Belt object growing by collisions early in the history of the solar system. Credit: Courtesy of Dan Durda/Southwest Research Institute
 
In a report published in the January 2005 issue of The Astronomical Journal, planetary scientist Dr. Alan Stern of the Space Science and Engineering Division at Southwest Research Institute shows Sedna could have formed far beyond the distance of Pluto.

"If this is actually what happened," Stern points out, "it would indicate that our solar system's planet factory operated across a much larger region than previously thought." It would also indicate that the mysterious Kuiper Belt "edge" near 50 AU (one AU is the distance from the Earth to the Sun) is not an outer edge, but simply the inner edge of an annular trough, or gap, that is carved out of a much broader structure that has been called the "Kuiper disk."

The new Sedna formation study used a planetary accretion code developed by Stern with funding from NASA's Origins of Solar System's Program in the late 1990s for studies of the formation of Kuiper Belt Objects. This software was used to explore the feasibility of building Sedna from boulder-sized and other small bodies at distances between 75 AU (Sedna's closest solar approach distance) and 500 AU (Sedna's average distance from the Sun).

Stern's Sedna formation simulations assumed that Sedna's original orbit, while distant from the Sun, was circular. Astronomers agree that Sedna could not have formed in its present, eccentric orbit because such an orbit allows only violent collisions that prevent the growth of small bodies. Stern's simulations further assumed that the solar nebula -- the disk of material out of which the planets formed -- was much more extended than most previous simulations had assumed.

"The Sedna formation simulations assumed that the primordial solar nebula was a disk about the size of those observed around many nearby middle-aged stars -- like the well-known example of the 1,500-AU-wide disk around the star Beta Pictoris," Stern says.

"The model calculations found that objects as large, or even larger, than Sedna could easily form in circular orbits at distances of 75 to 500 AU, and that their formation time could have been fairly short -- just a few percent the age of the solar system," Stern continues. "If Sedna did form this far out, it is likely to be accompanied by a cohort of other large planetoids in this very distant region of the solar system. One telltale sign that these objects were formed where they are, rather than in another location, would be if a good fraction of them are on near circular orbits."

SwRI is an independent, nonprofit, applied research and development organization based in San Antonio, Texas, with more than 2,800 employees and an annual research volume of more than $339 million.

Ares 1-X Patch
The official embroidered patch for the Ares 1-X rocket test flight, is available for purchase.
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Apollo Collage
This beautiful one piece set features the Apollo program emblem surrounded by the individual mission logos.
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Expedition 21
The official embroidered patch for the International Space Station Expedition 21 crew is now available from our stores.
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Hubble Patch
The official embroidered patch for mission STS-125, the space shuttle's last planned service call to the Hubble Space Telescope, is available for purchase.
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