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Discovery in the VAB
Shuttle Discovery enters into the Vehicle Assembly Building after a 10-hour journey from launch pad 39B. (4min 29sec file)
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Memorial Day message
The International Space Station's Expedition 11 crew pays tribute to our fallen heroes for Memorial Day. (1min 00sec QuickTime file)
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Apollo-era transporter
In the predawn hours, the Apollo-era crawler-transporter is driven beneath shuttle Discovery's mobile launch platform at pad 39B in preparation for the rollback to the Vehicle Assembly Building. (2min 37sec QuickTime file)
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Unplugging the shuttle
Workers disconnect a vast number of umbilicals running between launch pad 39B and Discovery's mobile launch platform for the rollback. The cabling route electrical power, data and communications to the shuttle. (2min 32sec file)
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Shuttle rollback
The crawler-transporter begins rolling space shuttle Discovery off launch pad 39B at 6:44 a.m. EDT May 26 for the 4.2-mile trip back to the Vehicle Assembly Building. (7min 28sec file)
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Voyager adventures
This animation shows the Voyager spacecraft heading into the solar system's final frontier and the edge of interstellar space. (1min 24sec file)
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Mike Griffin at KSC
NASA Administrator Mike Griffin and Kennedy Space Center Director Jim Kennedy chat with reporters at the Cape on a wide range of topics. The press event was held during Griffin's tour of the spaceport. (27min 48sec file)
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Delta rocket blasts off
The NOAA-N weather satellite is launched aboard a Boeing Delta 2 rocket from Vandenberg Air Force Base, California.

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NOAA pre-launch
Officials from NASA, NOAA, the Air Force and Boeing hold the pre-launch news conference at Vandenberg Air Force Base to preview the mission of a Delta 2 rocket and the NOAA-N weather satellite. (29min 54sec file)

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Countdown culmination
Watch shuttle Discovery's countdown dress rehearsal that ends with a simulated main engine shutdown and post-abort safing practice. (13min 19sec file)
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Going to the pad
The five-man, two-woman astronaut crew departs the Operations and Checkout Building to board the AstroVan for the ride to launch pad 39B during the Terminal Countdown Demonstration Test countdown dress rehearsal. (3min 07sec file)
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Suiting up
After breakfast, the astronauts don their launch and entry partial pressure suits before heading to the pad. (3min 14sec file)
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Telescope catches surprise ultraviolet light show
NASA/JPL NEWS RELEASE
Posted: May 31, 2005

It was a day like any other for a nearby star named GJ 3685A - until it suddenly exploded with light. At 2 p.m. Pacific time on April 24, 2004, the detectors on NASA's Galaxy Evolution Explorer ultraviolet space telescope nearly overloaded when the star abruptly brightened by a factor of at least 10,000. After the excitement was over, astronomers realized that they had just recorded a giant star eruption, or flare, about one million times more energetic than those from our Sun.


NASA's Galaxy Evolution Explorer show one of the largest flares, or star eruptions, ever recorded at ultraviolet wavelengths. Credit: NASA/JPL-Caltech
 
Findings on this intriguing event were presented at the 206th meeting of the American Astronomical Society in Minneapolis, Minn.

This dramatic flare is just one of many serendipitous discoveries made by the Galaxy Evolution Explorer since its 2003 launch. 

Though the telescope was originally designed to spot galaxies, it has repeatedly witnessed a sky flickering with ultraviolet flares, bursts and fast-moving streaks. While the flares and bursts are from different types of stars, the streaks are asteroids, satellites or possibly space debris floating across the telescope's field of view.

The findings have led astronomers to conclude that the ultraviolet sky, once thought to be a quiet backdrop for viewing galaxies, is, in fact, a rather festive place.

"We had no idea that the ultraviolet sky would be filled with so many things that go bump in the night," said Dr. Barry Welsh, University of California, Berkeley, co-discoverer of some of the flares. "All of these objects are a bonus to astronomers, since the observations come free when the telescope is aimed at distant galaxies."

"I was surprised by how often we have observed stellar flares and by the amazing size of some of them," said Dr. Chris Martin, principal investigator of the Galaxy Evolution Explorer, California Institute of Technology, Pasadena. "Nature rarely disappoints us."

So far, the Galaxy Evolution Explorer has recorded 84 bonus astrophysical events occurring on flaring stars, binary stars called dwarf novae, and pulsating stars, as well as countless pieces of space debris. These data are already being collected into public databases for other astronomers to study. For example, astronomers are using the new set of flare stars to test their flare theories.

The Galaxy Evolution Explorer is surveying the entire sky at ultraviolet wavelengths for clues to how the earliest galaxies evolved into mature galaxies like our own Milky Way. To detect these early, faint galaxies, the telescope was outfitted with specialized cameras that allow the arrival of each photon of ultraviolet light to be timed with a precision of about a microsecond.

"The telescope's detectors have provided an unprecedented time resolution of these astrophysical events," said Welsh. "Now, we can say what happens during each one-hundredth of a second of a flare event. That's better information than most video cameras have when they take slow motion shots of athletes."

A preliminary analysis of the enormous flare witnessed by the Galaxy Evolution Explorer around GJ 3685A - the largest ever recorded in ultraviolet light - shows that the mechanisms underlying these stellar eruptions may be more complex than previously believed. Evidence for the two most popular flare theories was found.

Flares are huge explosions of energy stemming from a single location on a star's surface. They happen regularly on many types of stars, though old, small "red dwarf" stars like

GJ 3685A tend to experience them most frequently and dramatically. These stars, called flare stars, can erupt as often as every few hours, and with an intensity far greater than flares from our Sun. One of the reasons astronomers study flare stars is to gain a better picture and history of flare events taking place on the Sun.

Caltech leads the Galaxy Evolution Explorer mission and is responsible for science operations and data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the mission and built the science instrument. The mission was developed under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. South Korea and France are the international partners in the mission.