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Atlantis' Success Good News For Hubble

By Traci Watson, USA TODAY



The Hubble Telescope as seen from the space

shuttle Discovery in February, 1997.



A safe landing Thursday by space shuttle Atlantis after a nearly flawless mission brightened the prospects for a repair flight to the ailing Hubble Space Telescope, space experts said.

"NASA is ready to make a positive decision and was mainly waiting for a successful" Atlantis flight, said space policy scholar John Logsdon of George Washington University. "I would be extremely surprised if they didn't give a go-ahead."

NASA chief Michael Griffin said after the landing that he'll decide in late October whether to send a shuttle to revive the telescope, which launched in 1990 and will shut down within a few years unless it gets new batteries and other parts.


Griffin emphasized that nothing's been decided. But he also noted that the Atlantis flight and a July flight by Discovery showed that the shuttle program had satisfied many of the prerequisites for a repair call to Hubble.

For example, if a shuttle flies to Hubble, "we want to know we're going to have a clean bird," he said. The orbiters from the last two flights have come back "very clean," or undamaged, he said.

Griffin said the last two flights also proved that astronauts in orbit can inspect the spacecraft for damage and make basic repairs to its exterior. Both abilities are key, because a shuttle going to Hubble would not have the fuel to reach the safe haven of the International Space Station should something go wrong.


Hubble is "one of the great scientific instruments of all time," Griffin said. "If we think we can (repair) it safely and well, then we will."

The Hubble was designed to be maintained and upgraded by shuttle astronauts, who have already made three trips to the telescope. NASA has no other spacecraft that could carry crews to Hubble.

Although Griffin said no decision has been made on a Hubble flight, he implied planning is well underway.

"We need to do a (Hubble fix) fairly soon. We're targeting early '08," he said. "Other (shuttle) missions ... would have to flow around that, and they will."

If a Hubble mission is approved, it would have to be shoehorned into the shuttle's schedule. NASA wants the spacecraft to make up to 16 more flights to the International Space Station before the shuttle retires in 2010. A major problem with the aging vehicles could make that goal difficult.

Atlantis touched down gently in Florida just before dawn Thursday, safely ending a 12-day mission that enlarged the half-built station for the first time since 2002. NASA suspended work on the station after the 2003 disintegration of shuttle Columbia, which killed the crew and led to the grounding of the shuttle fleet.

Atlantis commander Brent Jett said the mission had been tiring but worthwhile for him and his five crewmates.

"If you don't get off to a good start you just put yourself behind the eight-ball," he said. "We have several ... very, very tough missions ahead."


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Solar Power
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I hope they do send up a Hubble repair mission. It would be a shame to lose the Hubble when it could have been restored to health and used for a while longer.




“They can shoot me dead but the moral high ground is mine!” The 10th Doctor

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Proto Star
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I just thought this was so cool (and by suggestion).  Gravity is the reason for life in the universe, and a black hole is the ultimate gravitational force.


Scientists Nudge Closer to the Edge of a Black Hole

October 5, 2006....

NASA scientists and their international partners using the new Japanese Suzaku satellite have collected a startling new set of black hole observations, revealing details of twisted space and warped time never before seen with such precision.

Still from animation showing a spinning black hole Image/animation right: Supermassive black holes are a prime target for Suzaku. These are voids in the center of most galaxies containing the mass of millions to billions of suns, all confined within a region about the size of our solar system. The black hole itself emits no light, but the process of accreting matter causes the entire region to be extremely bright in all wavelengths. Close to the edge of a black hole, X-rays are the dominant wavelength. Suzaku is sensitive to the X-ray energies emitted close to supermassive black holes, such as quasars. Click image to view animation (2.6 Mb -- no audio). Credit: NASA/GSFC

The observations include clocking the speed of a black hole's spin rate and measuring the angle at which matter pours into the void, as well as evidence for a wall of X-ray light pulled back and flattened by gravity.

The findings rely on a special feature in the light emitted close to the black hole, called the "broad iron K line," once doubted by some scientists because of poor resolution in earlier observations, now unambiguously revealed as a true measure of a black hole's crushing gravitational force. This technique can be exploited in future X-ray missions.

Still from animation showing the cutaway of a black hole. Image/animation left: Zoom into the center of a spiral galaxy to reveal a black hole. Cutaway of accretion disks reveals inside of the black hole. The chaotic black hole activity is hard to discern. >From our perspective, all activity is enshrouded in dust and gas in a region that's only a pinpoint a few light-years across in the center of a galaxy hundreds of thousands of light-years across, all typically hundreds of millions of light-years from Earth. The Suzaku satellite is sensitive to key X-ray energies that enable scientists to discern properties of the black hole. Some X-rays are emitted at the edge of the black hole; others are reflected off of dust clouds several light-years away. Suzaku provides the most complete picture of this black hole activity, and when combined with optical and radio observations, even more can be learned. Click image to view animation (3.6 Mb -- no audio). Credit: NASA/GSFC

"Across the board, we are finding the broad iron K line to be an incredibly robust measure of black hole properties," said Andrew Fabian of Cambridge University, England, who led one of the teams. "We are entering the era of precision black hole measurements."

Fabian is the team leader on Suzaku's black hole spin and light-bending observations. James Reeves of NASA's Goddard Space Flight Center, Greenbelt, Md., and Johns Hopkins University, Baltimore, led a second team that observed the first accurate measurement of the angle of a disk of material swirling around a black hole.

Still from animation showing how scientists can trace matter movement through spectral analysis. Image/animation right: Shown here is the tale of two hot blobs of matter moving around a black hole. Scientists can trace the movement through spectral analysis. The broad iron K line is the signature of hot iron plasma in the presence of strong gravity. In the absence of gravity, hot iron will produce a clean spike on a spectrograph at 6.4 kiloelectron volts. Because a black hole's gravity will tug at light itself, this iron line, when emitted near a black hole, is stretched, or broadened. The result is something that resembles the outline of a mountain range instead of a single spike. And yet the spectral signature gets even more complicated: As matter moves around a black hole, moving away and then closer to us, the spectral line undergoes a Doppler shift. The X-rays increase in energy when emitted from mater moving towards us (called a blue-shift) and decrease in energy when moving away from us (called a red-shift). Click image to view animation (2.5 Mb -- no audio). Credit: NASA/GSFC

Suzaku contains a high-energy X-ray detector and an X-ray spectrograph. Together, these instruments detect a broad range of X-ray energies, particularly the higher X-ray energies. Supermassive black holes are a prime target. These are objects in the center of most galaxies, containing the mass of millions to billions of suns confined within a region about the size of our solar system.

This spectral signal has been seen before, most recently with Europe's XMM-Newton satellite in the very same black holes observed by Suzaku. However, Suzaku has a higher sensitivity at this important energy range compared to other telescopes. And Suzaku detects even higher energies, far above 6.4 keV, also with high sensitivity. This combination is a unique satellite feature and provides a more complete picture of black hole activity.

A series of Suzaku observations conducted in 2005 and 2006 demonstrates that the broad iron K line is found coming from almost all galaxies and that the signal is real, from strong gravity, and not noise due to poor resolution. Future X-ray missions can build upon this discovery and use the broad iron K line to "image" a black hole, a long-term goal for NASA space exploration.

Still from animation showing the difference between a spinning and nonspinning black hole. Image/animation left: Scientists can discern whether a black hole is spinning or not by studying the matter and energy around the black hole. If the black hole is spinning, matter can orbit more tightly. This is called the "innermost stable circular orbit," the closest you can get to a black hole without falling in. The faster the black hole spins, the tighter the orbit. Because gravity is stronger closer to the black hole, light is stretched more. So a spinning black hole has a spectrum that's "broader" --- a reflection of iron gas that usually emits X-rays at 6.4 kiloelectron volts but instead is broadened or stretched to lower energies. How low and how broad is a reflection of how fast the black hole is spinning and how close matter gets to it. Click image to view animation (4.3 Mb -- no audio). Credit: NASA/GSFC

In a galaxy called MCG-6-30-15, Fabian's group confirmed that the central black hole is spinning rapidly, taking space and time along for a ride with it. The group found evidence that X-rays emitted close to the black hole, trying to escape, are bent back into the disk of matter flowing inward, away from us. This is predicted by Einstein's general relativity, hinted at in earlier observations, but seen in remarkable new detail with Suzaku.

In a galaxy called MCG-5-23-16, Reeves' team determined that the disk of material feeding the black hole, called the accretion disk, is angled at 45 degrees with respect to our line of sight. Such a precision measurement has not been possible before.

"The broad iron K line is our ticket to view matter and energy very close to a black hole," said Reeves. "Only by probing the extremes of gravity will we find flaws, if any, in Einstein's theories."



Edited 10 Oct 2006 to remove duplicate content from an accidental double paste – MACJR


PS. Nice article. I have always been interested in black holes and such.


"What makes us human is that we care, and because we care we never stop trying."
~Jeffrey Sinclair; Babylon 5: Season I

Marbles still on loan. . .
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