NuSTAR = Pegasus-XL - 13.06.12 20:00:42 ЛМВ - Kwajalein

Автор Salo, 30.11.2011 19:36:52

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Salo

http://msdb.gsfc.nasa.gov/launches.php
Цитировать3/14/2012 NuSTAr   NASA SMD Reagan Test Site, Kwajalein Atoll
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Salo

http://space.skyrocket.de/doc_sdat/explorer_nustar.htm
ЦитироватьExplorer: NuSTAR (SMEX 11)[/size]


NuSTAR (SMEX 11) [OSC]

NuSTAR (Nuclear Spectroscopic Telescope Array) is a X-ray survey mission, which is first satellite to fly a focussing X-ray telescope in space for energies in the 8-80 keV.range.

NuSTAR will survey this energy band for X-ray emission from quasars and Galactic black hole binaries, and obtain spectra of hard X-ray emission from supernova remnants and study the spectral lines created by nuclear transitions which dominate this spectral range.

NuSTAR is a pointed telescope, which will be launched by a Pegasus-XL into a low-Earth, equatorial orbit from Kwajalein. The planned mission will last for three years, although less than half that time is required to meet the core science goals. NuSTAR will ordinarily follow a preprogrammed observation plan, but will have the capability of responding to transient opportunities within a day of notification.

The NuSTAR instrument consists of an array of two co-aligned hard X-ray telescopes. The grazing incidence mirrors focus onto two shielded solid-state pixel detectors, separated by a mast that extends the focal length to 10 m after launch. The optics utilize thin glass shells coated with depth-graded multi-layers to extend the bandpass and FOV over that achievable with standard metal surfaces. Cadmium Zinc Telluride (CdZnTe) detectors provide excellent spectral resolution and high quantum efficiency without requiring cryogenic operation. All major elements of the instrument have flight heritage (space flight and HEFT balloon experiment).

The long focal length requires the use of a 10 m extendable mast. The design chosen is produced by Able Engineering, and is a straightforward reduction of the 60 m mast successfully deployed for the SRTM program. A laser metrology system monitors the mast alignment.

A decision on proceeding to flight development with NuSTAR was to be made by early 2006 for a launch in 2008, but it was cancelled in February 2006. In September 2007 NASA restarted the program for a planned launch in early 2012.

The spacecraft was originally to be based on the Spectrum Astro SA-200S bus, but after the restart of the program Orbital was selected to provide a LEOStar-2 based bus. During development, the number of X-ray telescopes in the array was reduced from three to two.

Nation:   USA
Type / Application:   Particle imaging
Operator:   NASA
Contractors:   Orbital Sciences Corporation (OSC)
Equipment:   2 co-aligned hard X-ray telescopes
Configuration:   LEOStar-2
Propulsion:   ?
Power:   Deployable solar array, batteries
Lifetime:   2 years
Mass:   360 kg
Orbit:   525 km
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Salo

http://twitter.com/#/OrbitalSciences
Цитировать@NASAKennedy
NASA Kennedy / KSC
At VAFB, all Pegasus XL stages have been delivered for the NuStar launch in February. The rocket's overhead wing has now been attached.
Цитировать@NASAKennedy
NASA Kennedy / KSC
NuStar's Pegasus rocket will undergo a two-day "Vehicle Verification" test this week in preparation for Flight Simulation #1 on Dec. 9.
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Salo

http://science.nasa.gov/missions/nustar/
ЦитироватьNuSTAR[/size]



Nuclear Spectroscopic Telescope Array

Mission Project Home Page

The Nuclear Spectroscopic Telescope Array is an Explorer mission that will allow astronomers to study the universe in high energy X-rays. Launching in 2012, NuSTAR will be the first focusing hard X-ray telescope to orbit Earth and is expected to greatly exceed the performance of the largest ground-based observatories that have observed this region of the electromagnetic spectrum. NuSTAR will also complement astrophysics missions that explore the cosmos in other regions of the spectrum.

X-ray telescopes such as Chandra and XMM-Newton have observed the X-ray universe at low X-ray energy levels. By focusing higher energy X-rays, NuSTAR will start to answer several fundamental questions about the Universe including:

    How are black holes distributed through the cosmos?
    How were heavy elements forged in the explosions of massive stars?
    What powers the most extreme active galaxies?

NuSTAR's primary science objectives include:

    Conducting a census for black holes on all scales using wide-field surveys of extragalactic fields and the Galactic center.
    Mapping radioactive material in young supernova remnants; Studying the birth of the elements and to understand how stars explode.
    Observing relativistic jets found in the most extreme active galaxies and to understand what powers giant cosmic accelerators.

NuSTAR will also study the origin of cosmic rays and the extreme physics around collapsed stars while responding to targets of opportunity including supernovae and gamma-ray bursts. NuSTAR will perform follow-up observations to discoveries made by Chandra and Spitzer, and will team with Fermi, making simultaneous observations which will greatly enhancing Fermi's science return.[/size]
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Salo

"Были когда-то и мы рысаками!!!"

Salo

"Были когда-то и мы рысаками!!!"


Salo

"Были когда-то и мы рысаками!!!"

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NASA's NuSTAR Ships to Vandenberg for March 14 Launch

http://www.nasa.gov/mission_pages/nustar/multimedia/pia15263.html

ЦитироватьPASADENA, Calif. -- NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, shipped to Vandenberg Air Force Base, Calif., on Tuesday, to be mated to its Pegasus launch vehicle. The observatory will detect X-rays from objects ranging from our sun to giant black holes billions of light-years away. It is scheduled to launch March 14 from an aircraft operating out of Kwajalein Atoll in the Marshall Islands.

"The NuSTAR mission is unique because it will be the first NASA mission to focus X-rays in the high-energy range, creating the most detailed images ever taken in this slice of the electromagnetic spectrum," said Fiona Harrison, the mission's principal investigator at the California Institute of Technology in Pasadena, Calif.

The observatory shipped from Orbital Sciences Corporation in Dulles, Va., where the spacecraft and science instrument were integrated. It is scheduled to arrive at Vandenberg on Jan. 27, where it will be mated to the Pegasus, also built by Orbital, on Feb. 17.

The mission will be launched from the L-1011 "Stargazer" aircraft, which will take off near the equator from Kwajalein Atoll in the Pacific. NuSTAR and its Pegasus will fly from Vandenberg to Kwajalein attached to the underside of the L-1011, and are scheduled to arrive on March 7.

On launch day, after the airplane arrives at the planned drop site over the ocean, the Pegaus will drop from the L-1011 and carry NuSTAR to an orbit around Earth.

"NuSTAR is an engineering achievement, incorporating state-of-the-art high-energy X-ray mirrors and detectors that will enable years of astronomical discovery," said Yunjin Kim, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena.

NuSTAR's advanced telescope consists of two sets of 133 concentric shells of mirrors, which were shaped from flexible glass similar to that found in laptop screens. Because X-rays require large focusing distances, or focal lengths, the telescope has a lengthy 33-foot (10-meter) mast, which will unfold a week after launch.

These and other advances in technology will enable NuSTAR to explore the cosmic world of high-energy X-rays with much improved sensitivity and resolution over previous missions. During its two-year primary mission, NuSTAR will map the celestial sky in X-rays, surveying black holes, mapping supernova remnants, and studying particle jets travelling away from black holes near the speed of light.

NuSTAR also will probe the sun, looking for microflares theorized to be on the surface that could explain how the sun's million-degree corona, or atmosphere, is heated. It will even test a theory of dark matter, the mysterious substance making up about one-quarter of our universe, by searching the sun for evidence of a hypothesized dark matter particle.

"NuSTAR will provide an unprecedented capability to discover and study some of the most exotic objects in the universe, from the corpses of exploded stars in the Milky Way to supermassive black holes residing in the hearts of distant galaxies," said Lou Kaluzienski, NuSTAR program scientist at NASA Headquarters in Washington.

NuSTAR is a small-explorer mission managed by JPL for NASA's Science Mission Directorate. The spacecraft was built by Orbital Sciences Corporation. Its instrument was built by a consortium including Caltech, JPL, Columbia University, New York, N.Y., NASA's Goddard Space Flight Center in Greenbelt, Md., the Danish Technical University in Denmark, the University of California, Berkeley, and ATK-Goleta. NuSTAR will be operated by U.C. Berkeley, with the Italian Space Agency providing its equatorial ground station located at Malindi, Kenya. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

For more information, visit http://www.nasa.gov/nustar and http://www.nustar.caltech.edu/ .
http://www.nasa.gov/mission_pages/nustar/news/nustar20120124.html
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NuSTAR Spacecraft Arrives in California
ЦитироватьNASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, mission arrived at Vandenberg Air Force Base in California this morning after a cross-country trip by truck from the Orbital Sciences Corporation's manufacturing plant in Dulles, Va. The mission is scheduled to launch from Kwajalein Atoll in the Pacific Ocean on March 14.

Once the observatory is offloaded at Vandenberg, it will be moved into a processing hangar, joining the Pegasus XL rocket that is set to carry it to space. Over the weekend, technicians will remove its shipping container so that checkout and other processing activities can begin next week. Once the observatory is integrated with the rocket in mid-February, technicians will encapsulate it in the vehicle fairing, which is also scheduled to arrive at Vandenberg today.

After processing is completed, the rocket and spacecraft will be flown on Orbital's L-1011 carrier aircraft to the Ronald Reagan Ballistic Missile Defense Test Site at Kwajalein Atoll for launch in March.
http://www.nasa.gov/mission_pages/nustar/news/nustar20120127.html



http://www.nasa.gov/images/content/619282main_2012-01-27-2_full.jpg

http://www.nasa.gov/mission_pages/nustar/multimedia/gallery/2012-01-27-2.html
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Launch campaign begins for NASA's black hole hunter
ЦитироватьAfter a cross-country road trip from Orbital Sciences Corp. in Virginia last week, technicians have unpacked NASA's NuSTAR X-ray telescope at Vandenberg Air Force Base in California and begun methodically checking the craft for the final time before its launch date in mid-March.

The Nuclear Spectroscopic Telescope Array, or NuSTAR, is the space agency's next astrophysics probe. NuSTAR is a black hole hunter, and its innovative X-ray optics will explore the universe at unmatched sensitivities at high-energy wavelengths.

"We have a lot of exciting observations planned for the first six months," said Fiona Harrison, NuSTAR's principal investigator from the California Institute of Technology. "Everybody's getting really psyched."

NuSTAR will be mated to a 25-ton Pegasus XL launch vehicle around Feb. 17, if all goes according to plan, and the 800-pound spacecraft will be enshrouded inside the rocket's nose cone in the last week of February, according to Yunjin Kim, NuSTAR's project manager at the Jet Propulsion Laboratory in Pasadena, Calif.

Technicians will tow the 55-foot-long booster underneath an Orbital Sciences L-1011 carrier airplane March 4, and the jumbo jet will haul the Pegasus launcher and NuSTAR from Vandenberg to Kwajalein Atoll in the Marshall Islands two days later, based on the current schedule.

The three-stage, winged Pegasus will be dropped from the L-1011 mothership in the predawn hours of March 15, Kwajalein time, and fired into an equatorial low-inclination orbit more than 340 miles high. The launch is timed for approximately 10:30 a.m. EST (1430 GMT) on March 14, but engineers will select the final launch window in the coming weeks.

One week later, the NuSTAR satellite will extend a 33-foot mast with the telescope's precision coated mirrors. NuSTAR's two X-ray detector units are housed inside the craft's main body.

The deployable boom, coupled with new multilayer mirror coatings, allows NuSTAR to bring the high-energy X-ray universe into focus.

"Most X-ray telescopes have long focal lengths, or distances, between their optics and the detectors," Harrison said. "The reason for that is that it's only really possible to reflect X-rays at very glancing angles off of optics, and that requires that you have the detector far away."

The observatory will see the sky in wavelengths between 6,000 and 80,000 electron volts, about the same energies as a dental X-ray. NuSTAR will be the first focusing telescope to observe X-rays at such wavelengths, according to Daniel Stern, the mission's project scientist at JPL.

The European Space Agency's INTEGRAL space telescope observes in a similar range of energies, but NuSTAR is several hundred times more sensitive due to its focusing ability.

"At the resolution of INTEGRAL, you see maybe a half-dozen sources near the galactic center," Stern said. "NuSTAR's focusing X-ray optics buys us a large gain in how tight the resolution is. It will let us see several hundred sources in a similar exposure time, and the science you get from that is just immense."

Harrison said one of NuSTAR's first research targets will be Sagittarius A*, the supermassive black hole at the center of the Milky Way galaxy. Together with other observatories, such as NASA's Chandra telescope, NuSTAR will help explain the cause of occasional X-ray jets emanating from the black hole, which could be signs of planets being swallowed by the object's extreme gravity.

"You can start studying variability and what is going on with the black hole at the center of our galaxy," Stern said. "You can study the nearby populations of neutron stars, black holes, pulsars, and highly-magnetized neutron stars called magnetars. There is very broad science that will come out of that dataset."

NuSTAR will also study other nearby black holes and survey the universe for other supernova remnants.

"There are two objectives," Harrison said. "One is finding new black holes and trying to understand their distribution, their distances and their global properties. And the other is studying black holes that we know and trying to understand what they look like in detail."

According to Harrison, NuSTAR could discover hundreds of new black holes hidden from the views of existing telescopes.

It will also try to find the heat source of the solar corona, the sun's scalding million-degree atmosphere.

NASA has approved the $165 million mission for at least two years of observations, but scientists expect the spacecraft could continue returning science for up to seven years.
http://www.spaceflightnow.com/pegasus/nustar/120201update/
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Spacecraft Testing

In a clean room at Vandenberg Air Force Base's processing facility in California, NASA's NuSTAR spacecraft undergoes a limited performance test, a two-day functional checkout of the spacecraft.

Image credit: NASA/Randy Beaudoin, VAFB
Feb. 1, 2012

http://www.nasa.gov/mission_pages/nustar/multimedia/gallery/2012-02-01.html
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Guest Post: Jason Davis: NuSTAR telescope to get close look at black holes, supernovae
ЦитироватьAt the center of the Milky Way, a monster awaits. Known as Sagittarius A, this turbulent region of space is believed to contain a black hole four million times more massive than our own sun. Within the black hole -- known as Sagittarius A* (pronounced "A-star") -- space and time lose their conventional meanings, as surrounding matter is pulled to inescapable oblivion. A new NASA spacecraft called NuSTAR will study this singularity, along with its brethren in and outside of our galaxy, in unprecedented detail.

NuSTAR, the Nuclear Spectroscopic Telescope Array, is the most sensitive X-ray telescope ever developed, improving on the pioneering work of similar spacecraft like the Chandra X-ray Observatory. In addition to surveying a variety of black holes and supernovae, it will also peer into the heart of extreme active galaxies like M87, where streams of energized plasma spew thousands of light years into space from supermassive black holes.

NuSTAR will accomplish its objectives by analyzing the X-rays emanating from its astronomical targets. X-rays are short wavelength, high-energy forms of electromagnetic radiation that cannot be seen by human eyes. Consider a standard tungsten filament light bulb, glowing at a temperature of around 3000 degrees Kelvin. We only see the portion of the bulb's light that has a wavelength between 400 to 700 nanometers. In reality, that's only about a tenth of the bulb's total energy output; most is in the infrared, which has a longer wavelength than visible light.



For comparison, the core of a supernova has a temperature of about a billion degrees Kelvin. Again, some of the energy is emitted in the visible range, which is why we can see supernovae in other galaxies. Some of the exploding star's energy also blasts out in X-ray form, in very short wavelengths about the size of an atom. Being able to "see" these X-rays with a telescope can tell us a great deal about the most exotic processes in our universe.

So, how does an X-ray telescope work? For starters, it needs to be positioned above the Earth's atmosphere, which acts as a natural X-ray filter. It also requires a drastically different design from an optical telescope. Standard reflecting telescopes use large, curved mirrors nearly perpendicular to incoming light rays, which focus the light in one spot, called the focal point. Such mirrors are said to have a high incidence angle in reference to the incoming light rays. X-rays, however, do not reflect like visible light; they get absorbed by mirrors or pass through them. An X-ray telescope, therefore, must coax the X-rays to their focal point by using shallow incidence angles. The tradeoff is a very long distance between the reflecting optics and the focal point. This is called the focal length, and in NuSTAR's case, it ends up being about 10 meters.

Complicating matters further are the materials required for an X-ray telescope's reflecting surfaces. Even with shallow incidence angles, heavy metals must be used to prevent the X-rays from being absorbed. The Chandra X-ray Observatory users iridium and gold for this task, but these materials can only reflect X-rays with energies up to 10 kiloelectronvolts; anything higher-energy won't bounce towards the focal point. NuSTAR uses multilayer coatings of alternating high and low density materials to increase that limit. This includes tungsten and platinum for the high density coatings, and silicon and carbon for the low densities. The result? NuSTAR can reflect and focus X-rays all the way up to 79 Kiloelectronvolts, resolving images in previously unseen levels of detail.



Despite the fact that NuSTAR offers significant technological advancements, it won't break the bank -- or the scales -- as it heads into orbit. The telescope is categorized as a NASA Small Explorer mission, part of a spacecraft heritage dating back to Explorer I, America's first satellite. Small Explorers must not cost the space agency more than $120 million. To accomplish this, NuSTAR uses a deployable mast to save on weight and space. Once in orbit, the mast will extend the optics package the necessary 10 meters from the X-ray detectors. This feature allows the spacecraft to fit into a payload fairing only two meters long and one meter in diameter.

NuSTAR's small payload fairing will be sent towards low-Earth orbit by an air-launched Pegasus XL rocket. Air-launching allows for a wider variety of orbits at cheaper prices, providing the payload is light and small enough to qualify. The carrier vehicle -- Orbital Science Corporation's Stargazer aircraft -- will take off from Kwajalein Atoll in the Pacific Ocean, fly to an altitude of 12 kilometers, and drop the Pegasus from its belly. After free-falling for a few seconds, the rocket will ignite the first of its three solid rocket stages, sending it to an eventual altitude of 550 kilometers.

Kwajalein Atoll sits at 8
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http://www.nasa.gov/mission_pages/nustar/news/nustar20120217.html
ЦитироватьMating of NASA's NuSTAR observatory to its Pegasus rocket is underway.[/size]
02.17.12


 
Artist's Concept of NuSTAR Artist's concept of NuSTAR on orbit. NuSTAR has a 10-m (30') mast that deploys after launch to separate the optics modules (right) from the detectors in the focal plane (left). Image credit: NASA/JPL-Caltech

NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) is being mated, or attached, to its Pegasus XL rocket today at Vandenberg Air Force Base in central California. The mission's launch is now scheduled for no earlier than March 21 to allow the launch vehicle team an additional week to complete necessary engineering reviews. After the reviews, the team will begin final preparations for the rocket's delivery to the launch site at Kwajalein Atoll in the South Pacific.

NuSTAR will probe the hottest, densest and most energetic objects in space, including black holes and the remnants of exploded stars. It will be the first space telescope to capture sharp images in high-energy X-rays, giving astronomers a new tool for understanding the extreme side of our universe.

NuSTAR is a Small Explorer mission led by the California Institute of Technology and managed by NASA's Jet Propulsion Laboratory, both in Pasadena, Calif., for NASA's Science Mission Directorate. The spacecraft was built by Orbital Sciences Corporation, Dulles, Va. Its instrument was built by a consortium including Caltech; JPL; Columbia University, New York; NASA's Goddard Space Flight Center in Greenbelt, Md.; the Danish Technical University in Denmark; the University of California, Berkeley; and ATK Aerospace Systems, Goleta, Calif. NuSTAR will be operated by UC Berkeley, with the Italian Space Agency providing its equatorial ground station located at Malindi, Kenya. The mission's outreach program is based at Sonoma State University, Calif. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

For more information, visit http://www.nasa.gov/nustar and http://www.nustar.caltech.edu/ [/size]
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http://www.spaceflightnow.com/pegasus/nustar/120218delay/
ЦитироватьOne-week launch delay ordered for X-ray telescope[/size]
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: February 18, 2012

The launch of NASA's NuSTAR space telescope, a $165 million black hole-hunting X-ray observatory, will be delayed one week until March 21 to give engineers extra time to complete engineering rovers of the mission's air-launched Pegasus XL rocket, the space agency announced Friday.


Artist's concept of the NuSTAR spacecraft in orbit. Credit: NASA/JPL-Caltech
 
"The mission's launch is now scheduled for no earlier than March 21 to allow the launch vehicle team an additional week to complete necessary engineering reviews," said a statement released by NASA's Jet Propulsion Laboratory. "After the reviews, the team will begin final preparations for the rocket's delivery to the launch site at Kwajalein Atoll in the South Pacific."

Technicians are preparing the Orbital Sciences Corp. Pegasus XL rocket and the NuSTAR spacecraft for launch at Vandenberg Air Force Base, Calif. The rocket and its carrier airplane, an L-1011 jumbo jet, will fly from California to Kwajalein about a week before launch.

NASA did not disclose details of the engineering reviews on the Pegasus XL launcher. Engineers were attaching the NuSTAR spacecraft to the Pegasus rocket Friday, according to JPL.

The air-launched satellite booster has flown 40 times, and next month's flight will mark the 25th mission of the Pegasus XL configuration, which features more powerful rocket motors than earlier versions.


File photo of a Pegasus launch. Credit: NASA TV/Spaceflight Now
 
The L-1011 airplane will take off from an airstrip at Kwajalein and drop the Pegasus rocket at an altitude of about 39,000 feet, then the winged launcher will ignite and climb to space.

The 51,000-pound booster, powered by three solid rocket stages, will deploy NuSTAR in an equatorial orbit more than 340 miles high. The nearly 800-pound satellite will unfurl a 33-foot boom with X-ray optics a week later and begin its science mission in late April, if launch occurs March 21.

NuSTAR stands for the Nuclear Spectroscopic Telescope Array.

The mission will explore the high-energy X-ray universe for two years, probing the supermassive black hole at the center of the Milky Way galaxy, surveying for collapsed dead stars, and studying the exchange of heat between the sun and its million-degree atmosphere. [/size]
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NuSTAR's Mirrors Baked in Zhang's Glass Kitchen
ЦитироватьIt pays to persevere. No one knows this better than Will Zhang.

For more than a decade, the astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md., experimented with a new technique for efficiently manufacturing super-thin, low-cost curved telescope mirror segments to collect and focus ever-elusive, high-energy X-ray photons.

The fruits of that labor -- a total of 9,000 individual mirror segments -- are now assembled into telescope optics and installed inside NASA's Nuclear Spectroscopic Telescope Array (NuSTAR), a small Explorer mission managed by the Jet Propulsion Laboratory in Pasadena, Calif. The agency plans to launch NuSTAR on March 21, 2012 from Kwajalein Atoll in the Marshall Islands aboard a Pegasus rocket attached to the underside of the L-1011 Stargazer aircraft.



NASA's latest X-ray space telescope, which will detect X-rays from objects ranging from our sun to monstrous black holes billions of light-years away, is unique in that it will be the first orbiting telescope to focus X-rays in the high-energy range, creating the most detailed images ever taken in this slice of the electromagnetic spectrum.

In comparison, NASA's Chandra X-ray Observatory senses less energetic "soft" X-rays, and therefore, cannot pierce the dust that frequently enshrouds black holes. Once deployed, NuSTAR will complement measurements gathered by Chandra and give scientists a more complete picture of the X-ray universe.

One of NuSTAR's Enabling Technologies

Zhang's mirror segments are one of the advanced technologies that contributed to NuSTAR's development. The mirrors, combined with specialized coatings developed and applied by the Danish Technical University in Copenhagen and a mounting technique developed by Columbia University in New York City, enabled NuSTAR's optics.

The challenge for the observatory's developers was developing an optics system small enough to be housed in a small spacecraft yet provide unprecedented sensitivity and resolution. Measuring only 200 microns thick or 100 times thinner than Chandra's much heavier mirrors, Zhang's mirror segments, coupled with the other technologies, fit the bill.

"It sometimes takes a decade to bring an idea to the point where you have something to show," Zhang said, reflecting on the 14-year effort that started in 1998 when he first conceived a new way to manufacture lightweight, higher-resolution mirrors ideal for small missions, like NuSTAR. "We were fortunate. NASA provided my team with research and development funding, which helped us to advance the technology."

X-ray mirrors must be curved and nested inside an optical assembly so that the highly energetic X-ray photons graze their surface, instead of passing through them — much like a stone skimming the surface of a pond. To make these curved segments, Zhang used flat sheets of smooth, commercially available lightweight glass similar to those used in laptop screens.

The flat sheets of glass, which are about the thickness of three sheets of paper, were placed atop a mandrel or rounded mold that provided the appropriate geometry for mounting in NuSTAR's optic unit. Technicians then placed the mandrel inside an oven that heated the glass to about 1,100 degrees Fahrenheit. As the glass heated, it softened and folded over the mandrel to produce a curved mirror that was the accurate copy of the mandrel's surface.

"Zhang's technique for forming the thin glass improved the efficiency of producing high-quality segments significantly over what had been done by others, enabling the NuSTAR optics to be built during NuSTAR's rapid development period," said Fiona Harrison, the mission's principal investigator at the California Institute of Technology in Pasadena, Calif.

Ten Ovens Inside Zhang's Kitchen

At the height of production, Zhang's laboratory included 10 large ovens that produced the 9,000 individual segments. The secret in Zhang's "glass kitchen" was a release layer that prevented the glass from sticking. "This proprietary preparation technique preserved the mirror's surface quality, allowing a nearly 100-percent yield," Zhang said.

The team shipped the baked glass segments to the Danish Technical University where university scientists used a specialized vacuum deposition chamber to apply several hundred alternating layers of either silicon and tungsten, or platinum and carbon, to maximize X-ray reflectance. These thin layers each measured just a few atoms thick.

The Danish Technical University sent the coated mirrors to Columbia University, which used a novel machining and assembly process that it developed to align and assemble the 9,000 mirrors into concentric shells to form an optical assembly that, as an integrated unit, can focus X-rays. The completed optics were then integrated with a folded mast built by ATK-Goleta in Goleta, Calif. Stowed inside the NuSTAR spacecraft, the mast will unfold to a length of 33 feet (10 meters) a week after the spacecraft reaches its orbit to begin the two-year observing mission.

Together, these advances in technology will enable NuSTAR to explore the cosmic world of high-energy X-rays with much improved sensitivity and resolution over previous missions. Outside our galaxy, it will see some of the most powerful black holes and cosmic events known. Data from the mission will provide a better understanding of the extreme physics behind jets that travel nearly at the speed of light, exploding stars and more.

Closer to home, NuSTAR will probe the sun, looking for microflares on the surface that could explain how its million-degree solar corona, or atmosphere, is heated. It will even test a theory of dark matter, the mysterious substance making up about one-quarter of our universe, by searching the sun for evidence of a hypothesized dark matter particle.

"This is a revolutionary mission," Zhang said. "We're so glad we were able to advance our technology to the point where it was ready for NuSTAR. Precision slumping of thin glass sheets has shown to be an excellent way of making lightweight, higher-resolution x-ray optics, as evidenced by the delivery of our mirrors."

For more information about the NuSTAR mission, visit: http://www.nasa.gov/nustar

For more information about Goddard technology, visit: http://gsfctechnology.gsfc.nasa.gov
http://www.nasa.gov/topics/technology/features/mirror-bake.html
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