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Post by swamprat on Jan 12, 2013 22:33:10 GMT -6
NASA's Next Flagship Space Telescope Back on Track ... and on Budgetby Miriam Kramer, SPACE.com Staff Writer Date: 11 January 2013
LONG BEACH, Calif. — NASA's James Webb Space Telescope — the notoriously over-budget new space observatory slated to launch in 2018 — is on time and still within its new budget, the project's chief said Wednesday (Jan. 9).
“Our budget still stands and the schedule remains the same,” Eric Smith, the space telescope's program director, told astronomers here at a town hall meeting during the 221st meeting of the American Astronomical Society.
Smith also outlined the future of the James Webb Space Telescope program in 2013 and discussed its turbulent year in 2012.
With an $8.8 billion dollar price tag, JWST is destined to be one of the largest and most expensive projects in NASA history. Set to replace the venerable Hubble Space Telescope once it is launched, JWST will take infrared images of distant galaxies, probing the cosmos for hints and signals left behind from the Big Bang.
Of the four science instruments responsible for investigating those mysteries aboard the spacecraft, two were delivered to NASA in 2012. The Mid-Infrared Instrument (MIRI) — the instrument responsible for taking “Hubble-like” images of distant galaxies, comets and other heavenly bodies — was sent last year by the European consortium that built it.
The Canadian Space Agency has also delivered its instrument: the Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph (FGS/NIRISS) that will also take high-quality images of other bodies in space.
NASA is still awaiting two more contributions: the Near-Infrared Camera (NIRCam) from Lockheed Martin and the University of Arizona, and the Near-Infrared Spectrograph (NIRSpec) from the European Space Agency, which is still in its early testing phases. Both instruments measure light on the infrared spectrum. All of the science instruments are set to be integrated by the end of 2013, officials say.
The telescope's tennis court-size sunshield is in the early stages of testing as well. The sunshield itself is too large to launch in an unfurled state, creating a unique problem for JWST scientists to solve. Instead of launching the telescope with the sunshield in place, NASA is planning to unroll the shield once the craft is in orbit. At one-third of the way complete, NASA scientists are now starting to practice rolling and unrolling the shield to see how it might unfurl in space after launch.
Once all four instruments are finished, researchers will combine them to test JWST as one cohesive unit. While final testing on the ground should begin in 2015, simulation testing using Optimal Trajectories by Implicit Simulation — a space telescope tester that mimics the temperature and environment of a space telescope in Earth’s orbit — won’t start until 2017, a year before launch.
JWST is also going to investigate a few objects a little closer to home.
Mike Brown, an astronomer from Caltech, detailed a few of the more promising applications for JWST within the solar system. Planetary scientists have been interested in understanding what composes comets, protoplanets and other mysterious space objects.
JWST’s sensitive instruments should be able to deliver some information as to what elements created rocky and icy objects in the outer solar system, Brown said at the town hall meeting.
NASA officials, meanwhile, are hopeful that the JWST's predecessor — the iconic Hubble Space Telescope — will still be functioning by the time the new observatory launches. This week, agency officials said the 23-year-old Hubble telescope could potentially last through 2018, allowing for some overlap with the JWST mission that would be a boon for astronomers.
www.space.com/19235-james-webb-telescope-on-track.html
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Post by swamprat on Mar 19, 2013 13:12:26 GMT -6
NASA's Webb Telescope Gets Its WingsMar. 18, 2013 — A massive backplane that will hold the primary mirror of NASA's James Webb Space Telescope nearly motionless while it peers into space is another step closer to completion with the recent assembly of the support structure's wings.
The wings enable the mirror, made of 18 pieces of beryllium, to fold up and fit inside a 16.4-foot (5-meter) fairing on a rocket, and then unfold to 21 feet in diameter after the telescope is delivered to space. All that is left to build is the support fixture that will house an integrated science instrument module, and technicians will connect the wings and the backplane's center section to the rest of the observatory. The center section was completed in April 2012. "This is another milestone that helps move Webb closer to its launch date in 2018," said Geoff Yoder, NASA's James Webb Space Telescope program director, NASA Headquarters, Washington.
Designed, built and set to be tested by ATK at its facilities in Magna, Utah, the wing assemblies are extremely complex, with 900 separate parts made of lightweight graphite composite materials using advanced fabrication techniques. ATK assembled the wing assemblies like a puzzle with absolute precision. ATK and teammate Northrop Grumman of Redondo Beach, Calif., completed the fabrication.
"We will measure the accuracy down to nanometers -- it will be an incredible engineering and manufacturing challenge," said Bob Hellekson, ATK's Webb Telescope program manager. "With all the new technologies that have been developed during this program, the Webb telescope has helped advance a whole new generation of highly skilled ATK engineers, scientists and craftsmen while helping the team create a revolutionary telescope."
When fully assembled, the primary mirror backplane support structure will measure about 24 feet by 21 feet and weigh more than 2,000 pounds. The backplane must be very stable, both structurally and thermally, so it does not introduce changes in the primary mirror shape, and holds the instruments in a precise position with respect to the telescope. While the telescope is operating at a range of extremely cold temperatures, from minus 406 to minus 360 degrees Fahrenheit, the backplane must not vary more than 38 nanometers (about one one-thousandth the diameter of a human hair). The thermal stability requirements for the backplane are unprecedented.
The James Webb Space Telescope is the successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built and observe the most distant objects in the universe, provide images of the first galaxies formed and see unexplored planets around distant stars. The Webb telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.
www.sciencedaily.com/releases/2013/03/130318103848.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fmatter_energy+%28ScienceDaily%3A+Matter+%26+Energy+News%29
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Post by auntym on Apr 29, 2013 21:46:59 GMT -6
hubblesci.com/james-webb-space-observatory-poised-to-detect-extraterrestrial-life/James Webb Space Telescope –Will Exponentially Enhance Detection of Extraterrestrial LifePosted on April 29, 2013 The James Webb Space Telescope (JWST), set to be launched by NASA in 2018, will be capable of detecting oxygen and water in the atmosphere of an Earth-like planet orbiting a white dwarf after only a few hours of observation time—much more easily than for an Earth-like planet orbiting a sun-like star. Dan Maoz of Tel Aviv University and Avi Loeb, Director of Harvard University’s Institute for Theory and Computation and a Sackler Professor by Special Appointment at TAU, have shown that, using advanced technology to become available within the next decade, it should be possible to detect biomarkers surrounding these planets—including oxygen and methane—that indicate the presence of life. They estimate that a survey of 500 of the closest white dwarfs could spot one or more habitable planets. Evidence of heavy elements already observed on the surface of white dwarf stars suggest rocky planets orbit a significant fraction of them. “In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs,†said Prof. Loeb. Prof. Maoz agrees, noting that if “all the conditions are right, we’ll be able to detect signs of life†on planets orbiting white dwarf stars using the much-anticipated JWST. The unique characteristics of white dwarfs could make these planets easier to spot than planets orbiting normal stars, the researchers have shown. Their atmospheres can be detected and analyzed when a star dims as an orbiting planet crosses in front of it. As the background starlight shines through the planet’s atmosphere, elements in the atmosphere will absorb some of the starlight, leaving chemical clues of their presence—clues that can then be detected from the JWST. Journal reference: Monthly Notices of the Royal Astronomical Society MORE: hubblesci.com/james-webb-space-observatory-poised-to-detect-extraterrestrial-life/
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Post by swamprat on Feb 5, 2014 9:32:13 GMT -6
NASA's Next Great Space Telescope Passes Major MilestoneBy Tanya Lewis, Staff Writer | February 04, 2014
GREENBELT, Md. — The James Webb Space Telescope, NASA's next flagship space observatory, has passed a major milestone on its road to its planned 2018 launch: the delivery of the last three mirrors that will make up its complicated infrared-seeking innards.
The mirror delivery for the $8.8 billion James Webb Space Telescope lays a critical brick in the road toward deploying the most powerful space telescope ever built. When complete, the telescope is expected to have seven times the light-collecting power of its predecessor, the Hubble Space Telescope, and should provide answers to questions about the early universe and the chances of life on other planets.
www.livescience.com/43108-james-webb-space-telescope-nasa-milestone.html
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Post by skywalker on Feb 7, 2014 22:38:56 GMT -6
8.8 billion? How do they plan on launching this thing? We don't have space shuttles anymore and our rocket launches haven't had a very good track record lately. It would be a shame if NASA launched an 8.8 billion dollar telescope into the middle of the Atlantic.
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Post by swamprat on Apr 28, 2014 8:37:26 GMT -6
Update:James Webb Space Telescope's Near Infrared Spectrograph Installed In March 2014, the James Webb Space Telescope's flight Near Infrared Spectrograph (NIRSpec) was installed into the instrument module. NIRSpec joins the flight Near Infrared Camera (NIRCam) Fine Guidance Sensor/ Near Infrared Imager and Slitless Spectrograph (FGS/NIRISS) and Mid-Infrared Instrument (MIRI) which are already integrated into the ISIM, making the instrument module complete.
The James Webb is a large space telescope, optimized for infrared wavelengths. It is scheduled for launch later in this decade. Webb will find the first galaxies that formed in the early universe, connecting the Big Bang to our own Milky Way galaxy. Webb will peer through dusty clouds to see stars forming planetary systems, connecting the Milky Way to our own solar system. Webb's instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range.
Webb will have a large mirror, 6.5 meters (21.3 feet) in diameter, and a sunshield the size of a tennis court. The mirror and sunshade won't fit into a rocket fully open, so both will be folded and open once Webb is in outer space. Webb will reside in an orbit about 1.5 million km (1 million miles) from Earth at the second Lagrange point.
www.nasa.gov/mission_pages/webb/main/index.html
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Post by swamprat on Nov 25, 2015 11:55:50 GMT -6
Webb Space Telescope Receives First Mirror Installation Nov. 25, 2015
An engineer at NASA's Goddard Space Flight Center worked to install the first flight mirror onto the telescope structure at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Credits: NASA/Chris Gunn
NASA has successfully installed the first of 18 flight mirrors onto the James Webb Space Telescope, beginning a critical piece of the observatory’s construction.
In the clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland this week, the engineering team used a robot arm to lift and lower the hexagonal-shaped segment that measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The full installation is expected to be complete early next year.
The James Webb Space Telescope team successfully installed the first flight mirror onto the telescope structure at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Credits: NASA/Chris Gunn
“The James Webb Space Telescope will be the premier astronomical observatory of the next decade,” said John Grunsfeld, astronaut and associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. “This first-mirror installation milestone symbolizes all the new and specialized technology that was developed to enable the observatory to study the first stars and galaxies, examine the formation stellar systems and planetary formation, provide answers to the evolution of our own solar system, and make the next big steps in the search for life beyond Earth on exoplanets.”
Several innovative technologies have been developed for the Webb Telescope, which is targeted for launch in 2018, and is the successor to NASA's Hubble Space Telescope. Webb will study every phase in the history of our universe, including the cosmos’ first luminous glows, the formation of solar systems capable of supporting life on planets like Earth, and the evolution of our own solar system.
The 18 separate segments unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium chosen for its thermal and mechanical properties at cryogenic temperatures. Each segment also has a thin gold coating chosen for its ability to reflect infrared light. The telescope’s biggest feature is a tennis court sized five-layer sunshield that attenuates heat from the sun more than a million times.
“After a tremendous amount of work by an incredibly dedicated team across the country, it is very exciting to start the primary mirror segment installation process" said Lee Feinberg, James Webb Space Telescope optical telescope element manager at Goddard. "This starts the final assembly phase of the telescope."
The mirrors must remain precisely aligned in space in order for Webb to successfully carry out science investigations. While operating at extraordinarily cold temperatures between minus 406 and minus 343 degrees Fahrenheit, the backplane must not move more than 38 nanometers, approximately one thousandth the diameter of a human hair.
"There have many significant achievements for Webb over the past year, but the installation of the first flight mirror is special," said Bill Ochs, James Webb Space Telescope project manager. "This installation not only represents another step towards the magnificent discoveries to come from Webb, but also the culmination of many years of effort by an outstanding dedicated team of engineers and scientists."
The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system.
The James Webb Space Telescope is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency. NASA works with the international science community to explore our solar system and beyond. We look to unravel mysteries that intrigue us all as we explore to answer big questions, like how did our solar system originate and change over time, and how did the universe begin and evolve, and what will be its destiny?
You can follow the mirror installation on a live webcam by visiting: www.jwst.nasa.gov/webcam.html
To learn more about the James Webb Space Telescope, visit: www.nasa.gov/webb
www.nasa.gov/press-release/nasa-s-webb-space-telescope-receives-first-mirror-installation
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Post by swamprat on Jan 8, 2016 10:56:11 GMT -6
I can't wait until this "Looking Glass" is airborne! By the dozen: NASA's James Webb Space Telescope mirrors Date: January 7, 2016
Source: NASA/Goddard Space Flight Center
Summary: One dozen flight mirrors are now installed on NASA's James Webb Space Telescope, out of the eighteen mirror segments that make up the primary mirror. The assembly of the primary mirror is an important milestone for the Webb telescope, but is just one component of this huge and complex observatory.
One dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credit: Credits: NASA/Chris Gunn
One dozen flight mirrors are now installed on NASA's James Webb Space Telescope, out of the eighteen mirror segments that make up the primary mirror. The assembly of the primary mirror is an important milestone for the Webb telescope, but is just one component of this huge and complex observatory.
Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016.
"This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation," said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. "The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently."
Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months.
The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope.
While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb -- cameras and spectrographs with detectors able to record extremely faint signals -- are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year.
The Near InfraRed Spectrograph (NIRSpec) has programmable microshutters which enable observation up to 100 objects simultaneously. The Near Infrared Camera (NIRCam) is equipped with coronagraphs, instruments that allow astronomers to take pictures of very faint objects around a central bright object, like stellar systems.
The Webb telescope also has a cryocooler for cooling the Mid-Infrared Instrument (MIRI) to a very cold 7 Kelvin so they can work. MIRI has both a camera and a spectrograph that sees light in the mid-infrared region of the electromagnetic spectrum, with wavelengths that are longer than our eyes see. There's also the Fine Guidance Sensor (FGS) allows Webb to point precisely, so that it can obtain high-quality images.
Over the next two years in preparation for launch, various components of the Webb telescope will endure rigorous environmental and optical testing. The sunshield will be joined with the spacecraft bus (main structure) followed by more testing. The Webb telescope is planned for launch in 2018.
The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, the European Space Agency and the Canadian Space Agency.
For more information about NASA's Webb telescope and all of its components, visit: www.nasa.gov/webb or jwst.nasa.gov
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Post by swamprat on May 2, 2017 10:34:10 GMT -6
World's Largest Space Telescope Graduates Goddard Testing, Heads to TexasBy Sarah Lewin, Staff Writer May 2, 2017
The James Webb Space Telescope is on the road again. After passing its final test at NASA's Goddard Space Flight Center in Greenbelt, Maryland, the megatelescope is ready for the next stop on its trip to space: further testing at Johnson Space Center in Houston.
The final mirrors for the giant space observatory arrived at Goddard in 2014, and the telescope's construction was finally completed in November 2016, after more than 20 years of construction. Since then, the instrument has endured a battery of testing to ensure that it can withstand the rigors of launch and deep space. Webb is slated to launch in 2018, when it will become the world's largest telescope to fly to space. NASA highlighted some of Webb's testing in a new video:
www.space.com/36686-james-webb-space-telescopes-testing-at-nasa-goddard-highlighted-video.html
The final test at Goddard checked the curvature of the telescope's mirrors to see whether they had become warped during the year of intensive testing. To test this, engineers precisely measured the interference patterns of lasers reflected off of the mirrors, and then compared the measurements to those taken before environmental testing began last year, NASA officials said in a statement. The telescope's mirrors came out unchanged by the many stresses of simulated spaceflight.
"The Webb telescope is about to embark on its next step in reaching the stars as it has successfully completed its integration and testing at Goddard," Bill Ochs, NASA's Webb telescope project manager, said in a statement. "It has taken a tremendous team of talented individuals to get to this point from all across NASA, our industry, and international partners and academia.
"It is also a sad time, as we say goodbye to the Webb telescope at Goddard, but [we] are excited to begin cryogenic testing at Johnson," he added.
Once it arrives at Johnson, the telescope will be put to the ultimate test: The entire scope's optics will be tested in a vacuum in the space center's massive Chamber A and cooled to 11 degrees above absolute zero (minus 440 degrees Fahrenheit, or minus 262 degrees Celsius). Afterward, the telescope will continue on to Northrop Grumman Aerospace Systems in Redondo Beach, California, for its final testing and assembly. It will then go to French Guiana for launch.
Webb will probe the cosmos from a spot in space called Lagrange Point 2, located directly behind Earth from the sun's perspective, where the telescope can use one shield to protect itself from both the sun's and Earth's thermal emissions. From there, Webb will gather infrared views of the universe's first galaxies and of planets around distant stars; the use of infrared light will allow Webb to peer through interstellar dust for a better view.
NASA has positioned Webb as the Hubble Space Telescope's successor; the new instrument has seven times the collecting area of the famed Hubble instrument, and is chilled cold enough to collect infrared light that Hubble cannot. That will allow Webb to see even farther into space's outer reaches.
www.space.com/36684-james-webb-telescope-graduates-goddard-testing.html
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Post by swamprat on May 13, 2017 10:10:31 GMT -6
Two James Webb instruments are best suited for exoplanet atmospheresDate: May 9, 2017 Source: Penn State
The best way to study the atmospheres of distant worlds with the James Webb Space Telescope, scheduled to launch in late 2018, will combine two of its infrared instruments, according to a team of astronomers.
"We wanted to know which combination of observing modes (of Webb) gets you the maximum information content for the minimum cost," says Natasha Batalha, graduate student in astronomy and astrophysics and astrobiology, Penn State, and lead scientist on this project.
"Information content is the total amount of information we can get from a planet's atmospheric spectrum, from temperature and composition of the gas -- like water and carbon dioxide -- to atmospheric pressures."
Batalha and Michael Line, assistant professor, School of Earth and Space Science, Arizona State University, developed a mathematical model to predict the quantity of information that different Webb instruments could extract about an exoplanet's atmosphere.
Their model predicts that using a combination of two infrared instruments -- the Near Infrared Imager and Slitless Spectrograph (NIRISS) and the G395 mode on the Near Infrared Spectrograph (NIRSpec) -- will provide the highest information content about an exoplanet's atmosphere.
NIRISS is a versatile camera and spectrograph that will observe infrared wavelengths similar to those the Hubble Telescope covers. NIRISS, according to Batalha and Line, should be combined with the G395 mode on NIRSpec, which will observe targets in longer infrared wavelengths at Webb's highest resolution.
Three main characteristics affect how much information an instrument can extract -- resolution, maximum observable brightness, and wavelength range. These combined determine the total observable fraction of the information content of a planet's atmospheric spectrum.
Both NIRISS and NIRSpec will observe near-infrared wavelengths, the region of the electromagnetic spectrum in which the stars that exoplanets orbit around shine brightest. NIRISS is poised to measure a strong signature of water and NIRSpec can do the same for methane and carbon dioxide, three chemical compounds that provide a substantial amount of information about an atmosphere.
Batalha and Line tested each of ten likely observing methods on its own and in every possible combination with the other methods to determine which would maximize the total information content.
They retrieved the information from a set of simulated planets with temperatures and compositions that cover the range of previously observed exoplanet atmospheres. By comparing the retrievable information content in each planet's atmosphere, Batalha and Line found that this one combination of NIRISS and NIRSpec modes gives the most information regardless of the exoplanet's temperature or composition. The researchers published these results in The Astronomical Journal.
"We won't know a planet's temperature ahead of time," says Batalha. "If you're going to do a shot in the dark observation, you have the greatest chance of getting the information you want with this combination of instruments."
As an exoplanet crosses between its host star and Earth's telescopes, some of the star's light passes through the exoplanet's atmosphere. The exo-atmosphere leaves its fingerprint in the star's light -- the planet's transmission spectrum -- from which astronomers can learn about the exo-atmosphere's temperature, chemical composition and structure. The researchers' information content analysis focuses on the information retrievable from the transmission spectrum of a planet.
While Webb will not launch until late 2018, but astronomers are already planning the first set of observations they would like from the telescope.
"If we can strategize now," says Batalha, "by the time the first cycle of formal proposals comes around we can ensure that we are picking the best modes for larger proposals and not waste valuable observing time. This way everyone starts on an even playing field with the science."
While they highlight two NIRISS and NIRSpec modes as the best combination for observing most exo-atmospheres, Batalha and Line explain that the other modes will still be useful to observe different features of exo-atmospheres that the astronomers have not tested for, like clouds, haze and atmospheres hot enough to emit their own light.
"In the future," Batalha says, "there will be a push to characterize the first Earth 2.0. If we don't nail this down now and master the art of characterizing exo-atmospheres, we will never accurately characterize Earth 2.0." ________________________________________ Story Source: Materials provided by Penn State.
www.sciencedaily.com/releases/2017/05/170509145211.htm
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Post by swamprat on Oct 28, 2017 7:54:47 GMT -6
James Webb Space Telescope's laser-focused sightDate: October 26, 2017 Source: NASA/Goddard Space Flight Center
Summary: About 1 million miles away from the nearest eye surgeon, NASA's James Webb Space Telescope will be able to perfect its own vision while in orbit.
Though the Webb telescope will focus on stars and galaxies approximately 13.5 billion light-years away, its sight goes through a similar process as you would if you underwent laser vision correction surgery to be able to focus on an object 10 feet across the room. In orbit at Earth's second Lagrange point (L2), far from the help of a terrestrial doctor, Webb will use its near-infrared camera (NIRCam) instrument to help align its primary mirror segments about 40 days after launch, once they have unfolded from their unaligned stowed position and cooled to their operating temperatures.
Laser vision correction surgery reshapes the cornea of the eye to remove imperfections that cause vision problems like nearsightedness. The cornea is the surface of the eye; it helps focus rays of light on the retina at the back of the eye, and though it appears to be uniform and smooth, it can be misshapen and pockmarked with dents, dimples, and other imperfections that can affect a person's sight. The relative positioning of Webb's primary mirror segments after launch will be the equivalent of these corneal imperfections, and engineers on Earth will need to make corrections to the mirrors' positions to bring them into alignment, ensuring they will produce sharp, focused images.
These corrections are made through a process called wavefront sensing and control, which aligns the mirrors to within tens of nanometers. During this process, a wavefront sensor (NIRCam in this case) measures any imperfections in the alignment of the mirror segments that prevent them from acting like a single, 6.5-meter (21.3-foot) mirror. An eye surgeon performing wavefront-guided laser vision correction surgery (a process that was improved by technology developed to shape Webb's mirrors) similarly measures and three-dimensionally maps any inconsistencies in the cornea. The system feeds this data to a laser, the surgeon customizes the procedure for the individual, and the laser then reshapes and resurfaces the cornea according to that procedure.
Engineers on Earth will not use a laser to melt and reshape Webb's mirrors (feel free to give a sigh of relief); instead, they will use NIRCam to take images to determine how much they need to adjust each of the telescope's 18 primary mirror segments. They can adjust the mirror segments through extremely minute movements of each segment's seven actuators (tiny mechanical motors) -- in steps of about 1/10,000th the diameter of a human hair.
The wavefront sensing and control process is broken into two parts -- coarse phasing and fine phasing.
During coarse phasing, engineers point the telescope toward a bright star and use NIRCam to find any large offsets between the mirror segments (though "large" is relative, and in this case it means mere millimeters). NIRCam has a special filter wheel that can select, or filter, specific optical elements that are used during the coarse phasing process. While Webb looks at the bright star, grisms in the filter wheel will spread the white light of the star out on a detector. Grisms, also called grating prisms, are used to separate light of different wavelengths. To an observer, these different wavelengths appear as parallel line segments on a detector.
"The light from each segment will interfere with adjacent segments, and if the segments are not aligned to better than a wavelength of light, that interference shows up like barber pole patterns," explained Lee Feinberg, optical telescope element manager for the Webb telescope at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "The analysis of the barber pole patterns tell the engineers how to move the mirrors."
During fine phasing, engineers will again focus the telescope on a bright star. This time, they will use NIRCam to take 18 out-of-focus images of that star -- one from each mirror segment. The engineers then use computer algorithms to determine the overall shape of the primary mirror from those individual images, and to determine how they must move the mirrors to align them. These algorithms were previously tested and verified on a 1/6th scale model of Webb's optics, and the real telescope experienced this process inside the cryogenic, airless environment of Chamber A at NASA's Johnson Space Center in Houston. Engineers will go through multiple fine-phasing sessions until those 18 separate, out-of-focus images become a single, clear image.
After the engineers align the primary mirror segments, they must align the secondary mirror to the primary, then align both the primary and secondary mirrors to the tertiary mirror and the science instruments. Though the engineers complete the initial alignment with NIRCam, Feinberg explained they also test the alignment with Webb's other instruments to ensure the telescope is aligned "over the full field."
The entire alignment process is expected to take several months, and once Webb begins making observations, its mirrors will need to be checked every few days to ensure they are still aligned -- just as someone who underwent laser vision correction surgery will schedule regular eye doctor visits to make sure their vision is not degrading. ________________________________________ Story Source: Materials provided by NASA/Goddard Space Flight Center. Note: Content may be edited for style and length.
www.sciencedaily.com/releases/2017/10/171026135248.htm
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Post by swamprat on Nov 27, 2017 10:45:55 GMT -6
James Webb Telescope Emerges From 90 Days Under Lock and FreezeBy Harrison Tasoff, Space.com Staff Writer November 24, 2017
The James Webb Space Telescope sits in NASA's immense Chamber A at Johnson Space Center after completing its final series of tests in the frigid, airless room. Credit: Chris Gunn/NASA
The James Webb Space Telescope has just emerged into the light after more than 90 days sealed in NASA's giant cryogenic vacuum chamber. The test is crucial to ensuring the next-generation telescope is space-ready before its launch, which is currently scheduled for mid-2019.
James Webb is often touted as Hubble's cosmic successor. The two telescopes have similar mission profiles and overlap in the wavelengths of light they detect. But Webb's main mirror is more than six times the size of Hubble's. It's so large, that engineers had to constructed it out of 18 individual segments, which will unfold and align once it reaches its destination.
The mirror alignment was one of the systems that NASA tested inside Chamber A, the cavernous cryogenic vacuum chamber at Johnson Space Center in Houston. The team placed Webb's optical telescope and integrated science instrument module (OTIS) through many tests in the chamber, according to a statement the agency released on Monday (Nov. 20). Engineers monitored the telescope during testing with thermal sensors and specialized cameras.
www.space.com/38880-james-webb-emerges-90-day-freeze.html
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Post by swamprat on Mar 27, 2018 11:21:50 GMT -6
Rats! NASA Delays Launch of James Webb Space Telescope Until 2020By Sarah Lewin, Space.com Associate Editor March 27, 2018
NASA has delayed the launch of its next great space observatory, the James Webb Space Telescope, until no earlier than May 2020 — nearly a year later than planned — due to the need for more testing of the telescope's intricate systems, the space agency announced today (March 27).
The launch delay is not the only disappointing news for the space telescope. Its $8.8 billion price tag could rise, too, NASA officials told reporters today.
"All the observatory's flight hardware is now complete; however, the issues brought to light with the spacecraft element are prompting us to take the necessary steps to refocus our efforts on the completion of this ambitious and complex observatory," NASA Acting Administrator Robert Lightfoot said in a statement.
Billed as the successor to the Hubble Space Telescope, the new space telescope is an infrared observatory designed to peer deep into the universe, study the earliest stars and galaxies, and seek out strange new planets around distant stars. NASA built the space telescope in two parts: the telescope itself and a huge, complicated sun shield that will protect the observatory's sensitive instruments from the sun.
NASA originally hoped to launch the James Webb Space Telescope in 2018 but delayed it until 2019 last September due to delays in the observatory's assembly.
The potential for more issues arose in February, when a report from the U.S. Government Accountability Office warned that the telescope faced a high probability of more delays that could push the telescope beyond its budget cap. In 2001, Congress assigned the telescope a cost cap of $8 billion prior to launch.
When the James Webb Space Telescope finally flies, it will be the largest space observatory ever launched. The observatory has seven times the light-collecting power of Hubble. It will operate at ultracool temperatures and be able to detect infrared light from the universe's earliest stars and galaxies, as well as analyze the atmospheres of distant planets as they pass in front of their stars.
The assembled instruments and mirrors recently completed testing in an enormous cryovacuum chamber at Johnson Space Center in Houston, and the telescope was transported to California for final assembly with its tennis-court-size sun shield and spacecraft bus.
This story will be updated shortly with more details from a NASA teleconference on the James Webb Space Telescope launch delay.
www.space.com/40102-james-webb-space-telescope-launch-delay-2020.html
Building the James Webb Space Telescope: A Photo Tour: www.space.com/19441-james-webb-space-telescope-photo-tour.html
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Post by swamprat on Jun 28, 2018 13:09:50 GMT -6
I figured this was coming; sigh.....NASA Delays Launch of James Webb Space Telescope Again — This Time to 2021By Mike Wall, Space.com Senior Writer | June 27, 2018
NASA has delayed the launch of its huge, highly anticipated James Webb Space Telescope by another 10 months.
The liftoff of Webb, the successor to the agency's iconic Hubble Space Telescope, has been pushed back from May 2020 to March 2021, NASA officials announced today (June 27). The project's development cost has risen from $8 billion to $8.8 billion, and its total lifecycle price tag now stands at $9.66 billion, they added.
The rescheduling is the latest in a series of delays for Webb, which NASA had originally hoped to get off the ground way back in 2007.
"We have to get this right here on the ground before we go to space," Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate, said during a news conference today. "And I just want to re-emphasize: Webb is worth the wait."
Rocky road for a complex observatory Webb is a multipurpose observatory that will allow astronomers to study some of the first stars and galaxies in the universe, hunt for possible signs of life in the atmospheres of nearby alien planets, and do a variety of other high-profile work. Its primary mirror is 21.3 feet (6.5 meters) wide, compared to 7.8 feet (2.4 m) for that of Hubble.
"Webb is vital to the next generation of research beyond NASA's Hubble Space Telescope," NASA Administrator Jim Bridenstine said in a statement. "It's going to do amazing things — things we've never been able to do before — as we peer into other galaxies and see light from the very dawn of time."
Webb is optimized to view the heavens in infrared light, and its instruments must therefore be kept quite cool. So the telescope will sport a giant sunshield the size of a tennis court, which will unfold after Webb reaches its final destination, a gravitationally stable spot about 930,000 miles (1.5 million kilometers) from Earth.
The road to that destination has been quite bumpy to date. Webb is a very complex observatory that has proved difficult for primary contractor Northrop Grumman to build and test, as the repeated delays attest.
Until relatively recently, NASA had been targeting an October 2018 launch. In September of last year, however, NASA announced that spacecraft-integration issues had delayed the launch until spring 2019. Then, this past March, the agency pushed the scheduled liftoff date back again, to May 2020. More time was needed to test Webb's intricate systems and to deal with setbacks, such as small tears in the sunshield, NASA officials said at the time.
The agency also set up an independent review board (IRB) in March to monitor the observatory's progress and develop recommendations. The IRB submitted its report to NASA on May 31, and the agency wrapped up its response to that report yesterday (June 26). (You can read both the report and NASA's response here:) www.nasa.gov/sites/default/files/atoms/files/webb_irb_report_and_response_0.pdf
The IRB traced the 29-month delay (from a targeted launch date of October 2018 to March 2021) to five factors: human error, "embedded problems," excessive optimism, systems complexity, and a lack of experience in key areas, such as sunshade development.
IRB Chairman Tom Young laid out some of the most significant human errors during today's news conference. Technicians used the wrong solvent to clean propulsion valves; employed improper wiring that caused excessive voltage to be applied to transducers; and improperly installed sunshield-cover fasteners ahead of a key test, he said.
"All simple fixes that were not implemented resulted in approximately a 1.5-year schedule delay, at a cost of about $600 million," said Young, the former director of NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the former president and chief operating officer of aerospace company Martin Marietta (which merged with Lockheed Corporation in 1995, forming Lockheed Martin).
Going forward The IRB report was key in NASA's latest plan for Webb, agency officials said. Indeed, the review panel made 32 separate recommendations for the observatory's development going forward, 30 of which NASA fully agrees with, Zurbuchen said. (The agency is still considering the other two, he added.)
Crucially, the IRB did not recommend pulling the plug on the telescope.
"With all the factors that I've discussed considered, the IRB believes that JWST should continue, because of the compelling science, and because of JWST's national importance," Young said.
The bump in the mission's development cost from $8 billion to $8.8 billion may complicate that vision, however. The former number was a cap imposed by Congress, meaning that Webb needs another signoff from Capitol Hill to proceed.
"We submit our final 'breach report' to Congress this week," NASA Associate Administrator Steve Jurczyk said during today's news conference. "And then, it is true that Congress will have to reauthorize Webb through this next cycle of appropriations."
www.space.com/41016-nasa-delays-james-webb-space-telescope-2021.html
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Post by swamprat on Jul 30, 2018 9:25:20 GMT -6
Still on shaky ground; sigh... (This has been going on since 2012) Northrop CEO Offers to Link JWST Profit to Mission SuccessBy Jeff Foust, SpaceNews Writer | July 26, 2018
James Webb Space Telescope | Artist's impression
WASHINGTON — The chief executive of Northrop Grumman said July 26 he is willing to make the profit his company earns on the James Webb Space Telescope contingent on the overall success of the mission.
In the second half of a two-part hearing by the House Science Committee on the mission's latest overruns, Wes Bush endorsed an idea discussed by the committee a day earlier to put all the award fees due to the company on its cost-plus contract into an account to be released only after the spacecraft is successfully commissioned in space after launch.
"As a mechanism to ensure we are all aligned on mission success, Northrop Grumman has actually discussed this with NASA, and we are willing to place all of the fee that we've already earned and the fee that we may earn in the future at risk based on successful activation and demonstration of the telescope on orbit," he said when asked about the proposal by the committee's chairman, Rep. Lamar Smith (R-Texas).
Smith pressed for more. "Would you agree to pay the 800 [million dollars] above capped costs?" he asked, a reference to the recent overrun above the mission's $8 billion cost cap.
Bush declined. "Our view on that is that would create more of a fixed-price relationship on this program, which would significantly impede and impair the relationship between NASA and Northrop Grumman," he responded. "As we are focused on mission success, we think that would be the wrong approach."
Smith said he was disappointed. "I only wish that Northrop Grumman was willing to take responsibility and show a little bit more good faith," he said. "But it sounds like you've made up your mind. I just happen to disagree with you."
At the end of the hearing, Smith again questioned Bush on issues such as the financial impact the cost overruns have had on Northrop and whether any employees responsible for human errors that led to delays had lost the jobs.
"With respect to the mistakes we're talking about here today, I do not recall any losing their jobs," Bush said.
Smith grew frustrated when Bush repeatedly declined to state the company's profit last year, offering instead to provide that information for the record to ensure its accuracy. "How could a CEO not know what the profit of his company was last year?" Smith asked.
Northrop Grumman reported net earnings of just over $2 billion in 2017, according to the company’s 10-K filing with the U.S. Securities and Exchange Commission in January 2018.
Smith's questioning, though, was largely the exception to the rule in the hearing. Other members seemed less interested in assigning blame than seeking assurances that the problems that caused the latest overrun have been corrected.
"I'm not here to berate Northrop Grumman and its associated subcontractors, but rather see what needs to be done to keep this from happening again," said Rep. Eddie Bernice Johnson (D-Texas), ranking member of the committee, in her opening statement.
"I want to take issue with, I think, overstated allegations of poor management," said Rep. Don Beyer (D-Va.). "We make the best decisions we can on a minute-by-minute basis, with the best advice we have, and sometimes we're still going to get it wrong."
Bush said the company was taking steps to minimize the possibility of future problems, including a "safety net" to catch human errors early enough to limit their impact. "We're never going to be able to get human errors to zero. The word 'human' in that equation tells you that," he said.
"I feel very, very good about where we are in that regard," he said of those efforts to limit errors, adding the company has accepted and was implementing the recommendations of an independent review board (IRB) that released its final report a month ago.
Tom Young, the chairman of that board, argued at the hearing that NASA should reconvene the board in the near future — perhaps in the latter half of September — to check that the recommendations are being implemented. "Our belief is that it should be done. The IRB is willing to do that, and we personally think that it needs to be done early enough in the process that it can have an impact and late enough where things have been done," he said.
While most members appeared satisfied with Northrop Grumman's efforts to address the JWST overrun, and highlighted the science and inspirational benefits, one congressman was not moved.
"I cannot join you in this uplifting testimony," said Rep. Dana Rohrabacher (R-Calif.) Whoever was responsible for JWST at the company, he told Bush, "failed us and failed the American people."
www.space.com/41300-northrop-ceo-link-jwst-profit-mission-success.html
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Post by swamprat on Mar 27, 2019 20:40:10 GMT -6
Still not out of trouble!Space News
JWST review board raises schedule concernsby Jeff Foust — March 27, 2019
The chairman of the independent review board that examined progress on the James Webb Space Telescope said March 26 the mission appears to be consuming "significantly higher" schedule reserve as expected as it goes through integration and testing work. Credit: NASA/Desiree Stover
WASHINGTON — As NASA commits to performing another cost and schedule estimate for the James Webb Space Telescope, the chairman of an independent review board said he’s concerned about its ability to remain on track for a launch in two years.
Speaking at a meeting of the Committee of Astronomy and Astrophysics at the National Academies’ Space Science Week event here March 26, Tom Young, who chaired the Independent Review Board chartered by NASA last year to review cost and schedule problems with JWST, said that since the agency revised the schedule of the mission last June work on the space telescope appeared be taking longer than expected.
While the board completed its assessment last June, NASA brought the board back last fall to assess how NASA implemented its recommendations. Its final report on that assessment was released by NASA March 1.
“We went back and took a look at schedule performance as a part of our assessment,” he said. “One thing really did catch our attention and that was, in our judgement, that the consumption of margin at the time we looked at that was significantly higher than we would have expected.”
Young said the board didn’t do a formal analysis of the current target launch date of end of March 2021 but rather “some back-of-the-envelope looks” at the schedule for the remaining two years before launch. “It suggested to us there was cause for concern,” he said. “Reserved had been consumed at a pretty high rate and the impact of that should really be better understood and analyzed.”
Earlier in the meeting, Greg Robinson, JWST program director at NASA, played down schedule concerns. “We’re doing pretty good with these milestones,” he said of progress on the telescope, “and that means we have good margin in the schedule.” That includes, he said, 60 days of margin for integration and testing of the combined spacecraft bus and optical elements, three weeks after the observatory arrives at the launch site and four months of reserve held at NASA Headquarters.
However, he acknowledged that the program consumed the more than two months of schedule reserve that had been set aside for integration and testing of the spacecraft element at Northrop Grumman’s facilities. That margin was used up during vibration testing, he said, although he emphasized those tests concluded successfully. “Mission success is our number one aim,” he said. Thermal vacuum testing of the spacecraft is expected to begin this week, he added.
Robinson said JWST’s standing review board will meet April 2 and 3 to discuss the status of the mission. “One of the things they’re going to pay a lot of attention to is the schedule: how we’re doing on the schedule, what are the risks against it, et cetera,” he said.
The same day as the committee meeting, the U.S. Government Accountability Office issued a new report on JWST, the latest in a regular series by the agency tracking the progress of the telescope’s development. It also raised schedule concerns, noting that, as of last November, the mission “is about a week behind its replanned schedule because repairs on the membrane cover assembly took longer than planned.”
The GAO report recommended that NASA performed a detailed review of the mission’s cost and schedule, called joint confidence level (JCL), to be completed no later than the system integration review scheduled for August. NASA had previously declined to do a JCL because, at this phase of the mission’s development, it concluded it could more easily estimate costs and risks based on remaining work.
The GAO disagreed. “Conducting a JCL at system integration review — a review that occurs during the riskiest phase of development, the integration and test phase — would allow the project to update its assumptions of risk and uncertainty based on its experiences” testing the separate spacecraft bus and optical elements prior to integrating those two elements into a single spacecraft.
In a response included in the report, Thomas Zurbuchen, NASA associate administrator for science, accepted the report’s sole recommendation to perform a JCL. That review, he said, will be completed prior to the system integrated review. The independent review board chaired by Young came up with 32 recommendations. He said that, in the board’s later assessment, NASA was doing a good job implementing them. Of the 32, the board found that NASA had done an “appropriate” or “appropriate with additional work needed” job implementing 29 of them, ratings he likened to letter grades of A or A–.
For the other three, NASA’s response was inadequate, he said. Two of the three dealt with the reporting structure for the mission, which does not make the director of the Goddard Space Flight Center, the lead center for JWST, responsible for all aspects of the project. The board had recommended the Goddard director be given that responsibility and warned that otherwise it “will significantly reduce the probability of JWST success including cost, schedule and in-flight performance.”
A third recommendation deemed inadequate dealt with giving NASA’s Launch Services Program the same responsibility for the launch of JWST on an ESA-provided Ariane 5 as it has for launches on American vehicles. While NASA has increased its oversight of the mission, that work has fallen short of the recommendation, Young said.
That recommendation, he added, did not reflect any concerns with the Ariane 5 itself. “It has an impressive success record comparable to U.S. launch vehicles in the same class,” he said. “But there are impediments to having full visibility as would take place with U.S. launch vehicles.”
spacenews.com/jwst-review-board-raises-schedule-concerns/
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Post by swamprat on Jan 31, 2021 10:53:57 GMT -6
JADES will go deeper than the Hubble Deep FieldsPosted by Theresa Wiegert in SPACE | January 31, 2021
Astronomers announced this month that a new deep-field survey called JADES will be carried out with the James Webb Space Telescope, Hubble’s much-anticipated successor. The Webb is due to launch later this year.
Astronomers announced a new deeper-than-ever sky survey this month (January 15, 2021), to be conducted with the James Webb Space Telescope, the Hubble telescope’s successor, scheduled for launch in October of this year. The new survey is abbreviated JADES, which is short for James Webb Space Telescope Advanced Deep Extragalactic Survey. The survey will be like the Hubble Deep Fields, but deeper still. Its main goal is to see far away in space – and thus far back into the very young universe – and image it just at the end of the so-called Cosmic Dark Ages, that is, at the time when gas in the universe went from being opaque to transparent. This is also the time when the very first stars were forming – very large, massive and bright stars – in a veritable firestorm of star birth when the young universe was less than 5% of its current age.
The Webb telescope will be located near the secnd Lagrange point – a relatively stable region of space, gravitationally speaking, known as L2 – some 930,000 miles (1.5 million km) from Earth. To conduct the new survey, the Webb will be staring at a small point of space for nearly 800 hours (approximately 33 days) to be able to see fainter objects than those ever seen before and thus to find the first generation of galaxies. Astronomers want to know, among other things, how fast did these galaxies form, and how fast did their stars form? They also want to look for the very first supermassive black holes, which are thought to lie at the hearts of nearly all large galaxies, including our Milky Way.
The long-anticipated launch of the Webb has been postponed a number of times for a variety of reasons, most recently because of effects of the Covid-19 pandemic. It is the formal successor to the Hubble Space Telescope, but is equipped with instrumentation able to image further into the infrared part of the electromagnetic spectrum than Hubble did.
This capability also makes it a worthy successor to the infrared Spitzer Space Telescope which recently went into retirement. What makes the infrared part of the spectrum so important for surveys like JADES? If you look really deep, you will also look back in time, and the farther back in time you look, the more redshifted the galaxies are (the farther away they are, the faster they move away from us, and the more their light has been shifted towards the red part of the spectrum). This means that the light we want to observe, originally in the optical (visible) part of the electromagnetic spectrum, might not even show much in the optical part anymore. Instead, it’s been shifted to longer wavelengths, into the infrared regime.
In other words, the use of infrared cameras is necessary to be able to see the light from the first generation of galaxies. Daniel Eisenstein, a professor of astronomy at Harvard University, said:
"Galaxies, we think, begin building up in the first billion years after the Big Bang, and sort of reach adolescence at 1 to 2 billion years. We’re trying to investigate those early periods. We must do this with an infrared-optimized telescope because the expansion of the universe causes light to increase in wavelength as it traverses the vast distance to reach us. So even though the stars are emitting light primarily in optical and ultraviolet wavelengths, that light is shifted quite relentlessly out into the infrared. Only Webb can get to the depth and sensitivity that’s needed to study these early galaxies."
In fact, the James Webb Space Telescope was built specifically for this purpose. Up to now, infrared images are much less resolved – less clear – than optical images, because of their longer wavelength. With its much larger collecting area, the Webb will be able to image, in infrared, at the same resolution – detail – that Hubble could obtain in the optical part of the spectrum.
Get ready for a whole new set of mind-blowing images of the universe, this time in the infrared, from Webb!
After having successfully deployed its solar panels – precisely as it’s supposed to do once it’s in space – the Webb telescope is shown here ready for the final tests on December 17, 2020, at NASA’s Goddard Space Flight Center. Then it will be packed up and transported to French Guyana, to be launched on October 31, 2021, via an Ariane V rocket. Image via NASA/ Chris Gunn.
The use of deep field surveys is a young science, for two reasons. First, astronomers didn’t have the right instrumentation before Hubble to do them. Second, it’s also because no one initially knew the result of staring into a piece of empty space for a long time. Such a long stare into the unknown would require valuable observation time, and if this long observation didn’t produce any results, it would be considered a waste.
But in 1995, Robert Williams, then the director of the Space Telescope Science Institute (STSci), which administrates the Hubble telescope, decided to use his “director’s discretionary time” to point the Hubble toward a very small and absolutely empty-looking part of the sky in the direction of the constellation Ursa Major the Great Bear. There were no stars visible from our Milky Way (or extremely few), no nearby galaxies visible in the field, and no visible gas clouds. Hubble collected photons for 10 consecutive days, and the result, the Hubble Deep Field, was a success and a paradigm changer: A patch of sky about as small as the eye of George Washington on an American quarter (25-cent coin) held out at arm’s length, showed a 10 billion-light-years-long tunnel back in time with a plethora of galaxies – around 3,000 of them – at different evolutionary stages along the way. The field of observational cosmology was born.
This was done again in 1998 with the Hubble telescope pointed to the southern sky (Hubble Deep Field South), and the result was the same. Thus we learned that the universe is uniform over large scales.
Next was the installation of a new, powerful camera on Hubble (the Advanced Camera for Surveys) in 2002. The incredible Hubble Ultra Deep Field was acquired in 2004, in a similarly small patch of sky near the constellation Orion, about 1/10 of a full moon diameter (2.4 x 3.4 arc minutes, in contrast to the original Hubble Deep Fields north and south, which were 2.6 x 2.6 arc minutes). And so our reach was extended even deeper into space, and even further back in time, showing light from 10 thousand galaxies along a 13-billion-light-years-long tunnel of space. If you’ll remember that the universe is about 13.77 billion years old, you’ll see this is getting us really close to the beginning!
The Hubble Ultra Deep Field was the most sensitive astronomical image ever made at wavelengths of visible (optical) light until 2012, when an even more refined version was released, called the Hubble eXtreme Deep Field, which reached even farther: 13.2 billion years back in time.
The JADES survey will be observed in two batches, one on the northern sky and one on the southern in two famous fields called GOODS North and South (abbreviated from Great Observatories Origins Deep Survey).
Marcia Rieke, a professor of astronomy at the University of Arizona who co-leads the JADES Team with Pierre Ferruit of the European Space Agency (ESA), explained:
"We chose these fields because they have such a great wealth of supporting information. They’ve been studied at many other wavelengths, so they were the logical ones to do."
The GOODS fields have been observed with several of the most famous telescopes, covering a great wavelength range from infrared through optical to X-ray. They are not fully as deep (the observations don’t reach as far back) as the Ultra Deep Field, but cover a larger area of the sky (4-5 times larger) and are the most data-rich areas of the sky in terms of depth combined with wavelength coverage. By the way, the first deep field, HDF-N, is located in the GOODS north image, and the Ultra deep field/eXtreme (don’t you love these names?) is located in the GOODS south field.
There are a large number of ambitious science goals for the JADES program pertaining to the composition of the first galaxies, including the first generation of supermassive black holes. How these came about at such an early time is a mystery. As well, the transition of gas from neutral and opaque to transparent and ionized, something astronomers call the epoch of reionization, is not well understood. JADES team member Andrew Bunker, professor of astrophysics at the University of Oxford in the United Kingdom, who is also part of the ESA team behind the Webb telescope, said:
"This transition is a fundamental phase change in the nature of the universe. We want to understand what caused it. It could be that it’s the light from very early galaxies and the first burst of star formation … It is kind of one of the Holy Grails, to find the so-called Population III stars that formed from the hydrogen and helium of the Big Bang.
People have been trying to do this for many decades and results have been inconclusive so far."
But, hopefully, not for much longer!
Bottom line: JADES is an ambitious new deep sky survey to be observed with the James Webb Space Telescope, once launched. It will reach further back in time and space than any survey before, to study the very first generation of galaxies after the universe transitioned from opaque to transparent.
SOURCE: Space
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Post by swamprat on Mar 5, 2021 12:28:05 GMT -6
On track to launch in October 2021: the James Webb Space Telescope. NASA said that Webb cleared more key tests the observatory must pass before heading to the launch pad. Next up: technicians will fold Webb’s sunshield and deploy its mirror for the final time. Learn more about the mission: James Webb Space Telescope, the World's Next… | The Planetary Society
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Post by swamprat on Apr 20, 2021 18:44:55 GMT -6
When will the James Webb Telescope enter solar orbit, and how far will it be able to 'see'?Michael Schneider
If no more problems are found, it will be probably launch in 2021.This telescope is the pinnacle of technology, and the most risky, expensive, biggest and complex space telescope ever built. To give an idea of its size:
If and it is a big if everything goes well and JWST reaches L2, it will be able to see up to 13.5 billion years into the past. Many people will hold their breath when JWST launches, there are so many things that can go wrong. We will see the first stars form, the first planets and galaxies, it will tell us more about the origins of life. This telescope will look at the beginning of the universe, right after the dark age, when there was no light.
There are 10 brand new technologies on JWST. The NIR Spec Instrument is very special, it is a multi object spectograph and has a array of 62,000 microshutters. Each individual microshutter is about 100 by 200 microns in dimension and allows the instrument to do spectroscopy on many different selected objects simultaneously (max 100 targets at the same time).With this technology it is possible to find and measure exoplanets and stars at an unprecedented rate.
What it took a day to observe with the Kepler telescope, the JSWT will need a half hour. JWST is so powerful it could see a bumble bee on the moon from a million miles away. JWST is 100 times more sensitive in infrared then the Hubble telescope. If you would look through the JWST from a planet 21 light years away, you would still be able to see the earth.
(25) Michael Schneider's answer to When will the James Webb Telescope enter solar orbit, and how far will it be able to 'see'? - Quora
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Post by swamprat on Jun 1, 2021 20:46:09 GMT -6
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Post by swamprat on Aug 27, 2021 9:24:50 GMT -6
Webb Telescope Done Testing, Aims For SpaceportPosted by Lia De La Cruz and Deborah Byrd August 27, 2021
Webb Telescope is Hubble’s successor The European Space Agency (ESA) said on August 26, 2021, that the James Webb Space Telescope has now completed its final tests. It’s now being prepared for shipment to its launch site from the European Spaceport located near Kourou, French Guiana. Webb is an international partnership between NASA, ESA and the Canadian Space Agency. NASA had said on June 3 that the telescope would ship to the launch site in August “with little to no schedule margin.” That tight schedule would bring the telescope to launch readiness no earlier than October 31. But a November launch (or later) may still be more likely.
The space telescope underwent testing at Northrop Grumman’s facilities in California. ESA said: "Shipment operations have now begun. All the necessary steps are being taken to prepare Webb for a safe journey through the Panama Canal to its launch location … on the northeastern coast of South America."
Once Webb arrives at Europe’s Spaceport, launch processing teams will prepare and configure the observatory for flight. This involves post-shipment checkouts and carefully loading the spacecraft’s propellant tanks with fuel. Then, engineering teams will mate the observatory to its launch vehicle, an Ariane 5 rocket provided by ESA, and make a ‘dress rehearsal,’ before it rolls out to the launch pad two days before launch.
Launch from near Earth’s equator The upper stage of the Ariane 5, which will carry Webb to space later this year, is already on its way to Europe’s Spaceport. Overnight on August 17, 2021, the upper stage was transported in its container from Ariane Group in Bremen to Neustadt port in Germany. Here it boarded the MN Toucan vessel, alongside other Ariane 5 elements loaded in various European harbors, to continue its journey to Kourou, French Guiana.
Following launch, the massive space observatory will then make its way to Lagrange Point 2, a gravitationally stable point 930,000 miles (1.5 million km) from our planet. Webb will take about a month to fly to this location in space. As it travels there, beginning a few days after launch, it’ll begin slowly unfolding its biggest feature, its tennis court-sized sunshield, designed to reduce the sun’s heat by more than a million times to -364 degrees F (-220 degrees C). Webb’s mirror and instrumentation have to be kept cold. If they were to be heated up by the sun, they’d give off infrared radiation. And it’s faint infrared signals from the distant cosmos that the Webb is meant to measure. ESA commented that each step of the cool-down process:"… can be controlled expertly from the ground, giving Webb’s launch full control to circumnavigate any unforeseen issues with deployment."
ESA said the mission team can manage the cool-down, which will take several weeks, with heaters to control stresses on instruments and structures. In the meantime, ESA said: "… the secondary mirror tripod will unfold, the primary mirror will unfold, Webb’s instruments will slowly power up, and thruster firings will insert the observatory into a prescribed orbit."
After orbital insertion, and after the telescope has cooled down and stabilized at its frigid operating temperature, the mission team will spend several months aligning its optics and calibrating its scientific instruments. Then Webb will begin studying the cosmos in infrared light using its dazzling golden mirror.
What’s huge, grand, and golden? One of the Webb’s most important and identifiable attributes is its 21-foot-wide (6.5-meter-wide) primary mirror. A reflecting telescope’s primary mirror determines how much light it can collect, and thus how deeply it can see into the universe. Webb’s mirror is nearly three times wider than Hubble’s primary mirror.
You might hear people speak of the Webb’s golden mirror. The mirror is actually multiple mirrors. It’s composed of 18 separate hexagonal-shaped segments made of very strong, ultra-lightweight beryllium, which will unfold after launch. Each of the telescope’s mirror segments is covered in a microscopically thin layer of gold. This gold covering optimizes the mirror segments for reflecting infrared light, which is the primary wavelength of light this telescope will observe.
Webb Telescope has had a long road The Webb’s development began in 1996, with a $500 million budget. Space scientists and engineers initially planned the launch for 2007. But the project has had considerable delays and cost overruns, and it underwent a major redesign in 2005. Afterward, they planned the launch for March 2020, but the coronavirus pandemic struck and caused major setbacks. Yet, now, the team has made significant progress. NASA says existing program funding will have the Webb finished within its current $8.8 billion cost cap. In December 2020, the sunshield of a fully assembled James Webb Space Telescope successfully completed its own final tests, including a complete unfolding, just as the telescope will need to do once in space.
Formerly known as the Next Generation Space Telescope, scientists renamed the Webb in September 2002 after James Webb, who was an esteemed former NASA administrator.
NASA, the European Space Agency, and the Canadian Space Agency are partnering on the Webb. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the development effort, while Northrop Grumman serves as the project’s main industrial partner.
As it has for the Hubble Space Telescope, the Space Telescope Science Institute in Baltimore will be operating the Webb telescope after launch.
Technologies advance As you would expect, the capabilities of the Webb extend beyond those of the Hubble Space Telescope. NASA likes to say that the Webb is not a replacement for Hubble, but rather a successor. The two telescopes will collaborate side by side for a while, with a planned overlap.
The Webb will observe farther into the infrared regions of the electromagnetic spectrum than Hubble. It’ll go even deeper into space than Hubble, and thus it’ll look farther into the past. It’ll be able to peer inside stellar dust clouds where stars and star systems form. Thaddeus Cesari, a communications specialist for the mission, wrote: "In addition to the groundbreaking science expected from it after launch, Webb has required an improvement in the testing infrastructure and processes involved in validating large complex spacecraft for a life in space … Lessons learned from previous space telescope development were invested into Webb, and future space telescopes will be built upon the same collective knowledge."
Thousands of scientists, engineers, and technicians contributed to build, test, and integrate Webb. In total, 258 companies, agencies, and universities participated: 142 from the United States, 104 from 12 European nations, and 12 from Canada.
Bottom line: The James Webb Space Telescope is the world’s most complex infrared telescope. On August 26, 2021, ESA said the telescope has finished its testing and is being prepared for shipment to its launch site at the European Spaceport located near Kourou, French Guiana, on the northeastern coast of South America.
Via ESA
earthsky.org/space/james-webb-telescope-hubble-successor-to-launch/?utm_source=EarthSky+News&utm_campaign=c53e223418-EMAIL_CAMPAIGN_2018_02_02_COPY_01&utm_medium=email&utm_term=0_c643945d79-c53e223418-394368745
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Post by swamprat on Nov 23, 2021 9:40:39 GMT -6
James Webb Telescope – Hubble’s successor – launch delayed again
Posted by Editors of EarthSky November 22, 2021
UPDATE NOVEMBER 22, 2021. A NASA statement today said that the launch date for the James Webb Space Telescope has been pushed back again. The launch had been scheduled for December 18, 2021. NASA said the launch now will occur no earlier than December 22. The statement in its entirety follows:
The launch readiness date for the James Webb Space Telescope is moving to no earlier than December 22 to allow for additional testing of the observatory, following a recent incident that occurred during Webb’s launch preparations.
The incident occurred during operations at the satellite preparation facility in Kourou, French Guiana, performed under Arianespace overall responsibility. Technicians were preparing to attach Webb to the launch vehicle adapter, which is used to integrate the observatory with the upper stage of the Ariane 5 rocket. A sudden, unplanned release of a clamp band – which secures Webb to the launch vehicle adapter – caused a vibration throughout the observatory.
A NASA-led anomaly review board was immediately convened to investigate and instituted additional testing to determine with certainty the incident did not damage any components. NASA and its mission partners will provide an update when the testing is completed at the end of this week.
Webb was previously scheduled to launch December 18 on an Arianespace Ariane 5 rocket from Kourou.
Source: EarthSky
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Post by swamprat on Dec 6, 2021 16:21:35 GMT -6
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Post by swamprat on Dec 15, 2021 14:43:20 GMT -6
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Post by swamprat on Dec 21, 2021 15:32:11 GMT -6
The briefing starts about 3 or 4 minutes in......
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Post by swamprat on Dec 21, 2021 18:50:25 GMT -6
New update
Dec 21, 2021
James Webb Space Telescope Launch Update
NASA and Arianespace successfully completed the Launch Readiness Review for the James Webb Space Telescope on Dec. 21. The team authorized the Ariane 5 rocket carrying Webb to rollout and the start of launch sequencing for the mission.
However, due to adverse weather conditions at Europe’s Spaceport in French Guiana, the flight VA256 to launch Webb – initially scheduled for Dec. 24 – is being postponed.
The new targeted launch date is Dec. 25, as early as possible within the following launch window:
Between 7:20 a.m. and 7:52 a.m. Washington
Between 9:20 a.m. and 9:52 a.m. Kourou
Between 12:20 p.m. and 12:52 p.m. Universal (UTC)
Between 1:20 p.m. and 1:52 p.m. Paris
Between 9:20 p.m. and 9:52 p.m. Tokyo
Tomorrow evening, another weather forecast will be issued in order to confirm the date of December 25. The Ariane 5 launch vehicle and Webb are in stable and safe conditions in the Final Assembly Building.
Alise Fisher / Natasha Pinol
Headquarters, Washington
202-358-2546 / 202-358-0930
alise.m.fisher@nasa.gov / natasha.r.pinol@nasa.gov
Laura Betz
Goddard Space Flight Center, Greenbelt, Md.
301-286-9030
laura.e.betz@nasa.gov
Last Updated: Dec 21, 2021
Editor: Sarah Loff
www.nasa.gov/feature/james-webb-space-telescope-launch-update
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Post by swamprat on Dec 22, 2021 8:13:51 GMT -6
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Post by swamprat on Dec 25, 2021 8:18:09 GMT -6
SUCCESS!
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Post by swamprat on Dec 25, 2021 9:11:09 GMT -6
Dec 25, 2021 RELEASE 21-175NASA's Webb Telescope Launches to See First Galaxies, Distant Worlds NASA’s James Webb Space Telescope launched at 7:20 a.m. EST Saturday on an Ariane 5 rocket from Europe’s Spaceport in French Guiana, South America.
A joint effort with ESA (European Space Agency) and the Canadian Space Agency, the Webb observatory is NASA’s revolutionary flagship mission to seek the light from the first galaxies in the early universe and to explore our own solar system, as well as planets orbiting other stars, called exoplanets.
NASA’s James Webb Space Telescope launched Dec. 25 at 7:20 a.m. EST on an Ariane 5 rocket from Europe’s Spaceport in French Guiana, on the northeastern coast of South America.
“The James Webb Space Telescope represents the ambition that NASA and our partners maintain to propel us forward into the future,” said NASA Administrator Bill Nelson. “The promise of Webb is not what we know we will discover; it’s what we don’t yet understand or can’t yet fathom about our universe. I can’t wait to see what it uncovers!”
Ground teams began receiving telemetry data from Webb about five minutes after launch. The Arianespace Ariane 5 rocket performed as expected, separating from the observatory 27 minutes into the flight. The observatory was released at an altitude of approximately 75 miles (120 kilometers). Approximately 30 minutes after launch, Webb unfolded its solar array, and mission managers confirmed that the solar array was providing power to the observatory. After solar array deployment, mission operators will establish a communications link with the observatory via the Malindi ground station in Kenya, and ground control at the Space Telescope Science Institute in Baltimore will send the first commands to the spacecraft.
Engineers and ground controllers will conduct the first of three mid-course correction burns about 12 hours and 30 minutes after launch, firing Webb’s thrusters to maneuver the spacecraft on an optimal trajectory toward its destination in orbit about 1 million miles from Earth.
“I want to congratulate the team on this incredible achievement – Webb’s launch marks a significant moment not only for NASA, but for thousands of people worldwide who dedicated their time and talent to this mission over the years,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. “Webb’s scientific promise is now closer than it ever has been. We are poised on the edge of a truly exciting time of discovery, of things we’ve never before seen or imagined.”
The world’s largest and most complex space science observatory will now begin six months of commissioning in space. At the end of commissioning, Webb will deliver its first images. Webb carries four state-of-the-art science instruments with highly sensitive infrared detectors of unprecedented resolution. Webb will study infrared light from celestial objects with much greater clarity than ever before. The premier mission is the scientific successor to NASA’s iconic Hubble and Spitzer space telescopes, built to complement and further the scientific discoveries of these and other missions.
“The launch of the Webb Space Telescope is a pivotal moment – this is just the beginning for the Webb mission,” said Gregory L. Robinson, Webb’s program director at NASA Headquarters. “Now we will watch Webb’s highly anticipated and critical 29 days on the edge. When the spacecraft unfurls in space, Webb will undergo the most difficult and complex deployment sequence ever attempted in space. Once commissioning is complete, we will see awe-inspiring images that will capture our imagination.”
The telescope’s revolutionary technology will explore every phase of cosmic history – from within our solar system to the most distant observable galaxies in the early universe, to everything in between. Webb will reveal new and unexpected discoveries and help humanity understand the origins of the universe and our place in it.
NASA Headquarters oversees the mission for the agency’s Science Mission Directorate. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages Webb for the agency and oversees work on the mission performed by the Space Telescope Science Institute, Northrop Grumman, and other mission partners. In addition to Goddard, several NASA centers contributed to the project, including the agency’s Johnson Space Center in Houston, Jet Propulsion Laboratory in Southern California, Marshall Space Flight Center in Huntsville, Alabama, Ames Research Center in California’s Silicon Valley, and others.
For more information about the Webb mission, visit:
webb.nasa.gov
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Post by swamprat on Dec 25, 2021 9:26:42 GMT -6
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