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Astronomie - NASA´s Wide Field Infrared Survey Telescope (WFIRST) 2024 -Update

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25.12.2015

ASU scientists selected for NASA observatory Science Investigation Team

NASA has announced the selection of Science Investigation Teams for its Wide Field Infrared Survey Telescope (WFIRST). ASU will be the lead institution for one of these teams, which includes School of Earth and Space Exploration scientists James Rhoads, Sangeeta Malhotra, Rogier Windhorst, Rolf Jansen and Vithal Tilvi, along with scientists from the University of Texas, Texas A&M, University of Arizona, Stockholm University and Uppsala University in Sweden.
WFIRST will be a NASA observatory designed to settle essential questions in the areas of dark energy, exoplanets and infrared astrophysics. The telescope has a primary mirror 2.4 meters in diameter (7.9 feet) — the same size as the Hubble Space Telescope's primary mirror. WFIRST will have two instruments, the Wide Field Instrument and the Coronagraph Instrument.
The Wide Field Instrument will have a field of view 100 times greater than the Hubble wide field instrument, capturing more of the sky with less observing time. As the primary instrument, the Wide Field Instrument will measure light from 380 million galaxies over the course of the mission lifetime. The Coronagraph Instrument will capture light from around 2,600 exoplanets over the course of the mission.
The ASU team will develop a detailed plan for how to use WFIRST to study cosmic dawn, the period when the first stars formed in the earliest galaxies, and when the light produced by those earliest objects flooded the universe and ionized most of the ordinary matter.
“We made the case to NASA that WFIRST can and should explore this exciting time in cosmic history, in tandem with its primary science goals of studying dark energy and finding extrasolar planets,” said Rhoads. “And we put together a team with the scientific and technical expertise to help plan for that.”
Added Malhotra, “A six-month survey with WFIRST will be equivalent to about a hundred years of Hubble Space Telescope infrared observations. We will show how this can be used to chronicle both the early history of galaxy and quasar formation, and the effect those objects had on the universe around them.”
With this announcement, ASU’s School of Earth and Space Exploration, an academic unit of the College of Liberal Arts and Sciences, is now playing a significant role in three of NASA’s flagship observatories: the Hubble Space Telescope, the James Webb Space Telescope, and now the Wide Field Infrared Survey Telescope.
WFIRST is designed for a six-year mission and will launch on an Evolved Expendable Launch Vehicle out of Cape Canaveral in 2024.
Quelle: Arizona State Universit

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Update: 23.01.2016

NASA's WFIRST mission set for go-ahead

NASA's Wide-Field Infrared Survey Telescope will aim to answer fundamental questions about the universe, dark energy and exoplanets. (Courtesy: NASA)

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NASA's Wide-Field Infrared Survey Telescope (WFIRST) is expected to become a formal project next month, about a year earlier than initially planned. The decision was made after the US Congress provided $90m for WFIRST for the 2016 fiscal year – significantly more than the $14m NASA had requested.
With an estimated cost of $1.6bn, WFIRST is expected to launch in the next decade, and was listed as the top priority for NASA in its 2010 decadal survey carried out by the National Research Council. The probe is seen as a successor to the planned James Webb Space Telescope, which is set to launch in 2018.
One key scientific objective of WFIRST is to make "definitive measurements" of dark energy and the growth of structures in the universe. It will also aim to directly image exoplanets and take spectroscopic measurements of their atmospheres. "This is all part of NASA's overarching high-priority science goals to understand the nature of the universe that we live in and whether we are alone in it," says WFIRST programme scientist Dominic Benford.
Refurbished spy satellite
WFIRST will use a telescope given to NASA by the National Reconnaissance Office – a US government agency that builds and operates spy satellites. Although the telescope was designed for surveillance of targets on Earth, its capabilities are compatible with the goals of WFIRST. The telescope's 2.4 m primary mirror is the same size as the Hubble Space Telescope, but its field of view is 100 times larger, allowing it to capture more of the sky with less observing time. Over the course of the six-year primary mission, WFIRST will measure light from a billion galaxies and perform a gravitational micro-lensing survey of around 2600 exoplanets.
According to Benford, WFIRST is currently defined as "an option that NASA could choose to pursue". Yet he says that with the funding boost, it is now expected to become an official project in February. WFIRST will also be made available to the scientific community, through a competitive process, for a quarter of its mission time.
Quelle: Physics World
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Update: 18.02.2016
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NASA Introduces New, Wider Set of Eyes on the Universe 

 
NASA's Wide Field Infrared Survey Telescope (WFIRST), illustrated here, will carry a Wide Field Instrument to capture Hubble-quality images covering large swaths of sky, enabling cosmic evolution studies. Its Coronagraph Instrument will directly image exoplanets and study their atmospheres.
Credits: NASA/GSFC/Conceptual Image Lab
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After years of preparatory studies, NASA is formally starting an astrophysics mission designed to help unlock the secrets of the universe -- the Wide Field Infrared Survey Telescope (WFIRST).
With a view 100 times bigger than that of NASA’s Hubble Space Telescope, WFIRST will aid researchers in their efforts to unravel the secrets of dark energy and dark matter, and explore the evolution of the cosmos. It also will discover new worlds outside our solar system and advance the search for worlds that could be suitable for life.
NASA's Agency Program Management Council, which evaluates the agency's programs and projects on content, risk management, and performance, made the decision to move forward with the mission on Wednesday.
“WFIRST has the potential to open our eyes to the wonders of the universe, much the same way Hubble has,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate at Headquarters in Washington. "This mission uniquely combines the ability to discover and characterize planets beyond our own solar system with the sensitivity and optics to look wide and deep into the universe in a quest to unravel the mysteries of dark energy and dark matter.”
WFIRST is the agency's next major astrophysics observatory, following the launch of the James Webb Space Telescope in 2018. The observatory will survey large regions of the sky in near-infrared light to answer fundamental questions about the structure and evolution of the universe, and expand our knowledge of planets beyond our solar system – known as exoplanets.
It will carry a Wide Field Instrument for surveys, and a Coronagraph Instrument designed to block the glare of individual stars and reveal the faint light of planets orbiting around them. By blocking the light of the host star, the Coronagraph Instrument will enable detailed measurements of the chemical makeup of planetary atmospheres. Comparing these data across many worlds will allow scientists to better understand the origin and physics of these atmospheres, and search for chemical signs of environments suitable for life.
"WFIRST is designed to address science areas identified as top priorities by the astronomical community," said Paul Hertz, director of NASA's Astrophysics Division in Washington. “The Wide-Field Instrument will give the telescope the ability to capture a single image with the depth and quality of Hubble, but covering 100 times the area. The coronagraph will provide revolutionary science, capturing the faint, but direct images of distant gaseous worlds and super-Earths."
The telescope’s sensitivity and wide view will enable a large-scale search for exoplanets by monitoring the brightness of millions of stars in the crowded central region of our galaxy. The survey will net thousands of new exoplanets similar in size and distance from their star as those in our own solar system, complementing the work started by NASA's Kepler mission and the upcoming work of the Transiting Exoplanet Survey Satellite.
Employing multiple techniques, astronomers also will use WFIRST to track how dark energy and dark matter have affected the evolution of our universe. Dark energy is a mysterious, negative pressure that has been speeding up the expansion of the universe. Dark matter is invisible material that makes up most of the matter in our universe.
By measuring the distances of thousands of supernovae, astronomers can map in detail how cosmic expansion has increased with time. WFIRST also can precisely measure the shapes, positions and distances of millions of galaxies to track the distribution and growth of cosmic structures, including galaxy clusters and the dark matter accompanying them.
"In addition to its exciting capabilities for dark energy and exoplanets, WFIRST will provide a treasure trove of exquisite data for all astronomers," said Neil Gehrels, WFIRST project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "This mission will survey the universe to find the most interesting objects out there."
WFIRST is slated to launch in the mid-2020s. The observatory will begin operations after travelling to a gravitational balance point known as Earth-Sun L2, which is located about one million miles from Earth in a direction directly opposite the Sun.
WFIRST is managed at Goddard, with participation by the Jet Propulsion Laboratory (JPL) in Pasadena, California, the Space Telescope Science Institute in Baltimore, the Infrared Processing and Analysis Center, also in Pasadena, and a science team comprised of members from U.S. research institutions across the country.
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WFIRST im Vergleich zu HUbble 
Quelle: NASA
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Update: 3.05.2016
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NASA’s WFIRST Spacecraft Expected to Be a Huge Step Forward in Our Understanding of Dark Matter
NASA’s Wide Field Infrared Survey Telescope (WFIRST) could be a space observatory of the future, destined for great discoveries in the field of astrophysics. With a view about 100 times bigger than that of the iconic Hubble Space Telescope, WFIRST is expected to yield crucial results about the still-elusive dark matter and dark energy.
Perplexing astronomers for years, dark matter and dark energy could soon reveal their real nature. WFIRST is currently being designed to address the most baffling questions about these mysterious substances, together accounting for about 95 percent of the mass-energy of the universe. The spacecraft could provide a major improvement in our understanding of this subject.
“WFIRST will survey large areas of the sky measuring the effects of dark matter on the distribution of galaxies in the universe. It will also observe distant Type Ia supernovae to use them as tracers of dark matter and dark energy. It will provide a huge step forward in our understanding of dark matter and dark energy,” Brooke Hsu of NASA's Goddard Space Flight Center in Greenbelt, Md. told Astrowatch.net.
WFIRST is managed at Goddard, with participation by the Jet Propulsion Laboratory (JPL) in Pasadena, California, the Space Telescope Science Institute in Baltimore, the Infrared Processing and Analysis Center, also in Pasadena, and a science team comprised of members from U.S. research institutions across the country.
The spacecraft is currently in Phase A of preparations. The purpose of this phase is to develop the mission requirements and architecture necessary to meet the programmatic requirements and constraints on the project and to develop the plans for the Preliminary Design phase. The preparations are on track for a mid-2020 launch. After liftoff, the telescope will travel to a gravitational balance point known as Earth-Sun L2, located about one million miles from Earth in a direction directly opposite the Sun.
Operating at L2, WFIRST will study dark matter and dark energy with several techniques. The High Latitude Spectroscopic Survey will measure accurate distances and positions of a very large number of galaxies. It will measure the growth of large structure of the universe, testing theory of Einstein's General Relativity.
“It will perform large surveys of galaxies and galaxy clusters to see the effects of dark matter and energy on their shapes and distributions in the universe. All told, more than a billion galaxies will be observed by WFIRST,” Hsu revealed.
The spacecraft will conduct the Type Ia Supernovae (SNe) Survey which will use type Ia SNe as "standard candles" to measure absolute distances. Calculating the distance to and redshift of the SNe provides another means of measuring the evolution of dark energy over time, providing a cross-check with the high latitude surveys.
“It will observe Type Ia supernovae to determine their distance and properties. More than 2,000 supernovae will be observed,” Hsu said.
WFIRST will also carry out the High Latitude Imaging Survey that will measure the shapes and distances of a very large number of galaxies and galaxy clusters. This survey is expected to determine both the evolution of dark energy over time as well as provide another independent measurement of the growth of large structure of the universe.
But WFIRST is not only about astrophysics. The infrared telescope will also have a chance to prove its usefulness as an exoplanet hunter. It will use microlensing techniques to expand our catalog of known extrasolar planets and will directly characterize these alien worlds using coronagraphy.
“WFIRST will study exoplanets with two very different techniques: microlensing and coronagraph. The mission will stare at the a dense star region toward the direction of the center of our Milky Way galaxy to observe microlensing events. These brightenings caused when two stars exactly align and also provide a tally of the exoplanets around the stars. Over 2,000 exoplanets will be detected this way,” Hsu noted.
To fulfill its scientific goals, WFIRST will be equipped in a 2.4-meter telescope hosting two instruments: the Wide-Field Instrument (WFI) and a high contrast coronagraph. WFI will provide the wide-field imaging and slitless spectroscopic capabilities required to perform the Dark Energy, Exoplanet Microlensing, and near-infrared (NIR) surveys while the coronagraph instrument is being designed for the exoplanet high contrast imaging and spectroscopic science.
“The Wide Field Instrument provides wide-field imaging and spectroscopy in support of the dark energy and microlensing surveys and integral field spectroscopy in support of the supernova survey,” Hsu said.
The coronagraph will be able to detect more than 50 exoplanets and observe their properties.
“It will be a huge leap forward compared to current instruments. Most exciting will be spectral observations of the light from the planets to see what the properties are of the atmospheres and possibly surfaces. Searches will be made for signatures of life on the planets,” Hsu said.
By operating WFIRST, NASA hopes to make major discoveries in the areas of dark matter and energy, exoplanets and general astrophysics. The agency expects to learn the nature of dark matter and energy to determine what they are. 
“We will survey the sky to find the most exotic and interesting galaxies, black holes, and stars. We will take a census of exoplonets that are beyond on astronomical unit from their stars, a region that Kepler is not able to survey. We will make the first sensitive direct observation of nearby exoplanets and find what their nature is and if there are signatures of life,” Hsu concluded.
Quelle: ASTRO WATCH
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Update: 28.11.2017
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NASA’s next flagship telescope is “not executable” in its current form

"The NASA HQ-to-Program governance structure is dysfunctional."

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First came the Hubble Space Telescope. Now, NASA is finalizing development of the James Webb Space Telescope for launch in 2019. And finally, the space agency is beginning to design and develop its next great space telescope, the Wide Field Infrared Survey Telescope, or WFIRST.

This instrument will have a primary mirror of 2.4 meters, the same size as the Hubble's, and be designed to hunt for dark energy and spy on exoplanets. Although similar in size to Hubble, the WFIRST telescope's infrared instrument would have a field of view that is 100 times greater than the Hubble, allowing it to observe much more of the sky in less time. It was also supposed to carry a special coronagraph, which could block the light of stars and allow astronomers to observe exoplanets directly.

But a new report—released without fanfare on the Wednesday before the Thanksgiving holiday—calls into question the viability of the project. "The risks to the primary mission of WFIRST are significant and therefore the mission is not executable without adjustments and/or additional resources," the report states. It estimated the cost of the project at $3.9 billion to $4.2 billion, significantly above the project's $3.6 billion budget.

Produced by an independent and external team to review the technical aspects of the program, its management, and costs, the report is critical of a series of key decisions made by NASA. The addition of a coronagraph and other design choices have made for a telescope that is "more complex than probably anticipated" and have substantially increased risks and costs, according to the report.

It also offered a scathing review of the relationship between NASA headquarters and the telescope's program managers at Goddard Space Flight Center. "The NASA HQ-to-Program governance structure is dysfunctional and should be corrected for clarity in roles, accountability, and authority," the report states.

Even before the review's public release, NASA has been attempting to fix some of these issues. In an October memo, NASA science chief Thomas Zurbuchen told the director of Goddard Space Flight Center, Chris Scolese, to modify the telescope's design to reduce its cost and complexity. Such revisions would include treating the coronagraph as a "technology demonstration instrument" and using additional commercial components to bring the cost to $3.2 billion.

"WFIRST remains NASA's highest priority for a large astrophysics mission following the James Webb Space Telescope," Zurbuchen wrote. "Making these adjustments to WFIRST in response to the findings in the (new) report will ensure its success while preserving a balanced Astrophysics program."

Quelle: arsTechnica

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Update: 13.02.2018

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Trump's budget would kill NASA's WFIRST telescope. Astronomers say that would be a mistake

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An illustration of NASA's future Wide Field Infrared Survey Telescope, also known as WFIRST. Scientists say it will help them understand dark matter and look for distant planets; the Trump administration wants to cut it. (NASA)

A NASA space telescope that would probe distant planets and explore some of the biggest mysteries of the cosmos is on the chopping block in President Trump's 2019 budget proposal released Monday.

The request would zero out funding for NASA's Wide Field Infrared Survey Telescope, or WFIRST, a repurposed spy satellite donated by the Department of Defense. The move sent shock waves through the scientific community.

"It would be extraordinarily disappointing to see it canceled when a lot of work has gone into it already," Bruce Macintosh, a Stanford University astrophysicist with the mission, said in an interview.

With a planned launch in the mid-2020s, WFIRST would survey distant galaxies looking for the effects of dark matter, that mysterious stuff that can't be seen or touched but outnumbers normal matter by roughly 5 to 1. The telescope would study Type Ia supernovas to track dark energy, that strange repulsive force that is causing the universe to expand faster and faster. The observatory could even use its instruments to explore the planets around other stars.

Although the $19.6 billion proposed for NASA would represent a 2.6% bump from the previous year, WFIRST, along with five earth science missions, did not appear to make the cut.

According to documents from the White House's Office of Management and Budget, WFIRST received $105 million in funding in 2017, and continuing to develop it in future years would have ramped up the total cost to $3 billion.

"Given competing priorities at NASA, and budget constraints, developing another large space telescope immediately after completing the $8.8-billion James Webb Space Telescope is not a priority for the administration," the documents say. "The budget proposes to terminate WFIRST and redirect existing funds to other priorities of the science community, including completed astrophysics missions and research."

A recent analysis found that WFIRST would not be able to keep its costs under $3.2 billion, but Macintosh said that the agency had been successfully working to stay under that cap.

He was quick to point out that in 2010, astronomers had selected WFIRST as their highest priority for the decade.

The move attracted widespread scorn from scientists on Twitter, including David Spergel, a Princeton University theoretical astrophysicist and co-chair of WFIRST's science team.

Quelle: Los Angeles Times

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Update: 16.02.2018

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Astronomers Will Fight to Save WFIRST Space Telescope from Being Axed

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A picture of the primary mirror for the WFIRST mission. The mirror was previously part of a space telescope that was cancelled before it went to space..

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Leaders of the American Astronomical Society released a statement today (Feb. 15) denouncing the proposed cancellation of NASA's Wide Field Infrared Survey Telescope (WFIRST) in the White House budget proposal that was released this week. The AAS leadership also expressed its intention to rally support for the mission in Congress, where the final fiscal year 2019 budget will have to be approved. 

"We cannot accept termination of WFIRST, which was the highest-priority space-astronomy mission in the most recent decadal survey," AAS President-elect Megan Donahue said in a statement from the society. "And the proposed 10% reduction in NASA's astrophysics budget, amounting to nearly $1 billion over the next five years, will cripple US astronomy."

The AAS is the "major organization of professional astronomers in North America," according to the society's website, with a membership of about 7,000 people. On Twitter and in various news publications, individual scientists have already voiced their dismay at the mission's proposed cancellation, and the impact it would have on U.S. astrophysics.

WFIRST would be NASA's next "flagship" mission, which refers to large missions with a wide range of science capabilities. It would follow missions like the Hubble Space Telescope, the Chandra X-ray Observatory and the James Webb Space Telescope, set to launch in 2019. Its primary science objectives would be in the areas of cosmology, star and planet formation, and studies of planets around other stars. A significant portion of time would also be reserved for scientists to use the observatory for studies outside those topics.   

WFIRST received top ranking in the 2010 decadal survey, titled "New Worlds, New Horizons in Astronomy and Astrophysics." The decadal survey is a community-led report organized by the National Academies every 10 years that provides a roadmap for which missions or mission topics should be pursued by the community and supported by funding agencies. Compiling the report is a multiyear process that captures input from astronomers in various subfields as well as from funding agencies such as NASA and the National Science Foundation. 

"These efforts to achieve community consensus on research priorities are vital to ensuring the maximum return on public and private investments in the astronomical sciences," AAS Executive Officer Kevin B. Marvel said in the statement. "The cancellation of WFIRST would set a dangerous precedent and severely weaken a decadal-survey process that has established collective scientific priorities for a world-leading program for a half century. Such a move would also sacrifice US leadership in space-based dark energy, exoplanet, and survey astrophysics. We cannot allow such drastic damage to the field of astronomy, the impacts of which would be felt for more than a generation."

The call to cancel WFIRST could be interpreted as a warning to the mission managers to keep the cost of the program on track, according to Marcia Rieke, an astronomy professor at the University of Arizona and the Seward Observatory, who spoke with Space.com for this article about what the WFIRST cancellation could mean for U.S. astrophysics. Rieke is co-chair of the National Academies' Committee on Astronomy and Astrophysics, which monitors how the decadal survey's priorities are being implement by funding agencies. 

The WFIRST mission has steadily grown beyond its initial projected funding window, which prompted NASA to initiate an independent review of the project to find out why costs were swelling. Based on the findings of that review panel, in October the agency directed the mission planners to come up with a way to keep the mission within a lifetime-cost budget of $3.2 billion. The results of that evaluation are expected to be presented to NASA leadership in March. (For comparison, the Webb telescope is now expected to cost about $8.8 billion over its lifetime; Hubble's lifetime cost has exceeded $10 billion, although both of those telescopes have a larger array of science instruments than WFIRST.)

Jon Morse, former director of NASA's astrophysics division, told Space.com that the NASA science mission directorate (SMD) "would not have given programmatic direction to the WFIRST project last fall if SMD were planning to cancel the mission; this appears to have been dictated from outside the agency." Morse, now CEO of the BoldlyGo Institute, headed NASA's astrophysics division from 2007 to 2011, during the development of the WFIRST mission concept. He also served as a senior policy analyst in the White House Office of Science and Technology Policy from 2006 to 2007.    

The White House budget provides a $400 million overall increase in NASA's budget, but a $165 million cut for astrophysics. Planning numbers for WFIRST requested $302 million for the 2019 fiscal year, and upward of $400 million each year through 2022. If WFIRST is canceled, it will absorb the overall cut to astrophysics and leave about $137 million for other astrophysics research. 

But Morse told Space.com the proposed use of WFIRST funds to absorb the overall cut to astrophysics, "steals the JWST budget wedge from Astrophysics for 'other agency priorities';  an outrageous proposal that kills the top priority in the astrophysics decadal survey and undermines future U.S. leadership in space astrophysics."

Since 2008, NASA's astrophysics division's budget has been consistently below what it was in 2008, with the steepest reduction occurring in 2010. Meanwhile, every other science division (such as heliophysics and planetary science) has seen an overall rise in budgets, compared with 2008 levels. In the last three years, the astrophysics division has almost returned to 2008 levels, but the proposed FY19 budget would be a 15 percent reduction, compared with 2008 (and about a 10 percent reduction from FY18). 

"The community should make clear that WFIRST is crucial to future space astrophysics research and is entirely affordable if Astrophysics were provided the same kind of budgetary resources that other disciplines are receiving," Morse said. "The Astrophysics budget should be $1.6 [billion] per year, not going backwards!"

It appears the AAS leadership is preparing to fight to save the mission. 

"We look forward to working with Congress to restore funding for WFIRST and for NASA astrophysics overall," Donahue said.

Quelle: SC

 

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