A space telescope (also known as space observatory ) is a telescope in outer space used to observe astronomical objects. Suggested by Lyman Spitzer in 1946, the first operational telescopes were the American Orbiting Astronomical Observatory , OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971. Space telescopes avoid several problems caused by the atmosphere, including the absorption or scattering of certain wavelengths of light, obstruction by clouds, and distortions due to atmospheric refraction such as twinkling . Space telescopes can also observe dim objects during the daytime, and they avoid light pollution which ground-based observatories encounter. They are divided into two types: Satellites which map the entire sky ( astronomical survey ), and satellites which focus on selected astronomical objects or parts of the sky and beyond. Space telescopes are distinct from Earth imaging satellites , which point toward Earth for satellite imaging , applied for weather analysis , espionage , and other types of information gathering .
52-699: The Fermi Gamma-ray Space Telescope ( FGST , also FGRST ), formerly called the Gamma-ray Large Area Space Telescope ( GLAST ), is a space observatory being used to perform gamma-ray astronomy observations from low Earth orbit . Its main instrument is the Large Area Telescope (LAT), with which astronomers mostly intend to perform an all-sky survey studying astrophysical and cosmological phenomena such as active galactic nuclei , pulsars , other high-energy sources and dark matter . Another instrument aboard Fermi,
104-469: A gamma-ray burst with one of the highest energy outputs yet recorded. This included detection of a gamma-ray over 94 billion electron volts (GeV). This broke Fermi's previous record detection, by over three times the amount. Fermi reported that its GBM instrument detected a weak gamma-ray burst above 50 keV, starting 0.4 seconds after the LIGO event and with a positional uncertainty region overlapping that of
156-504: A low-Earth circular orbit at an altitude of 550 km (340 mi), and at an inclination of 28.5 degrees. GLAST received some minor modifications to its computer software on 23 June 2008. Computers operating both the LAT and GBM and most of the LAT's components were turned on 24 June 2008. The LAT high voltage was turned on 25 June, and it began detecting high-energy particles from space, but minor adjustments were still needed to calibrate
208-626: A better search for Galactic spectral lines from dark matter interactions, analysis of extended supernova remnants, and to search for extended sources in the Galactic plane. For almost all event classes, Version P8R2 had a residual background that was not fully isotropic. This anisotropy was traced to cosmic-ray electrons leaking through the ribbons of the Anti-Coincidence Detector and a set of cuts allowed rejection of these events while minimally impacting acceptance. This selection
260-672: A chosen target. Both science instruments underwent environmental testing, including vibration, vacuum, and high and low temperatures to ensure that they can withstand the stresses of launch and continue to operate in space. They were integrated with the spacecraft at the General Dynamics ASCENT facility in Gilbert, Arizona. Data from the instruments are available to the public through the Fermi Science Support Center web site. Software for analyzing
312-617: A gamma-ray burst which was later designated as GRB 170817A. Six minutes later, a single detector at Hanford LIGO registered a gravitational-wave candidate which was consistent with a binary neutron star merger , occurring 2 seconds before the GRB 170817A event. This observation was "the first joint detection of gravitational and electromagnetic radiation from a single source ". The Gamma-ray Burst Monitor (GBM) (formerly GLAST Burst Monitor) detects sudden flares of gamma-rays produced by gamma ray bursts and solar flares . Its scintillators are on
364-408: A global multi-wavelength follow-up campaign." Space observatory In 1946, American theoretical astrophysicist Lyman Spitzer , "father of Hubble" proposed to put a telescope in space. Spitzer's proposal called for a large telescope that would not be hindered by Earth's atmosphere. After lobbying in the 1960s and 70s for such a system to be built, Spitzer's vision ultimately materialized into
416-438: A name that is catchy, easy to say and will help make the satellite and its mission a topic of dinner table and classroom discussion". Fermi gained its new name in 2008: On 26 August 2008, GLAST was renamed the "Fermi Gamma-ray Space Telescope" in honor of Enrico Fermi , a pioneer in high-energy physics. NASA designed the mission with a five-year lifetime, with a goal of ten years of operations. The key scientific objectives of
468-408: A process termed pair production . These charged particles pass through interleaved layers of silicon microstrip detectors , causing ionization which produce detectable tiny pulses of electric charge. Researchers can combine information from several layers of this tracker to determine the path of the particles. After passing through the tracker, the particles enter the calorimeter , which consists of
520-425: A stack of caesium iodide scintillator crystals to measure the total energy of the particles. The LAT's field of view is large, about 20% of the sky. The resolution of its images is modest by astronomical standards, a few arc minutes for the highest-energy photons and about 3 degrees at 100 MeV . It is sensitive from 20 MeV to 300 GeV (from medium up to some very-high-energy gamma rays ). The LAT
572-705: Is a bigger and better successor to the EGRET instrument on NASA 's Compton Gamma Ray Observatory satellite in the 1990s. Several countries produced the components of the LAT, who then sent the components for assembly at SLAC National Accelerator Laboratory . SLAC also hosts the LAT Instrument Science Operations Center, which supports the operation of the LAT during the Fermi mission for the LAT scientific collaboration and for NASA. Education and public outreach are important components of
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#1732782794897624-483: Is now known as the Galactic Center GeV excess . The source of this surplus is not known. Suggestions include self-annihilation of dark matter or a population of pulsars. In February 2010, it was announced that Fermi-LAT had determined that supernova remnants act as enormous accelerators for cosmic particles . This determination fulfills one of the stated missions for this project. In March 2010 it
676-409: Is subject neither to twinkling nor to light pollution from artificial light sources on Earth. As a result, the angular resolution of space telescopes is often much higher than a ground-based telescope with a similar aperture . Many larger terrestrial telescopes, however, reduce atmospheric effects with adaptive optics . Space-based astronomy is more important for frequency ranges that are outside
728-590: The Burst Alert Telescope (BAT) on board the Swift Observatory Satellite . Black hole mergers of the type thought to have produced the gravitational wave event are not expected to produce gamma-ray bursts, as stellar-mass black hole binaries are not expected to have large amounts of orbiting matter. Avi Loeb has theorised that if a massive star is rapidly rotating, the centrifugal force produced during its collapse will lead to
780-733: The CNSA , scientists fear that there would be gaps in coverage that would not be covered immediately by future projects and this would affect research in fundamental science. On 16 January 2023, NASA announced preliminary considerations of several future space telescope programs, including the Great Observatory Technology Maturation Program, Habitable Worlds Observatory , and New Great Observatories. Cape Canaveral Air Force Station Space Launch Complex 17 Space Launch Complex 17 ( SLC-17 ), previously designated Launch Complex 17 ( LC-17 ),
832-653: The Delta family of launch vehicles. Thirty-five early Delta rocket missions were launched from Complex 17 between the beginning of 1960 and the end of 1965. At that time the complex was operated by the US Air Force . The US Air Force transferred Launch Complex 17A to NASA (SLC-17A) in 1965, but the site was returned to the US Air Force in 1988 to support the Delta II program. As Delta II launches continued over
884-583: The Hubble Space Telescope , which was launched on April 24, 1990, by the Space Shuttle Discovery (STS-31). This was launched due to many efforts by Nancy Grace Roman, "mother of Hubble", who was the first Chief of Astronomy and first female executive at NASA. She was a program scientist that worked to convince NASA, Congress, and others that Hubble was "very well worth doing". The first operational space telescopes were
936-439: The background . This improved understanding led to two major improvements: gamma-rays that had been missed by previous analysis were detected and the direction they arrived from was determined with greater accuracy. The impact of the latter is to sharpen Fermi LAT's vision as illustrated in the figure on the right. Pass 8 also delivers better energy measurements and a significantly increased effective area. The entire mission dataset
988-473: The gamma ray bands only, a first for its kind. This new pulsar sweeps the Earth every 316.86 milliseconds and is about 4,600 light-years away. In September 2008, the gamma-ray burst GRB 080916C in the constellation Carina was recorded by the Fermi telescope. This burst is notable as having "the largest apparent energy release yet measured". The explosion had the power of about 9,000 ordinary supernovae, and
1040-784: The optical window and the radio window , the only two wavelength ranges of the electromagnetic spectrum that are not severely attenuated by the atmosphere. For example, X-ray astronomy is nearly impossible when done from Earth, and has reached its current importance in astronomy only due to orbiting X-ray telescopes such as the Chandra X-ray Observatory and the XMM-Newton observatory . Infrared and ultraviolet are also largely blocked. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope
1092-520: The relativistic jet of material ejected in the blast must have moved at a minimum of 99.9999% the speed of light . Overall, GRB 080916C had "the greatest total energy, the fastest motions, and the highest initial-energy emissions" ever seen. In 2009, a surplus of gamma rays from a spherical region around the Galactic Center of the Milky Way was found in data from the Fermi telescope. This
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#17327827948971144-573: The American Orbiting Astronomical Observatory , OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971. Performing astronomy from ground-based observatories on Earth is limited by the filtering and distortion of electromagnetic radiation ( scintillation or twinkling) due to the atmosphere . A telescope orbiting Earth outside the atmosphere
1196-664: The Fermi LAT Collaboration released "Pass 8 LAT data". Iterations of the analysis framework used by LAT are called "passes" and at launch Fermi LAT data was analyzed using Pass 6. Significant improvements to Pass 6 were included in Pass 7 which debuted in August 2011. Every detection by the Fermi LAT since its launch, was reexamined with the latest tools to learn how the LAT detector responded to both each event and to
1248-602: The Fermi mission have been described as: The National Academies of Sciences ranked this mission as a top priority. Many new possibilities and discoveries are anticipated to emerge from this single mission and greatly expand our view of the Universe . On 4 March 2008, the spacecraft arrived at the Astrotech payload processing facility in Titusville, Florida . On 4 June 2008, after several previous delays, launch status
1300-437: The Fermi project. The main Fermi education and public outreach website at http://glast.sonoma.edu offers gateways to resources for students, educators, scientists, and the public. NASA's Education and Public Outreach (E/PO) group operates the Fermi education and outreach resources at Sonoma State University . The 2011 Bruno Rossi Prize was awarded to Bill Atwood, Peter Michelson and the Fermi LAT team "for enabling, through
1352-641: The Gamma-ray Burst Monitor (GBM; formerly GLAST Burst Monitor), is being used to study gamma-ray bursts and solar flares . Fermi, named for high-energy physics pioneer Enrico Fermi , was launched on 11 June 2008 at 16:05 UTC aboard a Delta II 7920-H rocket. The mission is a joint venture of NASA , the United States Department of Energy , and government agencies in France, Germany, Italy, Japan, and Sweden, becoming
1404-525: The LIGO observation. The Fermi team calculated the odds of such an event being the result of a coincidence or noise at 0.22%. However, observations from the INTEGRAL telescope's all-sky SPI-ACS instrument indicated that any energy emission in gamma-rays and hard X-rays from the event was less than one millionth of the energy emitted as gravitational waves, concluding that "this limit excludes the possibility that
1456-509: The Thor missile, to launch probes to the Moon and planets, solar observatories and weather satellites. SLC-17 features two expendable launch vehicle (ELV) launch pads, 17A and 17B . The pads were operated by the 45th Space Wing and have supported more than 300 Department of Defense , NASA and commercial missile and rocket launches. Following the last military launch, in August 2009, SLC-17A
1508-407: The data is also available. NASA's Alan Stern , associate administrator for Science at NASA Headquarters, launched a public competition 7 February 2008, closing 31 March 2008, to rename GLAST in a way that would "capture the excitement of GLAST's mission and call attention to gamma-ray and high-energy astronomy ... something memorable to commemorate this spectacular new astronomy mission ...
1560-569: The development of the Large Area Telescope, new insights into neutron stars, supernova remnants, cosmic rays, binary systems, active galactic nuclei and gamma-ray bursts." In 2013, the prize was awarded to Roger W. Romani of Leland Stanford Junior University and Alice Harding of Goddard Space Flight Center for their work in developing the theoretical framework underpinning the many exciting pulsar results from Fermi Gamma-ray Space Telescope. The 2014 prize went to Tracy Slatyer , Douglas Finkeiner and Meng Su "for their discovery, in gamma rays, of
1612-494: The entire sky every three hours (every two orbits). On 30 April 2013, NASA revealed that the telescope had narrowly avoided a collision a year earlier with a defunct Cold War-era Soviet spy satellite, Kosmos 1805 , in April 2012. Orbital predictions several days earlier indicated that the two satellites were expected to occupy the same point in space within 30 milliseconds of each other. On 3 April, telescope operators decided to stow
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1664-574: The event is associated with substantial gamma-ray radiation, directed towards the observer." If the signal observed by the Fermi GBM was associated with GW150914, SPI-ACS would have detected it with a significance of 15 sigma above the background. The AGILE space telescope also did not detect a gamma-ray counterpart of the event. A follow-up analysis of the Fermi report by an independent group, released in June 2016, purported to identify statistical flaws in
1716-492: The false coincidence probability is calculated empirically and is not refuted by the independent analysis. In October 2018, astronomers reported that GRB 150101B , 1.7 billion light years away from Earth, may be analogous to the historic GW170817 . It was detected on 1 January 2015 at 15:23:35 UT by the Gamma-ray Burst Monitor on board the Fermi Gamma-ray Space Telescope, along with detections by
1768-440: The formation of a rotating bar that breaks into two dense clumps of matter with a dumbbell configuration that becomes a black hole binary, and at the end of the star's collapse it triggers a gamma-ray burst. Loeb suggests that the 0.4 second delay is the time it took the gamma-ray burst to cross the star, relative to the gravitational waves. On 17 August 2017, Fermi Gamma-Ray Burst Monitor software detected, classified, and localized
1820-564: The highest energy light ever seen in a solar eruption. At the flare's peak, the LAT detected gamma rays with two billion times the energy of visible light, or about four billion electron volts (GeV), easily setting a record for the highest-energy light ever detected during or immediately after a solar flare Fermi telescope has observed and detected numerous terrestrial gamma-ray flashes and discovered that such flashes can produce 100 trillion positrons, far more than scientists had previously expected. On 27 April 2013, Fermi detected GRB 130427A ,
1872-400: The initial analysis, concluding that the observation was consistent with a statistical fluctuation or an Earth albedo transient on a 1-second timescale. A rebuttal of this follow-up analysis, however, pointed out that the independent group misrepresented the analysis of the original Fermi GBM Team paper and therefore misconstrued the results of the original analysis. The rebuttal reaffirmed that
1924-549: The instrument. The GBM high voltage was also turned on 25 June, but the GBM still required one more week of testing/calibrations before searching for gamma-ray bursts. After presenting an overview of the Fermi instrumentation and goals, Jennifer Carson of SLAC National Accelerator Laboratory had concluded that the primary goals were "all achievable with the all-sky scanning mode of observing". Fermi switched to "sky survey mode" on 26 June 2008 so as to begin sweeping its field of view over
1976-416: The instruments. It travels in a low, circular orbit with a period of about 95 minutes. Its normal mode of operation maintains its orientation so that the instruments will look away from the Earth, with a "rocking" motion to equalize the coverage of the sky. The view of the instruments will sweep out across most of the sky about 16 times per day. The spacecraft can also maintain an orientation that points to
2028-471: The large unanticipated Galactic structure called the Fermi bubbles ." The 2018 prize was awarded to Colleen Wilson-Hodge and the Fermi GBM team for the detection of GRB 170817A , the first unambiguous and completely independent discovery of an electromagnetic counterpart to a gravitational wave signal ( GW170817 ) that "confirmed that short gamma-ray bursts are produced by binary neutron star mergers and enabled
2080-468: The most sensitive gamma-ray telescope on orbit, succeeding INTEGRAL . The project is a recognized CERN experiment (RE7). Fermi includes two scientific instruments, the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). General Dynamics Advanced Information Systems (formerly Spectrum Astro and now Orbital Sciences ) in Gilbert, Arizona , designed and built the spacecraft that carries
2132-468: The next decades, Pad 17B was modified in 1997 to support a new, more powerful launch vehicle, the Delta III , which made its maiden flight from the complex on 26 August 1998. The launch ended in failure, as did a second launch the next year. After a third launch on 23 August 2000 placed a mass simulator into a lower than planned orbit, the program was abandoned. Among the major NASA missions launched from
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2184-503: The satellite was placed at a fixed angle relative to its orbit to maximize solar power. The next day the GBM instrument was turned back on. On 2 April, operators turned LAT on and it resumed operations on 8 April. Alternative observation strategies are being developed due to power and thermal requirements. The first major discovery came when the space telescope detected a pulsar in the CTA 1 supernova remnant that appeared to emit radiation in
2236-414: The satellite's high-gain parabolic antenna, rotate the solar panels out of the way and to fire Fermi's rocket thrusters for one second to move it out of the way. Even though the thrusters had been idle since the telescope had been placed in orbit nearly five years earlier, they worked correctly and potential disaster was thus avoided. In August 2013 Fermi started its 5-year mission extension. In June 2015,
2288-829: The sides of the spacecraft to view all of the sky which is not blocked by the Earth. The design is optimized for good resolution in time and photon energy, and is sensitive from 8 keV (a medium X-ray ) to 40 MeV (a medium-energy gamma-ray ). "Gamma-ray bursts are so bright we can see them from billions of light-years away, which means they occurred billions of years ago, and we see them as they looked then", stated Charles Meegan of NASA's Marshall Space Flight Center . The Gamma-ray Burst Monitor has detected gamma rays from positrons generated in powerful thunderstorms. The Large Area Telescope (LAT) detects individual gamma rays using technology similar to that used in terrestrial particle accelerators . Photons hit thin metal sheets, converting to electron - positron pairs, via
2340-526: Was a launch site at Cape Canaveral Air Force Station (CCAFS), Florida used for Thor and Delta launch vehicles launches between 1958 and 2011. It was built in 1956 for use with the PGM-17 Thor missile, the first operational ballistic missile in the arsenal of the United States . More recently the launch complex has been used for vehicles in the Delta launch vehicle family, derived from
2392-484: Was announced that active galactic nuclei are not responsible for most gamma-ray background radiation. Though active galactic nuclei do produce some of the gamma-ray radiation detected here on Earth, less than 30% originates from these sources. The search now is to locate the sources for the remaining 70% or so of all gamma-rays detected. Possibilities include star forming galaxies , galactic mergers , and yet-to-be explained dark matter interactions . In November 2010, it
2444-439: Was announced that two gamma-ray and X-ray emitting bubbles were detected around our galaxy, the Milky Way. The bubbles, named Fermi bubbles , extend about 25 thousand light-years distant above and below the galactic center. The galaxy's diffuse gamma-ray fog hampered prior observations, but the discovery team led by D. Finkbeiner, building on research by G. Dobler, worked around this problem. In early 2012, Fermi/GLAST observed
2496-428: Was reprocessed. These improvements have the greatest impact on both the low and high ends of the range of energy Fermi LAT can detect - in effect expanding the energy range within which LAT can make useful observations. The improvement in the performance of Fermi LAT due to Pass 8 is so dramatic that this software update is sometimes called the cheapest satellite upgrade in history. Among numerous advances, it allowed for
2548-549: Was retargeted for 11 June at the earliest, the last delays resulting from the need to replace the Flight Termination System batteries. The launch window extended from 15:45 to 17:40 UTC daily, until 7 August 2008. Launch occurred successfully on 11 June 2008 at 16:05 UTC aboard a Delta 7920H-10C rocket from Cape Canaveral Air Force Station Space Launch Complex 17-B . Spacecraft separation took place about 75 minutes after launch. Fermi resides in
2600-669: Was serviced by the Space Shuttle , but most space telescopes cannot be serviced at all. Satellites have been launched and operated by NASA , ISRO , ESA , CNSA , JAXA and the Soviet space program (later succeeded by Roscosmos of Russia). As of 2022, many space observatories have already completed their missions, while others continue operating on extended time. However, the future availability of space telescopes and observatories depends on timely and sufficient funding. While future space observatories are planned by NASA, JAXA and
2652-512: Was used to create the P8R3 version of LAT data. On 16 March 2018 one of Fermi's solar arrays quit rotating, prompting a transition to "safe hold" mode and instrument power off. This was the first mechanical failure in nearly 10 years. Fermi's solar arrays rotate to maximize the exposure of the arrays to the Sun. The motor that drives that rotation failed to move as instructed in one direction. On 27 March,
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#17327827948972704-407: Was withdrawn from use, and LC-17B was transferred to NASA (SLC-17B) for two remaining launches. Pad 17A supported its first Thor missile launch on 3 August 1957, and Pad 17B supported its first Thor launch on 25 January 1957. The site was upgraded in the early 1960s to support a variety of more modern ELVs, which were derived from the basic Thor booster. The modern ELVs based on Thor came to be called
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