Space Telescope Science Institute
Encyclopedia
The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope
(HST; in orbit since 1990) and for the James Webb Space Telescope
(JWST; scheduled to be launched in 2014). STScI is located on the Johns Hopkins University
Homewood campus in Baltimore
, Maryland and was established in 1981 as a community-based science center that is operated for NASA
by the Association of Universities for Research in Astronomy
(AURA). Today, in addition to performing continuing science operations of HST and preparing for scientific exploration with JWST, STScI manages and operates the Multi-mission Archive at Space Telescope (MAST), the Data Management Center for the Kepler mission
and a number of other activities benefiting from its expertise in and infrastructure for supporting the operations of space-based astronomical observatories. Most of the funding for STScI activities comes from contracts with NASA's Goddard Space Flight Center
but there are smaller activities funded by NASA's Ames Research Center, NASA’s Jet Propulsion Laboratory
, and the European Space Agency
(ESA). The staff at STScI consists of scientists (mostly astronomers and astrophysicists), software engineers, data management and telescope operations personnel, education and public outreach experts, and administrative and business support personnel. There are approximately 100 Ph.D. scientists working at STScI, 15 of which are ESA staff who are on assignment to the HST project. The total STScI staff consists of about 450 people.
STScI operates its missions on behalf of NASA, the worldwide astronomy community, and the general public. The science operations activities directly serve the astronomy community, primarily in the form of HST (and eventually JWST) observations and grants, but also include distributing data from other NASA missions (e.g., Far Ultraviolet Spectroscopic Explorer
, Galaxy Evolution Explorer) and ground-based sky surveys. The ground system development activities create and maintain the software systems that are needed to provide these services to the astronomy community. STScI's public outreach activities provide a wide range of information, on-line media, and programs for formal educators, planetariums and science museums, and the general public. STScI's award-winning public outreach websites receive millions of hits per month. STScI also serves as a source of guidance to NASA on a range of optical and UV space astrophysics issues.
The STScI staff interacts and communicates with the professional astronomy community through a number of channels, including participation at the bi-annual meetings of the American Astronomical Society
, publication of quarterly STScI newsletters and the STScI website, hosting user committees and science working groups, and holding several scientific and technical symposia and workshops each year. These activities enable STScI to disseminate information to the telescope user community as well as enabling the STScI staff to maximize the scientific productivity of the facilities they operate by responding to the needs of the community and of NASA.
and the National Optical Astronomy Observatories). STScI provides all technical and logistical support for these activities. The annual cycle of proposal calls is occasionally altered in duration in years when a HST servicing mission is scheduled.
Proposers fortunate enough to be awarded telescope time, referred to as General Observers (GOs), must then provide detailed requirements needed to schedule and implement their observing programs. This information is provided to STScI on what is called a Phase II proposal. The Phase II proposal specifies instrument operation modes, exposure times, telescope orientations, and so on. The STScI staff provide the web-based software called Exposure Time Calculators (ETCs) that allow GOs to estimate how much observing time any of the onboard detectors will need to accumulate the amount of light required to accomplish their scientific objectives. In addition, the STScI staff carries out all the steps necessary to implement each specific program, as well as plan the entire ensemble of programs for the year. For HST, this includes finding guide stars, checking on bright object constraints, implementing specific scheduling requirements, and working with observers to understand and factor in specific or any non-standard requirements they may have.
e or coordination with one-of-a-kind events such as comet
impact spacecraft). The STScI uses the Min-conflicts algorithm to schedule observation time on the telescope. The STScI is currently developing similar processes for JWST, although the operational details will be very different due to its different instrumentation and spacecraft constraints, and its location at the Sun-Earth L2 Lagrange point (~1.5 million km from Earth) rather than the low Earth orbit (~565 km) used by HST.
: Flexible Image Transport System), correct for missing data, and perform final calibration of the data by removing instrumental artifacts. The calibration steps are different for each HST instrument, but as a general rule they include cosmic ray removal, correction for instrument/detector non-uniformities, flux calibration, and application of world coordinate system information (which tells the user precisely where on the sky the detector was pointed). The calibrations applied are the best available at the time the data pass through the pipeline. The STScI is working with instrument developers to define similar processes for Kepler and JWST data.
(IUE), the Extreme Ultraviolet Explorer
(EUVE), the Far Ultraviolet Spectroscopic Explorer
(FUSE), and the Galaxy Evolution Explorer (GALEX). Kepler and JWST science data will be archived and retrieved in similar fashions. The internet serves as the primary user interface to the data archives at STScI (http://archive.stsci.edu). The archive currently holds over 30 terabyte
s of data. Each day about 11 gigabyte
s of new data are ingested and about 85 gigabytes of data are distributed to users. The Hubble Legacy Archive (HLA; http://hla.stsci.edu/), currently in development, will act as a more integrated and user-friendly archive. It will provide raw Hubble data as well as higher-level science products (color images, mosaics, etc.).
. Electronic failures in STIS (in 2001) and in the ACS Wide-Field Channel (in 2007) were also repaired on-orbit in May 2009, bringing these instruments back to active status. All 12 HST instruments plus the 4 planned for JWST are summarized in the table below. HST instruments can detect light with wavelengths from the ultraviolet
through the near infrared
. JWST instruments will operate from the red-end of optical wavelengths (~6000 Angstroms) to the mid-infrared (5 to 27 micrometres). Instruments listed as decommissioned are no longer on board.
STScI staff develops the calibration proposals, shepherd them through the scheduling process, and analyze the data they produce. These programs provide updated calibration and reference files to be used in the data processing pipeline. The calibration files are also archived so users can retrieve them if they need to manually recalibrate their data. All calibration activity and results are documented, usually in the form of Instrument Science Reports posted to the public website, and occasionally in the form of published papers. Results are also incorporated into the Data Handbooks and Instrument Handbooks.
In addition to calibration of the instruments, STScI staff characterizes and documents the performance of the instrument, so users can better understand how to interpret their data. These are generally effects that are not automatically corrected for in the pipeline (because they vary with time or depend on the brightness of the source). They include global effects, such as charge transfer efficiency in the charge coupled devices, as well as effects specific to modes and filters, such as filter “ghosts” (caused by subtle scattering of light within an instrument). Awareness of these effects can come from STScI staff as they analyze calibration programs, or from observers who find oddities in their data and provide feedback to STScI.
The STScI staff also performs the characterization and calibration of the telescope itself. In the case of HST, this has evolved to primarily be a matter of monitoring and adjusting focus, and monitoring and measuring point spread function
s. (In the early 1990s, the STScI was responsible for accurate measurement of the spherical aberration
, necessary for the corrective optics of all subsequent instruments). In the case of JWST, the STScI will be responsible for using the wavefront sensor
system developed by JPL and Northrop Grumman
Space Technology (NGST, the NASA contractor building the observatory) to monitor and adjust the segmented telescope.
(HDF), the Hubble Deep Field South
(HDFS), and the Ultra Deep Field (UDF). The raw and processed data for these observations are made available to the astronomy community nearly immediately. These products have then been used by many astronomers in pursuit of their own research topics, and have motivated a great deal of follow-up work (see, for example, http://www.stsci.edu/ftp/science/hdf/clearinghouse/clearinghouse.html and http://www.stsci.edu/hst/udf/index_html).
mode of HST operations. STScI also provides subsets of ground system services to other astronomy missions, including FUSE, Kepler, and JWST. STScI’s software engineers maintain about 7,900,000 source lines of code
.
, exoplanet detection and characterization, star formation
, galaxy
evolution, and cosmology
. STScI hosts an annual scientific symposium held each spring as well as several smaller scientific workshops. The employment of an active scientific staff at STScI helps to ensure that HST, and eventually JWST, perform at peak capability.
OPO's News Branch produces approximately 40 new press releases each year featuring HST discoveries and science results. These media packages include news stories, Hubble images, explanatory artwork, animations, and supplementary information for use by print, broadcast, and on-line media. The branch also conducts press conferences called "NASA Science Updates" for particularly newsworthy discoveries. Science Writers' Workshops and other special events bring reporters to the Institute for in-depth sessions with scientists working on current astrophysical research problems.
The Formal Education Branch develops standards-based and rigorously evaluated educational products and lessons for use in K-14 curricula throughout the country. Many of the branch's products are incorporated in its award-winning web site called Amazing Space (http://amazing-space.stsci.edu/) where lessons and exercises are readily accessible by both teachers and students and is used in more than 200 school districts and in all 50 states.
The Informal Education Branch creates a variety of Hubble-related products and features for use in informal venues including museums, science centers, planetariums, and libraries. These include ViewSpace, a multimedia display system providing a series of educational features on the science of Hubble and other missions using imagery, text, and music. A short film called "Hubble: Galaxies Across Space and Time" which features a three-dimensional fly-through of the Hubble Ultra Deep Field has been produced for IMAX
theaters and adapted for use in planetariums. The group also provides materials for conferences and workshops, manages Hubble traveling exhibits for national distribution, and creates video compilations of Hubble imagery and features.
OPO's Online Branch develops, improves and maintains a series of HST and JWST related web sites including the award-winning HubbleSite (http://hubblesite.org), which contains an image gallery of nearly 900 Hubble images that have been released for public consumption over the telescope's lifetime.
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
(HST; in orbit since 1990) and for the James Webb Space Telescope
James Webb Space Telescope
The James Webb Space Telescope , previously known as Next Generation Space Telescope , is a planned next-generation space telescope, optimized for observations in the infrared. The main technical features are a large and very cold 6.5 meter diameter mirror, an observing position far from Earth,...
(JWST; scheduled to be launched in 2014). STScI is located on the Johns Hopkins University
Johns Hopkins University
The Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university based in Baltimore, Maryland, United States...
Homewood campus in Baltimore
Baltimore
Baltimore is the largest independent city in the United States and the largest city and cultural center of the US state of Maryland. The city is located in central Maryland along the tidal portion of the Patapsco River, an arm of the Chesapeake Bay. Baltimore is sometimes referred to as Baltimore...
, Maryland and was established in 1981 as a community-based science center that is operated for NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
by the Association of Universities for Research in Astronomy
Association of Universities for Research in Astronomy
The Association of Universities for Research in Astronomy is a consortium of universities and other institutions that operates astronomical observatories and telescopes...
(AURA). Today, in addition to performing continuing science operations of HST and preparing for scientific exploration with JWST, STScI manages and operates the Multi-mission Archive at Space Telescope (MAST), the Data Management Center for the Kepler mission
Kepler Mission
The Kepler spacecraft is an American space observatory, the space-based portion of NASA's Kepler Mission to discover Earth-like planets orbiting other stars. The spacecraft is named in honor of the 17th-century German astronomer Johannes Kepler...
and a number of other activities benefiting from its expertise in and infrastructure for supporting the operations of space-based astronomical observatories. Most of the funding for STScI activities comes from contracts with NASA's Goddard Space Flight Center
Goddard Space Flight Center
The Goddard Space Flight Center is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight center. GSFC employs approximately 10,000 civil servants and contractors, and is located approximately northeast of Washington, D.C. in Greenbelt, Maryland, USA. GSFC,...
but there are smaller activities funded by NASA's Ames Research Center, NASA’s Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...
, and the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...
(ESA). The staff at STScI consists of scientists (mostly astronomers and astrophysicists), software engineers, data management and telescope operations personnel, education and public outreach experts, and administrative and business support personnel. There are approximately 100 Ph.D. scientists working at STScI, 15 of which are ESA staff who are on assignment to the HST project. The total STScI staff consists of about 450 people.
STScI operates its missions on behalf of NASA, the worldwide astronomy community, and the general public. The science operations activities directly serve the astronomy community, primarily in the form of HST (and eventually JWST) observations and grants, but also include distributing data from other NASA missions (e.g., Far Ultraviolet Spectroscopic Explorer
Far Ultraviolet Spectroscopic Explorer
The Far Ultraviolet Spectroscopic Explorer is a space-based telescope operated by the Johns Hopkins University Applied Physics Laboratory. FUSE was launched on a Delta II rocket on June 24, 1999, as a part of NASA's Origins program...
, Galaxy Evolution Explorer) and ground-based sky surveys. The ground system development activities create and maintain the software systems that are needed to provide these services to the astronomy community. STScI's public outreach activities provide a wide range of information, on-line media, and programs for formal educators, planetariums and science museums, and the general public. STScI's award-winning public outreach websites receive millions of hits per month. STScI also serves as a source of guidance to NASA on a range of optical and UV space astrophysics issues.
The STScI staff interacts and communicates with the professional astronomy community through a number of channels, including participation at the bi-annual meetings of the American Astronomical Society
American Astronomical Society
The American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
, publication of quarterly STScI newsletters and the STScI website, hosting user committees and science working groups, and holding several scientific and technical symposia and workshops each year. These activities enable STScI to disseminate information to the telescope user community as well as enabling the STScI staff to maximize the scientific productivity of the facilities they operate by responding to the needs of the community and of NASA.
Telescope science proposal selection
The STScI conducts all activities required to select, schedule, and implement the science programs of HST. The first step in this process is to support the annual community-led selection of the scientific programs that will be performed with HST. This begins with publishing of the annual Call for Proposals, which specifies the currently supported science instrument capabilities, proposal requirements and the submission deadline. Anyone is eligible to submit a proposal. All proposals are critically peer-reviewed by the Time Allocation Committee (TAC). The TAC consists of about 100 members of the U.S. and international astronomical community, selected to represent a broad range of research expertise needed to evaluate the proposals. Each proposal cycle typically involves reviewing 700 to 1100 proposals. Only 15 - 20% of these proposals will eventually be selected for implementation. The TAC reviews several categories of observing time, as well as proposals for archival, theoretical, and combined research projects between HST and other space-based or ground-based observatories (e.g., Chandra X-ray ObservatoryChandra X-ray Observatory
The Chandra X-ray Observatory is a satellite launched on STS-93 by NASA on July 23, 1999. It was named in honor of Indian-American physicist Subrahmanyan Chandrasekhar who is known for determining the maximum mass for white dwarfs. "Chandra" also means "moon" or "luminous" in Sanskrit.Chandra...
and the National Optical Astronomy Observatories). STScI provides all technical and logistical support for these activities. The annual cycle of proposal calls is occasionally altered in duration in years when a HST servicing mission is scheduled.
Proposers fortunate enough to be awarded telescope time, referred to as General Observers (GOs), must then provide detailed requirements needed to schedule and implement their observing programs. This information is provided to STScI on what is called a Phase II proposal. The Phase II proposal specifies instrument operation modes, exposure times, telescope orientations, and so on. The STScI staff provide the web-based software called Exposure Time Calculators (ETCs) that allow GOs to estimate how much observing time any of the onboard detectors will need to accumulate the amount of light required to accomplish their scientific objectives. In addition, the STScI staff carries out all the steps necessary to implement each specific program, as well as plan the entire ensemble of programs for the year. For HST, this includes finding guide stars, checking on bright object constraints, implementing specific scheduling requirements, and working with observers to understand and factor in specific or any non-standard requirements they may have.
Observation scheduling
Once the Phase II information is gathered, a long-range observing plan is developed that covers the entire year, finding appropriate times to schedule individual observations, and at the same time ensuring effective and efficient use of the telescope through the year. Detailed observing schedules are created each week, including, in the case of HST operations, scheduling the data communication paths via the Tracking and Data Relay Satellite System (TDRSS) and generating the binary command loads for uplink to the spacecraft. Adjustments can be made to both long-range and weekly plans in response to Targets of Opportunity (e.g., for transient events like supernovaSupernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
e or coordination with one-of-a-kind events such as comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
impact spacecraft). The STScI uses the Min-conflicts algorithm to schedule observation time on the telescope. The STScI is currently developing similar processes for JWST, although the operational details will be very different due to its different instrumentation and spacecraft constraints, and its location at the Sun-Earth L2 Lagrange point (~1.5 million km from Earth) rather than the low Earth orbit (~565 km) used by HST.
Flight operations
Flight Operations consists of the direct support and monitoring of HST functions in real-time. Real-time daily flight operations for HST include about 4 command load uplinks, about 10 data downlinks, and near continuous health and safety monitoring of the observatory. Real-time operations are staffed around the clock. Flight operations activities for HST are done at NASA's GSFC in Greenbelt, Maryland.Science data processing
Science data from HST arrive at the STScI a few hours after being downlinked from TDRSS and subsequently passing through a data capture facility at NASA's Goddard Space Flight Center. Once at STScI, the data are processed by a series of computer algorithms that convert its format into an internationally accepted standard (known as FITSFITS
Flexible Image Transport System is a digital file format used to store, transmit, and manipulate scientific and other images. FITS is the most commonly used digital file format in astronomy...
: Flexible Image Transport System), correct for missing data, and perform final calibration of the data by removing instrumental artifacts. The calibration steps are different for each HST instrument, but as a general rule they include cosmic ray removal, correction for instrument/detector non-uniformities, flux calibration, and application of world coordinate system information (which tells the user precisely where on the sky the detector was pointed). The calibrations applied are the best available at the time the data pass through the pipeline. The STScI is working with instrument developers to define similar processes for Kepler and JWST data.
Science data archiving and distribution
All HST science data are permanently archived after passing through the calibration pipeline. NASA policy mandates a one-year proprietary period on all data, which means that only the initial proposal team can access the data for the first year after it has been obtained. Subsequent to that year, the data become available to anyone who wishes to access it. Data sets retrieved from the archive are automatically re-calibrated to ensure that the most up-to-date calibration factors and software are applied. The STScI serves as the archive center for all of NASA’s optical/UV space missions. In addition to archiving and storing HST science data, STScI holds data from 13 other missions including the International Ultraviolet ExplorerInternational Ultraviolet Explorer
The International Ultraviolet Explorer was an astronomical observatory satellite primarily designed to take ultraviolet spectra. The satellite was a collaborative project between NASA, the UK Science Research Council and the European Space Agency...
(IUE), the Extreme Ultraviolet Explorer
Extreme Ultraviolet Explorer
The Extreme Ultraviolet Explorer was a space telescope for ultraviolet astronomy, launched on June 7, 1992. With instruments for UV radiation between wavelengths of 7 and 76 nm, the EUVE was the first satellite mission especially for the short-wave ultraviolet range...
(EUVE), the Far Ultraviolet Spectroscopic Explorer
Far Ultraviolet Spectroscopic Explorer
The Far Ultraviolet Spectroscopic Explorer is a space-based telescope operated by the Johns Hopkins University Applied Physics Laboratory. FUSE was launched on a Delta II rocket on June 24, 1999, as a part of NASA's Origins program...
(FUSE), and the Galaxy Evolution Explorer (GALEX). Kepler and JWST science data will be archived and retrieved in similar fashions. The internet serves as the primary user interface to the data archives at STScI (http://archive.stsci.edu). The archive currently holds over 30 terabyte
Terabyte
The terabyte is a multiple of the unit byte for digital information. The prefix tera means 1012 in the International System of Units , and therefore 1 terabyte is , or 1 trillion bytes, or 1000 gigabytes. 1 terabyte in binary prefixes is 0.9095 tebibytes, or 931.32 gibibytes...
s of data. Each day about 11 gigabyte
Gigabyte
The gigabyte is a multiple of the unit byte for digital information storage. The prefix giga means 109 in the International System of Units , therefore 1 gigabyte is...
s of new data are ingested and about 85 gigabytes of data are distributed to users. The Hubble Legacy Archive (HLA; http://hla.stsci.edu/), currently in development, will act as a more integrated and user-friendly archive. It will provide raw Hubble data as well as higher-level science products (color images, mosaics, etc.).
Science instrument calibration and characterization
STScI is responsible for in-flight calibration of the science instruments on HST and JWST. For HST, a calibration plan for the observatory is developed each year. This plan is designed to support the selected GO observation programs for that cycle, as well as to provide a basic calibration that spans the lifetime of each instrument. The calibration program includes measurements that are made relative to on-board calibration sources or to assess internal detector noise levels as well as observations of astronomical standard stars and fields, needed to determine absolute flux conversions and astrometric transformations. The external calibrations on HST typically total 5-10% of the GO observing program, with more time required when an instrument is still relatively new. HST has had a total of 12 science instruments to date, 6 of which are currently active. Two new instruments were installed during the May 2009 HST servicing mission STS-125STS-125
STS-125, or HST-SM4 , was the fifth and final space shuttle servicing mission to the Hubble Space Telescope .Launch occurred on 11 May 2009 at 2:01 pm EDT...
. Electronic failures in STIS (in 2001) and in the ACS Wide-Field Channel (in 2007) were also repaired on-orbit in May 2009, bringing these instruments back to active status. All 12 HST instruments plus the 4 planned for JWST are summarized in the table below. HST instruments can detect light with wavelengths from the ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
through the near infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
. JWST instruments will operate from the red-end of optical wavelengths (~6000 Angstroms) to the mid-infrared (5 to 27 micrometres). Instruments listed as decommissioned are no longer on board.
| Instrument name (and abbreviation) | Instrument function | Instrument Status | Telescope |
|---|---|---|---|
| High Speed Photometer High Speed Photometer The High Speed Photometer was a scientific instrument installed on the Hubble Space Telescope. The HSP was designed to measure the brightness and polarity of rapidly varying celestial objects. It could observe in ultraviolet, visible light, and near infrared at a rate of one measurement per 10... (HSP) |
Rapid Timescale Photometry Photometry (astronomy) Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation... |
Decommissioned in 1993 | HST |
| Wide Field and Planetary Camera Wide Field and Planetary Camera The Wide Field/Planetary Camera was a camera installed on the Hubble Space Telescope until December 1993. It was one of the instruments on Hubble at launch, but its functionality was severely impaired by the defects of the main mirror optics which afflicted the telescope... (WFPC) |
UV/Optical Imaging | Decommissioned in 1993 | HST |
| Faint Object Spectrograph Faint Object Spectrograph The Faint Object Spectrograph was a spectrograph installed on the Hubble Space Telescope. It was replaced by the Space Telescope Imaging Spectrograph in 1997, and is now on display in the National Air and Space Museum in Washington DC. -FOS facts:... (FOS) |
UV/Optical Spectroscopy Spectroscopy Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative... |
Decommissioned in 1997 | HST |
| Goddard High Resolution Spectrograph Goddard High Resolution Spectrograph The Goddard High Resolution Spectrograph was a spectrograph installed on the Hubble Space Telescope. It was replaced by the Near Infrared Camera and Multi-Object Spectrometer in 1997.-GHRS facts:... (GHRS) |
UV/Optical Spectroscopy | Decommissioned in 1997 | HST |
| Faint Object Camera Faint Object Camera The Faint Object Camera was a camera installed on the Hubble Space Telescope from launch in 1990 until 2002. It was replaced by the Advanced Camera for Surveys.The camera was built by Dornier GmbH and was funded by the European Space Agency... (FOC) |
UV/Optical Imaging | Decommissioned in 2002 | HST |
| Wide Field and Planetary Camera 2 Wide Field and Planetary Camera 2 The Wide Field and Planetary Camera 2 is a baby grand piano sized camera built by the Jet Propulsion Laboratory and formerly installed on the Hubble Space Telescope. It was installed by servicing mission 1 in 1993, replacing the telescope's original Wide Field and Planetary Camera... (WFPC2) |
UV/Optical Imaging | Decommissioned in 2009 | HST |
| Fine Guidance Sensor Fine Guidance Sensor The Fine Guidance Sensor is an interferometric instrument on board the Hubble Space Telescope that provides high-precision pointing information as input to the observatory's attitude control systems.... (FGS) |
Precision Astrometry Astrometry Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. The information obtained by astrometric measurements provides information on the kinematics and physical origin of our Solar System and our Galaxy, the Milky... |
Active | HST |
| Space Telescope Imaging Spectrograph Space Telescope Imaging Spectrograph The Space Telescope Imaging Spectrograph is a spectrograph, also with a camera mode, installed on the Hubble Space Telescope. It operated continuously from 1997 until a power supply failure in 2004. After repairs, it began operating again in 2009... (STIS) |
UV/Optical Spectroscopy | Active (repaired) | HST |
| Near Infrared Camera and Multi-Object Spectrometer Near Infrared Camera and Multi-Object Spectrometer The Near Infrared Camera and Multi-Object Spectrometer is a scientific instrument for infrared astronomy, installed on the Hubble Space Telescope , operating from 1997 to 1999, and from 2002 to 2008... (NICMOS) |
NIR Imaging and grism Grism A grism is a combination of a prism and grating arranged so that light at a chosen central wavelength passes straight through. The advantage of this arrangement is that one and the same camera can be used both for imaging and spectroscopy without having to be moved... Spectroscopy |
Active | HST |
| Advanced Camera for Surveys Advanced Camera for Surveys The Advanced Camera for Surveys is a third generation axial instrument aboard the Hubble Space Telescope . The initial design and scientific capabilities of ACS were defined by a team based at Johns Hopkins University. ACS was assembled and tested extensively at Ball Aerospace & Technologies Corp... (ACS) |
UV/Optical Imaging and grism Grism A grism is a combination of a prism and grating arranged so that light at a chosen central wavelength passes straight through. The advantage of this arrangement is that one and the same camera can be used both for imaging and spectroscopy without having to be moved... Spectroscopy |
SBC and WFC (repaired) Active; HRC Inactive http://www.stsci.edu/resources/acs.html | HST |
| Cosmic Origins Spectrograph Cosmic Origins Spectrograph The Cosmic Origins Spectrograph is a science instrument that was installed on the Hubble Space Telescope during Servicing Mission 4 in May 2009. It is designed for ultraviolet spectroscopy of faint point sources with a resolving power of ≈1,550–24,000... (COS) |
UV Spectroscopy | Active | HST |
| Wide Field Camera 3 Wide Field Camera 3 The Wide Field Camera 3 is the Hubble Space Telescope's last and most technologically advanced instrument to take images in the visible spectrum... (WFC3) |
UV/Optical/Near-IR Imaging and grism Grism A grism is a combination of a prism and grating arranged so that light at a chosen central wavelength passes straight through. The advantage of this arrangement is that one and the same camera can be used both for imaging and spectroscopy without having to be moved... Spectroscopy |
Active | HST |
| Near Infrared Camera (NIRCam) | Optical/Near-IR Imaging | Pre-flight (2014) | JWST |
| Near Infrared Spectrograph (NIRSpec) | Near-IR Spectroscopy | Pre-flight (2014) | JWST |
| Mid-Infrared Instrument (MIRI) | Mid-IR Imaging & Spectroscopy | Pre-flight (2014) | JWST |
| Tunable Filter Imager (FGS-TFI) | Near to Mid-IR Medium-band Imaging | Pre-flight (2014) | JWST |
STScI staff develops the calibration proposals, shepherd them through the scheduling process, and analyze the data they produce. These programs provide updated calibration and reference files to be used in the data processing pipeline. The calibration files are also archived so users can retrieve them if they need to manually recalibrate their data. All calibration activity and results are documented, usually in the form of Instrument Science Reports posted to the public website, and occasionally in the form of published papers. Results are also incorporated into the Data Handbooks and Instrument Handbooks.
In addition to calibration of the instruments, STScI staff characterizes and documents the performance of the instrument, so users can better understand how to interpret their data. These are generally effects that are not automatically corrected for in the pipeline (because they vary with time or depend on the brightness of the source). They include global effects, such as charge transfer efficiency in the charge coupled devices, as well as effects specific to modes and filters, such as filter “ghosts” (caused by subtle scattering of light within an instrument). Awareness of these effects can come from STScI staff as they analyze calibration programs, or from observers who find oddities in their data and provide feedback to STScI.
The STScI staff also performs the characterization and calibration of the telescope itself. In the case of HST, this has evolved to primarily be a matter of monitoring and adjusting focus, and monitoring and measuring point spread function
Point spread function
The point spread function describes the response of an imaging system to a point source or point object. A more general term for the PSF is a system's impulse response, the PSF being the impulse response of a focused optical system. The PSF in many contexts can be thought of as the extended blob...
s. (In the early 1990s, the STScI was responsible for accurate measurement of the spherical aberration
Spherical aberration
thumb|right|Spherical aberration. A perfect lens focuses all incoming rays to a point on the [[Optical axis|optic axis]]. A real lens with spherical surfaces suffers from spherical aberration: it focuses rays more tightly if they enter it far from the optic axis than if they enter closer to the...
, necessary for the corrective optics of all subsequent instruments). In the case of JWST, the STScI will be responsible for using the wavefront sensor
Wavefront sensor
A wavefront sensor is a device for measuring the aberrations of an optical wavefront. Although an amplitude splitting interferometer such as the Michelson interferometer could be called a wavefront sensor, the term is normally applied to instruments that do not require an unaberrated reference...
system developed by JPL and Northrop Grumman
Northrop Grumman
Northrop Grumman Corporation is an American global aerospace and defense technology company formed by the 1994 purchase of Grumman by Northrop. The company was the fourth-largest defense contractor in the world as of 2010, and the largest builder of naval vessels. Northrop Grumman employs over...
Space Technology (NGST, the NASA contractor building the observatory) to monitor and adjust the segmented telescope.
Post observation support
The post observation support includes a HelpDesk that users can contact to answer their questions about any aspect of observing – from how to submit a proposal to how to analyze the data.Science community service
The STScI performs large HST science programs on behalf of the community. These are programs with broad scientific applications. To date, these programs include the Hubble Deep FieldHubble Deep Field
The Hubble Deep Field is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area 2.5 arcminutes across, two parts in a million of the whole sky, which is equivalent in angular size to a 65 mm tennis...
(HDF), the Hubble Deep Field South
Hubble Deep Field South
The Hubble Deep Field South is a composite of several hundred individual images taken using the Hubble Space Telescope's Wide Field and Planetary Camera 2 over 10 days in September and October 1998. It followed the great success of the original Hubble Deep Field in facilitating the study of...
(HDFS), and the Ultra Deep Field (UDF). The raw and processed data for these observations are made available to the astronomy community nearly immediately. These products have then been used by many astronomers in pursuit of their own research topics, and have motivated a great deal of follow-up work (see, for example, http://www.stsci.edu/ftp/science/hdf/clearinghouse/clearinghouse.html and http://www.stsci.edu/hst/udf/index_html).
Ground systems
STScI is responsible for developing, enhancing, and maintaining most of the ground systems used to carry out our Hubble science operations described above. These systems originally (1980s, early 1990s) came from several sources, including in-house STScI developments and work done under NASA contracts with various vendors. Over HST's lifetime substantial work has been done on these systems - even while they were supporting daily operations of Hubble. They have been integrated into a more effective and easier to operate end-to-end system. They have been through major technology upgrades (e.g., improved operating systems and computer hardware, higher capacity archive storage media). They have also been modified to support the succession of instruments installed in the telescope. In the last several years, they have been modified to support WFC3 and COS, the two new instruments that will be installed during the next HST servicing mission, and to support the 2-GyroscopeGyroscope
A gyroscope is a device for measuring or maintaining orientation, based on the principles of angular momentum. In essence, a mechanical gyroscope is a spinning wheel or disk whose axle is free to take any orientation...
mode of HST operations. STScI also provides subsets of ground system services to other astronomy missions, including FUSE, Kepler, and JWST. STScI’s software engineers maintain about 7,900,000 source lines of code
Source lines of code
Source lines of code is a software metric used to measure the size of a software program by counting the number of lines in the text of the program's source code...
.
Mission development and operations support
STScI routinely participates with NASA and industry system engineers and scientists in developing the overall mission architecture. For HST, this includes helping to determine and prioritize servicing mission activities and development of the servicing strategy. For JWST, this includes participating in the definition of high-level science requirements and the overall architecture for the mission. In both cases, the STScI focuses on the scientific capabilities of the mission, and also the requirements for smooth and efficient operations of the observatory.Scientific research activities
STScI manages the selection of the Hubble Fellowship Program. Hubble Fellowships support outstanding postdoctoral scientists whose research is broadly related to the scientific mission of the Hubble Space Telescope. The research may be theoretical, observational, or instrumental. Each year, since HST’s launch in 1990, 8 to 12 fellowships are awarded. STScI also sponsors a summer student intern program that allows talented undergraduate students from around the world to work with the Institute’s scientific staff, providing these students with hands-on experience in state-of-the-art astronomical research. STScI’s full-time scientific staff conducts original research spanning a broad range of astrophysics including investigations of the solar systemSolar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
, exoplanet detection and characterization, star formation
Star formation
Star formation is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. As a branch of astronomy star formation includes the study of the interstellar medium and giant molecular clouds as precursors to the star formation process and the study of young...
, galaxy
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
evolution, and cosmology
Cosmology
Cosmology is the discipline that deals with the nature of the Universe as a whole. Cosmologists seek to understand the origin, evolution, structure, and ultimate fate of the Universe at large, as well as the natural laws that keep it in order...
. STScI hosts an annual scientific symposium held each spring as well as several smaller scientific workshops. The employment of an active scientific staff at STScI helps to ensure that HST, and eventually JWST, perform at peak capability.
Public outreach
The STScI’s Office of Public Outreach (OPO) provides a wide array of products and services designed to share and communicate the science and discoveries of HST (and eventually JWST) with the general public. OPO's efforts focus on meeting the needs of four communities: the news media, web users, the formal education community and informal science education venues.OPO's News Branch produces approximately 40 new press releases each year featuring HST discoveries and science results. These media packages include news stories, Hubble images, explanatory artwork, animations, and supplementary information for use by print, broadcast, and on-line media. The branch also conducts press conferences called "NASA Science Updates" for particularly newsworthy discoveries. Science Writers' Workshops and other special events bring reporters to the Institute for in-depth sessions with scientists working on current astrophysical research problems.
The Formal Education Branch develops standards-based and rigorously evaluated educational products and lessons for use in K-14 curricula throughout the country. Many of the branch's products are incorporated in its award-winning web site called Amazing Space (http://amazing-space.stsci.edu/) where lessons and exercises are readily accessible by both teachers and students and is used in more than 200 school districts and in all 50 states.
The Informal Education Branch creates a variety of Hubble-related products and features for use in informal venues including museums, science centers, planetariums, and libraries. These include ViewSpace, a multimedia display system providing a series of educational features on the science of Hubble and other missions using imagery, text, and music. A short film called "Hubble: Galaxies Across Space and Time" which features a three-dimensional fly-through of the Hubble Ultra Deep Field has been produced for IMAX
IMAX
IMAX is a motion picture film format and a set of proprietary cinema projection standards created by the Canadian company IMAX Corporation. IMAX has the capacity to record and display images of far greater size and resolution than conventional film systems...
theaters and adapted for use in planetariums. The group also provides materials for conferences and workshops, manages Hubble traveling exhibits for national distribution, and creates video compilations of Hubble imagery and features.
OPO's Online Branch develops, improves and maintains a series of HST and JWST related web sites including the award-winning HubbleSite (http://hubblesite.org), which contains an image gallery of nearly 900 Hubble images that have been released for public consumption over the telescope's lifetime.
External links
- stsci.edu - official site.