A space telescope or 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, 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.
Infrared astronomy is a sub-discipline of astronomy which specializes in the observation and analysis of astronomical objects using infrared (IR) radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers, and falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter waves.
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space telescope launched in 2003, that was deactivated when operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, following IRAS (1983) and ISO (1995–1998). It was the first spacecraft to use an Earth-trailing orbit, later used by the Kepler planet-finder.
The Space Interferometry Mission, or SIM, also known as SIM Lite, was a planned space telescope proposed by the U.S. National Aeronautics and Space Administration (NASA), in conjunction with contractor Northrop Grumman. One of the main goals of the mission was the hunt for Earth-sized planets orbiting in the habitable zones of nearby stars other than the Sun. SIM was postponed several times and finally cancelled in 2010. In addition to detecting extrasolar planets, SIM would have helped astronomers construct a map of the Milky Way galaxy. Other important tasks would have included collecting data to help pinpoint stellar masses for specific types of stars, assisting in the determination of the spatial distribution of dark matter in the Milky Way and in the local group of galaxies and using the gravitational microlensing effect to measure the mass of stars. The spacecraft would have used optical interferometry to accomplish these and other scientific goals.
NASA's series of Great Observatories satellites are four large, powerful space-based astronomical telescopes launched between 1990 and 2003. They were built with different technology to examine specific wavelength/energy regions of the electromagnetic spectrum: gamma rays, X-rays, visible and ultraviolet light, and infrared light.
The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is a scientific instrument for infrared astronomy, installed on the Hubble Space Telescope (HST), operating from 1997 to 1999, and from 2002 to 2008. Images produced by NICMOS contain data from the near-infrared part of the light spectrum.
Darwin was a suggested ESA Cornerstone mission which would have involved a constellation of four to nine spacecraft designed to directly detect Earth-like planets orbiting nearby stars and search for evidence of life on these planets. The most recent design envisaged three free-flying space telescopes, each three to four metres in diameter, flying in formation as an astronomical interferometer. These telescopes were to redirect light from distant stars and planets to a fourth spacecraft, which would have contained the beam combiner, spectrometers, and cameras for the interferometer array, and which would have also acted as a communications hub. There was also an earlier design, called the "Robin Laurance configuration," which included six 1.5 metre telescopes, a beam combiner spacecraft, and a separate power and communications spacecraft.
The Herschel Space Observatory was a space observatory built and operated by the European Space Agency (ESA). It was active from 2009 to 2013, and was the largest infrared telescope ever launched until the launch of the James Webb Space Telescope in 2021. Herschel carries a 3.5-metre (11.5 ft) mirror and instruments sensitive to the far infrared and submillimetre wavebands (55–672 µm). Herschel was the fourth and final cornerstone mission in the Horizon 2000 programme, following SOHO/Cluster II, XMM-Newton and Rosetta.
PLAnetary Transits and Oscillations of stars (PLATO) is a space telescope under development by the European Space Agency for launch in 2026. The mission goals are to search for planetary transits across up to one million stars, and to discover and characterize rocky extrasolar planets around yellow dwarf stars, subgiant stars, and red dwarf stars. The emphasis of the mission is on Earth-like planets in the habitable zone around Sun-like stars where water can exist in a liquid state. It is the third medium-class mission in ESA's Cosmic Vision programme and is named after the influential Greek philosopher Plato. A secondary objective of the mission is to study stellar oscillations or seismic activity in stars to measure stellar masses and evolution and enable the precise characterization of the planet host star, including its age.
The Nancy Grace Roman Space Telescope (shortened as Roman or the Roman Space Telescope, and formerly the Wide-Field Infrared Survey Telescope or WFIRST) is a NASA infrared space telescope in development and scheduled to launch to a Sun–Earth L2 orbit by May 2027.
The Astronomy and Astrophysics Decadal Survey is a review of astronomy and astrophysics literature produced approximately every ten years by the National Research Council of the National Academy of Sciences in the United States. The report surveys the current state of the field, identifies research priorities, and makes recommendations for the coming decade. The decadal survey represents the recommendations of the research community to governmental agencies on how to prioritize scientific funding within astronomy and astrophysics. The editing committee is informed by topical panels and subcommittees, dedicated conferences, and direct community input in the form of white papers summarizing the state of the art in each subdiscipline. The most recent report, Astro2020, was released in 2021.
Fast Infrared Exoplanet Spectroscopy Survey Explorer (FINESSE) was a NASA mission proposal for a space observatory operating in the Near-infrared spectrum for the Medium-Class Explorers program. The Principal Investigator was Mark Swain of the Jet Propulsion Laboratory in Pasadena, California.
Enduring Quests and Daring Visions is a vision for astrophysics programs chartered by then-Director of NASA's Astrophysics Division, Paul Hertz, and released in late 2013. It lays out plans over 30 years as long-term goals and missions. Goals include mapping the Cosmic Microwave Background and finding Earth like exoplanets, to go deeper into space-time studying the Large Scale Structure of the Universe, extreme physics, and looking back farther in time. The panel that produced the vision included many notable American astrophysicists, including: Chryssa Kouveliotou, Eric Agol, Natalie Batalha, Misty Bentz, Alan Dressler, Scott Gaudi, Olivier Guyon, Enectali Figueroa-Feliciano, Feryal Ozel, Aki Roberge, Amber Straughn, and Joan Centrella.
ULTRASAT is a space telescope in a smallsat format with a large field of view, 210 square degrees, that will detect and monitor transient astronomical events in the near-ultraviolet (220–280 nm) spectral region. ULTRASAT will observe a large patch of sky, alternating every six months between the southern and northern hemisphere. The satellite will be launched into geosynchronous orbit in early 2026. All ULTRASAT data will be transmitted to the ground in real time. Upon detection of a transient event, ULTRASAT will provide alerts within 20 minutes to other ground-based and space telescopes to be directed to the source for further observation of the event in other wavelength bands.
The Large Ultraviolet Optical Infrared Surveyor, commonly known as LUVOIR, is a multi-wavelength space telescope concept being developed by NASA under the leadership of a Science and Technology Definition Team. It is one of four large astrophysics space mission concepts studied in preparation for the National Academy of Sciences 2020 Astronomy and Astrophysics Decadal Survey.
The Habitable Exoplanet Observatory (HabEx) is a space telescope concept that would be optimized to search for and image Earth-size habitable exoplanets in the habitable zones of their stars, where liquid water can exist. HabEx would aim to understand how common terrestrial worlds beyond the Solar System may be and determine the range of their characteristics. It would be an optical, UV and infrared telescope that would also use spectrographs to study planetary atmospheres and eclipse starlight with either an internal coronagraph or an external starshade.
Origins Space Telescope (Origins) is a concept study for a far-infrared survey space telescope mission. A preliminary concept in pre-formulation, it was presented to the United States Decadal Survey in 2019 for a possible selection to NASA's large strategic science missions. Origins would provide an array of new tools for studying star formation and the energetics and physical state of the interstellar medium within the Milky Way using infrared radiation and new spectroscopic capabilities.
Cosmic Vision is the third campaign of space science and space exploration missions in the Science Programme of the European Space Agency (ESA). Formulated in 2005 as Cosmic Vision: Space Science for Europe 2015–2025, the campaign succeeded the Horizon 2000 Plus campaign and envisioned a number of missions in the fields of astronomy and solar system exploration beyond 2015. Ten missions across four funding categories are planned to be launched under Cosmic Vision, with the first being CHEOPS in December 2019. A mission to the Galilean moons (JUICE), the first deep space mission with an opportunistic target, and one of the first gravitational-wave space observatories (LISA), are planned for launch as part of the Cosmic Vision campaign.
The Habitable Worlds Observatory (HWO) is a large infrared, optical, and ultraviolet space telescope recommended by the National Academies’ Decadal Survey on Astronomy and Astrophysics 2020. It will be optimized to search for and image Earth-size habitable exoplanets in the habitable zones of their stars, where liquid water can exist, by using a coronagraph to block out the light of their stars, as well as provide broad astrophysics observations. HWO builds upon studies conducted for two earlier mission concepts called the Large Ultraviolet Optical Infrared Surveyor (LUVOIR) and Habitable Exoplanets Observatory (HabEx).
