Question: Which telescope's completion in the state of Hawaii will mark the decommission of the Unite Kingdom Infrared Telescope?
Context: The SAFARI imaging spectrometer is the European ‘nerve center’ of Japanese infrared telescope SPICA (Space Infra-Red Telescope for Cosmology and Astrophysics telescope) and is being developed under the leadership of SRON Netherlands Institute for Space Research.  SAFARI is an infrared camera with about 6,000 pixels that can make real ‘photos’ of the sky in three adjacent wavelength areas.  Using a Fourier transform spectroscopy (FTS) detailed spectral information is obtained, allowing astronomers to determine the chemical composition of the observed celestial sources.  TNO is developing the mechanism of this FTS. Irwin is known worldwide for the leading role he plays in processing of digital optical and infra-red survey data.  Currently, his efforts in processing of digital optical and infrared survey data of Vista Data Flow are being used for processing United Kingdom Infrared Telescope data. The UKIRT Infrared Deep Sky Survey or UKIDSS is an astronomical survey conducted using the WFCAM wide field camera on the United Kingdom Infrared Telescope on Mauna Kea in Hawaii.  Survey observations were commenced in 2005. The Telescopio InfraRosso del Gornergrat (TIRGO), or the Gornergrat Infrared Telescope, is located on the northern tower of the Kulm Hotel at Gornergrat (3135 m altitude) near Zermatt, Switzerland.  It was a 1.5 m Cassegrain telescope with a tip-tilt correcting secondary and optimized for infrared observations, but was decommissioned in March 2005.  The telescope and related instrumentation were run by the Istituto di Radioastronomia (IRA - C.N.R.), sezione di Firenze (former CAISMI), with the assistance of the Osservatorio Astrofisico di Arcetri and the Dipartimento di Astronomia e Scienza dello Spazio of the University of Florence. The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space telescope launched in 2003.  It is the fourth and final of the NASA Great Observatories program. The Mount Abu InfraRed Observatory is located near the town Mount Abu in the state of Rajasthan.  The observatory is at an altitude of 1680 metres and is adjacent to Guru Shikhar, highest peak of the Aravalli Range.  The 1.2 m Infrared Telescope at Mount Abu is the first major facility in India specifically designed for ground based infrared observations of celestial objects.  Further the low amount of precipitable water vapour (1–2 mm during winter) at Guru Shikhar makes it a good site for the infrared telescope observations.  The site has been found to be good (about 150 cloud free nights per year) for astronomical observations. The Thirty Meter Telescope (TMT) is a proposed astronomical observatory with an extremely large telescope (ELT) that has become the source of controversy over its planned location on Mauna Kea in the US state of Hawaii.  Construction of the TMT on land which is sacred to Native Hawaiian culture and religion attracted international coverage after October 2014, when construction was temporarily halted voluntarily due to protests.  While construction of the telescope was set to resume on April 2 and later on June 24, 2015, it was blocked by further protests each time.  The Board of Land and Natural Resources approved the TMT project, but the State Supreme Court of Hawaii invalidated the building permits in December 2015, ruling that the board had not followed due process.  Roque de los Muchachos Observatory, La Palma, Canary Islands, Spain is the alternative site if construction cannot go forward in Hawaii.  The TMT would become the last area on Mauna Kea on which any telescope will ever be built. UKIRT, the United Kingdom Infra-Red Telescope, is a 3.8 metre (150 inch) infrared reflecting telescope, the second largest dedicated infrared (1 to 30 micrometres) telescope in the world.  Until 2014 it was operated by the Joint Astronomy Centre in Hilo and located on Mauna Kea, Hawai'i as part of Mauna Kea Observatory.  It was owned by the United Kingdom Science and Technology Facilities Council.  UKIRT is currently being funded by NASA and operated under a Scientific Cooperation Agreement among Lockheed Martin Advanced Technology Center, the University of Hawaii, and the University of Arizona.  The telescope is set to be decommissioned after completion of the Thirty Meter Telescope as part of the Mauna Kea Comprehensive Management Plan. Xinglong Station () is an observatory (IAU code 327) situated south of the main peak of the Yanshan mountains in Hebei province, China.  Installed are seven telescopes: a Mark-III photoelectric astrolabe; a 60 cm reflector; an 85 cm reflector; a 60/90 cm Schmidt telescope; an 1.26-meter infrared telescope; and a 2.16-meter telescope.  The most recent telescope is the 4m LAMOST.  As of 2014 the observatory installed a 5.2-meter telescope as part of their Gamma-ray astronomy program, known colloquially as Sām Tām for its aggressive focal length.  It is a popular tourist site. The NASA Infrared Telescope Facility (NASA IRTF) is a 3 m telescope optimized for use in infrared astronomy and located at the Mauna Kea Observatory in Hawaii.  It was first built to support the Voyager missions and is now the US national facility for infrared astronomy, providing continued support to planetary, solar neighborhood, and deep space applications.  The IRTF is operated by the University of Hawaii under a cooperative agreement with NASA.  According to the IRTF's time allocation rules, at least 50% of the observing time is devoted to planetary science.
Answer: Thirty Meter Telescope