MSG satellites are 3.2 m in diameter and 2.4 m high and spin anti-clockwise at 100 rpm at an altitude of 36,000 km. On 29 January 2004 the first Meteosat Second Generation satellite MSG-1, renamed to Meteosat-8 once operational, commenced routine operations. In addition to the main optical payload SEVIRI (Spinning Enhanced Visible and Infrared Imager), Meteosat-8 also carries the secondary payload GERB (Geostationary Earth Radiation Budget) instrument. The launch of MSG-2 (renamed to Meteosat-9) took place on 21 December 2005. The launch of MSG-3 (renamed to Meteosat-10) took place on 5 July 2012. Meteosat-8 is stationed over the Indian Ocean, arriving at 41.5°E on 21 September 2016 and it took over as prime Indian Ocean Data Coverage (IODC) spacecraft on 1 February 2017 (replacing Meteosat-7). Meteosat-8 is to be retired on 1 July 2022. Meteosat-9 is also stationed over the Indian Ocean, arriving at 45.5°E on 20 April 2022 and it took over as prime IODC spacecraft on 1 June 2022 (replacing Meteosat-8). Meteosat-10 and -11 are located over Africa with various differences in operational configuration. Since 20 March 2018, Meteosat-10 provides an operational European 'rapid scan' mode service (the MSG RSS service first commenced in May 2008), with images of Europe every 5 minutes. Since 20 February 2018, Meteosat-11 provides the main full Earth imagery service over Europe and Africa (with images every 15-minutes). MSG-4 was successfully launched into space on 15 July 2015 at 18:42 local time on top an Ariane 5 Rocket from the Guiana Space Centre in Kourou, French Guiana. Like MSG-1, MSG-2 and MSG-3, MSG-4 was launched by Arianespace. The MSG-4 commissioning was successfully completed in December 2015 at which time the spacecraft was placed into in-orbit storage as planned, and renamed to Meteosat-11. Secondary Payloads Meteosat-8, -9, -10, and -11 each carry a GERB Instrument, DCP capable service equipment and a Search and Rescue signal Processor (SARP) that is capable of detecting 406 MHz distress signals from emergency position-indicating radiobeacon stations. For SARP, see more under Cospas-Sarsat. Third Generation ("MTG") Considering the long development cycle for a new observational space system, EUMETSAT has been working on the definition and the planning for a Meteosat Third Generation (MTG) system since the year 2000. MTG components providing continuity of MSG services need to be available before the end of the nominal lifetime of MSG. MTG preparatory activities started end of 2000 in cooperation with the