Syncom started as a 1961 NASA program for active geosynchronous communication satellites, all of which were developed and manufactured by Hughes Space and Communications. Syncom 2, launched in 1963, was the world's first geosynchronous communications satellite. Syncom 3, launched in 1964, was the world's first geostationary satellite.
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites which are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step for reaching their final orbit.
The Indian National Satellite System or INSAT, is a series of multipurpose geostationary satellites launched by ISRO to satisfy the telecommunications, broadcasting, meteorology, and search and rescue operations. Commissioned in 1983, INSAT is the largest domestic communication system in the Indo-Pacific Region. It is a joint venture of the Department of Space, Department of Telecommunications, India Meteorological Department, All India Radio and Doordarshan. The overall coordination and management of INSAT system rests with the Secretary-level INSAT Coordination Committee.
Geosynchronous Satellite Launch Vehicle (GSLV) is an expendable launch system operated by the Indian Space Research Organisation (ISRO). GSLV was used in thirteen launches from 2001 to 2018, with more launches planned. Even though GSLV Mark III shares the name, it is an entirely different launch vehicle.
GSAT-3, also known as EDUSAT, was a communications satellite which was launched on 20 September 2004 by the Indian Space Research Organisation. EDUSAT is the first Indian satellite built exclusively to serve the educational sector. It is mainly intended to meet the demand for an interactive satellite-based distance education system for the country.
GSAT-2 was an experimental communication satellite built by the Indian Space Research Organisation (ISRO) and launched on one of the first GSLVs. The satellite was positioned at 48 deg east longitude in the geo-stationary orbit.
The Geosynchronous Satellite Launch Vehicle Mark III, also referred to as the Launch Vehicle Mark 3 (LVM3), is a three-stage medium-lift launch vehicle developed by the Indian Space Research Organisation (ISRO). Primarily designed to launch communication satellites into geostationary orbit, it is also identified as the launch vehicle for crewed missions under the Indian Human Spaceflight Programme and dedicated science missions like Chandrayaan-2. The GSLV Mk III has a higher payload capacity than the similarly named GSLV Mk II.
GSAT-4, also known as HealthSat, was an experimental communication and navigation satellite launched in April 2010 by the Indian Space Research Organisation on the maiden flight of the Geosynchronous Satellite Launch Vehicle Mk.II rocket. It failed to reach orbit after the rocket's third stage malfunctioned. The third stage was the first Indian-built cryogenic-fuelled upper stage, and was making its first flight. The ISRO suspects that the failure was caused by the third stage not igniting.
The A2100 is a communications satellite spacecraft model made by Lockheed Martin Space Systems in the 1990s-2010s for telecommunications in geosynchronous orbit, as well as GOES-R weather satellites and GPS Block IIIA satellites.
An orbital propellant depot is a cache of propellant that is placed in orbit around Earth or another body to allow spacecraft or the transfer stage of the spacecraft to be fueled in space. It is one of the types of space resource depots that have been proposed for enabling infrastructure-based space exploration. Many different depot concepts exist depending on the type of fuel to be supplied, location, or type of depot which may also include a propellant tanker that delivers a single load to a spacecraft at a specified orbital location and then departs. In-space fuel depots are not necessarily located near or at a space station.
TDRS-9, known before launch as TDRS-I, is an American communications satellite which is operated by NASA as part of the Tracking and Data Relay Satellite System. It was constructed by the Boeing Satellite Development Center, formerly Hughes Space and Communications, and is based on the BSS-601 satellite bus. It was the second Advanced TDRS, or second-generation Tracking and Data Relay Satellite, to be launched.
GSAT-5P, or GSAT-5 Prime, was an Indian communications satellite which was lost in a launch failure in December 2010. Part of the Indian National Satellite System, it was intended to operate in geosynchronous orbit as a replacement for INSAT-3E.
Space Infrastructure Servicing (SIS) is a spacecraft being developed by Canadian aerospace firm MDA to operate as a small-scale in-space refueling depot for communication satellites in geosynchronous orbit.
INSAT-4CR is a communications satellite operated by ISRO as part of the Indian National Satellite System. Launched in September 2007, it replaced the INSAT-4C satellite which had been lost in a launch failure the previous year. The satellite is stationed in geostationary orbit at a longitude of 74 degrees east, and is expected to operate for ten years, however this may have been reduced by the underperformance of the Geosynchronous Satellite Launch Vehicle which placed it into orbit. INSAT-4CR is planned to be replaced by GSAT-31, which was launched on February 6, 2019.
GSAT-14 is an Indian communications satellite launched in January 2014. It replaced the GSAT-3 satellite, which was launched in 2004. GSAT-14 was launched by a Geosynchronous Satellite Launch Vehicle Mk.II, which incorporated an Indian-built cryogenic engine on the third stage.
INSAT-4E, also known as GSAT-6, is a member of the INSAT family and is a multimedia communication satellite that will offer a Satellite Digital Multimedia Broadcasting (S-DMB) service across several digital multimedia terminals or consoles which can be used to provide information services to vehicles on the fly and to the mobile phones. The satellite can be used for other social and strategic applications.
Intelsat III F-2 was a communications satellite operated by Intelsat. Launched in 1968 it was operated in geostationary orbit at a longitude of 24 degrees west for around eighteen months.
GSAT-6A was a communication satellite launched by the Indian Space Research Organisation. It featured a 6-metre (20 ft) unfurlable S-band antenna similar to the one used on GSAT-6. Around 17 minutes after lift-off, the three stage GSLV Mk.ll rocket flying on GSLV F08 mission successfully injected the satellite into a geosynchronous transfer orbit. Due to power failure during its orbit raising burns the communication was lost with GSAT-6A before it could reach its final circular Geostationary Orbit (GSO).
Iodine Satellite (iSat) is a technology demonstration satellite of the CubeSat format that will undergo high changes in velocity from a primary propulsion system by using a Hall thruster with iodine as the propellant. The spacecraft will also perform changes of its orbital altitude, and demonstrate deorbit capabilities to reduce space junk.
GSAT-29 is a high-throughput communication satellite developed by the Indian Space Research Organisation (ISRO). The mission aims at providing high-speed bandwidth to Village Resource Centres (VRC) in rural areas. The two Ku and Ka operational payloads will provide communication services to Jammu and Kashmir and Northeast India under Digital India programme. GSAT-29 was the heaviest satellite, weighing 3,423 kg (7,546 lb), that was placed in orbit by an Indian launch vehicle.
