The Indian Space Research Organisation (ISRO ) is the national space agency of India, headquartered in Bengaluru, Karnataka. It serves as the principal research and development arm of the Department of Space (DoS), overseen by the Prime Minister of India, with the Chairman of ISRO also working as the chief executive of the DoS. It is primarily responsible for space-based operations, space exploration, international space cooperation and the development of related technologies. The agency maintains a constellation of imaging, communications and remote sensing satellites. It operates the GAGAN and IRNSS satellite navigation systems. It has sent three missions to the Moon and one mission to Mars.
Formerly, ISRO was known as the Indian National Committee for Space Research (INCOSPAR), which was set up in 1962 by Prime Minister Jawaharlal Nehru on the recommendation of scientist Vikram Sarabhai. It was renamed as ISRO in 1969 and was subsumed into the Department of Atomic Energy (DAE). In 1972, the Government set up a space commission and the DoS bringing ISRO under its purview. It has since then been managed by the DoS, which also governs various other institutions in the domain of astronomy and space technology.
ISRO built India's first satellite, Aryabhata, which was launched by the Soviet space agency Interkosmos in 1975. In 1980, it launched the satellite RS-1 on board the indigenously built launch vehicle SLV-3, making India the seventh country to undertake orbital launches. It has subsequently developed various small-lift and medium-lift launch vehicles, enabling the agency to launch various satellites and deep space missions. ISRO has full launch capabilities with the ability to deploy cryogenic engines, launch extraterrestrial missions and artificial satellites. It is also the only one of the few governmental space agencies to have demonstrated unmanned landing capabilities.
ISRO's programmes have played a significant role in socio-economic development. It has supported both civilian and military domains in various aspects such as disaster management, telemedicine, navigation and reconnaissance. ISRO's spin-off technologies are commercial products and services which have been developed with the help of ISRO.
ISRO has an official logo since 2002. It consists of an orange arrow shooting upwards attached with two blue coloured satellite panels with the name of ISRO written in two sets of text, orange-coloured Devanagari on the left and blue-coloured English in the Prakrit typeface on the right.
Modern space research in India can be traced to the 1920s, when scientist S. K. Mitra conducted a series of experiments sounding the ionosphere through ground-based radio in Kolkata. Later, Indian scientists like C. V. Raman and Meghnad Saha contributed to scientific principles applicable in space sciences. After 1945, important developments were made in coordinated space research in India by two scientists: Vikram Sarabhai, founder of the Physical Research Laboratory at Ahmedabad, and Homi J. Bhabha, who established the Tata Institute of Fundamental Research in 1945. Initial experiments in space sciences included the study of cosmic radiation, high-altitude and airborne testing, deep underground experimentation at the Kolar mines—one of the deepest mining sites in the world—and studies of the upper atmosphere. These studies were done at research laboratories, universities, and independent locations.
In 1950, the DAE was founded with Bhabha as its secretary. It provided funding for space research throughout India. During this time, tests continued on aspects of meteorology and the Earth's magnetic field, a topic that had been studied in India since the establishment of the Colaba Observatory in 1823. In 1954, the Aryabhatta Research Institute of Observational Sciences (ARIES) was established in the foothills of the Himalayas. The Rangpur Observatory was set up in 1957 at Osmania University, Hyderabad. Space research was further encouraged by the government of India. In 1957, the Soviet Union launched Sputnik 1 and opened up possibilities for the rest of the world to conduct a space launch.
INCOSPAR was set up in 1962 by the Government of India on the suggestion of Dr. Vikram Sarabhai. H. G. S. Murthy, an Indian Ordnance Factories Service (IOFS) officer, was appointed the first director of the Thumba Equatorial Rocket Launching Station, where sounding rockets were fired, marking the start of upper atmospheric research in India. An indigenous series of sounding rockets named Rohini was subsequently developed and started undergoing launches from 1967 onwards.
Under the government of Indira Gandhi, INCOSPAR was superseded by ISRO. Later in 1972, a space commission and Department of Space (DoS) were set up to oversee space technology development in India specifically. ISRO was brought under DoS, institutionalising space research in India and forging the Indian space programme into its existing form. India joined the Soviet Interkosmos programme for space cooperation and got its first satellite Aryabhata in orbit through a Soviet rocket.
Efforts to develop an orbital launch vehicle began after mastering sounding rocket technology. The concept was to develop a launcher capable of providing sufficient velocity for a mass of 35 kg (77 lb) to enter low Earth orbit. ISRO developed the Satellite Launch Vehicle (SLV) capable of putting 40 kg (88 lb) into a 400-kilometre (250 mi) orbit. An SLV Launch Pad, ground stations, tracking networks, radars and other communications were set up for a launch campaign. The SLV's first launch in 1979 carried a Rohini technology payload but could not inject the satellite into its desired orbit. It was followed by a successful launch in 1980 carrying a Rohini Series-I satellite. RS-1 was the third Indian satellite to reach orbit as Bhaskara had been launched from the USSR in 1979. Efforts to develop a medium-lift launch vehicle capable of putting 600-kilogram (1,300 lb) class spacecrafts into 1,000-kilometre (620 mi) Sun-synchronous orbit had already begun in 1978. The SLV-3 later had two more launches before discontinuation in 1983. ISRO started working on a more powerful engine, Vikas, based upon the French Viking. Later, facilities to test liquid-fuelled rocket engines were established and development and testing of various rocket engines began.
At the same time, another solid-fuelled rocket, the Augmented Satellite Launch Vehicle (ASLV), whose design was based upon SLV-3 was being developed, with technologies to launch satellites into geostationary orbit (GTO). The ASLV had limited success and multiple launch failures; it was soon discontinued. Alongside these developments, communication satellite technologies for the Indian National Satellite System and the Indian Remote Sensing Programme for earth observation satellites were developed and launches from overseas were initiated. The number of satellites eventually grew and the systems were established as among the largest satellite constellations in the world, with multi-band communication, radar imaging, optical imaging and meteorological satellites.
The arrival of the Polar Satellite Launch Vehicle (PSLV) in 1990s was a major boost for the Indian space programme. With the exception of its first flight in 1994 and two partial failures later, the PSLV had a streak of more than 50 successful flights. The PSLV enabled India to launch all of its low Earth orbit satellites, small payloads to GTO and hundreds of foreign satellites. Along with the PSLV flights, development of a new rocket, a Geosynchronous Satellite Launch Vehicle (GSLV) was going on. India tried to obtain upper-stage cryogenic engines from Russia's Glavkosmos but was blocked by the US from doing so. As a result, KVD-1 engines were imported from Russia under a new agreement which had limited success and a project to develop indigenous cryogenic technology was launched in 1994, taking two decades to reach fulfillment. A new agreement was signed with Russia for seven KVD-1 cryogenic stages and a ground mock-up stage with no technology transfer, instead of five cryogenic stages along with the technology and design in the earlier agreement. These engines were used for the initial flights and were named GSLV Mk I. After the United States refused to help India with Global Positioning System (GPS) technology during the Kargil War, ISRO was prompted to develop its own satellite navigation system NavIC, officially called the IRNSS.