Inspired by Sputnik, India's strides in space since Sarabhai

It was on April 19, 1975, that India strode into the 'space age' with the successful launch of 'Aryabhata', the first satellite, named in honour of the ancient mathematician and astronomer Aryabhata.

Since then, India has made significant leaps in the vast and endless domain of space through Indian Space Research Organisation (ISRO), the nodal agency and flag-bearer of the Indian Space Programme.

The purview of the Indian space programme includes a gamut of specialised fields such as remote sensing, astronomy and astrophysics, atmospheric sciences, and space sciences in general. The twin objectives of India's space programme are: Space discovery and exploration through space missions, and the promotion of research and education related to space science in India.

Besides, the space programme has several other functions including resource management such as mineral resources, agriculture, marine resources etc; environment conservation; internal security and terrorism; weather forecasting, disaster management, communication, etc.

Commissioned in 1983, Indian National Satellite (INSAT), a series of multipurpose geostationary satellites launched by ISRO to conduct telecommunications, broadcasting, meteorology, and search and rescue operations. With nine operational communication satellites in the geostationary orbit, the INSAT system is one of the largest domestic communication satellite systems in the Asia-Pacific.

The INSAT satellites have application in the areas of educational TV services, television, satellite-aided search and rescue, disaster management and geopolitics (such as the SAARC satellite).

It also helps in commercialising space programmes, such as launching communication satellites of other countries or agencies.

In 1988, ISRO deployed several operational remote sensing satellites which provide disaster management support, aid bio-resources and environment survey and mapping (RESOURCESAT), cartography (CARTOSAT), agriculture, rural and urban development (for example: National Drinking Water Mission).

These landmark developments would not have been possible without the vision of Dr Vikram Sarabhai, the founding father of the Indian space programme.

In the history of India's space programme, the first phase was from 1960-70. Dr Sarabhai highlighted the potential of satellites after the launch of Sputnik in 1957.

The leadership of that time, Prime Minister Jawaharlal Nehru held scientific advancement as a core component of India's future. Research in the domain of space was under the jurisdiction of the Department of Atomic Energy in 1961.

Subsequently, Homi Jahangir Bhabha, father of India's atomic programme, founded the Indian National Committee for Space Research (INCOSPAR) in 1962, with Dr Sarabhai as Chairman.

In 1962, the Indian space programme began gaining prominence with the launch of sounding rockets. This was aided by India's geographical proximity to the equator.

In 1963, Thumba Equatorial Rocket Launching Station (TERLS) was established near Thiruvananthapuram in Kerala.

Over subsequent years, India developed an indigenous technology of sounding rockets called the 'Rohini Family'. These rockets are capable of carrying payloads of 2 to 200 kilograms between 100 to 500 kilometre altitudes.

While ISRO was established in 1969, the Department of Space was established in 1972.

In the second phase of India's space programme (the decade from 1970-80), Sarabhai joined an early NASA study on the viability of employing satellites for uses as diverse as direct television broadcasting.

In this decade, India developed satellite technology in anticipation of remote sensing and communication requirements in future.

In 1975, India ventured into space for the first time with the launch of their satellite Aryabhata by a Soviet launcher.

By 1979, the Satellite Launch Vehicle (SLV) was ready to launch from the Sriharikota Rocket Launching Station, a newly created second launch site.

The 1979 launch, however, failed due to a control malfunction in the second stage. This glitch was resolved by 1980.

In 1980, India's first indigenous satellite called Rohini was launched.

In the third decade from 1980-90, following the success of the SLV, ISRO was eager to begin work on an SLV capable of placing a satellite in the polar orbit.

In 1987, the Augmented Satellite Launch Vehicle (ASLV) was tested, but the launch failed.

In 1988, after modest adjustments, another launch attempt was made but that too failed.

It was only in 1992 that the first successful launch of the ASLV happened in the fourth decadal phase from 1990-2000.

Since its first successful launch in 1994, the PSLV became the workhorse launch vehicle, launching both remote sensing and communications satellites into orbit, establishing the world's largest cluster and giving unique data to Indian industry and agriculture.

Developments after 2000 are listed herewith:

In 2001, the first development flight of the GSLV took place.

In 2008, in the first attempt to explore the solar system, India pursued a mission to send unmanned probes to the moon, namely Chandrayaan.

After 2010, ISRO embarked on launch vehicle development programmes such as Polar Satellite Launch Vehicle (PSLV), Geosynchronous Satellite Launch Vehicle (GSLV), and next-generation GSLV Mark-III launch vehicle missions.

The Earth Observation programme includes cutting-edge Indian remote sensing satellites such as Resourcesat, Cartosat, Oceansat, Radar Imaging Satellite, Geo-Imaging Satellite, and weather/climate satellites such as INSAT-3DR missions.

In August 2016, ISRO has successfully conducted the Scramjet (Supersonic Combusting Ramjet) engine test. The Scramjet engine uses Hydrogen as fuel and Oxygen from the atmospheric air as the oxidizer.

This test was the maiden short-duration experimental test of ISRO's Scramjet engine with a hypersonic flight at Mach 6.

ISRO's futuristic-sounding rocket, the Advanced Technology Vehicle (ATV), served as the solid rocket booster for the supersonic testing of Scramjet engines.

The new propulsion system will complement ISRO's reusable launch vehicle that would have a longer flight duration.

In 2019, a Central Public Sector Enterprise of the Government of India called NewSpace India Limited (NSIL) was founded and is managed by the Department of Space.

Headquartered in Bengaluru, this is ISRO's commercial arm, and it seeks to enable Indian enterprises to engage in high-technology space-related operations.

In the most recent development, India plans to launch an unmanned mission and send a female robot in the first and second missions, respectively, preceding the Gaganyaan human space-flight programme by the end of 2023 or in 2024.

Under ISRO's mission Gaganyaan, three flights will be sent into orbit including two unmanned flights and one human spaceflight.

The Gaganyaan system module, known as the Orbital Module, would house three Indian astronauts, one of them will be a woman. For 5-7 days, it will circle the Earth in a low-Earth orbit at an altitude of 300-400 km.