With the first launch of 2025, the Indian Space Research Organization (ISRO) achieved the significant milestone of having carried out 100 launches on 29 January, 2025. The GSLV-F15 put in orbit the navigation satellite NVS-02 on Wednesday early morning. After the launch, the new ISRO chairperson Dr V Narayanan, recalled the greats like Vikram Sarabhai, Satish Dhawan, and APJ Abdul Kalam. “On behalf of the present generation of ISRO leaders, I salute all the previous generation of leaders, the past and present employees, and our family members,” he said.
Significance of ISRO’s Achievement
The Bharatiya space agency ISRO has its roots in the Indian National Committee for Space Research (INCOSPAR) set up under the Department of Atomic Energy in 1962. The ISRO that we know today was set up in 1969 — the same year that the United States sent men to the moon. A separate department of space was created only in 1972. The space agency has since developed several rockets, becoming a reliable launch partner even for satellites from other countries. It has also carried out scientific missions such as the three Chandrayaan missions, which provide useful data not only to researchers from within the country but across the world.
Among its remarkable achievements is the Mars Orbiter Mission (Mangalyaan), which made Bharat the first Asian nation to reach Mars’s orbit. Additionally, ISRO’s cost-effective launches, particularly through the Polar Satellite Launch Vehicle (PSLV), have successfully deployed numerous satellites for Bharat and international clients. ISRO’s dedication to developing indigenous satellite navigation systems and testing reusable launch vehicles highlights its growing influence in global space exploration.
The country’s space programme has set audacious goals in the next two decades, fueled by the successful development of powerful, reusable rockets and next generational launch vehicle (NGLV). One of Isro’s most crucial projects is the Gaganyaan mission, which will launch an Bharatiya crew to space for the first time. The year 2024 saw significant groundwork being laid for the human spaceflight project which will demonstrate the country’s ability to launch and sustain human presence in space and beyond.
Expected to be launched by the end of 2026, Gaganyaan envisages a demonstration of human spaceflight capability by launching a crew of three members to an orbit of 400 km for a three-day mission and bringing them back safely to Earth. Furthermore, he government has approved Rs 2,104 crore for the Chandrayaan-4 mission expected to be launched in 2028. In this mission, samples of the lunar surface and soil will be collected and brought back for research.
At this juncture, it is important to have a relook at the major achievements of Bharatiya space organization since its inception till date.
1. Aryabhata, 1975
Named after the legendary Bharatiya astronomer, Aryabhata, the Aryabhata satellite was the first Bharatiya satellite. It was completely manufactured, designed, and assembled in Bharat. Weighing over 360 kg, the satellite was launched on April 19, 1975, by a Soviet Kosmos-3M rocket, from Volgograd Launch Station in Russia. It paved the way for other successful missions to come.
2. Indian National Satellite System (INSAT) Series, 1983
Initially launched in 1983, the INSAT series brought a revolution in the telecommunications sector of Bharat. With nine operational communication satellites in Geo-stationary orbit, the Indian National Satellite (INSAT) system is one of the largest domestic communication satellite systems in the Asia-Pacific area. The INSAT system has over 200 corresponders and provides television transmission, satellite newsgathering, social applications, weather forecasting, catastrophe warning, and Search and Rescue activities.
3. GSAT Series
GSAT (Geosynchronous Satellite) satellites are communications satellites constructed in Bharat. These satellites are mainly utilized for digital audio, data, and video transmission. Out of the many GSAT satellites launched by ISRO, 18 are still operational.
4. Chandrayaan-1, 2008
It was Bharat’s first mission to the Moon. Launched successfully on October 22, 2008, the mission turned out to be one of the biggest scientific breakthroughs as the craft detected the presence of water molecules on the lunar surface. It was through Chandrayaan-1 that the world got to know about water on the Moon.
5. Mars Orbiter Mission (MOM), 2014
With the Mars Orbiter Mission, popularly known as MOM, Bharat became the first nation to reach the red planet Mars on its first try. It was also the nation’s first interplanetary mission. Mangalyaan was launched on November 5, 2013, by the PSLV-C25 rocket, from Sriharikota. With this, ISRO became the fourth space agency to successfully launch a spacecraft into orbit around Mars. Despite having a mission duration of 6 months, MOM has been in orbit for 7 years as of September 24, 2021.
6. Chandrayaan-3
Chandrayaan-3 is the next mission after Chandrayaan-2, which aims to land safely and explore the moon’s surface. With its success, Bharat has become one of the four elite nations in the world to have landed on the Moon, after the US, and China. It is a major historical event not only for Bharat but for the whole world. Bharat has become the first nation in the world to successfully land on the South Pole of the Moon.
7. Rockets
ISRO has so far developed at least six generations of launch vehicles, of which four remain in operation. The first two generations of launchers are no longer in use. There were three developmental flights and one operational flight of the four-stage, solid fuel vehicle SLV-3 that could carry 40 kg to low earth orbit. And, there were only four development flights of its augmented version that could carry 150 kg to low earth orbit.
It was the third generation PSLV that continues to be ISRO’s workhorse launcher. The four-stage rocket with solid and liquid fuel-based engines is capable of carrying just under 2,000 kg to low earth orbit. There have been 62 flights of PSLV, including three development flights. Only two of the launches using PSLV have been unsuccessful.
Then came the GSLV, whose initial flights used cryogenic engines supplied by Russia. When the technology could not be transferred from Russia because of geopolitical reasons, Bharat developed its own cryogenic engine. GSLV-F15 utilised for the 100th launch is a variation of this vehicle — and the eleventh flight using an indigenously developed cryogenic engine. The GSLV MkIII, now called LVM3, capable of carrying nearly 8,500 kg to low earth orbit, is the heaviest vehicle Bharat has. The vehicle has been used for seven launches so far, none of which have been unsuccessful. The vehicle was used for Chandrayaan-2 and 3 missions. And, a modified, human-rated version will be used for the Gaganyaan mission.
ISRO has also developed the Small Satellite Launch Vehicle to transfer to private industry for commercial launch of small satellites. There have been three developmental flights of the launcher.
Upcoming major developments
With the space agency targeting big-ticket missions such as the sample return mission from the moon, the mission to Venus, setting up an Indian space station, and sending a man to the moon, Isro is working towards developing a heavier rocket called Next Generation Launch Vehicle.
NGLV will be capable of carrying up to 30,000 kg to low earth orbit. It will be 91 metres tall as compared to the 43 metres of LVM3. It will also have a re-usable first stage, which would be utilized 15 to 20 times, to make the launches more affordable.
The cabinet has also green-lit the setting up of the third launch pad needed for NGLV launches. Built at an estimated cost of Rs 3984.86 crores over four years, the third launch pad would also be capable of launching human missions along with the modified second launch pad. It will also help in increasing the number of LVM3 launches, thereby increasing the space agency’s capability of carrying out heavy commercial missions.
There are many more space missions to come and it is expected that Bharat will continue to grow and dominate the global scientific and space exploration domain.