ISRO and India’s Space Programs

ISRO and India’s Space Programs

ISRO and India’s Space Programs

  • Indian Space Research Organisation (ISRO) is the space agency of India.
  • ISRO is a major constituent of the Department of Space (DOS), Government of India.
  • The department executes the Indian Space Programme primarily through various Centres or units within ISRO.

1.  Background

  • As a first step, the Department of Atomic Energy formed the INCOSPAR (Indian National Committee for Space Research) under the leadership of Dr. Sarabhai and Dr.Ramanathan in 1962.
  • The Indian Space Research Organisation (ISRO) was later formed on August 15, 1969.
  • The prime objective of ISRO is to develop space technology and its application to various national needs.
  • The Department of Space (DOS) and the Space Commission were set up in 1972 and ISRO was brought under DOS on June 1, 1972.

2. Major Milestones

  • Indian Space Programme began at Thumba Equatorial Rocket Launching Station (TERLS) located at Thumba near Thiruvanathapuram.
  • On November 21, 1963, the first sounding rocket was launched from TERLS. The first rocket, a Nike-Apache was procured from the US.
    • A sounding rocket is a rocket, which is intended for assessing the physical parameters of the upper atmosphere.
  • India’s first indigenous sounding rocket, RH-75, was launched on November 20, 1967
  • Aryabhata First Indian Satellite was launched on April 19, 1975.
    • It was launched from the former Soviet Union.
    • It provided India with the basis of learning satellite technology and designing.
  • Bhaskara-I an experimental satellite for earth observations was launched on June 7, 1979.
  • First Experimental launch of SLV-3 with Rohini Technology Payload on board (August 10, 1979).
    • Satellite could not be placed in orbit.
    • Satellite Launch Vehicle-3 (SLV-3) is the first launch vehicle of India.
  • Ariane Passenger Payload Experiment (APPLE), an experimental geo-stationary communication satellite was successfully launched on June 19, 1981.
  • On April 2, 1984, the first Indo-Soviet manned space mission was launched.
    • Rakesh Sharma became the first Indian citizen to go into space.
  • On March 24, 1987, the first developmental launch of Augmented Satellite Launch Vehicle (ASLV) that supported a larger payload than the SLV-3 happened.
  • Second developmental launch of Polar Satellite Launch Vehicle (PSLV) occurred in 1994.
  • The first developmental launch of Geosynchronous Satellite Launch Vehicle (GSLV) in 2001.
  • PSLV-C11 successfully launches CHANDRAYAAN-1 from Sriharikota on October 22, 2008.
  • November 5, 2013 – PSLV – C25 successfully launches Mars Orbiter Mission (Mangalyaan) Spacecraft from Sriharikota
  • Geosynchronous Satellite Launch Vehicle, GSLV MkIII-M1 rocket, carrying Chandrayaan-2 spacecraft was launched from the Satish Dhawan Space Centre, Sriharikota in Andhra Pradesh on July 22, 2019.

3. Launchers of ISRO

  • Launchers or Launch Vehicles are used to carry spacecraft to space.
  • India has three active operational launch vehicles:
    • Polar Satellite Launch Vehicle (PSLV),
    • Geosynchronous Satellite Launch Vehicle (GSLV), and
    • Geosynchronous Satellite Launch Vehicle Mk-III (LVM3).

      About SLV

  • Satellite Launch Vehicle-3 (SLV-3) was India’s first experimental satellite launch vehicle.
  • It was an all solid, four stage vehicle weighing 17 tonnes with a height of 22m and capable of placing 40 kg class payloads in Low Earth Orbit (LEO (Low Earth Orbit)).
  • SLV-3 was successfully launched on July 18, 1980 from Sriharikota Range (SHAR), when Rohini satellite, RS-1, was placed in orbit.
    • It made India the sixth member of an exclusive club of space-faring nations.
  • The successful culmination of the SLV-3 project showed the way to advanced launch vehicle projects such as:
    • Augmented Satellite Launch Vehicle (ASLV), Polar Satellite Launch Vehicle (PSLV) and the Geosynchronous satellite Launch Vehicle (GSLV).

     About ASLV

  • The Augmented Satellite Launch Vehicle (ASLV) Programme was designed to augment the payload capacity to 150 kg, thrice that of SLV-3, for Low Earth Orbits (LEO).
  • ASLV proved to be a low cost intermediate vehicle to demonstrate and validate critical technologies, that would be needed for the future launch vehicles like strap-on technology, inertial navigation, etc.

     About PSLV

  • Polar Satellite Launch Vehicle (PSLV) is the third generation launch vehicle of India.
  • It is the first Indian launch vehicle to be equipped with liquid stages.
  • Features: 04 stage vehicle, multiple satellite launch capability and multiple orbit capability.
  • It can take up to 1,750 kg of payload to Sun-Synchronous Polar Orbits of 600 km altitude.
  • Due to its unmatched reliability, PSLV has also been used to launch various satellites into Geosynchronous and Geostationary orbits, like satellites from the IRNSS constellation.
  • The vehicle has launched numerous Indian and foreign customer satellites.
  • Besides, the vehicle successfully launched two spacecraft “Chandrayaan-1 in 2008 and Mars Orbiter Spacecraft in 2013″that later travelled to Moon and Mars respectively.
  • PSLV earned its title ‘the workhorse of ISRO’ through consistently delivering various satellites into low earth orbits, particularly the IRS Series of satellites.
  • The PSLV is capable of placing multiple payloads into orbit, thus multi-payload adaptors are used in the payload fairing.

     About GSLV

Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk II) is the launch vehicle developed by India, to launch communication satellites in geo transfer orbit using cryogenic third stage.

  • This operational fourth generation launch vehicle is a three stage vehicle with four liquid strap-ons.
  • Payload capacity to LEO (Low Earth Orbit) : 6,000 kg
    • GSLV’s capability of placing up to 6 tonnes in Low Earth Orbits broadens the scope of payloads from heavy satellites to multiple smaller satellites.
  • Payload to GTO (Geosynchronous Transfer Orbit): 2,250 kg

     About GSLV MkIII or LMV3

  • LVM3 is the new heavy lift launch vehicle of ISRO for achieving a 4000 kg spacecraft launching capability to GTO (Geosynchronous Transfer Orbit) in a cost effective manner.
  • Payload to LEO (Low Earth Orbit): 8,000 kg
    • The powerful cryogenic stage of LVM3 enables it to place heavy payloads into Low Earth Orbits of 600 km altitude.



  • The idea of an Indian mission to the Moon was initially mooted in ameeting of the Indian Academy of Sciences in 1999.
  • It was followed upby discussions in the Astronautical Society of India in 2000.
  • A National Lunar Mission Task Force was constituted by the Indian SpaceResearch Organisation (ISRO) with leading scientists and technologists.
    • The objective was to make an assessment ofthe possible configuration and feasibility of taking up an Indian Missionto the Moon.
  • Study Report of the Task Team was submitted in 2003 and it unanimously recommended that India should undertake the Mission tothe Moon.
  • Subsequently, Government of India approved ISRO’s proposal for the first Indian Moon Mission, called Chandrayaan-1 in November 2003.

The Launch

  • Chandrayaan-1, India’s first mission to Moon, was launched successfully on October 22, 2008 from SDSC SHAR, Sriharikota.
  • The spacecraft was orbiting around the Moon at a height of 100 km from the lunar surface for chemical, mineralogical and photo-geologic mapping of the Moon.
  • The spacecraft carried 11 scientific instruments built in India, USA, UK, Germany, Sweden and Bulgaria.
  • The satellite made more than 3400 orbits around the Moon and the mission was concluded when the communication with the spacecraft was lost on 29 August 2009.

In Image: Payload of Chandrayaan I showing various instruments attached to it.   

Objectives of the Mission:

  • One of the objectives was to prepare a three-dimensional atlas (with high spatial and altitude resolution) of both near and far side of the moon.
  • It aimed at conducting chemical and mineralogical mapping of the entire lunar surface for distribution of mineral and chemical elements such as:
    • Magnesium, Aluminium, Silicon, Calcium, Iron and Titanium as well as high atomic number elements such as Radon, Uranium & Thorium with high spatial resolution.

The Success

  • The Chandrayaan-1 mission performed high-resolution remote sensing of the moon in visible, near infrared (NIR), low energy X-rays and high-energy X-ray regions.
  • The most significant result from Chandrayaan-1 is the discovery of the presence of hydroxyl (OH) and water (H2O) molecules on the lunar surface.
    • The data also revealed their enhanced abundance towards the polar region.
  • Other Significant findings:
    • inference of sub surface water-ice deposits in the base of craters in permanent sun shadow,
    • detection of possible existence of water molecules in the lunar environment,
    • validation of Lunar Magma Ocean hypothesis,
    • detection of reflection of 20% of solar wind protons,
    • detection of presence of Mg, Al, Si, Ca on the lunar surface, and
    • three dimensional conceptualization of many lunar crater.

The mission goal of harnessing the science payloads, lunar craft and the launch vehicle with suitable ground support systems including Deep Space Network (DSN) station were realised, which were helpful for future explorations.


Chandrayaan-2 mission was a highly complex mission, which represents a significant technological leap compared to the previous missions of ISRO.

  • It comprised an Orbiter, Lander (Vikram) and Rover (Pragyan) to explore the unexplored South Pole of the Moon.
  • The Chandrayaan-2 mission was successfully launched on 22nd July 2019 by GSLV MkIII-M1 from Satish Dhawan Space Centre (SDSC), Sriharikota.
  • Lunar Orbit Insertion (LOI) manoeuvre was performed on August 20th, thereby Chandrayaan-2 was successfully inserted into the elliptical orbit around the Moon.

Mission Objectives

  • To develop and demonstrate the key technologies for end-to-end lunar mission capability, including soft-landing and roving on the lunar surface.
  • To expand the lunar scientific knowledge through detailed study of topography, mineralogy, surface chemical composition, thermo-physical characteristics and tenuous lunar atmosphere.

Chandrayaan 2 Lander

  • The lander of the mission was named Vikram, after Vikram Sarabhai, the founder of India’s space program.
  • It would have landed near the Moon’s South Pole, at a latitude of about 70 degrees south.
  • ISRO lost contact with Vikram on the day of landing when it was barely 335 metres (0.335 km) from the surface of the Moon.
  • The initial data from the space agency’s Telemetry Tracking and Command Centre suggested that the failure occurred in the “Fine braking phase” in the final part of Vikram’s journey.
  • All the systems and sensors of the Lander functionedexcellently until this point and proved many new technologies such as variable thrustpropulsion technology used in the Lander.

Note: However, the Orbiter is healthy and allthe payloads are operational.


  • Chandrayaan-2 Orbiter is currently in a 100 km x 100 km orbit around the Moon,carrying 8 experiments for studies ranging from surface geology and composition toexospheric measurements.
  • These measurements will continue to enhance upon the understanding built from previous lunar missions.
  • The various payloads include the following:
    • Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS)
    • Solar X-ray Monitor (XSM)
    • CHandra’s Atmospheric Compositional Explorer 2 (CHACE 2)
    • Dual Frequency Synthetic Aperture Radar (DFSAR)
    • Imaging Infra-Red Spectrometer (IIRS)
    • Terrain Mapping Camera (TMC 2)
    • Orbiter High Resolution Camera (OHRC)
    • Dual Frequency Radio Science (DFRS) Experiment
  • The Orbiter placed in its intended orbit around the Moon will enrich our understanding of the moon’s evolution and mapping of the minerals and water molecules in Polar Regions, using its eight state-of-the-art scientific instruments.
  • The Orbiter camera is the highest resolution camera (0.3 m) in any lunar mission so far and will provide high resolution images which will be immensely useful to the global scientific community.

In Image: Chandrayaan II payload carrying various tools for studying Moon.

Chandrayaan 3

Chandrayaan-3 is a follow-on mission to Chandrayaan-2 to demonstrate end-to-end capability in safe landing and roving on the lunar surface. It consists of Lander and Rover configuration.

  • It was launched by LVM3 from SDSC SHAR, Sriharikota.
  • Chandrayaan-3 consists of an indigenous Lander module (LM), Propulsion module (PM) and a Rover with an objective of developing and demonstrating new technologies required for Inter planetary missions.
  • The Lander will have the capability to soft land at a specified lunar site and deploy the Rover which will carry out in-situ chemical analysis of the lunar surface during the course of its mobility.
    • The small rover, which weighs just 26 kilograms (57 pounds), will fly to the Moon inside the lander.
  • The Lander and the Rover have scientific payloads to carry out experiments on the lunar surface.

In Image: ISRO’s Chandrayaan-3 lander is seen here with its ramp unfolded, revealing a small rover that will drive on the lunar surface.

Mission Objectives:

  • To demonstrate Safe and Soft Landing on Lunar Surface
  • To demonstrate Rover roving on the moon and
  • To conduct in-situ scientific experiments.

The Launch

  • Chandrayaan-3 was launched on 14 July 2023, as scheduled, from Satish Dhawan Space Centre Second Launch Pad in Sriharikota, Andhra Pradesh.
  • The spacecraft has been effectively placed in the trajectory which it will take to reach the moon.
  • It is anticipated that the Chandrayaan-3 mission will achieve a soft landing on the lunar South Pole region on 23 August.

Note: Thus far, only three countries, the U.S., Russia and China, have successfully soft-landed on the moon.