Home | IAF | Janes Fighters Anthology | Articles and Reviews | Downloads | Football | Medley | Links | About Me
Indian Space History and Technology





"There are some who question the relevance of space activities in a developing nation. To us, there is no ambiguity of purpose"


"But we are convinced that if we are to play a meaningful role nationally, and in the community of nations, we must be second to none in the application of advanced technologies to the real problems of man and society."


- Dr. Vikram A. Sarabhai, Father of India's Space Program

Indian space history:


Early Rockets:


Rockets were first invented in China in the early 10th century, and their use was mainly for festival times etc, the first proper use of rockets for more serious purposes was made by the Great Tipu Sultan in the first battle of Srirangapatnam, after which some of the captured rockets and their parts were sent back to Britain, where they were reverse-engineered and used in many battles.


Rockets in post-independence India:


INCOSPAR (Indian Committee for Space Research) lead by Prof Sarabhai was then part of Tata Institute of Fundamental research (TIFR).

In 1962 INCOSPAR took the decision to setup Thumba Equatorial Rocket Launching Station (TERLS) at Thumba (Thiruvananthapuram, Kerala) very close to earth's magnetic equator.


 Dr. APJ Abdul Kalam (now President of India) was amongst the initial team of rocket engineer forming the INCOSPAR. The initial team went to America for 6 months training program on sounding rocket launching techniques.


The Rohini Sounding Rocket (RSR) program to develop indigenously developed and fabricated sounding rockets launched the first single-stage Rohini (RH-75) rocket (32 Kg rocket with 7 Kg payload to ~10 Km altitude) in 1967, followed by a two-stage Rohini rocket (100 kg payload to over 320 Km altitude).


Infrastructure for the Indian Space programme:


  • ISRO was established in 1969 as India's primary space Research & Development organization, responsible for developing launcher and propulsion systems, launch sites, satellites and their tracking networks.
  • Vikram Sarabhai Space Centre, ISRO's single largest facility, near Trivandrum providing the technology base for launcher & propulsion development.
  • Liquid Propulsion Systems Centre has development branches in Bangalore and Trivandrum and are supported by major test facilities at Mahendragiri for wide spectrum of liquid motors.
  • ISRO Satellite Centre, lead centre for the design, fabrication & testing of science, technology and applications satellites.
  • SHAR Centre, The ISRO's orbital launch site and largest solid motor production and test facility.
  • ISRO Inertial Systems Unit. Provides inertial systems & components for satellites and launchers.
  • ISRO Telemetry, Tracking & Command Network (T.T&C). Headquartered in Bangalore, ISTRAC operates a network of ground station to provide TTC support for launcher & satellite operations.
  • Space Applications Centre. Located at Ahmedabad, SAC is ISRO's applications R&D centre, including communications, remote sensing and geodesy.
  • INSAT Master Control Facility (MCF) at Hassan, Karnataka; 180km from Bangalore.

Space Launching Vehicles:


India has developed a quite wide range of launch vehicles to launch its own and in a few instance, satellites from friendly nations as well.


The Launchers are:


SLV (Satellite Launch Vehicle)

ASLV (Augmented SLV)

PSLV (Polar SLV)

GSLV (Geosynchronous SLV)



1) SLV:


The SLV project was started in the early seventies and was designed to put a 40 Kg payload into a 400Km circular orbit. SLV3 rocket had four solid-propellant rocket motors, inter-stages connecting the forward skirt of one stage with the rear skirt of the next stage, inertial guidance and control systems to steer the vehicle along a predetermined trajectory and a heat shield to protect the fourth stage and the satellite payload .


The forth stage required composite structure and required many innovations in fabrication technology. The last stage motor was reconfigured and upgraded from a 250 Kg , 400mm diameter stage to 600 Kg, 650 mm stage for compatibility with a French Rocket project(which was later scrapped). Amongst the 4 rocket stages, the critical stages were the 8.6 tonne booster Stage-1 and high mass ratio apogee rocket motor (Stage-4) using high energy propellant.


First and Last Launch Date: 10 August 1979, 17 April 1983.

LEO Payload: 40 kg. to 400 km Orbit.

Liftoff Thrust: 46,390 kgf.

Total Mass: 17,610 kg.

Core Diameter: 1.0 m.

Total Length: 24.0 m.


There were various flights of the SLV-3, which included 2 experimental flights with nominal payloads and 2 developmental flights.


SLV-3 E1 (Experimental)


Flight date: 10 August 1979

Payload: Rohini-1A Experimental Technology mission, 30 Kg


SLV-3 E2 (Experimental)


Flight date: 18 July1980, 02:31 GMT

Payload: Rohini-1B RS-1 Experimental Technology mission, 35 Kg


SLV-3 D3 (Developmental)

Flight date: 31 May 1981, 05:00GMT

Payload: Rohini D-1 RS-1 Experimental Technology mission, 38 Kg

SLV-3 D4 (Developmental)

Flight date: 17 April 1983, 05:44 GMT

Payload: Rohini D-2 RS-1 Experimental Technology mission, 41.5 Kg


2) ASLV:

The ASLV was derived from the SLV-3 with the addition of 2 boosters while dimensions and performances were similar to those of the first stage. These boosters provided the takeoff of the vehicle by providing each 440kN thrust during 49 seconds. ASLV was 24m high and its capacity reached 150 kg payload in LEO (40km).

First Launch: 24 March 1987

Launched Site: SHAR Centre (Sriharikota).

Principal Use: Small LEO payloads.

Performance: 150 kg into 400km near-circular orbit, with inclination at about 46.5

Number of Stages: 4 solids plus 2 solid strap-ons (Stage 1 ignites at altitude following strap-on                                                              burnout).

Overall Length: 23.6 metres.

Principal Diameter: 100 cm.

Launch Mass: 41 tons.

Guidance: Closed loop inertial system housed atop Stage 3 with the S-band telemetry system and flight sequencer. Inertial platform module, navigation electronics module, guidance & control processors and stage processor modules. Steering during strap-on and Stage 1 phases are effected by the exhaust secondary injection, and during Stage 2 and Stage 3 by dedicated thruster modules. Stage 4 is spin stablilised.


3) PSLV:

India's Polar Satellite Launch Vehicle represents the first stage in acquiring launcher autonomy for application satellites. It is sized for placing a 1-ton IRS-class satellite in a 904km sun-synchronous orbit from Sriharikota. The PSLV also offers growth potential for a Geosynchronous SLV to handle 2.5t into GTO. 

The PSLV is a 4-stage launcher measuring 44 metres high with a 2.8 metre diameter, and weighing 275 tons. It can orbit around a 1-ton payload in sun-synchronous polar orbit.

        The first stage is powered by a solid fuel engine (Hydroxyl-Terminated Poly-Butadiene) which burns during 100 seconds and provides 3500kN thrust at sea level and 4600kN in vacuum. It is supported by 6 boosters which is switched on by a group of two and then four which is derived from the SLV-3 and ASLV's first stage. Each of those deliver 440kN thrust at sea level and 660kN in vacuum.

        The second stage is powered by the Vikas engine, which is built under French SEP licence, and consumes liquid propellant (Unsymmetrical DiMethylHydrazine and nitrogen tetraoxide). It provides 725kN thrust during 150 seconds.

        The third stage is powered by a solid fuel engine (HTPB) which provides 340kN of thrust.

        The fourth stage is protected by a bulb cap and is propulsed by 2 engines (Peroxyde D'azote and MonoMethylHydrazine) which burn in about 7 minutes.

First Launch: 20 September 1993.

Launched Site: SHAR Centre (Sriharikota).

Principal Use: 1-ton IRS Class satellites into sun-synchronous orbit or 3-ton class into LEO.

Performance: Sun-synchronous: 1000kg into 904km, 99.1 from SHAR (1.6t without range safety constraints)

Number of Stages: Four (2 solid and 2 liquid) plus six solid strap-ons.

Overall Length: 44.18 metres.

Fairing Diameter: 3.2 metres (5.1 metres base circle with strap-ons)

Launch Mass: 275 tons.

Guidance: Inertial guidance system located in vehicle equipment bay surrounding Stage 4 base. A redundant strap-down inertial navigation system (resins, incorporating three dry-tuned gyros and four servo accelerometers) feeds the navigation processor, which produces navigation data every 500 milliseconds for the guidance and control processor to issue steering commands at similar intervals. Open loop guidance is employed during Stage 1 burn before switching to closed loop from Stage 2 onwards.


4) GSLV:

ISRO developed the PSLV into an Ariane-Class Geosynchronous SLV with a 3.6 meter diameter fairing, capable of handling 2.5 ton INSAT-3 satellites. The GSLV will replace the PSLV's six solid strap-ons with liquids and substitute a cryogenic stage for the two upper stages. A heatshield, which is 7.8 m long and 3.4 m in diameter, protects the vehicle electronics and the spacecraft from the hostile environment during the ascent flight through the atmosphere. The heatshield is discarded at about 110 km during the second stage propulsion.

Launch Mass: 401 tons.

Length: 50.9 meters.

Strap-ons: Has four L-40 engines, each having 40 tons of UDMH (Unsymmetrical DiMethyl Hydrazine) and NTO (Nitrogen TetrOxide). PSLVs Vikas engine is due to replace the L-40 engines as the GSLVs strap-ons.


  • Stage 1: S-125, as the PSLV Stage 1 (129 tons solid).

        Stage 2: (GS2) is powered by a single liquid propellant engine (L37.5) - same as the PSLV.

        Stage 3: (GS3) is a cryogenic stage (C12) with re-startable engines. Length - 8.7m, Diameter - 2.8m, Mass - 15t (of which 12.5t is for the propellant). Propellant - LH2 (Liquid Hydrogen) & LOX (Liquid Oxygen).

Guidance and Control: The three-axis attitude stabilization of the vehicle is achieved by autonomous control systems provided in each stage.

Single plane Engine Gimbal Control (EGC) of the four strapons of the first stage are used for pitch, yaw and roll control. The core motor of the first stage (S125) is provided with Secondary Injection Thrust Vector Control (SITVC) to augment the pitch and yaw control.

The second stage has Engine Gimbal Control (EGC) for pitch and yaw and hot gas Reaction Control System (RCS) for roll. For the third stage, two swivellable auxiliary engines, using LH2 and LOX, provide pitch, yaw and roll control during thrusting phase and cold gas system during coast phase.

The Inertial Guidance System (IGS) in the Equipment Bay (EB) housed above the third stage guides the vehicle till spacecraft injection. The closed loop guidance scheme resident in the on-board computer ensures the required accuracy in the injection conditions.

The vehicle performance is monitored with extensive instrumentation. The performance data is transmitted via telemetry systems to the ground station. In addition to the performance parameters, the inertial position of the vehicle and its orientation are computed by the vehicle inertial system and computers which are also transmitted via the telemetry to the ground stations.

A telecommand system is used to terminate the flight, in case the vehicle deviates from its flight path beyond the specified limits.

A C-band transponder on the vehicle helps in tracking it from ground based radars. The complete telemetry and tracking coverage of the vehicle from lift-off to satellite injection will be provided by four ground stations.









Apple - Araine Passenger Payload Experiment:

Launched on 19 June 1981 from Kourou, it was India's first indigenous GEO test communications satellite, launched with the ESA's Meteosat 2. The Indian TV programs and educational teleconferences were relayed .

Mass at Launch: 670 kg

Geostationary Orbit: 102 East


The objective of this satellite was to study astronomy sources and relations between the earth and the sun (ionosphere study). The satellite was launched on 19 May 1975 aboard the Intercosmos launch vehicle.

Mass at Launch: 360 kg.

Launch Site: Kapustin Yar

Perigee/Apogee: 398 km / 409 km

Inclination: 50.7


There were two satellites in the Bhaskara series

1) Bhaskara 1 Launched on 7th June 1979 from Kapustin Yar aboard the Intercosmos launch vehicle. The satellite consisted of two TV cameras and microwave radiometers, and it spent one year studying India's resources. Useful ocean and land surface data were received. Housekeeping telemetry was received until re-entry on 17 February 1989.

Mass at Launch: 444 kg.

Perigee/Apogee: 394 km / 399 km.

Inclination: 50.7

2) Bhaskara 2 Launched on 20 November 1981 from Kapustin Yar. It was declared operational after receipt of 300 television images of the Indian sub-continent. The housekeeping telemetry was still being received until 1991. It re-entered orbit on 30 November 1991.

Mass at Launch: 436 kg.

Perigee/Apogee: 368 km / 372 km.

Inclination: 50.7




The Rohini series of satellites were designed and built for Indian scientific programs. Four satellite were launched in the the Rohini series; Rohini-1A, -1B, -2 and -3.  The Rohini-1B was also the first Indian satellite launched by an Indian rocket.

1) Rohini 1B: Launched on 18 July 1980 from Sriharikota aboard the SLV-3. It's weight was 35kg and the orbit was 305x919km, 44.7. It was India's first successful launch. This experimental satellite followed the failure of the Rohini-1A on 10 August 1979. Re-entered orbit on 20 May 1981.


2) Rohini 2: Launched on 31 May 1981 by SLV-3 from Sriharikota. It had a weight of 38kg and carried an imaging system. However the orbit achieved was 186x418km instead of the planned 296x834km, leading to re-entry after eight days.


3) Rohini 3: Launched on 17 April 1983 from Sriharikota aboard the SLV-3. It's weight was 41.5kg and its orbit was 371x861km, 46.6. Carried two cameras and L-band beacon. This satellite returned around 5000 earth images.


INSAT - Indian National Satellite System:

The INSAT 1 series:

The INSAT system uniquely provides geostationary platforms for simultaneous domestic communications and earth observation functions.

The satellites are handled from the INSAT Master Control Facility (MCF) at Hassan in Karnataka. They can also be controlled through two Satellite Control Earth Stations (one with a 14 metre fully steerable antenna and the other with a 7.5 metre limited steerability dish), one additional 14 metre fully steerable antenna and an INSAT-1 Satellite Control Centre (SCC) with Telemetry Tracking & Control (TTC) equipment, on-orbit checkout equipment, computer facilities and auxiliary power services.

1) INSAT-1A: The INSAT-1A system was envisaged with a space segment comprising two multi-purpose satellites, each providing two high power TV broadcast and twelve telecommunications national coverage transponders, in addition to also providing meteorological services.

2) INSAT-1B: Launched on 30 August 1983 from Canaveral. It continued to operate into 1990 with all its 4375 two-way voice or equivalent circuits in use. Around 36,000 earth images were returned.

Eleven of its 12 C-band transponder and its two S-band transponders provided direct nationwide TV & communications to thousands of remote villages, plus a detailed weather and disaster-warning service.


3) INSAT-1C: The INSAT-1C satellite was launched on 21 July 1988 from Kourou for location at 93.5E, the meteorological earth images and its data collection systems being fully operational.


4) INSAT-1D: The specification for the INSAT-1D is the same as the INSAT-1B but with expanded battery and propellant capacities. Launched on 12 June 1990, from Canaveral, to conclude the first generation INSAT series.


INSAT-1D's Transponders:

Twelve 4.5W TWTA 5935-6425/3710-4200MHz up/down, C-band all-India beam, 36MHz bandwidth, 32dBW EOL EIRP over primary coverage area linear polarisation.

Two (plus one backup) 50W TWTA 5855-5935/2555-2635MHz up/down, S-band all-India beam, 42dBW EOL EIRP over primary coverage area linear polarisation.


Principle Applications:

Domestic communications on C-band, one S-band channel dedicated to direct TV broadcast and other to five low-level carriers for services such as radio program distribution, disaster warning, etc. They relay 402.75MHz transmissions from 100 hydrological, meteorological and oceanographic data collection platforms.



The INSAT 2 Series:


The total number of satellites launched of the INSAT-2 series range include 4 (INSAT-2A, -2B, -2C and -2D), the most recent launch being that of INSAT-2D on 4 June 1997.


1) INSAT-2A:  Launched on 9 July 1992 from Kourou for location at 74E. It entered service on 6 August 1992. It has a design life of seven years.


The INSAT 2A's Transponders:

124.5 SSPA 5930-6410/ 3705-4185 MHz and six (three backup; 2-for-1) 6735-6975/ 4510-4750 MHz up/down C-band and external C-band, all-India beam, 36MHz bandwidth, 32dBW EOL EIRP for 16 transponders, 34dBW for two.

Two (plus one backup) 50W TWTA 5858-5930 /2550-2630MHz up/down S-band all-India BSS beam, 36MHz bandwidth, 42 dBW EOL EIRP.

Single 402.75MHz Data Collection System transponder.

Single 406MHz Cospas/Sarsat search & rescue package.


2) INSAT-2B: Specifications same as INSAT-2A. Launched on 22 July 1993 from Kourou and was declared operational at 93.5E on 10 August 1993.


3) INSAT-2C: Launched on 6 December 1995 from Kourou. The INSAT-2C replaced the imaging payload with improved telecom services. Declared operational at 93.5E.


The INSAT-2C's Transponders;

12 C-band (2x50W TWTA, tx10WSSPA & 3x4W SSPA) all-India beam.

Six extended C-band (2x10W & 4x4W SSPAs), all-India beam.

Three 20W TWTA Ku-band all-India, 41dBW EIRP

Two (plus one backup) 50W TWTA 5858-5930 /2550-2630MHz up/down S-band all-India BSS beam, 36MHz bandwidth, 42 dBW EOL EIRP.

One 50W TWTA 2670-2690/2500Mhz up/down S-band all-India mobile communications beam.

1 (plus one backup) 4W SSPA C-band all-India mobile communications feeder link.


4) INSAT-2D: Launched on 4 June 1997 from Kourou. This satellite gave a big boost to television and telephone services. Specifications same as the -2C.


5) INSAT-2E: Launched on 03 April 1999, the 2550 kg satellite has a design life of 12 years and carries 17 C-band transponders of which 11 transponders have been leased to the International Telecommunication Satellite Organisation (Intelsat). For the first time, the satellite, carries an improved version of a very high resolution radiometer (VHRR) and a high-resolution charge coupled device (CCD) camera. The VHRR payload will be used for imaging the cloud coverage including cyclone formation. Data from the CCD camera will assist in cyclone analysis, local storm monitoring, heavy rain forecast, snow detection and long term climatic studies.


The satellite is configured with a single sided solar array consisting of four panels which will deploy in an accordion fashion by a single command operation. The satellite's power system provides regulated dual power bus wherein certain subsystems could be connected to any of the bus by ground command. Apart from regular and selected power buses, an uninterrupted power bus is available for the domestic power control electronics and tele-command functions. The solar panels are populated with gallium-arsenic/germanium cells to generate a net power of about 2240 Watts to meet spacecraft power demands with adequate margin. The payload power requirement alone is 1755 Watts.



IRS - Indian Remote Sensing satellite:


The Indian Remote Sensing satellite system is India's first domestic dedicated earth resources satellite program and an element of the National Natural Resource Management System. IRS is an Indian program to develop an indigenous capability to image earth, particularly India. Its mission is ground water exploration, land use, forest & flood mapping, inventory of surface  water.


1) IRS-1A: The IRS-1A was launched on 17 March 1988 from Tyuratam. Weight was 950kg. A four-band imaging system, with CCD cameras returned overlapping 73m & 36.5m res images from sun-synchronous orbit. The series extends the work of earlier satellites in conducting forestry surveys, snow cover & flood control work, location of underground water supplies, determination of salinity, of water used for agricultural irrigation and land management. All three imaging systems have been opertional since 7 April 1988. Over 700,000 scenes had been returned by mid-1996. The satellite carried a real time LISS-2A/B data downlink with a transfer rate of 10.4Mbit/s. The data is down-linked to the 10 metre dish at Shadnagar on 20W X-band & LISS 1 data on 5W S-band at 5.4Mbit/s.


2) IRS-1B: Launched on 29 August 1991 from Tyuratam, aboard a SL-2 Vostok. Declared operational 16 September 1991. Its orbit was 857x919km, 99.25. Sun-synchronous. Other specifications are same as the IRS-1A.



3) IRS-1C: Launched on 28 December 1995 from Baikonur into a retrograde (99 inclination). It's orbit was 816km/816km (sun-synchronous). The IRS-1C acquires the highest spatial resolution remote sensing data commercially available today. The 5 metre panchromatic data is especially useful for urban planning and mapping, the 25 metre multi-spectral data is good for vegetation monitoring and natural resource planning; and the 180 metre wide-field data band has a 740km swath and 5-day repeat coverage which is excellent for large-area vegetation monitoring.


Communications: Recorded data is down-linked on the 40W 8 GHz X-band link. Three cameras all utilize push-boom CCD units, continuing and expanding the IRS-1A/B imagers.


4) IRS-P2: Launched on 15 October 1994 from Sriharikota aboard the PSLV-D2. Specifications are the same as the IRS-1C.


5) IRS-P3: Launched on 21 March 1996 from Sriharikota aboard the PSLV-D3. This was the third test launch of the PSLV. The satellite's perigee/apogee was 802km/848km and inclination was 98.8 Specification are the same as the IRS-P2.


6) IRS-1D: Launched in September 1997, IRS-1D was launched from Sriharikota using the PSLV. However the PSLV placed in an elliptical orbit, instead of a circular orbit. It is being used to map and monitor calamities. Specifications are the same as the IRC-1C satellite.


7) IRS-P4: Also known as the Oceansat-1, the IRS-P4, has a Multi-frequency Scanning Microwave Radiometre (MSMR) and a nine-band Ocean Colour Monitor (OCM). It was launched in a polar sun-synchronous orbit at 720 km away from the earth. It was launched successfully into space on 26 May 1999 by PSLV-C2 and is currently in orbit. The main application of this satellite is for gathering information related to water vapour and carrying out ocean colour monitoring. The data collected from ocean colour monitoring will be used for conducting a fisheries survey and development of a fisheries forecast model based on the data.


The satellite will have a great impact on environment studies as it will prove to be of great use in learning about marine pollution and oil slicks. Also important will be its use in coral reef studies.


8) IRS-P5: Also known as the Cartosat, the IRS-P5, has been intended for cartographic applications and is reported to have a pan camera with a resolution of 1 - 2.5 metres. It would be mainly useful for map making and terrain modelling.


9) IRS-P6: Also known as the Resorcesat, the IRS-P6, is reported to have a high resolution multi-spectral camera.






Bharat Rakshak (http://www.bharat-rakshak.com/SPACE/index.html)


Indian Space Research Org. ( http://www.isro.org/index.htm )


Antrix Corpn. (www.antrix.org )


National Remote Sensing Agency ( www.nrsa.gov.in )





KV Aditya Mohan

Chirag Modi

Saran G