On the silver jubilee of the first successful SLV-3 flight, Indian space scientists begin to think of making reusable launch vehicles and sending a manned mission to space.
THE silver jubilee celebrations of the first successful flight of the Satellite Launch Vehicle-3 (SLV) held at the Vikram Sarabhai Space Centre (VSSC) at Thumba near Thrivananthapuram on July 28, were not a mere exercise in nostalgia. Space scientists took the occasion to make a clear appraisal of the Indian Space Research Organisation's past and present and, most important, where it will be headed in the next 30 years.
If the presentations made at the symposium entitled "Launch Vehicles: Past, Present and Way Ahead" held on the occasion are any indication, ISRO is preparing itself technologically for sending manned missions to space between 2012 and 2015. The need to build reusable launch vehicles (RLVs) dominated the discussions.
Today, the cost of putting a satellite into orbit works out to between $12,000 and $15,000 a kg. About 70 per cent of this goes towards building the hardware (rocket stages), which fall into the sea and cannot be recovered. Since this cost is prohibitive, ISRO scientists underscored the need to build RLVs that can put a satellite into orbit at $1,000 a kg. Such RLVs would be an amalgam of rocket and aircraft. They will blast off from a spaceport, go into space like an aircraft, place or repair a satellite in orbit, and glide back to land in an airport. If ISRO's plans work, an RLV Technology Demonstrator will fly into space by 2010. This will be followed by a hyperplane. "Some thought processes have originated" also on nuclear propulsion to space too.
President A.P.J. Abdul Kalam, who was the Project Director of the first successful SLV-3 flight in 1980, set the tone for the symposium. In his inaugural address, he predicted that "the coming years will see the domination of reusable launch vehicles". Emphasising the importance of manned missions to the moon and Mars, he said, "We need to go to the moon and different planets to get materials... . We missed the first Industrial Revolution. India is still a developing country. The next Industrial Revolution will not take place on our land, on the earth, but will take place in space."
(Right now, "preparations are going on well" for sending Chandrayaan-1 to the moon by 2007-08. It will be India's first scientific mission to the moon. A Polar Satellite Launch Vehicle (PSLV) will take off from the spaceport at the Satish Dhawan Space Centre, Sriharikota, Andhra Pradesh, and orbit the Chandrayaan-1 satellite about 100 km above the moon. The mission will have a lander - that is, a probe will detach itself from the satellite and as it descends towards the moon's surface, its cameras will take pictures of the moon's soil.)
President Kalam wanted India to join the race in setting up mining and manufacturing facilities on the moon and Mars as it had the capability. India was self-reliant in space technology and it could build any type of launch vehicle, fabricate any kind of satellite, and put satellites in different orbits. It had an operational missile programme. BrahMos, the supersonic cruise missile developed jointly by India and Russia, represented a breakthrough in supersonic cruise missile technology, he remarked. "It is the best among the missiles in the world," Kalam said.
ON July 18, 1980, SLV-3 lifted off from Sriharikota at 8-03-45 a.m. and put the 38.5 kg Rohini satellite into orbit. Dr. B.N. Suresh, Director, VSSC, recalled, "At T minus 14 minutes, the Mission Director, Abdul Kalam, authorised the launch and [14 minutes later] the first stage of the four-stage 22-metre-tall SLV-3, weighing 17 tonnes, ignited." Rohini went into orbit about 11 minutes later, with a perigee of 308 km and an apogee of 916 km. It was in orbit for 371 days. "SLV-3 had 44 major systems and 250 sub-systems. Its launch laid the firm foundation for our future launch vehicles. It represented the dawn of our launch vehicle era," he said.
The SLV-3 project was the culmination of seven years of developmental efforts of several hundreds of personnel belonging to various ISRO centres. While the VSSC built the vehicle, ISRO Satellite Centre, Bangalore, fabricated the Rohini satellite.
The objective of the flight was to test the vehicle's major systems and sub-systems and its capability to put a 40-kg satellite in orbit. "The fantastic success" of the flight, according to Dr. Vasant Gowariker, the then Director of the VSSC, propelled India into the exclusive space club as its seventh member.
A blurb on the souvenir "Development of SLV-3, Retrospective", commemorating the silver jubilee of the SLV-3 launch, put the issue in perspective: "It is a cliche to say that the SLV-3 earned us the membership of the exclusive club of the space-faring nations in the world. It is perhaps more appropriate to say that the SLV-3 broke the monopoly of the `advanced countries'."
Besides Kalam, the core SLV-3 project team consisted of Dr. S. Srinivasan (who died in 1999 as VSSC Director), Ved Prakash Sandlas, D. Narayanamoorthi, G. Madhavan Nair (now ISRO Chairman), M.S.R. Dev, M.K. Abdul Majeed, D. Sasikumar, P.S. Veeraraghavan and A. Sivathanu Pillai.
According to D. Narayanamoorthi, Director, ISRO Launch Vehicles Programme, the core team's job was a "life-cycle" one that covered the spectrum from the specification of a product, to its production and qualification. There were other teams involved in specific areas: design reviews, configuration, control, vehicle, satellite, telemetry, tracking network and so on. "Even as we began our work on SLV-3, we started to think of the Augmented Satellite Launch Vehicle (ASLV) and the PSLV," Narayanamoorthi said.
Those were hard days, with just elementary facilities available at Thumba. "When we designed SLV-3, we had only mechanical calculators," Madhavan Nair said. There were only drafting boards with T-square. There were no powerful computers. The computers needed punch cards even for elementary computation. Propellant development often turned out to be an adventure. The propellants were ground on ammikkal (Tamil and Malayalam for grinding stone) and stuffed into tubes. Engineers and scientists worked in sheds with asbestos roofs, in 40o Celsius temperature. "In that environment, we made pyrotechnics, rockets, avionics and then SLV-3," Madhavan Nair recalled.
Dr. S.C. Gupta, former VSSC Director, gave a contra-distinction: "We have progressed from hand-mixing to remotely controlled mixing of propellants." Out of the 1,200 scientists and engineers who worked on the SLV-3 project, fewer than 20 were educated abroad. "All the people of the SLV-3 era stayed on with ISRO," he said.
The 1980 flight was the second experimental mission of SLV-3. The first one, on August 10, 1979, failed owing to "a silly fault". The nitric acid in the solenoid valve had leaked before the lift-off took place.
"Trying to send up a rocket without nitric acid is like trying to drive a car without petrol," Dr. Gowariker explained. Kalam was the Project Director of that flight. After the flight failure, Professor Satish Dhawan, who was then the ISRO Chairman, told the media, "It was our first step. We stumbled a little but did not fall flat on our face."
Within a year, SLV-3 lifted off and made history. The third SLV-3 flight, on May 31, 1981, was a partial success. The Rohini satellite did not reach the targeted orbit because of the malfunctioning of one of the one lakh components of the vehicle. The satellite burnt up just nine days after the launch though its intended life span was 300 days.
The fourth SLV-3 flight on April 17, 1983, was a huge success. Prime Minister Indira Gandhi, who witnessed the launch from Sriharikota, did not hide her emotions. She said, "For me, it is a special thrill even though I am above 60 years. I am thrilled, excited and proud."
Today, India is a space power. Twenty home-grown vehicles have raced into the sky from Sriharikota since 1979. These include four flights each of SLV-3 and the ASLV, nine flights of the PSLV, and three flights of the Geo-synchronous Satellite Launch Vehicle (GSLV). These flights have orbited 24 satellites, including four belonging to other countries. Eight PSLV and three GSLV flights have been successful in a row.
The ASLV was a complicated vehicle and its first two flights failed. Several technologies were tried out in the ASLV for the first time. They included strap-on booster motors, closed loop guidance system and the bulbous heat shield. Besides, it was vertically integrated in a mobile service tower unlike SLV-3, whose stages were integrated horizontally, and the entire vehicle lifted up vertically before ignition.
This was the assessment of Professor U.R. Rao, former ISRO Chairman, about the ASLV: "It was the failure of the ASLVs that taught us real rocketry. ASLV-1 failed because of some ignition problem. It did not give us any database. In the ASLV-2 flight, everything went well and yet the rocket broke [into pieces]... It was an unstable vehicle. It taught us everything."
ISRO has attained maturity in building satellites too. Beginning with Aryabhata in 1975, it has so far built 38 satellites - 18 of them have been launched from abroad. The Satellite Instructional Television Experiment (SITE), conducted in 1975-76, took television for the first time to the heart of India. This experiment established India's capability to operate a complex, satellite-based television system.
Similarly, the Satellite Telecommunications Experiments Project (STEP), conducted from 1977 to 1979, established India's expertise in operating a space-based domestic communication system. Space Applications Centre, Ahmedabad, builds some of the finest camera systems used on Indian satellites. The ISRO Satellite Centre in Bangalore builds world-class remote-sensing, meteorological and communication satellites. Dr. P.S. Goel, until recently the Director of the ISRO Satellite Centre, is respected worldwide as a builder of satellites. The National Remote-Sensing Agency (NRSA) disseminates images beamed by the satellites to user-agencies.
According to Kerala Chief Minister Oommen Chandy, the State used remotely sensed images from the Indian Remote-sensing Satellites to study forest cover, assess the environment, undertake wasteland studies and help fishermen locate fishing grounds. ISRO satellites are used for telemedicine and tele-education (Edusat).
President Kalam predicted that forecasting of earthquakes would be possible in about six years by studying the build-up of the stress level and the resultant signature. Carbon nano-tubes and carbon nano fibres would emerge as important fields. Carbon nano fibre, which was light in weight but had high strength, "will play an important role" in building hypersonic aircraft, he said. There would be solar-powered satellites. The life of satellites in orbit could be extended by repairing and refuelling them, he said.
Dr. C.B. Kartha, chairman of the organising committee of the celebrations, recalled his association with Kalam during the latter's days at the VSSC.
