PSLV, the Workhorse PSLV, the Workhorse 2017 has been special for ISRO, the Indian Space Research Organisation. In the year’s first rocket launch on 15 February, ISRO’s polar satellite launch vehicle did a first in the world, lifting off from Sriharikota with 104 satellites on board. What was significant in the feat was that 98 of the 104 satellites were for American and European customers, three for Asian and only three for India. It was also the 38th consecutive successful launch for the “workhorse”, one that ISRO scientist Devi Prasad Karnik said was “achieved at a very short deadline, where the challenge was to make the launches within the time frame of the customer, and also ensure that the satellites are placed so with minimal chance of collision in future.
”The 3rd-Generation PSLV first rose in 1994 and developed to lift loads twelve times that of previous SLV and ASLV rockets. With capacity to carry 1860 kg, placing it 475 kms in sun-synchronous polar orbit and 1300 kg in geosynchronous transfer orbit, the vehicle was used in the Chandrayaan-1 Moon Mission in 2008 and the Mars Orbiter mission in 2013.While ISRO continued with the PSLV that proved to be most reliable, work was on for a larger rocket that could carry much heavier loads, the 4th generation GSLV, the geosynchronous satellite launch vehicle.Early failures: GSLV missions had mixed results in success. On Christmas day 2010, the GSLV F06 lifted off perfectly after days’ launch delay to repair a faulty rocket pump. However, the rocket, with its GSAT 5P satellite, veered away from its path minutes in flight, necessitating ISRO scientist Dr. Srivastava to remote blast the truant GSLV. The irony was that this GSLV’s mission failed because of a loose contact on a control card inside the vehicle.The GSLV’s cryogenic engine stock was threadbare. An international embargo stopped more supplies and prevented tech tie-ups to make the engines here. ISRO resolved to make a cryogenic engine from scratch, at its own labs. It would be 15 years before a cryo would emerge for the GSLV.
Good tidings came with the Feb 2014 GSLV launch that set off a successful and consecutive four missions. Excited scientists now referred to the GSLV rocket as the “mischievous boy was now behaving”. On May 5 2017, GSLV Mk-2 lifted off from India’s spaceport, carrying the 2230 kg GSAT-9, with an “exclusive” satellite to serve south Asian nations. This was a launch where the Press and other visitors would be barred at the site, due to a perceived security threat at the launch site.
GSLV Mk-3 Thunders to GloryJune 5th recorded a memorable launch. The morning before, Telugu dailies dubbed the geosynchronous satellite launch rocket, “Baahubali”, the 142- foot high, GSLV MK 3 D1, ISRO’s heavy launch vehicle. On it was India’s heaviest-ever satellite, GSAT-19. As we were ushered in into the Sriharikota Press Room, it was 5.23 PM, when Dr. Alok Srivastav’s announcement informed that it was five minutes to launch. Daily Thanti’s Subramanian nudged me and we sprinted up the five flights of stairs to the terrace. “Ten seconds” to the launch, Dr. Srivastav said, as we readied our equipment into position. At 5.28, the lift-off began.
”Plus 4 seconds, Plus 5 seconds”, it was, when the roaring rocket with its flaming exhaust came into view. As it rose above the Asoka tree line, the thunder resonated. Amidst the sonic boom, an excited Subramanian asked, “Sir, can you feel our building’s tremor?” The roar continued as the rapidly climbing rocket donning the Indian tricolor vanished into the clouds.
There was palpable tension in the minutes before and after the launch. This rocket weighed 640 tons and was to carry the communication satellite which itself weighed 3.136 tons. Moreover, the GSLV rocket had a fully indigenous cryogenic engine, carrying solid and liquid propellants, in addition to 28.3 tons of cryogenic hydrogen stored at -253 degrees C and oxygen at -198 degrees C. It was after the 7th minute of the flight and we heard “cryogenic performance normal”, when scientist Guru Prasad smiled and said, “Sustaining ignition for 640 seconds of cryogenic engine is an achievement in rocket science”.At the 16th minute, the cryogenic engine cut off as per plan, the satellite separated and was placed in its initial orbit. The terrace was smile-filled and we all ran down the flight of stairs for the Press Meet with the ISRO Chairman and team.
“A dream come true”: A delighted Chairman Kiran Kumar first gave the good news. It was just over 50 minutes of flight, and the satellite was already working. Scientist S.Somanath said that this was a dream come true for a team that worked on the cryo-project for over 12 years. Scientist Dr. K. Sivan said that the day’s achievement was a revolutionary breakthrough.
Dr. Sivan was right. That evening, the world had just witnessed India’s first cryogenic development flight, one that could carry a 10-ton load and successfully put it into low earth orbit, or place 4-ton satellites into geosynchronous transfer orbit. This revolutionary breakthrough augurs well for India’s future space efforts. For similar payloads, ISRO could now do without expensive overseas launchers.
Sriharikota to Antarctica in 28 minutes: Barely 18 days after this success, ISRO launched the PSLV rocket carrying 31 satellites, of which 29 were for customers from the US, UK, Europe and Japan. The PSLV rapidly picked up speed and in 28 minutes, flew over the south polar tracking station of Troll, in Antarctica; the Workhorse had galloped at an amazing speed of 27,000 km/hour.
$ US 6 Billion Market: Today, the global launch market is estimated to be $ US 6 billion. Satellite companies are also thinking of 1400-satellite constellations; the scope of more multi-satellite launches has become a growing reality. With its PSLV and the GSLV rockets, ISRO can see future success in this rewarding market.
Distance & Safety: ISRO norms prescribe that all humans be at a safe 6 kms away from the launch pad, to protect them from the fatal shock of high-decibelled sound of a launching rocket. One wonders how Indian television beams close-up, multi-angled visuals of the rocket’s lift-off and flight. Cameras are positioned at the site, but all equipment is remote controlled by technicians from a safe location. Our Press Corp records the ascent from the media centre’s terrace, seven kms away from the pad.
ISRO’s systems also involve the spray of thousands of gallons of water into the rocket’s flame pit to absorb the launch noise and reduce the heat, which would otherwise melt the launch pad.
During recent launches, viewers also saw images in flight, beamed from cameras on the rocket.