Why today’s ISRO launch is the most important in 23 years

Tyagarajan S June 5, 2017

At 5:28pm today (June 5), the Indian Space Research Station (ISRO) will attempt to launch the most powerful rocket it has ever made, the GSLV MKIII (Geosynchronous Launch Vehicle) from its Sriharikota launch pad in Andhra Pradesh. The launcher will be carrying a GSAT-19, a satellite of strategic importance to India, onboard.

The GSLV MKIII is a beast capable of carrying of payloads up to 4,000kg into what are called geosynchronous transfer orbits (GTO, or 35,000km above the earth’s atmosphere) and upto 8,000kg into the low earth orbits (600km above). It follows ISRO’s nearly 30-year journey to put a heavy launch vehicle in operation.

GSLV MKIII rocket ISRO
Source: ISRO

In 1993, India launched the PSLV (Polar Satellite Launch Vehicle) rocket which was a major milestone that redefined India as one of the top space faring nations. Today’s launch, by all measures, is an equally important milestone. It positions India among an elite group of nations that have the self-sufficiency to carry large, powerful satellites into space. It also opens up the lucrative parts of the multi-billion dollar satellite launch market to Antrix, ISRO’s commercial arm.

The GSLV MKIII is a beast capable of carrying of payloads up to 4,000kg into geosynchronous transfer orbits (35,000km above the earth’s atmosphere) and upto 8,000kg into low-earth orbits  

In order to build a heavy launch rocket, ISRO needed to perfect multi-stage cryogenic engines (engines that use gases liquefied and stored at very low temperatures). Cryogenic engines powered a lot of NASA’s successes during the age of space race between the US and the erstwhile USSR, including America’s journey to the moon. However, restrictive international embargoes meant that ISRO did not get access to any of that technology.

Watch ISRO’s GSLV MKIII launch live here.

Taming the ‘naughty boy’

With complete lack of international support, ISRO did what it usually does best  —  build from scratch and build indigenously. But the struggle was real.

ISRO’s quest to master a cryogenic upper stage (CUS) engine was carried out through the GSLV MKII launch buggy. The organisation faced a series of failures during the process which led the MKII being called the “naughty boy” within the halls of ISRO. Some scientists believe that ISRO’s attempts to perfect the MKII may have even cost it several years of delay in getting the MKIII going, a program that was funded all the way back in 2001.

ISRO faced a series of failures in its quest to master a cryogenic upper stage engine, which led the MKII being called the “naughty boy” within the halls of ISRO

The GSLV MKIII uses C25, a cryogenic three-stage engine that is slightly different from the CUS. In 2014, a successful test flight of GSLV MKIII with a dummy cryogenic engine helped ISRO prove the first and second stages using the cryogenic engine. Since then, ISRO has been intensely focussed on developing the C25 that would carry this mega rocket off the ground.

Also read: Space is becoming big business, but ISRO is getting left behind

The urgency is also driven by a growing imperative to improve India’s self-sufficiency in launching large satellites.

Despite the incredibly reliable PSLV ferrying more and more satellites into space, it is limited in the weight it can carry. With an upper limit of less than 1,500kg, India has been reliant on European space agency’s Ariane V launch vehicle (which has a payload capacity of more than 10,000kg) for its heftier satellites. It has been an expensive proposition for ISRO. For instance, the 3,404kg GSAT-18 satellite, launched through Ariane 5 in October 2016, must have cost ISRO anywhere between Rs 136-340 crores (estimated based on Ariane 5’s full load launch price).

ISRO payload
ISRO has limited capacity and can carry an even smaller fraction of that as commercial payload

Launching into the future

A successful launch of GSLV MKIII will give India the ability to now launch heftier satellites on its own. The GSAT-19 that will go up in this launch weighs 3,136kg, the heaviest satellite India has ever launched. Prior to the MKIII, ISRO would have had to rely on a foreign launch agency for this.

The GSAT-19 itself is worth dwelling on for a moment. This ‘Made in India’ satellite is packed with indigenous innovations including homemade lithium-Ion batteries. Li-ion self-sufficiency plays well with India’s terrestrial goals of aggressively pursuing electric vehicles on the road.

A successful launch of GSLV MKIII will give India the ability to now launch heftier satellites on its own. The GSAT-19 that will go up in this launch weighs 3,136kg — prior to the MKIII, ISRO would have had to rely on a foreign launch agency for this  

More importantly, when launched, this will be the country’s first satellite that can provide internet services using the high throughput ka/ku-band (six-seven times faster than current satellites). This provides India a satellite-based internet backbone that reduces our reliance on only terrestrial fibre optics and copper wires. In the future, this could be used by the government to connect parts of the country that are off fibre optic networks.

Also read: ISRO, it is time you outsourced to get to the next orbit

The GSAT-19 is also carrying a ton of new technologies that are being tested for future missions, including miniaturised heat pipe, fibre optic gyro and micro electro mechanical systems (MEMS) accelerometer. The Geostationary Radiation Spectrometer (GRASP) on board will monitor and study the nature of charged particles and the influence of space radiation on satellites and their electronic components.

Bigger satellites means better revenues for Antrix, which would reduce the pressure on the government to fund ISRO’s increasingly complex ambitions  

GSLV’s 4,000 kg GTO launch capacity still trails the popular heavy launch vehicles. Space X chief launch buggy, Falcon 9 has a payload capacity in excess of 8,000 kg. There are even more monstrous rockets on the horizon like China’s Long March 5 rocket, with a potential GTO payload capacity of 14,000 kg.

Still, given ISRO’s cost competitiveness, a successful launch of MKIII here will open up the much bigger large-satellite launch market to Antrix. Bigger satellites means better revenues for Antrix, which would reduce the pressure on the government (to the little extent possible) to fund ISRO’s increasingly complex ambitions.

More importantly, it will also be the perfect testament to decades of perseverance from ISRO, an organisation that has over-delivered time and again.

Also read: India needs manned missions to space. Or we’ll lose out to China in the race for resources: U R Rao