ISRO’s launch: Tech denied, how this was Made in India
Monday’s
launch of a geostationary communication satellite, GSAT-19, is perhaps
ISRO’s most important mission in the last three decades. Bigger,
probably, in technological significance than even the hugely popular Chandrayaan
or Mangalyaan space missions. Not because of the satellite that is
being put in space, though that, in itself, is no less special. The
launch is a giant leap for ISRO because of the rocket it is using. More
precisely, because of the engine that is powering this rocket. In fact,
it is just the third and uppermost stage of that engine that has made
this launch extra-special.
The
mission happens to be the first “developmental” flight of the next
generation Geosynchronous Satellite Launch Vehicle, called GSLV-MkIII
with an entirely indigenous cryogenic upper stage that ISRO has been
trying to master since the 1990s. This cryogenic stage, that involves
handling fuel at very low temperatures, is crucial to providing the
extra thrust required by the rocket to carry heavier satellites deeper
into space.
GSLV-MkIII
is meant to carry payloads up to four to five tons and that was not
possible with conventional propellants used by ISRO’s main launch
vehicle, called PSLV, which can take satellites only up to 2 tons
to orbits and that too until orbits of 600-km altitude from the earth’s
surface. It will not just help ISRO probe deeper into space but will
also bring it extra revenue, enabling it to make commercial launches of
heavier satellites.
“It
is definitely the biggest event for ISRO in the last couple of decades.
For ISRO’s launch vehicle programme, this probably is the most
important day. This is a success in which there has been
absolutely no foreign assistance. The GSLV-MkIII is entirely home grown
and that is why it is so satisfying,” G Madhavan Nair, former chairman
of ISRO, told The Indian Express.
Behind
the success of the launch is nearly three decades of hard work in
taming cryogenic technology and an interesting history of this
technology was denied to ISRO by the United States in the early 1990s,
forcing it develop it on its own.
Amongst
all rocket fuels, hydrogen is known to provide the maximum thrust. But
hydrogen, in its natural gaseous form, is difficult to handle, and,
therefore, not used in normal engines in rockets like PSLV. However,
hydrogen can be used in liquid form. The problem is hydrogen liquifies
at very low temperature, nearly 250 degrees Celsius below zero. To burn
this fuel, oxygen also needs to be in liquid form, and that happens at
about 90 degrees Celsius below zero. Creating such a low-temperature
atmosphere in the rocket is a difficult proposition, because it creates
problems for other material used in the rocket.
ISRO
had planned the development of a cryogenic engine way back in the
mid-1980s when just a handful of countries — the United States, the
erstwhile USSR, France and Japan — had this technology. To
fast-track its development of next-generation launch vehicles — the GSLV
programme had already been envisioned — ISRO had decided to import a
few of these engines.
It
had discussions with Japan, US and France before finally settling for
Russian engines. In 1991, ISRO and the Russian space agency, Glavkosmos,
had signed an agreement for supply of two of these engines along with
transfer of technology so that the Indian scientists could build these
on their own in the future.
However,
the United States, which had lost out on the engine contract, objected
to the Russian sale, citing provisions of Missile Technology Control
Regime (MTCR) that neither India nor Russia was a member of. MTCR
seeks to control the proliferation of missile technology. Russia, still
emerging from the collapse of the USSR, succumbed to US pressure and
cancelled the deal in 1993.
In
an alternative arrangement, Russia was allowed to sell seven, instead
of original two, cryogenic engines but could not transfer the technology
to India. These engines supplied by Russia were used in the
initial flights of first and second generation GSLVs (Mk-I and Mk-II).
The last of these was used in the launch of INSAT-4CR in September 2007.
But
ever since the cancellation of the original Russian deal, ISRO got down
to develop the cryogenic technology on its own at the Liquid Propulsion
Systems Centre at Thiruvananthapuram. It took more than a decade to build the engines and success did not come easily.
In 2010, two launches of second generation GSLV rockets, one having the Russian engine and the other indigenously developed, ended in failures.
The
big success came in December 2014 with the experimental flight of third
generation (Mk-III) GSLV containing an indigenous cryogenic similar to
the one used today. This mission also carried out an experimental
re-entry payload, that ejected after reaching a height of 126 km and
landed safely in the Bay of Bengal.
After
that, there have been three successful launches of second generation
GSLV (Mk-II), the latest one, in May, being GSLV-F09 that launched the
South Asian satellite.
Today’s success will open up a number of new opportunities for ISRO. Its
ambitions to send manned mission to space and planetary exploration
satellites hinge totally on GSLV. It can also hope to garner a
significant share of the international satellite launch market now that
it is able to launch payloads heavier than 3 tons.
“ISRO is now in a completely different trajectory. We
hope that this GSLV would become as reliable and as consistent as the
PSLV has proven to be over the years,” Madhavan Nair said.
Comments
Post a Comment