The textbook launch of the Geosynchronous Satellite Launch Vehicle (GSLV)-F12 that carried India’s navigation satellite, NVS-01 into a transfer orbit around the Earth is significant for more than one reason.
The 2.2-tonne satellite is an important cog in the constellation of eight satellites launched earlier, and now wheeling around Earth to make up the Navigation with Indian Constellation (NavIC) network.
The NVS-01 belongs to a new generation of satellites that are equipped with indigenously-developed rubidium atomic clocks to give precise positional data, and joins the cluster as its ninth member.
Four more in offing
The Indian Space Research Organisation (Isro) plans to launch four more similar satellites to complete the NavIC, making it one of the best regional satellite navigation networks in the world.
The successful launch on May 29, however, was not just about the NVS01. The GSLV’s flight, in a sense, was a redemption-of-sorts for Isro which was eager to send the big booster aloft after the GSLV-F10’s launch failure in August 2021 when one of the booster engines failed, and the rocket crashed into the Indian Ocean.
Investigators later found that a faulty valve had led to low pressure in the liquid hydrogen tank in the indigenously-built cryogenic upper stage (CUS) of the rocket. Isro has put that setback behind as the GSLV’s latest mission validated all its flight parameters.
“The corrections and modifications in the cryogenic stage that we have done in this stage and the lessons that we learnt out of it to make the cryogenic stage more reliable have paid benefits,” said Isro chief S Somanath.
Workhorse launchers
Rockets such as the GSLV are the workhorse launchers for satellite launching agencies of the United States, the EU, Russia, China, and Japan.
But there is a twist in the tale of Isro’s homegrown cryogenic technology — and it comes from the Liquid Propulsion Systems Center (LPSC) in Kerala, which has developed the propellant for a semi-cryogenic engine.
The LPSC’s answer to the risky liquid hydrogen is the humble kerosene, which can be stored at normal temperatures. Using oxygen as an oxidiser, the kerosene pumps up rocket thrust almost three times.
In fact, NASA used kerosene and oxygen in the first stage of its mighty Saturn rocket to beat the Soviets to the Moon in the 1960s. Even today, SpaceX’s Falcon 9 uses rocketgrade kerosene and liquid oxygen in its Merlin engines.
Chances are that a semi-cryogenic engine will power the GSLV in its new avatar, the LVM 3, as it carries India’s first crewed space mission, Gaganyaan, into orbit
