‘Naughty boy’ tamed: ISRO’s GSLV injects weather satellite into orbit

Chairperson S Somanath, too, said: “With this mission, our confidence in GSLV is (even more) high. The next mission of GSLV is going to be NISAR. This gives us greater confidence to take on NISAR soon.” NISAR, being developed jointly by NASA and ISRO, will study changes to ice sheets, glaciers and sea ice brought about by climate change.

VIDEO | GSLV-F14/INSAT-3DS Mission: INSAT-3DS meteorological satellite launched by ISRO from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota. pic.twitter.com/4fg2TpvcaL

— Press Trust of India (@PTI_News) February 17, 2024

Not only was Saturday’s launch a textbook one, the GSLV also carried an additional 50 kg to a 2,800-km higher orbit, increasing the life of the satellite by three months, said Director of UR Rao Satellite Centre M Sankaran.

The weather observation satellite was injected into a geosynchronous transfer orbit. From here, over the next few days, orbit raising manoeuvres will be conducted to place the satellite in its final orbit. Once the satellite is tested in-orbit and becomes operational, it will provide advanced weather observations of land and ocean surfaces.

While the last GSLV mission, in 2023, also used the new and bigger four-metre ogive-shaped payload fairing — the top part of the launch vehicle within which the satellite is placed till it crosses the dense atmosphere — this was the first time the additional space was utilised for a bigger satellite. In the 2023 mission, the GSLV successfully placed the NVS-01 navigation satellite in a geosynchronous transfer orbit.

The director of Liquid Propulsion Systems Centre, Dr V Narayanan, said that the GSLV in its first development flight carried a satellite weighing only 1,526 kg, compared to the 2,274-kg INSAT-3DS. He said gradual improvements have ensured that the payload capacity has increased by 50 per cent since the vehicle was first used.

Satellite director Imteyaz Ahmad said: “I should thank the GSLV team for precise injection into the orbit and maximising the lift-off mass. The four metre payload fairing is extremely important for the satellite community as it provides flexibility for building larger spacecraft. INSAT-3DS is an example where a lot of improvement will be achieved because of the larger payload fairing.”

At least four of GSLV’s sixteen launches have failed. Only two of 60 missions by the workhorse PSLV have failed. And all of the seven launches by ISRO’s heaviest vehicle, LVM-3, have been successful.

The last failure of GSLV occurred in August 2021 when a malfunctioning valve led to insufficient pressure in the liquid hydrogen tank in the cryogenic upper stage, resulting in the stage not igniting.

The INSAT-3DS will help in short-range forecasts of extreme weather events such as thunderstorms, provide visibility estimation for aviation and help in studying forest fire, smoke, snow cover and climate. It will also help in detecting potential fishing zones. The satellite will provide imaging data in six wavelengths and will be an upgrade over the INSAT 3D and INSAT 3DR satellites that it is meant to replace.

The satellite will have a mission life of ten years and has been fully funded by the Ministry of Earth Sciences.

During the past five years, the IMD’s services included relaying vital meteorological information once every 15 minutes which was facilitated by the combination of INSAT 3D and 3DR. “But as INSAT-3D has completed its ten year lifetime, its data quality was not as expected. INSAT-3DR, too, has completed eight years of its mission. So, as satellites get older we need new satellites to replace the older ones. This is a continuous exercise,” said Mrutyunjay Mohapatra, director general, IMD. Now, the data will be generated by INSAT-3DR and 3DS.

The next series of meteorological satellites — the INSAT-4 — will be a major upgrade to the meteorological services and products. “INSAT-4 will use entirely new technologies. We have placed an order for the same,” Mohapatra said.