On Wednesday (14 November), the Indian Space Research Organisation (ISRO) successfully launched communication satellite GSAT-29 on the Geosynchronous Launch Vehicle (GSLV) Mark-III, which placed it into the Geosynchronous Transfer Orbit (GTO) – 36,000 kilometres from the Earth's surface in just 16 minutes after launch. The satellite, weighing 3,423 kilograms, will provide high-speed internet connectivity and improve telecommunication in remote areas of the country, specially Jammu and Kashmir and parts of north-eastern India, taking Prime Minister Narendra Modi’s ‘Digital India’ mission a step closer to success.

While the launch looked similar to other satellite launches undertaken by ISRO, there are reasons why it was more significant than most of those.

One, this satellite launch atop GSLV Mark-III was the second development flight of the vehicle. As the launch was successful, the vehicle, India’s heaviest, will be declared operational by the ISRO.

Although India has been a space-faring nation for more than 50 years, it has had to depend on others for the launch of its larger satellites to the GTO. Most recently, India used a heavy-duty rocket of Arianespace, world's first commercial launch service provider, for placing communication satellite GSAT-18 into the GTO. This is because India’s most capable launch vehicle until now, the GSLV Mark-II, is capable of launching payloads of only up to 2.2 tonnes into the geostationary orbit. However, the GSLV Mark-III will allow India to place satellites as heavy as 4-tonnes into the GTO. The maximum payload limit for the GSLV Mark-III is 60 per cent greater than that of the GSLV Mark-II.

Satellites in the GTO have advantages over those in other orbits. Satellites that are placed in the geosynchronous orbit, a high Earth orbit, move slower compared to satellites in the low Earth orbit (LEO) and the medium Earth orbit. This gives the satellites more time over any given area, allowing them to study the region in detail. Also, in the geosynchronous orbit, the time taken by a satellite to complete one revolution around the Earth is equal to the period of rotation of the earth on its axis. A satellite in this orbit moves at the same speed that the Earth is turning in. Therefore, the satellite seems to stay in place over a single longitude, though it may drift from north to south.