NSIL Picks SpaceX to Launch ISRO Satellite GSAT-20

On January 3rd, NewSpace India Limited (NSIL) announced it has contracted American firm SpaceX to launch an Indian communication satellite aboard the Falcon 9 rocket. NSIL is the commercial arm of the Indian Space Research Organisation (ISRO).

This will be the first time an Indian government satellite launches on SpaceX’s workhorse Falcon 9 launcher. The mission is scheduled in the second quarter of 2024.

Key Details About GSAT-20

The satellite that will launch on Falcon 9 is GSAT-20. It was recently renamed as GSAT-N2. Weighing 4.7 tons, it is ISRO’s latest high-capacity communication satellite. GSAT-20 is also NSIL’s second fully funded satellite mission.

GSAT-20 will operate in the Ka-band spectrum and provide high-throughput satellite capacity primarily for broadband connectivity and cellular backhaul services. Its coverage zone spans the entire Indian mainland and the island chains of Andaman-Nicobar and Lakshadweep.

About Ka-Band

The Ka-band refers to radio frequencies ranging from 27 to 40 GHz. It allows high-speed satellite data transfers with wide coverage through focused spot beams.

Compared to other bands, Ka-frequencies enable using smaller satellite antennas. This reduces overall costs of establishing the communication system.

Ka-bands are often preferred in satellites as they provide high bandwidth and data rates required for good performance. The circular polarization used also avoids complex antenna adjustments during installation.

Additionally, the same Ka-band frequency can be reused through different spot beams directed at different locations. This frequency reuse greatly enhances the coverage footprint and capacity of Ka-band satellite communication systems.

It strikes an optimal balance between high frequency, large bandwidth, reuse of frequencies, and reasonably compact components. This makes it very well suited for contemporary satellite-based communication networks.

About SpaceX’s Falcon 9 Rocket

The reusable Falcon 9 rocket is a pioneering orbital-class launch vehicle built by Elon Musk’s SpaceX. To date, it has executed over 280 successful launches and 200 re-flights of used first stages.

Falcon 9 can lift 22,800 kg payload mass to Low Earth Orbit, making it ideal for launching heavier satellites like GSAT-20. Its reusability also reduces overall launch costs.

Why Not ISRO’s Own Rockets?

ISRO rockets like GSLV and LVM3 have flown many foreign satellites over the years. But GSAT-20’s 4.7 ton weight exceeds their lift capacities to deliver satellites to higher orbits. With Ariane 5 retired too, SpaceX’s larger launcher emerged the right fit.

In the long run, ISRO aims to develop more powerful semi-cryogenic engines and new reusable methane-LOX rockets allowing 5000 kg+ satellite launches without overseas providers.



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