India is preparing to launch its largest communication satellite, GSAT-20, with the help of SpaceX's Falcon 9 rocket. Weighing 4,700 kg, GSAT-20 is too heavy for India's current launch vehicles. ISRO's heavy-lift rocket, the LVM-3, also known as "Bahubali" or "Fat Boy," can only carry satellites weighing up to 4 tonnes into Geostationary Transfer Orbit (GTO). ISRO turned to SpaceX, whose Falcon 9 rocket can handle payloads of up to 8.3 tonnes in GTO, making it ideal for this mission.
SpaceX was chosen for the task after other options became unavailable. Arianespace, part of the ArianeGroup, was not accessible, and the ongoing conflict with Russia further limited alternatives.
GSAT-20 will play a critical role in enhancing India's communication infrastructure, supporting initiatives like smart cities, and providing in-flight internet access. By leveraging SpaceX's Falcon 9, ISRO ensures that GSAT-20 can be successfully deployed, marking a significant step forward for India's satellite capabilities.
In the past, ISRO depended on Arianespace to launch its larger satellites. However, Arianespace could not offer a slot for the GSAT-20 launch this time. This is because the available commercial slots for the upcoming launches of their new rocket, Ariane 6, are already booked, and their previous rocket, Ariane 5, was retired last year. As a result, ISRO had to look for other options, eventually turning to SpaceX.
The Ariane 5 rocket can carry payloads of up to 10 tonnes to Geostationary Transfer Orbit (GTO), while the newer Ariane 6 has two variants, namely Ariane 62 (with two boosters) that can carry up to 4.5 tons to GTO, and Ariane 64 (with four boosters) that can carry up to 11 tonnes to GTO.
ALSO READ: Indian on the moon by 2040 'a powerful inspiration for next generation', says ISRO chief Somanath
SpaceX is India's only reliable option since India doesn't consider using China's commercial launch services, and Russia is currently involved in the conflict with Ukraine. ISRO's commercial arm, New Space India Ltd., is in charge of funding, owning, and operating the GSAT-20, also called GSAT N-2. This satellite is part of the ongoing Gsat series of communication satellites.
“The satellite is equipped with a cutting-edge Ka-band high-throughput communication system, designed to deliver faster and more efficient data transmission. It has a mission life of 14 years and operates using 40 beams to send signals. By leveraging dual polarization technology, each beam is effectively doubled, resulting in a total of 80 beams. This advanced system is capable of delivering data at an impressive rate of 70 Gbit/s, with an operational high-throughput capacity of around 48 Gbit/s,” explained space expert Girish Linganna.
As per this expert, in simple terms the satellite functions like an ultra-fast internet provider in space. “Imagine 40 water hoses spraying signals across different regions. With dual polarization, each hose doubles its output, creating 80 streams of data flow. This innovative setup enables the satellite to handle enormous amounts of data with ease. It translates to stronger, faster, and more reliable internet connections, enabling smooth streaming of your favorite shows, crystal-clear video calls, and even internet access during flights. This state-of-the-art technology is built to ensure high-speed, dependable connectivity for everyone, no matter where they are,” added Linganna.
The Ka-band is a specific range of radio frequencies in the electromagnetic spectrum, typically between 26.5 GHz and 40 GHz, and is part of the broader microwave frequency range and is commonly used in satellite communications.
“Satellites using the Ka-band can transmit large amounts of data at high speeds, making it ideal for broadband internet services, high-definition television, and other communication applications. Compared to lower-frequency bands (like C-band or Ku-band), Ka-band allows for smaller antennas and higher data throughput, but it is more sensitive to weather conditions, such as rain, which can affect signal quality,” remarked Linganna.
The satellite is designed to enhance the country's communication infrastructure, increasing data transmission capacity, which is essential for the Union government's Smart City initiative. It will also provide internet access during flights. The estimated cost of the mission is expected to be between $60 and $70 million.
Currently, ISRO is working on the Next Generation Launch Vehicle (NGLV) to overcome the limitation of launching satellites over four tonnes. With a budget of Rs 8,240 crore, the NGLV aims to triple the payload capacity of the current LVM-3. It will have a reusable first stage and will be capable of carrying up to 30 tonnes to Low Earth Orbit or 10 tonnes to Geostationary Transfer Orbit (GTO). The vehicle is designed to be cost-efficient, with its cost only 1.5 times higher than the LVM-3.
