This is CMS-01, an Indian communications satellite that will replace the aging GISAT-12 craft that has been operational for 9 years, one year longer than originally planned.

The new satellite, originally called GISAT-12R (with ‘R’ meaning “replacement”) will feature upgraded technologies from its predecessor and will be placed in Geostationary Orbit in a specific location directly above the Indian Ocean.

Image: A GISAT craft being placed inside a payload fairing for launch. Credit: Indian Space Research Organisation

The PSLV-XL is a powerful variant of India's Polar Satellite Launch Vehicle (PSLV), developed by the Indian Space Research Organisation (ISRO). The “XL” stands for “Extended Length,” referring to its larger solid strap-on boosters, which give it more thrust than the standard PSLV version. It is ISRO’s most frequently used configuration when missions require heavier payloads or higher orbits, such as sun-synchronous orbits (SSO) or geosynchronous transfer orbits (GTO).

Specs
Height: 44.5 meters

Diameter: 2.8 m (9 ft 2 in)

Mass:

PSLV-G: 295,000 kg (650,000 lb)
PSLV-CA: 230,000 kg (510,000 lb)
PSLV-XL: 320,000 kg (710,000 lb)

Stages: 4

The PSLV-XL features a four-stage design with alternate solid and liquid propulsion systems. The first stage is powered by a large solid rocket motor (S139), supported by six extended strap-on boosters (PSOM-XL), each loaded with 12 tonnes of solid propellant. The second stage uses a liquid Vikas engine fueled by UH25 and nitrogen tetroxide. The third stage is again solid-fueled, while the fourth and final stage consists of two liquid-fueled engines using MMH and MON-3, allowing fine orbital adjustments.

This configuration has earned a reputation for high reliability and flexibility, having launched a wide variety of payloads including remote sensing satellites, navigation spacecraft, and interplanetary probes. It’s particularly known for notable missions such as Chandrayaan-1, India’s first lunar orbiter, and the Mars Orbiter Mission (Mangalyaan). The PSLV-XL also made headlines for launching 104 satellites in a single mission (PSLV-C37), a world record at the time.

The Second Launch Pad (SLP) at the Satish Dhawan Space Centre (SDSC) in Sriharikota, India, is one of ISRO’s primary launch complexes. Operational since 2005, it was developed to support the growing number of satellite launches and to reduce dependence on the older First Launch Pad. The SLP is a versatile and modular facility, capable of launching all of ISRO's current rockets, including the Polar Satellite Launch Vehicle (PSLV), Geosynchronous Satellite Launch Vehicle (GSLV), and LVM3 (formerly GSLV Mk III).

Located on the eastern coast of India, the site allows for launches over the Bay of Bengal, ideal for a range of orbital inclinations. The SLP features a Mobile Service Tower (MST) and a Fixed Umbilical Tower (FUT) for vehicle integration, fueling, and payload access, enhancing launch preparation efficiency and safety. It has been used for major missions like Chandrayaan, Mars Orbiter Mission, and several NavIC satellites.

Image courtesy of ISRO.