The countdown for ISRO's LVM-3-M6 mission, carrying AST SpaceMobile's BlueBird Block-2 satellite, commenced at 8.55 am on 23 December 2025 from the second launch pad at Sriharikota spaceport.

This marks the sixth operational flight of the LVM-3, India's reliable heavy-lift launch vehicle, and the third dedicated commercial mission facilitated by NewSpace India Ltd (NSIL).

Lift-off remains scheduled for 8.24 am IST on 24 December, placing the 6,100 kg payload into a circular Low Earth Orbit at 520 km altitude and 53° inclination approximately 16 minutes after launch.

During the ongoing countdown, teams are loading propellants into the rocket's liquid core stage and cryogenic upper stage while conducting final systems checks. The LVM-3 stands 43.5 metres tall with a lift-off mass of 640 tons, comprising two S200 solid strap-on boosters, an L110 liquid core stage using UH25 and N2O4, and a C25 cryogenic upper stage powered by LH2 and LOX.

This configuration has proven its mettle in prior successes, including Chandrayaan-2, Chandrayaan-3, two OneWeb missions with 72 satellites, and the recent LVM-3-M5/CMS-03 on 2 November 2025.

BlueBird Block-2, weighing around 6,100-6,500 kg, represents the heaviest payload ever deployed by LVM-3 from Indian soil and the largest commercial communications satellite for Low Earth Orbit. It debuts AST SpaceMobile's next-generation fleet, featuring a massive 223 m² (nearly 2,400 sq ft) phased-array antenna—3.5 times larger than Block-1 predecessors—offering tenfold data capacity for direct-to-smartphone cellular broadband.

This technology aims to deliver 4G/5G voice, video, texting, streaming, and data globally without specialised terminals, targeting remote and underserved areas.

AST SpaceMobile, a Nasdaq-listed US firm, envisions the world's first space-based cellular network connecting unmodified smartphones for commercial and government use. Founder and CEO Abel Avellan highlighted its role in advancing US space innovation and global connectivity.

The company accelerates production, with hardware for 40 satellites ready by early 2026, planning five SpaceX launches by Q1 end and 45-60 birds in orbit by year-end for continuous US and select market coverage. Backed by 500,000 sq ft of facilities—mostly in the US—and 1,800 employees, it builds on prior Block-1 satellites.

This NSIL-arranged contract positions AST SpaceMobile as LVM-3's second satellite broadband client after Eutelsat OneWeb's 72 satellites across two missions in 2022-2023.

The mission timeline includes S200 ignition at T-0, L110 ignition at 106 seconds, strap-on separation at 132 seconds, payload fairing jettison at 174 seconds, core separation at 302 seconds, C25 ignition shortly after, and satellite release at 943 seconds when velocity hits 7.60 km/s. Public viewing is available from Sriharikota's Launch View Gallery via online registration, with ISRO livestreaming from 8.24 am on launch day.

LVM-3's pedigree underscores ISRO's commercial prowess, with eight straight successes boosting India's space economy. BlueBird Block-2's deployment advances direct-to-device connectivity, potentially transforming telecommunications in unserved regions worldwide.

As countdown progresses smoothly, this Christmas Eve launch reinforces Indo-US space ties and NSIL's growing role in global launches.

Based On UNI Report