The Isro is all set for its "heaviest" commercial mission to launch five British satellites into orbit, with the countdown beginning on Wednesday for the July 10 launce of India's PSLV-C28 from Sriharikota in Andhra Pradesh.
The 62.5-hour countdown began at 0728 AM and is progressing smoothly, an ISRO official told PTI. ISRO's workhorse Polar Satellite Launch Vehicle (PSLV) will blast off at 958 PM on July 10 from the Satish Dhawan Space Centre at Sriharikota, about 90 km from here, and put in orbit the five satellites.
With the overall lift-off mass of the five satellites amounting to about 1440 kg, this mission becomes the "heaviest commercial mission" ever undertaken by Isro and its commercial arm Antrix, the agency said.
The Mission Readiness Review Committee and Launch Authorisation Board cleared the countdown for the PSLV C28/ DMC3 mission on Tuesday, he said.
PSLV, in its 30th mission, will launch three identical DMC3 optical earth observation satellites, built by Surrey Satellite Technology Limited (SSTL), United Kingdom, and two auxiliary satellites.
The three DMC3 satellites, each weighing 447 kg, will be launched into a 647 km Sun-Synchronous Orbit (SSO) using the high-end version of PSLV-XL.
In addition to the three DMC3 satellites, the PSLV C28 will also carry two auxiliary satellites from UK -- CBNT-1, a technology demonstrator earth observation micro satellite built by SSTL, and De-OrbitSail, a technology demonstrator nano satellite built by Surrey Space Centre.
The five international satellites are being launched as part of the arrangement entered into between DMC International Imaging (DMCii), a wholly owned subsidiary of SSTL, UK and Antrix Corporation Limited.
The DMC3 constellation, comprising three advanced mini-satellites DMC3-1, DMC3-2 and DMC3-3, is designed to address the need for simultaneous high spatial resolution and high temporal resolution optical Earth Observation.
These satellites can image any target on the Earth's surface every day. Major application areas include surveying the resources on earth and its environment, managing urban infrastructure and monitoring disasters.