July 10 is going to be special for ISRO. Here’s why!

The Indian Space Research Organisation (ISRO) is all set for its "heaviest" commercial mission to place five British satellites in the orbit. The countdown begins today for the launch of India's PSLV-C28 on July 10 from Sriharikota in Andhra Pradesh.

An ISRO official told PTI that the 62.5-hour countdown began on Wednesday at 07.28 a.m. and is progressing smoothly.

ISRO's workhorse Polar Satellite Launch Vehicle (PSLV) will blast off on July 10 at 9.58 p.m. from the Satish Dhawan Space Centre at Sriharikota, about 90 km from Chennai.

With the overall lift-off mass of the five satellites amounting to about 1,440 kg, this mission becomes the "heaviest commercial mission" ever undertaken by the Indian space agency and its commercial arm Antrix.

The official said that the Mission Readiness Review Committee and Launch Authorization Board cleared the countdown for the PSLV C28/ DMC3 mission on Tuesday.

In its 30th mission, PSLV will launch three identical DMC3 optical earth observation satellites, built by Surrey Satellite Technology Limited (SSTL), UK, 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.

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 take images of any target on the Earth's surface. Major application areas include surveying the resources on earth and its environment, managing urban infrastructure and monitoring disasters.

(Image: ISRO)