SRIHARIKOTA: Heralding a new era, India tonight launched its heaviest commercial space mission ever with its polar rocket successfully putting five British satellites into the intended orbit after a flawless takeoff.Indian Space Research Organisation( ISRO ) workhorse 44.4 metre tall Polar Satellite Launch Vehicle PSLV-C28--a PSLV-XL version--hurtled towards the night skies with a rich orange flame at its tail and a plume of white fume and placed the five satellites in sun synchronous orbit about 20 minutes after lift off at 9.58 PM from the Satish Dhawan space Centre here."It's been a wonderful mission. We have had an extremely successful mission," a beaming ISRO Chairman Kiran Kumar said from the Mission Control Centre amidst resounding cheers from the assembled scientists. The life of the mission is seven years.With the overall mass of five satellites being about 1,440 kg, this launch becomes the "heaviest commercial mission" ever undertaken by ISRO and its commercial arm Antrix Corporation.PSLV's 30th mission saw the launch of 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, was launched into a Sun-Synchronous Orbit (SSO) using the high-end version of PSLV-XL.Earlier successful launches by ISRO -- Mars Orbiter Mission which was launched in Nov 5, 2013 and Chandrayaan-1 launched in Oct 22, 2008 were with similar PSLV-XL variants.In addition to the three DMC3 satellites, PSLV C28 also carries 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 satellites were launched as part of an arrangement to 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.