The 48-hour countdown for the launch of India's Cartosat-2 series and 19 other satellites slated for Wednesday, began on Monday morning, the Indian space agency said. According to Indian Space Research Organisation (ISRO), on Wednesday at 9.25 a.m., Indian rocket Polar Satellite Launch Vehicle (PSLV) will lift off from the rocket port at Sriharikota in Andhra Pradesh with 20 satellites.The rocket's main cargo will be India's 725.5 kg Cartosat-2 series satellite for earth observation.The other 19 satellites weighing totally around 560 kg are from US, Canada, Germany and Indonesia as well as one satellite each from Chennai's Sathyabama University and College of Engineering, Pune.The rocket will blast off from the second launch pad with a total payload of 1,288 kg.The whole mission will get over in around 26 minutes.The images sent by Cartosat satellite will be useful for cartographic, urban, rural, coastal land use, water distribution and other applications.On the other hand, the 1.5 kg Sathyabamasat from Sathyabama University will collect data on green house gases while the 1 kg Swayam satellite from College of Engineering, Pune will provide point-to-point messaging services to the HAM radio community.Wednesday's mission will be the first time the ISRO will be launching more the 10 satellites with a single rocket.In 2008, the ISRO had launched 10 satellites with the PSLV rocket.