Bangalore: The morning of 3 May, Tuesday saw the start of the countdown for India's twin satellites- the remote sensing 1560 kg. CARTOSAT-1 and the 42.5 kg. HAMSAT that will ride piggyback on the polar satellite launch vehicle (PSLV-6) from the Satish Dhawan Space Center (SDSC) at the Sriharikota rocket launching station. This is the first time that PSLV will be used for carrying two Indian satellites.

CARTOSAT-1, meant for remote sensing has two cameras with a spatial resolution of 2.5 meters for mapping, town planning and environment sensing, while HAMSAT will provide the UHF-VHF frequency sought after by amateur radio operators.

Indian Space Research Organisation (ISRO) officials admitted that the weather held the key to the timely launch of the vehicle (between 10.15 am and 10.40 am on Thursday, May 5, 2005). Squally weather over the last two days has already resulted in a launch delay of about half an hour.

As reported by indiantelvision.com earlier, CARTOSAT-1 is one of the four satellites to be launched in 2005 by ISRO, the others being CARTOSAT-2, ISAT 4A at heavy 3800 kgs and INSAT 4C. The launch of CARTOSAT-2 is scheduled from Kourou in French Guyana in July or August this year.