Home Minister Rajnath Singh on Friday congratulated the Indian Space Research Organisation (ISRO) on the successful launch of its 100th satellite, and said the step is a "big landmark in India's journey into the space".The ISRO launched the 42nd Polar Satellite Launch Vehicle (PSLV), PSLV-C40, on Friday from the first launch pad of the Satish Dhawan Space Centre (SDSC) in Sriharikota and it placed 31 satellites across two orbits."Congratulations to team ISRO on the successful launch of its 100th satellite with Cartosat-2 series Satellite Mission. The scientists at ISRO have made the nation proud with their successes on several occasions. They have done it again by hitting a century," Rajnath tweeted. Of 31 satellites, three are Indian and 28 are from Canada, Finland, France, South Korea, the UK and the US. Rajnath said that ISRO's achievement of launching "100 satellites is historic in many ways and a big landmark in India's journey into the space". "The scientists at ISRO have carved a special place in the astronomical space."