ISRO chief K Sivan rejected NASA's claims that they have located the debris of the crashed Vikram lander on the lunar surface. Sivan said that the Indian Space Research Organisation had located it long back. On Tuesday, NASA released images showing the site of Vikram lander’s impact the related debris field. They acknowledged the role of a Chennai-based mechanical engineer and app developer in locating the site of the debris. Space enthusiast, Shanmuga Subramanian spotted the crashed Vikram lander on the lunar surface after going through the images released by the US space agency's Moon orbiting spacecraft.