India's first unmanned lunar mission was named Chandrayaan-1, successfully launched in October 2008. The name comes from Sanskrit, where 'Chandra' means moon and 'Yaan' means vehicle. The mission was a major milestone in India's space program and included payloads from NASA, ESA, and Bulgaria. The other options are fictitious names created for the question - Chandravahan, Chandravimaan, and Chandrakhoj are not actual mission names.