Chandrayaan-1 was India's first lunar probe. It was launched by the Indian Space Research Organisation in October 2008, and operated until August 2009. The mission included a lunar orbiter and an impactor. India launched the spacecraft using a PSLV-XL rocket, serial number C11, on 22 October 2008 at # UTC from Satish Dhawan Space Centre, about 80 km (50 mi) north of Chennai. Prime Minister Atal Bihari Vajpayee announced the project on course in his Independence Day speech on 15 August 2003. The mission was a major boost to India's space program, as India researched and developed its own technology in order to explore the Moon.The vehicle was inserted into lunar orbit on 8 November 2008.
On 14 November 2008, the Moon Impact Probe separated from the Chandrayaan orbiter at # UTC and struck the south pole in a controlled manner, making India the fourth country to place its flag on the Moon. The probe hit near the crater Shackleton at # UTC, ejecting sub-surface soil that could be analysed for the presence of lunar water ice.
The estimated cost for the project was ₹386 crore (US$59 million).
The remote sensing lunar satellite had a mass of 1,380 kg (3,040 lb) at launch and 675 kg (1,488 lb) in lunar orbit. It carried high resolution remote sensing equipment for visible, near infrared, and soft and hard X-ray frequencies. Over a two-year period, it was intended to survey the lunar surface to produce a complete map of its chemical characteristics and three-dimensional topography. The polar regions are of special interest as they might contain ice. The lunar mission carried five ISRO payloads and six payloads from other space agencies including NASA, ESA, and the Bulgarian Aerospace Agency, which were carried free of cost. Among its many achievements, the greatest achievement was the discovery of the widespread presence of water molecules in the lunar soil.
After almost a year, the orbiter started suffering from several technical issues including failure of the star sensors and poor thermal shielding; Chandrayaan stopped sending radio signals about # UTC on 28 August 2009, shortly after which the ISRO officially declared the mission over. Chandrayaan operated for 312 days as opposed to the intended two years but the mission achieved 95% of its planned objectives.
On 2 July 2016, NASA used ground-based radar systems to relocate Chandrayaan-1 in its lunar orbit, more than seven years after it shut down. Repeated observations over the next three months allowed a precise determination of its orbit which varies between 150 and 270 km (93 and 168 mi) in altitude every two years.