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Chandrayaan-1 was India's first unmanned lunar probe. It was launched by the Indian Space Research Organization (ISRO) in October 2008, and operated until August 2009. The mission included a lunar orbiter and an impactor. ISRO launched the spacecraft by a modified version of the PSLV, PSLV-XL (C11 mission) on 22 October 2008 from SHAR at 06:22 IST (00:52 UTC). 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 successfully inserted into lunar orbit on 8 November 2008. Total cost of Chandrayaan-1 project including the ground facilities and launch vehicle was only USD 75 million dollars (USD 30 million for the payload.)

On 14 November 2008, the Moon Impact Probe (MIP) separated from the Chandrayaan orbiter at 20:06 and struck the South Pole in a controlled manner, making India the fourth country to place its flag on the Moon. The probe impacted near Shackleton Crater at 20:31 ejecting underground soil that could be analyzed for the presence of lunar water ice.

At a Glance

• Launch Vehicle: PSLV-XL (C11 mission)
• Launch Date: 22 October 2008
• Total Weight: 1,380 kg
  • 675 kg on lunar orbit
  • 523 kg after releasing the impactor
• Dimensions: Cuboid in shape of approximately 1.5 m
• Communications: X band, 0.7 m diameter dual gimballed parabolic antenna for payload data transmission. The Telemetry, Tracking & Command (TTC) communication operates in S band frequency.
• Power: The spacecraft is mainly powered by its solar array, which includes one solar panel covering a total area of 2.15 x 1.8 m generating 750 W of peak power, which is stored in a 36 A·h lithium-ion battery for use during eclipses.
• Propulsion: The spacecraft uses a bipropellant integrated propulsion system to reach lunar orbit as well as orbit and altitude maintenance while orbiting the Moon. The power plant consists of one 440 N engine and eight 22 N thrusters. Fuel and oxidizer are stored in two tanks of 390 litres each.
• Navigation & Control: The craft is 3-axis stabilized with two star sensors, gyros and four reaction wheels. The craft carries dual redundant bus management units for attitude control, sensor processing, antenna orientation, etc.

The remote sensing lunar satellite had a mass of 1,380 kg (3,042 lb) at launch and 675 kilograms (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 carries five ISRO payloads and six payloads from other space agencies including NASA, ESA, and the Bulgarian Aerospace Agency, which were carried free of cost.

End of the mission

After suffering from several technical issues including failure of the star sensors and poor thermal shielding, Chandrayaan stopped sending radio signals at 1:30 AM IST on 29 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 90% of its planned objectives. Among its many achievements was the discovery of the widespread presence of water molecules in lunar soil.

The data collected from the mission have been disseminated to Indian scientists and also the partners from Europe and U.S.A. for analysis. Although the mission was less than 10 months in duration, and less than half the intended 2 years in length, a review by scientists termed the mission successful, as it had completed 90% of its primary objectives, consisting of:

• To construct the complex spacecraft with 11 scientific instruments.
• To place the spacecraft in a circular orbit around the Moon by orbit raising manoeuvres from a near Earth orbit.
• To place the Flag of India on the Moon.
• To carry out imaging operations and to collect data on the mineral content of the lunar soil.
• To set up a deep space tracking network and implement the operational procedures for travel into deep space.