INDIAN LUNAR MISSION

On 22nd October 2008, the Indian Space Research Organisation's (ISRO's) Polar Satellite Launch Vehicle, PSLV-C11, has successfully launched the 1380 kg Chandrayaan-1 spacecraft into a transfer orbit from Satish Dhawan Space Centre (SDSC) in the South of India. PSLV-C11 is the uprated version of ISRO's Polar Satellite Launch Vehicle in its standard configuration. Weighing 320 tonnes at lift-off, the vehicle uses larger strap-on motors (PSOM-XL) to achieve higher payload capability.

Chandrayaan-1 is India's first spacecraft mission beyond Earth's orbit. It aims to further expand our knowledge about Earth's only natural satellite - the moon. With well-defined objectives, Chandrayaan-1 mission intends to put an unmanned spacecraft into an orbit around the moon and to perform remote sensing of our nearest celestial neighbour for about two years using eleven scientific instruments built in India and five other countries.

The primary objectives of Chandrayaan-1 are:
To place an unmanned spacecraft in an orbit around the moon
To conduct mineralogical and chemical mapping of the lunar surface
To upgrade the technological base in the country

Chandrayaan-1 aims to achieve these well-defined objectives through high-resolution remote sensing of moon in the visible, near infrared, microwave and X-ray regions of the electromagnetic spectrum. With this, preparation of a 3-dimensional atlas of the lunar surface and chemical and mineralogical mapping of entire lunar surface is envisaged.

The Chandrayaan-1 spacecraft weighed about 1380 kg at the time of its launch and is a 1.5 m cuboid with a solar panel projecting from one of its sides. The spacecraft is powered by a single solar panel generating electrical power of 700 W. A Lithium ion battery supplies power when the solar panel is not illuminated by the sun. To make Chandrayaan-1 spacecraft to travel towards the Moon, its Liquid Apogee Motor (LAM) is used. Liquid propellants needed for LAM as well as thrusters are stored onboard the spacecraft. Chandrayaan-1 spacecraft's Dual Gimballed Antenna transmits the scientific data gathered by its eleven scientific instruments to Earth.

Chandrayaan-1 spacecraft was built at ISRO Satellite Centre, Bangalore with contributions from Vikram Sarabhai Space Centre (VSSC), Liquid Propulsion Systems Centre (LPSC) and ISRO Inertial Systems Unit (IISU) at Tiruvananthapuram, Space Applications Centre (SAC) and Physical Research Laboratory (PRL), Ahmedabad and Laboratory for Electro-optic Systems (LEOS), Bangalore.

Chandrayaan-1, India's maiden lunar mission, is taken to the launch pad at the Satish Dhawan Space Centre in Sriharikota Chandrayaan-1, India's maiden lunar mission, is taken to the launch pad at the Satish Dhawan Space Centre in Sriharikota, about 100 kilometers (63 miles) north of Chennai. India launched its first lunar mission from the center in southern India at 06:20 a.m (0050 GMT) Wednesday, Oct. 22, 2008, putting the country in an elite group of nations with the scientific know-how to reach the moon, but also heating up a burgeoning Asian space race. The 3,000 pound (1,400 kilogram) satellite Chandrayaan-1 (Moon Craft in ancient Sanskrit) will join Japanese and Chinese crafts currently in orbit around the moon for a two-year mission designed to map out the whole lunar surface.

Scientific Objectives
The Chandrayaan-1 mission is aimed at high-resolution remote sensing of the moon in visible, near infrared (NIR), low energy X-rays and high-energy X-ray regions. Specifically the objectives are:
To prepare a three-dimensional atlas (with high spatial and altitude resolution of 5-10 m) of both near and far side of the moon.
To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of mineral and chemical elements such as Magnesium, Aluminum, Silicon, Calcium, Iron and Titanium as well as high atomic number elements such as Radon, Uranium & Thorium with high spatial resolution.

The Simultaneous photo geological, mineralogical and chemical mapping through Chandrayaan-1 mission will enable identification of different geological units to infer the early evolutionary history of the Moon. The chemical mapping will enable to determine the stratigraphy and nature of the Moon's crust and thereby test certain aspects of magma ocean hypothesis. This may allow to determine the compositions of impactors that bombarded the Moon during its early evolution which is also relevant to the formation of the Earth.

Mission Objectives
To realise the mission goal of harnessing the science payloads, lunar craft and the launch vehicle with suitable ground support systems including Deep Space Network (DSN) station.
To realise the integration and testing, launching and achieving lunar polar orbit of about 100 km, in-orbit operation of experiments, communication/ telecommand, telemetry data reception, quick look data and archival for scientific utilisation by scientists.

Chandrayaan-1 Mission Sequence Mission Sequence
Chandrayaan-1 spacecraft was launched from the Satish Dhawan Space Centre, SHAR, Sriharikota by PSLV-XL (PSLV-C11) on 22 October 2008 at 06:22 hrs IST in an highly elliptical initial orbit (IO) with perigee (nearest point to the Earth) of 255 km and an apogee (farthest point from the Earth) of 22,860 km, inclined at an angle of 17.9 deg to the equator. In this initial orbit, Chandrayaan orbited the Earth once in about six and a half hours.

Subsequently, the spacecraft's Liquid Apogee Motor (LAM) firing was done on 23 October at 09:00 hrs IST, when the spacecraft was near perigee, to raise the apogee to 37,900 km while the perigee to 305 km. The spacecraft took eleven hours to go round the Earth once.

The orbit was further raised to 336 km x 74,715 km on 25 October at 05:48 hrs IST. In this orbit, spacecraft took about twenty-five and a half hours to orbit the Earth once.

The LAM was fired again on 26 October at 07:08 hrs IST to take the Chandrayaan-1 spacecraft to extremely high elliptical orbit with apogee 164,600 km and perigee at 348 km. Chandrayaan-1 took about 73 hours to go round the Earth once.

On 29 October, orbit raising was carried out at 07:38 hrs IST to raise the apogee to 267,000 km and perigee to 465 km. Chandrayaan’s present orbit extends more than half the way to moon and takes about six days to orbit the Earth.

On 4 November at 04:56 hrs IST, Chandrayaan entered the Lunar Transfer Trajectory with an apogee of 380,000 km.

On 8 November at 16:51 hrs IST, the spacecraft’s Liquid engine was fired to reduce its velocity to insert the spacecraft in the lunar orbit (LOI) and enable lunar gravity to capture it. As a result, the spacecraft was in an elliptical orbit with periselene (nearest point to the moon) of 504 km and aposelene (farthest point from the moon) of 7,502 km.

The first orbit reduction manoeuvre was carried out successfully on 9 November at 20:03 hrs IST. Thus the spacecraft was in lunar orbit with 200 km periselene. The aposelene remains unchanged (i.e 7,502 km).

After careful and detailed observation, a series of three orbit reduction manoeuvres were successfully carried out and the spacecraft’s orbit was reduced to its intended operational 100 km circular polar orbit on November 12.

On 14 November at 20:06 hrs IST, the Moon Impact Probe (MIP) was ejected from the Chandrayaan-1 spacecraft and hard landed on the lunar surface near the South Polar Region at 20:31 hrs IST after 25 minutes journey. It placed the Indian tricolour, which was pasted on the sides of MIP on the Moon.

The scientific instruments/payloads are being commissioned sequentially and exploration of Moon with the array of onboard instruments is carrying on.

History of Indian Space Research
India's experience in rocketry began in ancient times. Military use of rockets by Tipu Sultan during the Mysore War against the British inspired William Congreve to invent the Congreve rocket, predecessor of modern artillery rockets, in 1804. After India gained independence from British occupation in 1947, Indian scientists and politicians recognized the potential of rocket technology in both defence applications, and for research and development.

The Indian Space Research Organisation (Bharatiya Antariksh Anusandhan Sangathan) or ISRO, is India's national space agency. With its headquarters in Bangalore, ISRO employs approximately 20,000 people, with a budget of around Rs. 65 billion (US$1.3 billion). Its mandate is the development of technologies related to space and their application to India's development. The current Chairman of ISRO is G. Madhavan Nair. In addition to domestic payloads, it offers international launch services. ISRO currently launches satellites using the Polar Satellite Launch Vehicle and the GSLV for geostationary satellites.

Dr. Vikram Sarabhai was the founding father of the Indian space program, and is considered a scientific visionary by many, as well as a national hero. The Department of Atomic Energy (DAE) director Homi Bhabha, who was father of India's atomic programme, then established the Indian National Committee for Space Research (INCOSPAR) with Dr. Sarabhai as Chairman in 1962. Having recognized the benefits that satellites could bring to India from the very start, Sarabhai and the Indian Space Research Organisation (ISRO) set about designing and creating an independent launch vehicle, capable of launching into orbit, and providing the valuable experience needed for the construction of larger launch vehicles in future.

India concentrated more on practical missions, directly beneficial to people, instead of manned space programs or robotic space explorations. The Aryabhata satellite, launched in 1975 using a Soviet Cosmos-3M launch vehicle, was India's first satellite. By 1979 the SLV was ready to be launched from a newly-established second launch site, the Satish Dhawan Space Centre (SDSC). The first attempted launch in 1979 was a failure, attributed to a control failure in the second stage. By 1980 this problem had been worked out. The first indigenous satellite launched by India was called Rohini-1.

Following the success of the SLV, it was decided by the ISRO that it would be prudent to develop a smaller rocket, based on the SLV that would serve as a test-bed for many of the new technologies that would be used on the PSLV. The Augmented Satellite Launch Vehicle (ASLV) would test technologies like strap-on boosters and new guidance systems, so that experience could be gained before the PSLV went into full production. Eventually, the ASLV was flight tested in 1987, and then again in 1988, but these launches were a failure. The first successful launch of the ASLV took place in 1992. In 1993 the time had come for the maiden flight of the PSLV. The first launch was a failure. The first successful launch took place in 1994, and since then, the PSLV has become the workhorse launch vehicle – placing both remote sensing and communications satellites into orbit, creating the largest cluster in the world, and providing unique data to Indian industry and agriculture. Continual performance upgrades have increased the payload capacity of the rocket significantly since then.

The first development flight of the GLSV – currently the most powerful Indian launch vehicle in operation – took place in 2001. The program’s benefits have been scrutinized due to frequent payload cutbacks and delays. The indigenous cryogenic engine for the GSLV's upper stage was tested in 2007. ISRO had reconsidered the effectiveness of the GSLV for the needs of the 2000–2010 decade and begun development of a new indigenous heavy launch vehicle, GSLV-III. The latter is not related to the GSLV-I/II and will be based around the proven format of liquid main stages and two solid strap-on boosters. It will resemble the Ariane 5 and other modern launchers and will have sufficient payload capacity for manned spaceflight. The inaugural flight is scheduled for 2009.

ISRO has entered the lucrative market of launching payloads of other nations. Prominent among them are the launches of Israel Space Agency’s TecSAR spy satellite, and the Israeli Tauvex-II satellite module. On April 28, 2008 ISRO successfully launched 10 satellites in a single mission, further boosting its capabilities in space. These comprised the 690 kg CARTOSAT-2, another 83 kg mini Indian satellite, IMS-1, and eight other nano-satellites made by various universities and research and development institutions in Canada and Germany, offered at a subsidized price as part of a goodwill gesture by the Indian Department of Space.

ISRO successfully launched its first unmanned moon mission, Chandrayaan-1, mounted on PSLVC11 at 0622 hrs IST on October 22, 2008. The spacecraft was placed into lunar orbit and will survey the surface of the moon in greater detail than ever before and attempt to locate resources. As per the agreement between ISRO and NASA, two NASA instruments are also part of the Chandrayaan mission.