India's first Moon mission - FAQs

?  What is Chandrayaan-1?

Chandrayaan-1 is a scientific investigation -- by spacecraft -- of the Moon. The name Chandrayaan means Chandra (Moon), Yaan (vehicle). Chandrayaan-1 is the first Indian planetary science and exploration mission.

?  When, and from where, Chandrayaan-1 will be launched?

Chandrayaan-1 will be launched on October 22, 2008 from Satish Dhawan Space Centre at Sriharikota (SHAR).

?  How long will it take Chandrayaan-1 to get to Moon?

It will take about 5 days for Chandrayaan-1 to get to the Moon.

?  How close to Moon will Chandrayaan-1 come while orbiting the Moon?

Chandrayaan-1 spacecraft will be in a 100 km polar orbit around the Moon.

?  What are Chandrayaan' s scientific goals?

The Chandrayaan-1 mission is aimed at high-resolution remote sensing of the Lunar surface in visible, near Infrared, low energy X-rays and high-energy X-ray regions.

Specific scientific goals are:
To prepare a three-dimensional atlas (with a high spatial and altitude resolution of 5-10m) of both near and far side of the moon.
To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of elements such as Magnesium, Aluminum, Silicon, Calcium, Iron and Titanium with a spatial resolution of about 20 km and high atomic number elements such as Radon, Uranium & Thorium with a spatial resolution of about 40 km.

By simultaneous photo geological and chemical mapping we will be able to identify different geological units, which will test the hypothesis for the origin and early evolutionary history of the moon and help in determining the nature of the lunar crust.

What are the basic components of the Chandrayaan-1 spacecraft?

The basic components of the chandrayaan-1 spacecraft are:
The scientific payloads: the instruments that will gather science data.
The solar array that provides power to the spacecraft. Chandrayaan also carries a battery that stores the power generated by the solar array and feeds it to other systems.
The thrusters perform fuel burns to change the spacecraft's trajectory and attitude.
The various functional requirements of the spacecraft such as Attitude and Orbit Control, Command processing, House keeping telemetry, Sensor data processing, Thermal management, payload data handling operation, duel gimbaled data transmission antenna pointing, onboard mission management etc would be taken care by the Bus Management Unit (BMU).
The spacecraft also carries two star sensors and inertial reference unit based on miniaturized gyros providing absolute attitude.

?  What are the scientific instruments onboard Chandrayaan-1?

There are altogether eleven scientific instruments onboard Chandrayaan-1 spacecraft. Five of them are Indian and other six are from European Space Agency (3), NASA (2) and Bulgarian Academy of Sciences (1) selected through ISRO Announcement of Opportunity (AO). Two of the ESA instruments have Indian collaboration.

?  What type of propulsion system will Chandrayaan-1 use? How much propellant will it carry?

Chandrayaan-1 will use bipropellant integrated propulsion system. The propulsion system consists of a unified bi-propellant system for orbit raising and attitude control.

It consists of one 440N engine and eight numbers of 22N thrusters, mounted on the negative roll face of the spacecraft. Two tanks each with a capacity of 390 liter are used for storing fuel and oxidizer.

?  How will mission controllers communicate with the spacecraft?

If the spacecraft encounters a problem, it can establish contact with controllers on Earth through the Deep Space Network.

?  Can the team fix the spacecraft from Earth?

If a component on the spacecraft fails, controllers on Earth can instruct Chandrayaan to bring a backup online. If the spacecraft points in the wrong direction, its attitude can be corrected. If the spacecraft deviates from the desired trajectory, a controlled burn (thruster firing) can be performed to put it back on track.

Most minor problems can be corrected from Earth with existing onboard instruction systems.

?  How is the spacecraft powered?

The spacecraft is mainly powered by its solar array, which includes one solar panel covering a total area of 2.15 X 1.8 square meters, generating 700W power. The panels are made of materials rated to withstand extreme temperatures -- 119 degree C to minus 165 degree C.

The power produced by the solar array is stored in a Lithium-ion battery, and then distributed from the battery to the spacecraft subsystems. The power system is designed to support various phases of the mission. The power will supplement the mission with equal efficiency in both noon/midnight and dawn/dusk orbits.

The power system consists of power generation, energy storage and power conditioning elements. 36AH Li-Ion battery powers the spacecraft during orbital and lunar eclipses. Power electronics system controls the solar array power to supply the load and charge the batteries.

?  What is the total budget for realising Chandrayaan-1 mission?

The budgetary estimate for realising the proposed Indian lunar mission Chandrayaan-1 stands at Rs. 386 crore (about $76 million). This includes Rs 53 crore (about $11 million) for Payload development, Rs. 83 crore (about $17 million) for Spacecraft Bus, Rs 100 crore ($20 million) towards establishment of Deep Space Network, Rs 100 crore ($20 million) for PSLV launch vehicle and Rs 50 crore ($10 million) for scientific data centre, external network support and programme management expenses.

What other missions are scheduled to study Moon?

The first leap in Lunar observation was made by Galileo Galilei who used his new invention the telescope to observe mountains and craters on the lunar surface.

The first man-made object to reach the Moon was the unmanned Soviet probe Luna 2 in September 1959. Luna 9 was the first probe to soft land on the Moon in February 1966 and transmit pictures from the Lunar surface.

The first robotic lunar rover to land on the Moon was the Soviet Lunokhod 1 in November 1970.

Humans first landed on the Moon on July 20, 1969. The first man to walk on the lunar surface was Neil Armstrong, commander of the American mission Apollo 11. The last man to walk on the Moon was in December 1972 by Eugene Cernan during Apollo 17 mission.

Moon samples have been brought back to Earth by three Russian Luna missions (16, 20, and 24) and the US Apollo missions 11, 12 and 14 through 17.

The European Space Agency has launched European spacecraft Smart1 on September 27 2003 to explore the Moon, survey the lunar environment and create an X-ray map of the Moon.

Japan has two planned lunar missions, LUNAR-A and Selene.

India plans to launch a lunar orbiter for simultanious chemical and mineralogical study of the lunar surface. The People's Republic of China has also expressed ambitious plans for exploring the Moon (Change series).

The Lunar Reconnaissance Orbiter (LRO) of USA is designed to map the surface of the Moon and characterize future landing sites in terms of terrain roughness, usable resources, and radiation environment with the ultimate goal of facilitating the return of humans to the Moon.