Chandrayaan-1 Successfully Enters Lunar Orbit

Chandrayaan-1 Successfully Enters Lunar Orbit
Chandrayaan-1, India’s first unmanned spacecraft mission to moon, entered lunar orbit today (November 8, 2008). This is the first time that an Indian built spacecraft has broken away from the Earth’s gravitational field and reached the moon. This historic event occurred following the firing of Chandrayaan-1 spacecraft’s liquid engine at 16:51 IST for a duration of 817 seconds. The highly complex ‘lunar orbit insertion manoeuvre’ was performed from Chandrayaan-1 Spacecraft Control Centre of ISRO Telemetry, Tracking and Command Network at Bangalore.

Indian Deep Space Network (IDSN) at Byalalu supported the crucial task of transmitting commands and continuously monitoring this vital event with two dish antennas, one measuring 18 m and the other 32 m.

Chandrayaan-1’s liquid engine was fired when the spacecraft passed at a distance of about 500 km from the moon to reduce its velocity to enable lunar gravity to capture it into an orbit around the moon. The spacecraft is now orbiting the moon in an elliptical orbit that passes over the polar regions of the moon. The nearest point of this orbit (periselene) lies at a distance of about 504 km from the moon’s surface while the farthest point (aposelene) lies at about 7502 km. Chandrayaan-1 takes about 11 hours to go round the moon once in this orbit.

The performance of all the systems onboard Chandrayaan-1 is normal. In the coming days, the height of Chandrayaan-1 spacecraft’s orbit around the moon will be carefully reduced in steps to achieve a final polar orbit of about 100 km height from the moon’s surface. Following this, the Moon Impact Probe (MIP) of the spacecraft will be released to hit the lunar surface. Later, the other scientific instruments will be turned ON sequentially leading to the normal phase of the mission.


It may be recalled that Chandrayaan-1 spacecraft was launched on October 22, 2008 by PSLV-C11 from India’s spaceport at Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota. As intended, PSLV placed the spacecraft in a highly oval shaped orbit with a perigee (nearest point to Earth) of 255 km and an apogee (farthest point to Earth) of 22,860 km. In the past two weeks, the liquid engine of Chandrayaan-1 has been successfully fired five times at opportune moments to increase the apogee height, first to 37,900 km, then to 74,715 km, later to 164,600 km, after that to 267,000 km and finally to 380,000km, as planned. During this period, the Terrain Mapping Camera (TMC), one of the eleven payloads (scientific instruments) of the spacecraft, was successfully operated twice to take the pictures, first of the Earth, and then moon.

With today’s successful manoeuvre, India becomes the fifth country to send a spacecraft to Moon. The other countries, which have sent spacecraft to Moon, are the United States, former Soviet Union, Japan and China. Besides, the European Space Agency (ESA), a consortium of 17 countries, has also sent a spacecraft to moon.

India's Mission Moon

First Time MOON MEETS INDIA so close - by Chandrayaan - I


India's first Moon mission, Chandrayaan is all set to add a golden chapter to India's space endeavour when it takes off from the Satish Dhawan Space Centre at Sriharikota on October 22.

Here's all that you wanted to know about India's first Moon mission

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).
The launch of Chandrayaan-1 takes place from the Second Launch Pad at Satish Dhawan Space Centre, SHAR, Sriharikota in the Nellore district of Andhra Pradesh state. Sriharikota is situated at a distance of about 80 km to the North of Chennai.

Chandrayaan-1 spacecraft begins its journey from earth onboard India's Polar Satellite Launch Vehicle (PSLV-C11) and first will reach a highly elliptical Initial Orbit (IO). In the Initial Orbit, the perigee (nearest point to earth) is about 250 km and apogee (farthest point from the earth) is about 23,000 km.

After circling the Earth in its Initial Orbit for a while, Chandrayaan-1 spacecraft is taken into two more elliptical orbits whose apogees lie still higher at 37,000 km and 73,000 km respectively. This is done at opportune moments by firing the spacecraft's Liquid Apogee Motor (LAM) when the spacecraft is near perigee.

Subsequently, LAM is fired again to take Chandrayaan-1 spacecraft to an extremely high elliptical orbit whose apogee lies at about 387,000 km.

In this orbit, the spacecraft makes one complete revolution around the Earth in about 11 days. During its second revolution around the Earth in this orbit, the spacecraft will approach the Moon's North pole at a safe distance of about a few hundred kilometers since the Moon would have arrived there in its journey round the Earth.

Once the Chandrayaan-1 reaches the vicinity of the Moon, the spacecraft is oriented in a particular way and its LAM is again fired. This slows down the spacecraft sufficiently to enable the gravity of the moon to capture it into an elliptical orbit.

Following this, the height of the spacecraft's orbit around the moon is reduced in steps. After a careful and detailed observation of perturbations in its intermediate orbits around the moon, the height of Chandrayaan-1 spacecraft's orbit will be finally lowered to its intended 100 km height from the lunar surface.

Later, the Moon Impact Probe will be ejected from Chandrayaan-1 spacecraft at the earliest opportunity to hit the lunar surface in a chosen area. Following this, cameras and other scientific instruments are turned ON and thoroughly tested. This leads to the operational phase of the mission. This phase lasts about two years during which Chandrayaan-1 spacecraft explores the lunar surface with its array of instruments that includes cameras, spectrometers and SAR.
Chandrayaan-1 is the first spacecraft mission of ISRO beyond Earth orbit. Chandrayaan-1 will be followed by Chandrayaan-2 which features a lander and a rover. India and Russia will jointly participate in this project. However, there may be a provision to accommodate payloads from other space agencies as happened in Chandrayaan-1. This apart, studies are being conducted by ISRO on sending unmanned spacecraft to planet Mars as well as to asteroids and comets. Through such programmes, ISRO intends to undertake the exploration of space besides its primary mission of developing and utilising space technology for the overall development of the country.

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.

The primary objectives of Chandrayaan-1 are:
1. To expand scientific knowledge about the moon
2. To upgrade India's technological capability
3. To provide challenging opportunities for planetary
research to the younger generation of Indian scientists


Chandrayaan-1 aims to achieve these well defined objectives through high resolution remote sensing of the 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 mapping of entire lunar surface is envisaged.

Indian Mission Moon -First pictures by Chandrayaan-1

Mission Moon - Chanadrayaan 1
It was another proud moment for the country. Prime Minister Manmohan Singh was shown the first pictures that were taken by Chandrayaan-1 through the Terrain Mapping Camera on Friday.

The TMC was operated in October through a series of commands, which were issued from the Spacecraft Control Centre of the Indian Space Research Organisation Telemetry, Tracking and Command Network in Bengaluru.

The first images, which were received by the Indian Deep Space Network at Byalalu was later processed by the Indian Space Science Data Centre. The first images were taken at 8 am from a height of 9,000 km.
The Terrain Mapping camera (TMC) on board Chandrayaan-1 spacecraft was successfully operated on October 29, 2008 through a series of commands issued from the Spacecraft Control Centre of ISRO Telemetry, Tracking and Command Network (ISTRAC) at Bangalore.Analysis of the first imagery received by the Indian Deep Space Network (IDSN) at Byalalu and later processed by Indian Space Science Data Centre (ISSDC) confirms excellent performance of the camera.The first imagery (image 1) taken at 8:00 am IST from a height of 9,000 km shows the Northern coast of Australia while the other (image 2) taken at 12:30 pm from a height of 70,000 km shows Australia’s Southern Coast.

TMC is one of the eleven scientific instruments (payloads) of Chandrayaan-1. The camera can take black and white pictures of an object by recording the visible light reflected from it. The instrument has a resolution of about 5 metres.

Besides TMC, the other four Indian payloads of Chandrayaan-1 are the Hyper spectral Imager (HySI), Lunar Laser Ranging Instrument (LLRI), High Energy X-ray Spectrometer (HEX) and the Moon Impact Probe (MIP). The other six payloads of Chandrayaan-1 are from abroad.

It may be recalled that the 1380 kg Chandrayaan-1 was successfully launched into an initial elliptical orbit around the Earth by PSLV-C11 on October 22, 2008. This was followed by four orbit raising manoeuvres, which together raised Chandrayaan-1’s orbit to a much higher altitude. The spacecraft is now circling the Earth in an orbit whose apogee (farthest point to Earth) lies at 267,000 km (Two lakh sixty seven thousand km) and perigee (nearest point to Earth) at 465 km. In this orbit, Chandrayaan-1 takes about six days to go round the Earth once. The spacecraft performance is being continuously monitored and is normal.