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View Full Version : Chandrayaan-1 spacecraft completes 3000 orbits around the Moon (Forwarded)


Andrew Yee[_1_]
July 20th 09, 05:16 AM
Indian Space Research Organisation
Bangalore, India

July 17, 2009

Chandrayaan-1 spacecraft completes 3000 orbits around the Moon

Chandrayaan-1, India's first mission to Moon, launched on October 22, 2008
from Satish Dhawan Space Centre, Sriharikota, has completed eight months of
successful operation and has made 3,000 revolutions around the Moon. Besides
sending more than 70,000 images of the lunar surface which provide
breathtaking views of lunar mountains and craters, especially craters in the
permanently shadowed areas of the Moon's polar region, Chandrayaan-1
spacecraft is also collecting valuable data pertaining to the chemical and
mineral content of the Moon. Chandrayaan-1's orbit was raised from 100 km to
200 km circular on May 19, 2009. The high orbital altitude of Chandrayaan-1
reduces the resolution of the imagery but provides a wider swath and the
data is of good quality.

The onboard star sensor used for determining the orientation of the
spacecraft started malfunctioning on April 26, 2009. To overcome this
anomaly, ISRO devised an innovative technique of using redundant sensors --
gyroscopes -- along with antenna pointing information and images of specific
location on the surface of the moon, for determining the orientation of the
spacecraft. This method has been validated and based on this information,
mission operations are being carried out satisfactorily. Other than the
failure of the star sensor and one of the Bus Management Units, health of
the spacecraft is normal.

Recent review by scientists has confirmed that all primary mission
objectives of Chandrayaan-1 have been successfully realised during the eight
months of its operation. The spacecraft continues to send high quality data
as per planned sequence to its ground station at Byalalu near Bangalore.
Detailed review of the scientific objectives and the performance results on
the Chandrayaan-1 mission is scheduled within three months after which
further operational procedures will be worked out.

It may be recalled that the primary mission of Chandrayaan-1 were:

* To realise the complex spacecraft with 11 scientific instruments
* To launch the spacecraft in near earth orbit and to carry out orbit
raising manoeuvres of the spacecraft from 22,000 km to 3,84,000 km and place
the spacecraft in a circular orbit around the moon
* To place the Indian Tricolour on the moon
* To carry out the imaging operation of the lunar surface and collect data
on the mineral content of the lunar surface
* To realise the deep space tracking network and implement the operational
procedures for travel into deep space

With the successful realisation of these objectives, additional data that
will be derived during the remaining part of Chandrayaan-1's life will be
complementary to already derived information.

The data collected from Chandrayaan-1 instruments have been disseminated to
the Indian scientists and also the partners from Europe and USA. The
scientific community is extremely happy with the already obtained data and
the results of analysis could be expected in about 6 months to 1 year
period.