Events
& Issues
New Delhi, 31 August 2009
Chandrayan-I Loss
MAY NOT ECLIPSE SPACE
AGENDA
By Radhakrishna Rao
The abrupt termination of
India’s
a maiden mission to the moon, Chandrayaan-1, is not all bad news.
Notwithstanding its formal end late August, after the Indian space agency could
not establish radio links with it, the course of the country’s space programme
is not going to be affected. The Indian Space Research Organisation’s plan for
the follow on moon mission Chandrayaan-II is proceeding smoothly and the
lessons learnt from Chandrayaan-1 will be applied for this mission.
The premature demise of the
orbiting lunar spacecraft Chandrayaan-1 originally designed for a life span of
two years was not wholly unexpected. For this first-ever Indian effort at deep
space exploration was beset with a variety of hitches including the loss of
vital star sensor and bus management system.
Though the factors
responsible for the end of the Chandrayaan-1 mission in less than one year of
its launch are yet to be conclusively established, in all likelihood the high
levels of radiation around the orbit of Chandrayaan-1 had resulted in the
failure of power supply feeding to the two onboard computers. These computers
were meant to control the telemetry data flow from the spacecraft to the round
and the tele-commands given to the spacecraft from the ground.
The primary lesson learnt
so far is that ISRO has to have a detailed understanding and knowledge of the
environment it is working with, according to the ISRO Chairman, G Madhavan Nair.
There was a higher level of radiation around the moon than assessed that caused
the failure. In future it will have to use devices that are more resistant to
radiation. On a happy note, another point driven home is that 95 per cent of
Chandrayaan’s mission objectives have been realized.
This apart, India has already initiated discussion with Russia and the US to explore the possibility of
using their radars to track Chandrayaan-1, which is now in 200-km orbit around
the moon. The very fact that Chandrayaan-1 could survive for more than 300 days
and provide a wealth of data on various aspects of earth’s nearest celestial
neighbour stands as a tribute to the vision of the Indian space scientists. For
most of the lunar missions launched by other space-faring nations have burnt in
a couple of months after their launch.
Incidentally,
Chandrayaan-1 mission was taken up by ISRO to sustain India’s
position as a forward-looking space power keen on exploring the deeper space
with a greater vigour in the years ahead. The launch of lunar spacecraft in
October last by means of an augmented version of the four stage trusted space
workhorse PSLV (Polar Satellite launch Vehicle) from Satish Dhwan Space Centre (SDSC)
in the spindle shaped Sriharikota island in the Bay of Bengal catapulted the India
into the elite league of nations—the US, Russia, Japan, China and European
Space Agency (ESA)—which have launched their own lunar missions.
Moreover, Chandryaan-1 with
its eleven payloads, five Indian and six international, had the largest
scientific instruments on board and was described appropriately as an
international mission with India
as the captain. The mission’s biggest achievement has been the inputs it has
provided for preparing a three dimensional atlas of the lunar surface for the
first time. Chandrayaan-1 data has also provided clues to the presence of
minerals on the surface of the moon.
Further, the wealth of
data made available by Chandrayaan-1 would help researchers get a better
insight into the early history and evolution of the moon. The spacecraft
entered its final lunar orbit on November 4 after a series of complicated
manoeuvres and ten days later i.e. on November 14, the Moon Impact Probe (MIP),
an Indian technology payload, carried by Chandrayaan-1 successfully crash-landed
on the lunar surface.
It may be recalled that
in April this year, Chandrayaan-1 faced a serious crisis in the aftermath of
the detection of the loss of its vital star sensor meant to determine the
orientation of the spacecraft. Subsequently, the orientation of the Indian
lunar orbiter was stabilized by the activation of onboard gyroscopes. This was
a contingency measure aimed at keeping the mission alive. Further with a view to
shelter Chandrayaan-1 in a benign environment, its orbit was raised to 200-km
from 100-km. The spacecraft had also run into trouble after one of its bus
management systems performing the vital function of control had come a cropper.
A statement issued by
ISRO says that the spacecraft has completed more than 3,400 orbits around the
moon and provided a wealth of data from its onboard payloads, including TMC (Terrain
Mapping Camera) Hyper Spectral Imager and Moon Mineralogy Mapper. It further
confirmed that Chandrayaan-1 has sent back more than 70,000 imageries of good
quality and some of these have provided breathtaking views of lunar mountains
and craters, especially craters in the permanently shadowed areas of the moon’s
polar region.
In a significant development,
on August 21, Chandrayaan-1 in tandem with the American lunar probe Lunar
Reconnaissance Orbiter (LRO) successfully carried out what was described as a
“Bistatic Experiment”. During this unique experiment, radar instruments onboard
these two lunar spacecraft were focussed on the same location—of course from
different angles—in a permanently shadowed crater near the north pole of the
moon. The objective of the experiment was to gather additional and more
conclusive information on the possibility of water ice existing in this
shadowed polar region of the moon.
Meanwhile, former
President and well-known space scientist Dr APJ Abdul Kalam, who during his
long stint with ISRO had provided leadership for the development of the
county’s first launch vehicle SLV-3 that had a successful flight in the ’80s
has stated that for a first launch, Chandrayaan-1 stands out as a great
success. He has said: “We have got images and data from ten instruments onboard
the spacecraft in the last ten months. This means the mission is completed”.
Insofar as Chandrayaan-II
mission is concerned, it is slated for launch in 2012-13 and will be an
Indo-Russian enterprise. While ISRO will be responsible for the main orbiter, Russia will
develop lane/rover forming part of the mission. The robotic rover which is
designed for a soft landing on the surface of the moon, will pick up soil and
rock samples, subject these to in-situ chemical analysis and send the data
instantly to the mother spacecraft.
The Rs.4250-million
Chandrayaan-II will be launched by means of the three-stage Geosynchronous
Satellite Launch Vehicle (GSLV) featuring an Indian made upper cryogenic engine
stage. However, ISRO is also looking at a sample return mission to the moon as
a follow up to Chandrayaan-11. But as of now there is no firm plan for such a
mission. Whether ISRO will attempt a human landing mission to moon by the end
of next decade, only time will tell? ---INFA
(Copyright, India News and Feature Alliance)
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