Indian ingenuity saves moon craft, for now
By Sudha Ramachandran
BANGALORE - India's maiden moon mission has run into some serious trouble. Its
unmanned satellite orbiting the moon, Chandrayaan-I, has developed technical
problems in a critical sensor which, though rectified for now, could result in
the mission being aborted halfway into its two-year lifespan.
Chandrayaan-I's star sensor began malfunctioning on April 26 due to
overheating, ISRO scientists admitted last week. The star sensor keeps the
satellite oriented, ensuring its cameras and other recording equipment are
aimed at the moon's surface. A malfunctioning star sensor can affect the
satellite's data collection.
India's first lunar spacecraft, Chandrayaan-I (Sanskrit for moon craft) was
launched successfully in October 2008, propelling India
into an exclusive club consisting of the United States, Russia, the European
Space Agency (ESA), Japan and China which have sent missions to the moon.
Chandrayaan-I's objective is to create a three-dimensional atlas of the moon,
survey its chemical and mineral composition and look for Helium-3 - a possible
future energy source. The moon's polar regions are of particular interest to
Chandrayaan-I as they might contain ice.
Of the 11 payloads (scientific instruments) the unmanned spacecraft is
carrying, five are Indian. The rest - three from ESA, two from the US's
National Aeronautics and Space Administration (NASA) and one from Bulgaria -
are piggybacking for free.
Technical issues first arose in Chandrayaan-I's heat protection system when it
reached its 100 kilometer orbit around the moon, around a month after its
launch. Temperatures inside the spacecraft reached 80 degrees Celsius, twice
the optimal temperature, making it difficult for scientists to operate power
consuming surface monitoring instruments.
"Chandrayaan I faced a hostile environment around the moon ... The first
encounter was when it was put in its 100 kilometer orbit. The spacecraft
reached a stage of thermal runaway about a month after it was inserted into the
lunar orbit. The entire spacecraft would have been baked. We would have lost
it," Nair said at a press conference on July 17.
To address the overheating crisis, the spacecraft was put into a "summer break
mode", with some instruments rested while others worked to conserve power.
The failure of the star sensor in April was far more serious. Caused by
"excessive radiation from the sun", it left the spacecraft virtually blind, the
ISRO chief said. But ISRO scientists now say they have found a way to save the
spacecraft. "Innovative techniques which can only be called Indian jugaad,
have been found to keep maneuvering the spacecraft," said Pallav Bagla, NDTV's
science correspondent.
A colloquial Hindi word, jugaad means an innovative fix, a work-around
forced by a lack of resources. While the word is sometimes used pejoratively,
in essence it is a tribute to native genius.
Nowhere is this native genius and jugaad more visible than at ISRO.
Decades of technology sanctions imposed on ISRO and other scientific
establishments following India's 1974 testing of a nuclear device denied Indian
scientists access to advanced Western technologies. They worked their way
around the sanctions by finding cheaper and indigenously developed
technologies.
The approach has paid off handsomely. Indian scientists learned to work and
innovate on shoestring budgets. The jugaad of its scientists has
contributed to ISRO's formidable achievements and its multi-million dollar
annual profits.
It is this jugaad that seems to be providing Chandrayaan-I with an
extended lease of life.
Faced with the failed star sensor, ISRO's scientists devised a ingenious
technique of using outboard gyroscopes and antenna pointing information and
images of specific location on the surface of the moon to orientate the
spacecraft. Chandrayaan-I's orbit was raised from 100 kilometers to 200
kilometers.
This appears to have worked, at least for now. "The information that comes out
to us is the same quality as before - it's just as good," Barry Kellet, the
science investigator for one of the instruments at the Rutherford Appleton
Laboratory in Britain, told local media.
On Wednesday, the ISRO chief told the media that Chandrayaan-I is "doing fine",
as was evident from pictures taken recently by the satellite's terrain mapping
camera.
Still the mission will have to compromise on several fronts. An ISRO scientist
working on the Chandrayaan-I project told Asia Times Online that some of the
scientific instruments, especially the European lunar resource mappers, may not
be able to gather all the data they needed. India's instruments for estimating
lunar heights and the resolution of some on-board cameras may also be
compromised.
It is also unclear how long the makeshift arrangement will last.
"We are not sure how long we will be able to sustain it. Chandrayaan-I was
designed for [a] two year [lifespan] but this may be reduced," ISRO spokesman S
Satish has said. The mission "will be subject to a review in September to
analyze the space craft’s functioning and its future," Nair said.
So is India's first moon mission a failure? According to the ISRO chief, in the
past eight months of the operation more than 90% of the Chandrayaan-I's mission
objectives have been achieved. "We have collected almost all the data that we
wanted," he said.
Scientists point out that while they are disappointed with the "handicap"
suffered by Chandrayaan-I, that this is certainly not a failed mission.
According to an ISRO statement, Chandrayaan-I has made 3,000 revolutions around
the moon and sent over 70,000 images of its surface. These have been described
as breathtaking images of lunar mountains and craters, including craters in the
permanently shadowed areas of the moon's polar region.
A scientist on the Chandrayaan-I project has said the team was hoping for
better images and more detailed maps of the lunar surface as this would have
made things easier for the ISRO's moon rover - the space agency plans to land a
robotic vehicle on the moon as part of its next mission, Chandrayaan-II.
"Chandrayaan-I's images will not provide us with all that they were hoping
for," he said. "Still, this mission is not a failure, as we will draw on our
mistakes and experience with Chandrayaan-I."
Chandrayaan-I's troubles have been blamed by some on ISRO's "cost-cutting
habits". There are charges that ISRO has compromised the quality of certain
parts to hold down costs. The ISRO's budget for Chandrayaan-I was around US$300
million, a fraction of what has been spent by other space-faring nations on
their moon missions. China, for instance, spent $500 million on its maiden moon
mission.
While the ISRO does keep costs to a minimum, scientists deny that it
compromises on quality to keep costs down. "Scientists are paid a fraction of
what their counterparts get in the West," the scientist said. "Manpower costs
are controlled. There is no compromise on the quality of materials we use." He
pointed out that spacecraft running into trouble is routine, especially over
heat-management issues.
Despite vast experience in moon landings, NASA also encountered trouble in 1994
when its satellite Clementine failed a mere three months after its launch. The
Japanese moon mission Kaguya in 2007 also had to be cut short by months.
Will Chandrayaan-I's troubles darken India's space ambitions? It seems
unlikely. Scientists are already steaming ahead with preparations for
Chandrayaan-II, which is scheduled for launch in 2012-13.
They are already drawing lessons from Chandrayaan-I's troubles to improve the
next spacecraft. According to Mylswami Annadurai, project director of
Chandrayaan-I and II, scientists are looking at "increasing the thickness of
the radiation shield for Chandrayaan-II".
Improving the heat and radiation shield is essential, not only to protect
spacecraft but also possible crew - ISRO's plans manned Chandrayaan missions in
the future and hopes to land a man on the moon by 2015.
And Chandrayaan-I's troubles are unlikely to affect the ISRO's multi-million
dollar business or future funding for its missions into space. If its revenues
over the past year are any indication of what lies ahead, it has little reason
to worry. Earlier this month, the ISRO chief announced that ISRO expected a 25%
increase in last year revenues of $210 million this fiscal year.
Sudha Ramachandran is an independent journalist/researcher based in
Bangalore.
(Copyright 2009 Asia Times Online (Holdings) Ltd. All rights reserved. Please
contact us about
sales, syndication and
republishing.)
Head
Office: Unit B, 16/F, Li Dong Building, No. 9 Li Yuen Street East,
Central, Hong Kong Thailand Bureau:
11/13 Petchkasem Road, Hua Hin, Prachuab Kirikhan, Thailand 77110
