'Designing Chandrayaan was
like writing lyrics to a set tune'
Oct 19 (IANS) While building India's first moon craft, Chandrayaan
project director Mylswamy Annadurai was reminded of his engineering
college days when he wrote lyrics to the tunes of his classmates.
that time he used to write poetry - some were published in
the college magazine.
of the many challenges in building the spacecraft is to accommodate
the six overseas pre-built payloads. We had to design the
spacecraft accordingly - sort of writing lyrics to a tune,"
50-year-old Annadurai told IANS from the Satish Dhawan Space
Centre at Sriharikota, 80 km from here.
man who will go down in space annals as the designer of India's
first moon orbiter was born in the small village of Kotavadi
in Pollachi district of Tamil Nadu. He graduated from the
Government College of Engineering, Coimbatore, and did his
Masters at PSG College of Technology in the same city.
Annadurai is a veteran at the India Space Research Organisation
(ISRO), having joined it in 1982.
offers the good freedom even to freshers," he said, citing
his own experience when he suggested software modelling of
is something like a flight simulator. Operators can operate
the computer-modelled satellites. Viewing the screen they
can take corrective steps before a satellite is actually built
and sent up," he explained.
the years Annadurai has worked in different satellite projects
- from Indian Remote Sensing (IRS) satellites 1A, 1B and communication
satellites Insat 2A to 3E series.
was mission director for the Insat 2C to 3E satellites and
was associate project director for the country's first education
satellite Edusat before being assigned the prestigious Chandrayaan
project in 2004.
Chandrayaan is not just another satellite," Annadurai
told IANS. "There were many new challenges in building
challenges started from the launch vehicle itself, as that
is what determines the weight of the satellite.
years ago it was decided that Chandrayaan would be carried
on a Polar Satellite Launch Vehicle (PSLV).
that time PSLV was ISRO's tried and tested rocket, while its
heavier Geosynchronous Satellite Launch Vehicle (GSLV) was
still in its infancy.
can carry a payload of around 1,500 kg for geostationary transfer
Annadurai and his team knew the maximum permissible weight
of the satellite.
thumb rule is that a rocket can carry around one percent of
its total liftoff weight as luggage.
was one boundary within which Annadurai had to work. The next
was the communications challenge.
to Annadurai, the Insat satellites cannot be put in lunar
communication to and from the satellite will be very difficult.
The moon satellite will be orbiting at 3,86,000 km from the
earth - over 10 times the distance at which communication
a result ISRO's satellite centre had to develop far more advanced
communication sensors to receive and transmit signals.
will be orbiting just 100 km above the lunar surface. So the
extrme climate near the moon was another challenge that Annadurai's
team had to take into account.
satellites while in orbit are manoeuvred to maintain equilibrium
between the hot and cold climes up above the earth,"
he explained. "In a moon orbit the satellite will be
exposed to high heat and thermally it needed a different design."
there was the question matching the payloads the PSLV will
carry in addition to the experimental instruments aboard Chandrayaan.
They are from multiple sources - the US, different European
countries and ISRO.
spacecraft had to be designed for them. "In respect of
one overseas instrument we had to come up with a slightly
different design so that it would perform as expected,"
to reach the lunar orbit, the satellite's propulsion system
needs high-thrust engines.
the on-board motors of Insat satellites are fired for a maximum
of one week to lift it to the intended orbit around the earth,
Chandrayaan will have to travel 18 days or more to reach the
the buzzword for Annadurai and his team was maximum possible
miniaturisation of components to reduce weight.
hyper spectral imager that will photograph the lunar surface
has been reduced in size and weight, for instance. "The
spin-off benefit will be that future satellites can carry
smaller equipment," Annadurai said.
space bug obviously affects more than one member of the Annadurai
family. His son is now studying aerospace engineering in Bangalore.
"He is showing interest in space science but it's too
early to say whether he will follow his father's footsteps."
hasn't written a poem on Chandrayaan yet.