Confederation of Central Government Gazetted Officers’ Organisations
(CCGGOO),All India DRDO Technical Officers Association (AIDTOA) & All India
People’s Science Network (AIPSN) congratulate the entire ISRO fraternity for
successful launch of GSLV Mk III- D1 and placing communication satellite
GSAT-19 into a precise orbit.
Though the US sanctions on India in 1992 prevented the country from
getting cryogenic engine technology from Russia, it failed to halt ISRO’s
relentless effort to develop indigenous rocket and cryogenic engine
technologies.
The Indian Space Research Organisation has crossed a significant
milestone with the successful developmental flight of the country’s heaviest
Geosynchronous Satellite Launch Vehicle, the GSLV Mark-III. This is the first
time a satellite weighing over 3.1 tonnes has been launched from India to reach
the geostationary orbit about 36,000 km from Earth. The Mk-III can launch
satellites weighing up to four tonnes, which almost doubles India’s current
launch capacity.
With communication satellites becoming heavier (up to six tonnes),
the capability for larger payloads is vital. This can be done by switching over
to electric propulsion for orbit rising and to keep the satellite in the right
position and orientation in the orbit through its lifetime (that is, station
keeping). The switch-over would reduce the weight of the vehicle as it can do
away with nearly two tonnes of propellants and carry heavier satellites.
Towards this end, ISRO has started testing electric propulsion in a small way;
the South Asia Satellite (GSAT-9) that was launched last month used electric
propulsion for station keeping.
On 05.06.17, an indigenously
developed lithium-ion battery was used for the first time to power the
satellite. Another key achievement is the use of an indigenously developed
cryogenic stage, which uses liquid oxygen and liquid hydrogen; the 2010 GSLV
launch using an indigenous cryogenic stage ended in failure. It can now be said
without hesitation that India belongs to the elite club of countries that have
mastered cryogenic technology. In the December 2014 experimental flight of the
GSLV Mk-III, a passive cryogenic stage was used. Though the cryogenic stage was
not meant to be ignited, the launch provided invaluable data on aerodynamic
behaviour of the vehicle.
The
Mark-III will be operational with the success of one more developmental flight,
which is set to take place within a year. This will make India self-reliant in
launching heavier satellites, bringing down costs substantially. Till now,
heavier communication satellites have been launched on Europe’s Ariane rockets;
in fact, ISRO will soon be using Ariane rockets to launch two of its heavier
satellites. But as has been the case with lighter satellites, it is likely that
other countries will soon turn to ISRO for the launch of heavier satellites at
a lower cost. With fewer propulsion stages and, therefore, control systems, the
Mk-III is far more reliable than the GSLV and the PSLV.
Combined
with its ability to carry eight to 10 tonnes into a low Earth orbit, the Mk-III
can be considered for human-rating certification (to transport humans) once
some design changes are made. Compared with the two-member crew capacity of the
GSLV, the Mk-III can carry three astronauts and have more space to carry out
experiments. The next developmental flight, therefore, will be crucial. CCGGOO,
AIDTOA & AIPSN wish all the ISRO officers & employees success
in all their future endeavours.
No comments:
Post a Comment