Air-breathing engines use atmospheric oxygen
and burn it with the stored on-board fuel to generate
the onward thrust.
Conventional rockets carry both oxygen and chemical
fuel on board.
"We will be doing a series of ground tests
of the air breathing engine soon. We are planning
an actual launch of a sounding rocket - ATV D02
- powered by such an engine by the end of this
year," an official of Indian Space Research
Organisation (ISRO) told IANS on condition of
anonymity.
The rocket will fly from Sriharikota, India's
rocket port located around 80 km from here.
In March, ISRO flew an advanced technology vehicle
D01 (ATV-D01) weighing three tonnes from Sriharikota.
ATV-D01, the heaviest sounding rocket developed
by ISRO, carried a passive scramjet (supersonic
combustion ramjet) engine combustor module as
a test bed for demonstration of air breathing
propulsion technology.
A scramjet consists of a tube through which inlet
air is compressed by the high speed of the vehicle,
a chamber where fuel is combusted, and a nozzle
through which the exhaust jet leaves at higher
speed than the inlet air.
Jet engines use a compressor to squeeze air into
the engine, then spray fuel into the compressed
air and ignite it to produce thrust by funnelling
it through the back.
The advantage of air breathing engine is that
it makes the rocket lighter - as oxygen is not
carried - enabling it to carry heavier satellites.
Further, it reduces the cost of launch and will
help make ISRO a very cost competitive player
in the global satellite launch industry.
However, as air breathing engine systems can
operate only during the atmospheric phase of flight,
they will have to be adapted along with the conventional
chemical rockets.
(IANS)
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