In its tenth flight conducted from Satish Dhawan Space Centre (SDSC) SHAR,
Sriharikota, on January 10, 2007, ISRO's Polar Satellite Launch Vehicle,
PSLV-C7, successfully launched four satellites - India's CARTOSAT-2 and Space
capsule Recovery Experiment (SRE-1), Indonesia's LAPAN-TUBSAT and Argentina's
PEHUENSAT-1 into a 635 km high polar orbit. For the first time, a Dual Launch
Adopter (DLA) was used in PSLV to accommodate two primary satellites in tandem.
PSLV is the workhorse launch vehicle of the Indian Space Research Organisation
(ISRO) with eight consecutively successful nights so far. Since its first
successful launch in 1994, PSLV has launched seven Indian remote sensing
satellites, an amateur radio satellite, HAMSAT and four small satellites for
foreign customers into 550-800 km high polar SSOs. Besides, it has also
launched India's exclusive meteorological satellite, Kalpana-I, into
Geosynchronous Transfer Orbit (GTO). PSLV will also be used to launch India's
first spacecraft mission to moon. Chandrayaan-I, during 2008.
The 44 m tall PSLV has a lift-of mass of 295 tonne. It is a four-stage launch
vehicle with the first and the third stages as well as the six strap-ons
surrounding the first stage using HTPB based solid propellant. PSLV's first
stage is one of the largest solid propellant boosters in the world. Its second
and fourth stages use liquid propellants.
PSLV's bulbous payload fairing has a diameter of 3.2 metre. The vehicle has
S-band telemetry and C-band transponder systems for monitoring its health and
flight status. It also has sophisticated auxiliary systems like stage and
payload fairing separation systems.
PSLV was originally designed to put 1.000 kg class of India's remote sensing
satellites into a 900 km polar SSO. The payload capability of PSLV has been
successively enhanced and in its last flight, PSLV-C6 in May 2005, it launched
two payloads - a 1,560 kg CARTOSAT-1 and the 42 kg HAMSAT into a 620 km SSO.
Some of the modifications incorporated in PSLV-C7 compared to the previous
flight, PSLV-C6 are:
Use of Dual Launch Adopter
Reduction of propellant from 2.5 tonne to 2 tonne in the
fourth liquid propellant stage (PS4)
Modifications in PSLV fourth stage control electronics
Incorporation of Video Imaging System to capture payload and
DLA separation events
Altitude based Day of Launch wind biased steering programme
during Open Loop Guidance
Deletion of Secondary Injection Thrust Vector Control (SITVC)
system for one of the strapons ignited in the air
Reduction of PSLV first stage SITVC injectant by 500 kg