MUMBAI: In its 10th launch on 10 January India's Polar Satellite Launch Vehicle (PSLV) PSLV-C7 has successfully launched four satellites namely 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 Sun Synchronous Orbit (SSO).
Isro claims to having used a Dual Launch Adopter (DLA) in PSLV for the first time to accommodate two primary satellites in tandem.
PSLV-C7 lifted off from the first launch pad at SDSC Shar at 9:23 am with the ignition of the core first stage and four of the six strap-on motors. The remaining two strap-on motors were ignited 25 seconds after lift-off.
The important flight events included the separation of the ground-lit strap-on motors, separation of air-lit strap-on motors and the first stage, ignition of the second stage, separation of the heatshield at about 121 km altitude after the vehicle had cleared the dense atmosphere, second stage separation, third stage ignition, third stage separation, fourth stage ignition and fourth stage cut-off.
Cartosat-2 was the first satellite to be injected into orbit at 981.3 seconds after lift-off at an altitude of 639 km. DLA with the 6 kg Pehuensat-1 was separated about 45 seconds later followed by the 550 kg Space capsule Recovery Experiment (SRE-1) after 120 seconds and the 56 kg Lapan-Tubsat after 190 seconds.
The four satellites have been placed in a polar orbit at an altitude of 637 km with an inclination of 97.9 degrees with respect to the equator. The initial signals indicate their normal health.
After its separation from the DLA, the two solar arrays of Cartosat-2 were automatically deployed to generate the electrical power for the satellite. The satellite health is being continuously monitored from the Spacecraft Control Centre of Istrac at Bangalore with the help of its network of stations at Bangalore, Lucknow, Mauritius, Bearslake in Russia, Biak in Indonesia, as well as support from Svalbard ground station in Sweden for the initial phase of the Cartosat-2 mission.
With Isro Satellite Centre (Isac), Bangalore, as the lead Centre, Cartosat-2 was realised with major contributions from Space Applications Centre (SAC), Ahmedabad, LPSC at Bangalore, and IISU, Thiruvanantha-puram. Istrac is responsible for initial and in-orbit operation of Cartosat-2. The National Remote Sensing Agency (NRSA), Hyderabad receives and processes the data from Cartosat-2.
Space capsule Recovery Experiment (SRE-1): Space capsule Recovery Experiment (SRE-1), developed by Isro's VSSC and Isac, is a 550 kg capsule, intended to demonstrate the technology of an orbiting platform for performing experiments in microgravity conditions. After the completion of the experiments, the capsule will de-orbited after a few days and recovered.
Two days before de-orbiting, SRE-1 will be placed in a Repetitive Elliptical Orbit. Subsequently, it will be reoriented and deboost rocket is fired to make it reenter the earth's atmosphere. SRE-1 will splashdown in the Bay of Bengal, east of Sriharikota coast.
SRE-1 is being tracked and monitored by ground stations at Bangalore, Lucknow, Mauritius, Biak in Indonesia, Bearslake in Russia, Saskatoon in Canada and Svalbard in Sweden/Transo in Norway.
Lapan-Tubsat and Pehuensat-1 were launched under commercial agreements. Lapan-Tubsat is a cooperative venture between Indonesian Space Agency, Lapan and Technical University of Berlin. It is an earth observation satellite besides a technical demonstrator in control systems.
Pehuensat-1 is a 6 kg Argentinean nano-satellite meant to serve educational, technological and scientific fields. Its developed by University of Comahue of Argentina, AMSAT (Amateur Satellite Association of Argentina) and Argentina Association for Space Technology and is intended to provide an experiment platform to perform amateur radio experiments between colleges and universities of Argentina.
