First Indo-French mission a success

Defying cloudy skies, Isro’s proven workhorse, the 44-metre tall PSLV-C18, with a total payload mass of 1,047 kg, roared through the dense cloud mass spewing bright fumes to inject the Megha-Tropiques (MT) satellite and three other nano-satellites in the targeted circular orbit in what was PSLV’s 19th consecutively successful flight.

The PSLV-C18 blasted off from the first launch pad at the Satish Dhawan Space Centre here at 1101 hours, a minute later than the scheduled 1100 hours. The Isro used a “core-alone” configuration of PSLV in this mission, sans its usual solid strap-on motors. The slight delay in launch was to avert any probable space-debris collision with the rocket. 

Nearly 26 minutes after the lift-off, the four-stage rocket fired by a mix of solid and liquid propellants, completed its entire mission when “Jugnu,” the IIT-Kanpur built nano-satellite was separated from PSLV-C18 in its fourth and last stage. Seconds before, the MT satellite was injected first, followed by the other two smaller satellites, “SRMSat” and “VesselSat-1” in that order.

Space Scientists at the Mission Control Centre here greeted that moment with a loud applause, even as a beaming Isro Chairman, K Radhakrishnan announced that the “PSLV-C18’ mission “has been a grand success”. It very precisely injected the four satellites into the targeted circular orbit, he said, even as veterans led by former Isro chief, Dr K Kasturirangan congratulated the entire team.

Andhra Pradesh Chief Minister Kiran Kumar Reddy and representatives of the French National Centre for Space Research (CNES), were among those to greet the project team in the MCC.

Against the targeted orbit of 867 km altitude and an inclination of 20 degrees with respect to equator, Radhakrishnan later told reporters the PSLV-C18 had injected the satellites at an altitude of 865 km and at an orbit inclination of 19.8 degrees, very close to the designed parameters.

Shortly after the successful launch, Isro’s Telemetry, Tracking and Command Network in Bangalore took charge. The solar panels were deployed in time to energise MT, even as over the next few days commands and controls will emanate from Isro’s Bangalore station to stabilise the satellite and switch on its payloads, Radhakrishnan said.

Megha-Tropiques carries four instruments as payloads. They include MADRAS (Scanning Microwave Imager for Detection of Rain and Atmospheric Structures) developed jointly by the Isro and CNES, a sounder instrument for probing “vertical profiles of humidity,” and a scanner for measuring radiation levels (both developed by CNES). The fourth payload is a “radio occultation sensor for vertical profiling of temperature and humidity,” which was received from Italy.

Radhakrishnan described the Indo-French joint project as opening up of a bold new area of scientific collaboration. The launch was a fulfillment of an over decades-long efforts, given shape initially in the late 1990s’ by Kasturirangan and eminent scientist Roddam Narasimha.

The Isro and the French National Space Agency got into a project mode in 2003-04, and “what we saw is the culmination of the joint work for a better understanding of the tropical climate globally,” Radhakrishnan said. Megha-Tropiques is the only second such mission in the world now, the first one being the Tropical Rainfall Measurement Mission jointly launched by the USA and Japan in 1997, he pointed out.

While PSLV-C18 has cost Isro Rs 90 crore, the MT satellite has cost both India and France each Rs.86 crore, said the Isro chief to a query. The MT satellite has been designed to last five years.

While the 10.90-kg nanosatellite “SRMSat” has been built by the students and faculty of the private “SRM University” near Chennai to study global warming, the 28.7-kg “VesselSat-1” built by Luxembourg’s “LuxSpace” tracks signals from ships at sea.