ISRO Launches Joint French-Indian Satellite To Study Tropical Monsoons

by

NEW YORK — An Indian PSLV rocket successfully placed the Franco-Indian Megha-Tropiques Earth observation satellite into low Earth orbit Oct. 12 along with three microsatellites, the Indian and French space agencies said.

Indian Space Research Organisation (ISRO) Chairman K. Radhakrishnan described the launch as “a grand success.”

“What this Indo-French collaborative project is going to give the world is a lot of information for the tropical regions,” Radhakrishnan said in a televised statement immediately following the launch from Satish Dhawan Space Centre in southeast India. “This is a truly global mission.”

Megha-Tropiques, which will spend about three months in testing before being declared operational, is designed to operate for at least three years studying tropical monsoons using a microwave imager from an orbit of about 865 kilometers inclined at 20 percent relative to the equator.

In addition to giving the satellite a frequent revisit over the monsoon regions — three to six times per day between 25 degrees north and 25 degrees south latitude — the unusual orbit will mean that Megha-Tropiques never overflies the French mainland.

The French space agency, CNES, financed about 40 percent of the mission. Megha-Tropiques managers at CNES said they are unaware of any precedent for a bilateral space cooperation in which the satellite being developed does not fly over one of the partners’ capitals.

CNES spent 45 million euros ($61 million) on Megha-Tropiques, a figure that about doubles when CNES personnel salary costs are included in the budget.

The satellite was first designed by CNES and the ISRO, in the late 1990s. Development was suspended in 2002 following a financial shortfall at CNES. The mission was reorganized in 2003 with greater ISRO responsibility, including provision of the IRS satellite platform.

A final agreement between the two agencies was concluded in November 2004.

Remy Roca, Megha-Tropiques program manager at CNES, said that despite the long decision and development, the value of Megha-Tropiques in studying humidity profiles, cyclones and flooding in the tropical belt has not diminished. Few satellites are equipped with sensors to take the measure of the water cycle in this region. Microwave instruments on satellites in geostationary orbit 36,000 kilometers over the equator are still insufficiently precise, Roca said.

Megha-Tropiques nonetheless will be inserted into a constellation of satellites that will have both research and operational weather-monitoring functions.

The operational aspect confronts Megha-Tropiques with the same problem faced earlier by the French-U.S. Jason series of ocean-topography satellites.

Space agencies such as CNES and NASA are principally tasked to perform nonrecurring research missions. Building multiple copies of the same basic satellite is left to commercial companies or to agencies other than those charged with carrying out space research — such as the U.S. National Oceanic and Atmospheric Administration and Europe’s Eumetsat meteorological satellite organization.

At a press briefing at CNES headquarters in Paris Oct. 3, Roca said Megha-Tropiques’ operational use is threatened by the fact that, as of now, there is no planned follow-up mission. Talks with India, Brazil and others continue. For the moment, the data will be limited to Megha-Tropiques’ three- to five-year lifespan. CNES and ISRO have funded the mission for three years, but Roca said the satellite has sufficient fuel to operate for at least five years.

Didier Renault, a manager in CNES’ atmosphere and climate division, referred to the “valley of death” that research missions must traverse as they await endorsement, and funding, from organizations that will assure an uninterrupted data flow.

Megha-Tropiques has four instruments. The Madras microwave imager, developed by CNES and ISRO, will measure precipitation and cloud cover. The French Saphir microwave sounder will develop humidity profiles in the tropical region. The Scarab instrument, also developed in France, is an optical sensor to measure solar radiation at the top of the atmosphere. The Rosa GPS occultation atmospheric sounder instrument was provided by ISRO with the assistance of the Italian Space Agency and was developed by Thales Alenia Space of France and Italy.

Three microsatellites, two for research and one for a commercial ship-monitoring mission, were also aboard the PSLV rocket. The 10-kilogram SRMSat, built by India’s SRM University, will study greenhouse gases. The 3-kilogram Jugnu satellite, provided by the Indian Institute of Technology, carries a near-infrared camera for Earth observation.

The 30-kilogram Vesselsat satellite, built by LuxSpace of Luxembourg, will be used by Orbcomm of Fort Lee, N.J., to develop Orbcomm’s commercial Automatic Ship Identification (AIS) service while Orbcomm awaits its AIS-equipped constellation of 18 second-generation messaging satellites.

LuxSpace is owned by OHB AG of Bremen, Germany, which is providing the satellite as part of an arrangement with Orbcomm following the failure of the AIS units aboard previous OHB-provided Orbcomm satellites built by a Russian company and launched in 2008.

 

K.S. Jayaraman contributed to this story from Bangalore, India.

 

RELATED ARTICLE

Proposals Sought for Indo-French Missions