NEW DELHI — Four Indian satellites are slated for launch over the next two months, a senior space scientist says, using both Indian and foreign launchers.

“Between July 1 and July 26, we hope to loft a navigation satellite and Insat-3D meteorological satellite, followed by the launch of a communication satellite, GSAT-14, and a military satellite, GSAT-7, in August,” the scientist at the Indian Space Research Organization (ISRO) tells Aviation Week.

GSAT-14 will launch aboard India’s Geosynchronous Satellite Launch Vehicle (GSLV). The launch of GSLV-D5, fitted with an indigenous cryogenic engine, is expected to take place in “July-end or early August,” from the spaceport in Sriharikota, off the coast of the south Indian state of Andhra Pradesh, he says. GSAT-14 features six extended C band and 6 Ku band transponders.

The GSLV is a three-stage vehicle and stands 49 meters (160 ft.) tall, with a 414-ton liftoff weight. It has a maximum diameter of 3.4 meters at the payload fairing.

ISRO’s last two attempts to launch the rocket — GSLV-F06 carrying satellite GSAT-5P on Dec. 25, 2010, and GSLV-D3 carrying satellite GSAT-4 on April 15, 2010 — were unsuccessful.

“We have done studies related to previous failures and results of those studies have been thoroughly incorporated in the current GSLV for better results,” the official says.

On July 1, the Indian Regional Navigation Satellite System (IRNSS), the country’s first navigation and timing satellite, will be lofted on a Polar Satellite Launch Vehicle (PSLV-C22) from the spaceport.

Originally planned to take place on June 12, the launch of IRNSS was delayed due to a malfunction in one of the rocket’s systems.

IRNSS is designed to provide position accuracy of better than 10 meters over India and the region extending about 932 mi. around the subcontinent. It is designed to provide real-time position, navigation and timing services under all weather conditions for users including airlines, ships and observational posts.

Following that launch, there will be two separate launches on board a European Ariane 5 launcher from Kourou, French Guiana: the Insat-3D meteorological satellite on July 26 and the GSAT-7 advanced communication spacecraft in early August, the official says.