Chennai: Rocket navigation systems designed by the Indian Space Research Organisation (ISRO) will be used in the geosynchronous launch vehicle (GSLV) flight slated for sometime in March-April 2008.

The new navigation system''s functionality and efficiency on an actual flight were tested on board of the Polar Satellite Launch Vehicle C8 (PSLV-C8) that flew this April. The rocket had a second equipment bay to test the mission computers, navigation and telemetry systems.

The test results met the expectations of the ISRO scientists and that of the existing flight navigation systems.

"The ISRO-designed new avionics weighing around 185kg is lighter than the navigation systems that guides the PSLV and GSLV now," says Dr. B N Suresh, director, Vikram Sarabhai Space Centre, ISRO.

According to him every one kg reduction in the weight of the launch vehicle translates into a one kg increase in the payload, other things remaining the same.

The new navigation system is powered by Vikram, the microprocessor chip designed by ISRO. Presently ISRO uses Motorola''s processor. The designing of the chip is of strategic interest to the country. According to ISRO scientists the Vikram chip is far faster than what is used now.

The flight path of the forthcoming GSLV will be guided by the existing navigation systems.

According to Dr Suresh, ISRO will be testing its air-breathing engine on its sounding rockets this October. Air breathing engines are the ones, which use the atmospheric oxygen from their surroundings and burn it with the stored on-board fuel for producing the forward thrust in contract to the convention chemical rocket systems, which carry both oxygen and fuel on-board.

As a result, the air breathing systems become much lighter and more efficient, leading to reduced overall costs. The air breathing systems have the capability to operate only during the atmospheric phase of flight, they always have to be adopted along with the conventional chemical rockets, for meeting the final orbital velocity requirements.