ISRO scientists reveal details of sub-orbital flight of re-usable launch vehicle

Brussels: Indian scientists from the Indian Space Research Organisation (ISRO), speaking at the second European Conference for Aerospace Sciences in Brussels, have provided details of the reusable launch vehicle demonstrator's sub-orbital flight, due for 2009.

To be launched on an 11.5m (38.3ft)-tall solid rocket booster and using 9,000kg (4,090lb) of propellant, the X-37-like 1,400kg vehicle is 6.5m long with a 3.6m wingspan. Flight apogee will be 67km (42 miles) and it has a downrange of 650km.

The vehicle will splash down in the Indian Ocean.

To model the mission, ISRO scientists said that they have developed six degrees of freedom simulation software to encompass all the environmental conditions and flight dynamics.

A scale model of the test vehicle's nosecone, with nine ports for sensors to aid flight control, will be built for wind tunnel tests.

According to ISRO Vikram Sarabhai Space Centre's, Ramesh Narayanan, the solid rocket booster is an existing design modified for this task. "The grain has to be modified to reduce the maximum dynamic pressure," he said at the conference.

The booster will use its four control fins' adjustable tips to regulate ascent.

The test vehicle will use a reaction control system to modify its altitude to descend initially at a 35° to 45° angle of attack. For flight control within the atmosphere during descent, the vehicle has a body flap at the rear, a rudder on each of its two tail fins, and outer and inner ailerons.

The rudders and ailerons both have a maximum deflection of +/-30°, and will be used as speed brakes.