The Indian Space Research Organisation (ISRO)has given details of ongoing work for its 2009 reusable launch vehicle demonstrator suborbital flight.
Launched on a 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 has 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 air ports for sensors to aid flight control, will be built for windtunnel tests.
The solid rocket booster is an existing design modified for this task. "The grain has to be modified to reduce the maximum dynamic pressure," says ISRO Vikram Sarabhai Space Centre's Ramesh Narayanan, speaking at the second European Conference for Aerospace Sciences in Brussels.
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 attitude to descend initially at a 35° to 45° angle of attack. During flight, the vehicle will experience its greatest thermal load - 40W/cm2 (101.6W/in2) - 100s after launch.
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°. The rudders will be used as speed brakes.
Source: Flight International
