Taking what the head of the program described as “a baby step” toward developing a reusable space vehicle, the India Space Research Organization (ISRO) carried out a successful test of a scale-model winged-body vehicle on May 23.
Dr. K. Sivan, Director of the Vikram Sarabhai Space Center, said after the successful test, “There are many technology challenges that have to be overcome” before there is an operational system that can take satellites to orbit and then return to be reused. Eventually, a more advanced vehicle would be capable of carrying a crew to low Earth orbit. “We have to go a long way,” Sivan said, “But these are very essential steps we have to take.”
The purpose of the experiment was to test the hypersonic aero-hydrodynamic characteristics of the test article’s reentry; its control and guidance systems; autonomous mission management, and the materials to protect the vehicle. The Reusable Launch Vehicle-Technology Demonstrator (RLV-TD) made an autonomous, unpowered glide from a hypersonic speed (more than Mach 5) through the atmosphere, and carried out a precise spashdown into the Bay of Bengal. Sensors on board recorded pressure, temperature, and structural loads on the vehicle, and transmitted the data back in real time. Although ISRO has retrieved unmanned capsules before, this is the first time a winged vehicle reentered at hypersonic speeds.
The solid-fueled rocket with the RLV-TD atop burned for about 90 seconds, taking the test vehicle to an altitude of about 40 miles. It then glided back to Earth, in a mission lasting about 770 seconds. “The vehicle’s navigation, [and] guidance and control system accurately steered the vehicle during this phase for safe descent,” ISRO said in a statement. Similar to the U.S. Space Shuttle, the RLV-TD has silica tiles on its belly, and a carbon-carbon composite nose cap, in order to survive the heat of reentry.
This experiment will be followed by a landing experiment (LEX), a return flight experiment (REX), and a scramjet propulsion experiment (SPEX), in which the engine will use oxygen from the atmosphere, rather than carry it along.