CHENNAI, Oct 19:The 24-hour countdown for the first unmanned Flight Test Vehicle Abort Mission-1 (TV-D1) to demonstrate the crew escape system of the Gaganyaan programme, will begin at 8.00 am at SHAR Range, Sriharikota on Friday.The Indian Space Research Organisation (ISRO) sources on Thursday said the countdown will commence at 0800 hrs tomorrow.The launch of the short duration mission will take place from the First Launch Pad at 0800 hrs on Saturday morning and the entire mission will last 531 secs (about nine minutes).This flight test will mark a major milestone in the overall Gaganyaan programme–which will be India’s first manned mission to space–and will define the in-flight abort demonstraton of Crew Escape System (CES) at Mach Number 1.2 with the newly developed Test Vehicle followed by Crew Module Separation and Recovery.The objective of the mission is Flight demonstration and evaluation of Test Vehicle sub systems, Crew Escape System including various separation systems and Crew Module characteristics & deceleration systems demonstration at higher altitude and its recovery.The 35 m tall Liquid Propelled Single StageTest Vehicle, weighing about 44 ton, uses a modified Vikas engine with 4,520 kg Crew Module (CM) and CES mounted at its fore end.“The entire flight sequence, right from lift off from the First Launch Pad to the crew module touchdown at sea about 10 km frm Sriharikota, with the deployment of parachutes, will last 531 seconds”, ISRO said.The CM is a single walled unpressurised aluminium structure. It said about 60 seconds after the lift, the test vehicle — crew escape system will get separated at an altitude of 11.7 km and 30 seconds later, the CM-CES will get separated at an altitude of 16.7 km at a velocity of 148.7 m/s.Subsequently, the abort sequence will be executed autonomously commencing with the separation of CES and deployment of series of parachutes, finally culminating in the safe touchdown of the CM in the sea, about 10 km from the coast of Sriharikota, the Space Agency said. Stating that the TV-D1 test flight will demonstrate the performance of the CES, it said this would be a significant milestone for the overall Gaganyaan programme as a near-complete system is integrated for the flight test. The unmanned test flight mission of the crew module escape system, will take place using ISRO’s heaviest rocket LVM3.“The first unmanned test mission TV-D1 will be followed by three more test flights TV-D2, TV-D3 and TV-D4 to test the systems before the maiden human flight mission”, ISRO Chairman S.Somanath said.The test is intended to test the ‘crew module’ or the part of vehicle where the Indian astronauts will be housed.The test involves launching the module to outer space and bringing it back to earth and recovering it after touchdown in the Bay of Bengal. (PTI)The TV-D1 will demonstrate the in-flight system. In manned missions “We are testing and ensuring that the escape system has got a very high reliability…the escape system will be activated in transonic conditions, which is Mach 1.2 and we will demonstrate how the crew will be rescued”, ISRO sources said.The Navy personnel have already started mock operations to recover the module, he said, adding, along with the crew module, there will also be a ‘crew escape’ system.If the spacecraft while ascending into space faces a problem, this escape system is expected to separate and bring the crew safely back to sea from where they will be picked by th e Navy personnel.The Gaganyaan mission is expected to take place in the second quarter of next year.ISRO said this would be a significant milestone. for the overall Gaganyaan programme as a near-complete system is integrated for the flight test.The Test Vehicle is a single-stage liquid rocket developed for this abort mission.The payloads consist of the Crew Module (CM) and Crew Escape Systems (CES) with their fast-acting solid motors, along with CM fairing (CMF) and Interface Adapters.It said this flight will simulate the abort condition during the ascent trajectory corresponding to a Mach number of 1.2 encountered in the Gaganyaan mission.For the Test Vehicle Abort mission-1 (TV-D1), the CM is an unpressurised version. This unpressurised CM version has to have an overall size and mass of actual Gaganyaan CM. It houses all the systems for the deceleration and recovery.With its complete set of parachutes, recovery aids actuation systems and pyros, the avionics systems in CM are in a dual redundant mode configuration for navigation, sequencing, telemetry, instrumentation and power.The CM in this mission is extensively instrumented to capture the flight data for evaluation of the performance of various systems.The Crew Module will be recovered after touchdown in the Bay of Bengal, using a dedicated vessel and diving team from the Indian Navy.The Gaganyaan Mission envisages launching a crew of two to three members to an orbit of 400 km for a 3-day mission and bringing them back safely to the earth by facilitating the landing in Indian sea waters.The spacecraft mainly consists of Crew Module and Service Module. The CM structure, simulates the shape and size of the actual Gaganyaan crew module.The Integrated Air Drop Test will be performed using an Indian Air Force helicopter by taking the Crew Module structure to an altitude of 3.6 to 4 km to validate the deceleration system (parachute pyro’s) performance.ISRO said the Gaganyaan mission project will be accomplished through an optimal strategy by considering inhouse expertise, experience of Indian industry, intellectual capabilities of Indian academia and research institutions along with cutting edge technologies available with international agencies.The pre-requisites for Gaganyaan mission include development of many critical technologies including human rated launch vehicle for carrying crew safely to space, Life Support System to provide an earth like environment to crew in space, crew emergency escape provision and evolving crew management aspects for training, recovery and rehabilitation of crew.It said various precursor missions are planned for demonstrating the Technology Preparedness Levels before carrying out the actual Human Space Flight mission.These demonstrator missions include Integrated Air Drop Test (IADT), Pad Abort Test (PAT) and Test Vehicle (TV) flights. Safety and reliability of all systems will be proven in unmanned missions preceding manned mission.LVM3 rocket–the well proven and reliable heavy lift launcher of ISRO, will be the launch vehicle for Gaganyaan mission. It consists of solid stage, liquid stage and cryogenic stage, which will have increased thrust of 22 tonnes.All systems in LVM3 launch vehicle are re-configured to meet human rating requirements and christened Human Rated LVM3. HLVM3 will be capable of launching the Orbital Module to an intended Low Earth Orbit of 400 km.HLVM3 consists of Crew Escape System (CES) powered by a set of quick acting, high burn rate solid motors which ensures that Crew Module along with crew is taken to a safe distance in case of any emergency either at launch pad or during ascent phase.(UNI)
