Can you explain how reusable launch vehicle works?
Like to some altitude RLV and from their using boosters?
DETAILS OF RLV-TD:
Introduction
ISRO is developing fully Reusable Launch Vehicle (RLV) technology for two stage to orbit (TSTO) capability.
The first stage will be powered by a semi cryogenic winged booster capable of flying back and landing on a runway near the launch site like a conventional aircraft after burnout.
The second stage will be cryogenic. It will deliver the satellite into orbit, de-orbit and re-enter the atmosphere and parachute down to a soft landing on balloons.
The RLV has been conceived by ISRO as a space launch system that will significantly cut down launch cost from the present level of around $12,000 / kg.
RLV-TD
As a first step towards developing TSTO capability based on RLVs, ISRO will flight test a Reusable Launch Vehicle - Technology Demonstrator (RLV-TD) that will serve as a flying test bed to evaluate various technologies viz., hypersonic flight, autonomous landing, powered cruise flight and hypersonic flight using air breathing propulsion.
ISRO displayed a scale model of the RLV-TD at Aero India 2009.
The RLV-TD will possess wings and tail fins, and will be launched atop a 9 ton solid booster called S-9, similar to the ones on the PSLV.
RLV-TD is reported to be 9m long, with its wing span also measuring 9m.
Design Approval
On January 5, 2012, DNA reported that the National Review Committee had approved the design of the RLV-TD.
An Isro official said design-related issues have been addressed and presented to the National Review Committee and clearance obtained to go ahead to build the RLV-TD.
Wind Tunnel Tests
ISRO has a hypersonic wind tunnel facility at VSSC, Trivandrum installed by Hind High Vacuum (HHV) Bangalore. The system comprises three Horton Spheres, each 16.3m dia. and 2200 cu m capacity. The system has two parallel pumping trains, each with two mechanical booster pumps with pumping speed of 30,000 cu m / hr backed successively by a 14,000 cu m / hr and 7,000 cu m / hr booster pump and finally by three rotary piston pumps, each with a pumping speed of 1325 cu m / hr.
As in January 2012, the facility was in the process of being commissioned.
Phased Development
Reusable Launch Vehicle technology will be developed in phases through a series of trial flights.
The first in the series of trials is the hypersonic flight experiment (HEX) followed by the landing experiment (LEX), return flight experiment (REX) and scramjet propulsion experiment (SPEX).
Hypersonic Flight Experiment (HEX)
Flight testing will start with RLV-TD (HEX). During the mission, a booster rocket will take the RLV to a specific altitude and release it. The booster rocket will fall back into the sea. The lofted RLV will re-enter the atmosphere independently and be guided for a controlled landing in the sea.
In the first trial-flight, the RLV will not be recovered from sea because it will not be cost-effective to do so. ISRO will instead use telemetry data data on the re-entry, deceleration and return.
Landing Experiment (LEX)
In the second phase RLV will be tested without its scramjet engine. After burnout, the booster will separate and fall away, and the RLV-TD will go on to make an unpowered ascent.
The RLV-TD will then re-enter the atmosphere at hypersonic speed and use aerodynamic breaking to decelerate. It will be brought to a gliding, unpowered cruise speed of about 0.8 mach, and slowed down further to make a horizontal landing.
Return Flight Experiment (REX)
In this phase, the RLV-TD will be launched to orbit and then de-orbited for a landing on a runway.
Scramjet Propulsion Experiment (SPEX)
Eventually, the RLV will be powered by an air breathing scram jet which is being developed under a separate project called Advanced Technology Vehicle (ATV).
Target Completion Date
When initially announced, it was hoped that RLV technology will mature by 2015, by which time the solid rocket booster capable of being recovered and reused would have been developed, as also the scramjet engine to power the RLV.
In June 2011, ISRO Chairman Dr. Radhakrishnan indicated that the program is behind schedule.
First flight of RLV, initially planned for 2010-2011 will now take place in 2012-2013.
“We have to understand a gamut of technologies and also prove many new systems. We have to study the aerodynamics of a winged body, the auto pilot, the aero-thermo dynamics, thermal protection system, the de-boost operations for re-entry, navigation and guidance to land precisely on the ground. Of course, some of the lessons learnt from the space shuttle will be incorporated in this vehicle,” Dr. Radhakrishnan said.
Reusable Launch Vehicle - Technology Demonstrator (RLV-TD) - Indian Space Projects