2. 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.
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4. ABOUT 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.
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6. 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.
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8. 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.
9. 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).
10. 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 on the re-entry, deceleration and
return.
11. 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 perform a range maneuver at 15-km, a 2g turn towards its launch site.
Once the TD reaches 0.8 M, it will light up a turbofan engine to cruise back
to its launch site at 0.6M and make a horizontal landing on a runway.
12. OTHER EXPERIMENTS
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 Air
Breathing Propulsion Project (ABPP).
13. DEVELOPMENT PROGRESS
Major highlights of RLV-TD during the year include completion of major actions identified by the
National Review Committee during the Integrated Technical Review (ITR) of hypersonic experimental
flight (RLV-TD HEX-01). Mission analyses on the design of trajectory, autopilot and guidance have been
completed.
The Avionics Bay powering for the Avionics packages in the Technology Demonstrator Vehicle (TDV)
was carried out through Checkout System and On-Board Checkout Computer (OBCC). The second
phase of the full scale Flush Air Data System (FADS) model was successfully tested and validated at the
Wind Tunnel Facility, IIT, Kanpur with modified algorithms and recalibrated sensors. Radar Altimeter
along with antenna was also validated through a Balloon test at Tata Institute of Fundamental
Research (TIFR), Hyderabad and the capability of the system has been demonstrated.
Trial assembly of Thermal Protection System for qualifying the bonding procedure and trial assembly
of Booster with Interstage and TDV have been completed. The realization of the flight hardware and
its assembly and integration is in progress. The launch of RLV-TD HEX-01 mission is planned in 2014.
ISRO has announced that it will test the RLV-TD in 2014.