ISRO’s RLV-TD (Technology Demonstrator) is one of the most challenging endeavours towards developing essential technologies for a fully reusable launch vehicle to enable low-cost access to space.

The configuration of RLV-TD is similar to that of an aircraft and combines the complexity of both the launch vehicle and the aircraft.

The winged RLV-TD — configured to act as a flying test bed to evaluate various technologies, including hypersonic flight, autonomous landing and powered cruise flight — will be scaled up in the coming years to become the first stage of India’s reusable two-stage orbital launch vehicle.

The RLV-TD, however, is not the first such launch vehicle. Government and private players worldwide have experimented with partial and fully reusable technology for their launchers for cost-effectiveness and efficiency.

Blue Origin’s New Shepherd is an example of a functional reusable launcher that undertook a sub-orbital flight in 2015. SpaceX’s Falcon 9 is a two-stage reusable rocket capable of transporting crew and cargo to the International Space Station.

The Indian launcher has a fuselage (body), a nose cap, double delta wings, and twin vertical tails. It also features symmetrically placed active control surfaces — elevons and rudder.

This technology demonstrator was boosted to Mach-5 by a conventional solid booster (HS9) designed for a low burn rate.

RLV-TD Launch Sequence
Senior ISRO scientists said that selecting materials like special alloys, composites, and insulation materials for developing an RLV-TD and crafting its parts is a complex process demanding highly skilled manpower.

In May this year, the Indian space agency conducted the second landing experiment for Pushpak, RLV-LEX-02, at the Aeronautical Test Range (ATR), Chitradurga, Karnataka.

The RLV-LEX-02 demonstrated the autonomous landing capability of RLV from off-nominal initial conditions at release from the helicopter. In the test flight, the RLV undertook challenging manoeuvres with dispersions. After corrections of the cross-range and downrange, it landed on the runway in fully autonomous mode.

The space agency conducted the first landing experiment, RLV-LEX-01, with a scaled-down version of the RLV-TD last year. Once the aircraft attained the predetermined pillbox parameters covering position, velocity, altitude, etc., during the demonstration, based on the RLV’s mission management computer command, it was released mid-air at a down range of 4.6 km.

“Developing a technology from scratch takes time. We are progressing at a good pace, and in a few years, we will be able to launch missions on an Indian-made RLV,” Somanath said.

(With Agency Inputs)