India’s private space sector is witnessing a bold leap as Bangalore-based Ethereal Exploration Guild (EtherealX) develops Pegasus, a reusable upper-stage engine for its Razor Crest MK-1 launch vehicle, introducing a novel Full Flow Segregated Cooling Cycle (FSCC) that uses re-entry heat to enhance propellant enthalpy.

This innovation, combined with recent funding and ambitious test schedules, positions EtherealX as a serious contender in the global reusable launch race.

EtherealX has designed Pegasus as a reusable upper-stage engine, central to its Razor Crest MK-1 medium-lift rocket. The FSCC cycle is unconventional, relying on re-entry heat to increase propellant enthalpy and transfer that energy to oxygen, which in turn drives the turbine.

This approach eliminates the need for a pre-burner, a departure from traditional staged combustion cycles, and represents a significant engineering gamble.

The company has teased an 80 kN dual-thrust-chamber Pegasus configuration, showing how the propulsion system is evolving. Earlier Pegasus hardware was described as a semi-cryogenic thrust chamber assembly delivering 40 kN thrust with a targeted 293-second sea-level specific impulse.

The latest specifications now indicate 80 kN thrust, 100 bar chamber pressure, and 323 seconds vacuum-specific impulse, running on RP-1 and liquid oxygen. EtherealX claims combustion efficiency above 99%, a figure that, if validated in hot-fire tests, would surpass most conventional designs.

Pegasus is notable for being the world’s first RP-1/LOX thrust chamber assembly running on an expander-type cycle, a feat previously thought impractical due to kerosene’s tendency to crack under heat.

EtherealX’s solution involves regenerative cooling channels that absorb thermal energy during re-entry, vaporising and pressurising propellants before injection. This innovation could redefine expander-cycle applications beyond hydrogen-based systems.

The company has raised significant funding, including a ₹170 crore Series A round led by TDK Ventures and BIG Capital, following a ₹41 crore seed round. Its valuation has surged to over ₹680 crore, reflecting investor confidence in its reusable launch ambitions.

EtherealX plans hot-fire tests of Pegasus and its 1.2 MN Stallion booster engine by mid-2027, with a technology demonstration flight targeted for late 2027 and commercial missions by 2028.

EtherealX’s Razor Crest MK-1 is designed to return both booster and upper stage, unlike partially reusable systems such as Falcon 9.

Payload capacity is projected at 24.8 tons to LEO and 10.8 tons to GTO, with launch costs aimed at ₹41 lakh per kilogram, a disruptive benchmark in global space access. The company is building infrastructure at BASE-001 in Cuddalore, Tamil Nadu, for Pegasus testing, and BASE-002 in Andhra Pradesh, for integrated stage and booster qualification.

The FSCC cycle also enables EtherealX to attempt upper-stage recovery without a heat shield, a radical departure from conventional designs. By treating re-entry heat as an asset rather than a threat, the company hopes to achieve full reusability at lower cost and higher flight cadence.

If successfully developed and flight-proven, Pegasus and its FSCC technology could become a cornerstone of India’s private reusable-launch ecosystem.

Alongside other players like Skyroot Aerospace, Agnikul Cosmos, Abyom SpaceTech, and Astrobase Space Technologies, EtherealX is helping India push towards a ₹3.7 lakh crore space economy by 2034, ensuring the nation remains competitive in the global race for sustainable and cost-effective launch solutions.

Agencies