Hypersonic Flight Experiment

Hypersonic Flight Experiment or HEX will be the first test flight in the Avatar Reusable launch vehicle development program or the RLV-TD Program. It is first in a series of demonstration trials to be carried out by ISRO to validate the design of the Avatar RLV.

The demonstration trials will pave the way for a Two-Stage-To-Orbit (TSTO) fully re-usable Avatar launch vehicle. The Hypersonic Flight Experiment (HEX) is scheduled for launch no earlier than 2012.^[1]

Configuration

• First stage: live, 9 ton solid booster (S-9)
• Second stage: dummy (Scramjet will be used in the future)

Objectives

HEX will be the first test flight of a reusable launch vehicle like the Avatar. The test flight objectives include:^[2]

• Validating the aerodynamic design characteristics during Hypersonic flight.
• Characterize induced loads during the Hypersonic re-entry into the atmosphere.
• Recovery of the HEX vehicle from the sea.
• Assess the performance of the carbon fibre used in construction of the nose of the vehicle.
• Demonstrating First Stage separation sequencing.

Flight

The HEX sits atop a 9 ton solid booster(S-9) which will propel the vehicle to a predetermined altitude. The first stage is then jettisoned and the vehicle re-enters the atmosphere at hypersonic speed. The vehicle gradually glides through the atmosphere and a parachute is deployed. The vehicle is then recovered from the sea.^[2]

Current status

As of 2009, Airframe Engineering model, axisymmetric proto nose cap after graphitisation (C-C) and slow burn rate propellant were realized. Aerodynamic characterization of technology demonstration vehicle was completed at NAL, VSSC and IIST.

Computational flow simulation and supersonic combustion in ground testing have been successfully achieved. Scramjet engine modules (passive) for the DMRJ flight demonstration were realised and alignment / integration with the test vehicle is progressing. Real time decision based ignition of second stage, a first of its kind is ready for implementation in the test flight.^[3]

As of 2010, HEX is scheduled to take place in 2011.^[4]

See also

• Avatar RLV
• Reusable launch system

References

External links

• HEX in ISRO's 2008-09 Annual Report