newstodaynet.com May 31, 2016
The low-down on the ambitious RLV
Chennai: While most developed countries have dropped their plans of the building a Relaunch Vehicle (RLV) due to high cost involved, India successfully test launched its indigineous Relaunch Vehicle-Technical Demonstrator (RLV-TD) on 23 May.
This is an effort by ISRO to come up with an economicaly affordable one like Mangalyan. Though still in the making, if successful, it would bring down the cost of space missions by 80 per cent.
Here are some other interesting facts about the RLV and the test.
• In 2009, an airframe engineering model, axisymmetric proto nose cap after graphitisation (Carbon-Carbon material) and slow burn rate propellant were completed.
• Aerodynamic characterisation of technology demonstration vehicle was completed at NAL, VSSC and IIST. Computational flow simulation and supersonic combustion in ground testing were also completed.
• In 2012, ISRO announced that its RLV-TD was approved to be built and tested.
• In May 2015, engineers at VSSC in Thumba installed thermal tiles on the outer surface of the RLV-TD which protects the vehicle from the heat during re-entry into the earth’s atmosphere.
• This prototype weighs around 1.5 tonnes, 6.5 m long and flew to an altitude of 65 km and was mounted on HS9 booster.
• A total of four RLV-TD flights were planned namely the HEX (Hypersonic flight experiment), LEX (Landing Experiment), REX (Return flight experiment), SPEX (Scramjet Propulsion Experiment).
• HEX was the first test that was carried out in May this year. The descent was made at Mach 5 (five times the speed of sound). The total duration from launch to splash down lasted about 770 seconds.
• The peak altitude was expected to be around 65 (+/- 6)km and 64.8 was achieved. Peak Mach number expectation was 4.8 (+/-) 0.6 and 4.78 was achieved. Return Mach number expectation was 3.95 (+/-0.8) and 3.9 was achieved. The splash down point was expected to be 425 (+/-100) km and it was 412 km.
• Vehicles Navigations system, guidance and control system were also tested during this launch.
• The vehicle was tracked from Sriharikota and a ship-borne terminal NIOT, Sagar Manjusha was deployed for this purpose.
• Critical technologies like autonomous navigation, guidance and control, and reusable thermal protection have been validated.
• The RLV-TD was built only as a flying test bed and never was not designed to recover.
• In the next stages of testing, the design will be changed to adjust the landing gears and it will be launched on its own without the booster. There are also plans to increase the Mach number.