Talk:Hypersonic Flight Experiment

Tidying up and adding more content
With RLV-TD HEX test flight news coming much more frequently now this might be a time to make any relevant pages neater. I have been noticing a lot of speculation has crept in as facts in articles related to RLV-TD. Less speculative references to Avatar fully Reusable launch vehiclecould be a good step as there are no official ISRO references to that. Also HEX is for 'Hypersonic Experiment' and not 'Hypersonic Flight Experiment'. Also since HEX has nothing to do with air breathing technologies or its development status, any info/updates related to that should be kept on Reusable Launch Vehicle-Technology Demonstrator. These are very significant tests and wiki should reflect that. Ohsin (talk) 21:23, 15 March 2016 (UTC)

Clarify 2nd stage - not dummy
Article says 2nd stage was "dummy" yet later it says it navigated and steered - so not a dummy - just unpowered ? - Rod57 (talk) 20:10, 29 June 2020 (UTC)
 * Yes, RLV-TD HEX01 winged flight article aka TDV had active control surfaces (rudder, elevons) as well as twelve RCS thrusters but apart from that no other main engine to provide any thrust. Ohsin  16:37, 30 June 2020 (UTC)
 * thanks, I've replaced 'dummy'. - Rod57 (talk) 14:16, 5 July 2020 (UTC)

What thermal protection system
What thermal protection system ? Why didn't they try to recovery the test article to see how the TPS survived ? - Rod57 (talk) 20:39, 29 June 2020 (UTC)
 * TDV uses 600 or so heat resistant silica tiles and Flexible External Insulation, nose-cap is made out Carbon-Carbon composite with SiC coating. The leading edges of twin rudders are Inconel-718, wing leading edges of 15CDV6.  Here are few articles covering the subject based on official presentations and papers.   On recovery aspect we have to keep in mind there were no airbags or chutes on TDV as it wasn't expected to survive the planned high speed simulated landing on 'virtual airstrip' over water. After the HEX01 mission was declared success a news report leaked with a detail that TDV survived and was floating on sea surface.

"Sources told the Express that a coast guard helicopter which was employed by the ISRO located the RLV-TD floating in the sea around 20 minutes after the splashdown. The coast guard reportedly took the pictures and sources said the vehicle didn’t suffer major damage as against the popular view that the winged body will disintegrate at the point of touchdown.

“It would have been recovered, if planned. Since the mission didn’t involve recovery as one of the objectives, the vehicle will die the natural death. We were told by coast guard personnel onboard the helicopter that the RLV-TD was in one piece and floating. They also informed that there were strong tides threatening to drown it,” a senior ISRO official told Express."


 * This report was later heavily updated with above information mysteriously removed.. As far as we know no recovery was planned and occurred even though a reasearch vessel of NIOT caled' Sagar Manjusha was nearby the splashdown area. Ohsin  17:11, 30 June 2020 (UTC)
 * Another report quoting then VSSC Director K Sivan.

""We have located the place where the vehicle is floating. The landing was soft as the vehicle was intact and did not break up on impact," Sivan claimed."

Ohsin 18:10, 30 June 2020 (UTC)


 * many thanks, I've put the first part of that in the article as a starter if you want to amend. - Rod57 (talk) 14:26, 5 July 2020 (UTC)