Delta IV Heavy launch video rockets, secrets, spacecraft, youtube Add comments Aug 282013 Quite good video quality. [youtube Ja1Fi_xPdEQ] Anonymous I’ve not seen a video of a Delta IV before. I’m curious, what’s with the inconsistencies of the flame (brighter flashes)? Just a little extra fuel from time to time? Also, is it just a reflection or some such, or is there really a flame on the bottom of the rocket, above the nozzle bell? Anonymous > brighter flashes My guess: the engine bells are coated with an ablative material. The flashes may be specks of the stuff coming loose and being consumed. > is there really a flame on the bottom of the rocket Yes. Not uncommon for flames to lurk in this region of launch vehicles, superheated gases and actual ongoing combustion trapped in a recirculation zone. Adam Holtz You are correct with regards to ablative material. http://en.wikipedia.org/wiki/RS-68 publiusr The SSMEs also burn LH2, but the near trnslucent mach cones/diamonds are the only giveaway. The yellowish tint to the RS-68’s flames here is probably fom the abalatives. Now is it just me, or did it look like this D-IV H left the pad a bit more quickly this time? Anonymous Ah, thanks for the info! Grif Ingram Scott, just a “heads-up”: this site: http://theunwanted.wordpress.com/ is stealing your name! Grif Ingram Jim R. Sweet video. Thanks.