The Teslarati article SpaceX Falcon 9 Block 5 rocket’s drone ship return captured in stunning detail [gallery] and accompanying photo spread shows many interesting details of "SpaceX’s first West Coast Falcon 9 Block 5 booster recovery in the best detail yet seen of the rocket upgrade, well-worn after its first successful launch of Iridium NEXT-7, July 25."
Of particular note are detailed views of the silky black “highly flame-resistant felt” now covering Falcon 9’s interstage (the top segment), landing legs, octaweb section, and raceways (the black lines traveling up and down the rocket). Compared to beat-up, older Falcon 9s, B1048’s shielded components look barely worse for wear, and it would genuinely be difficult to determine if the rocket had flown before without the telltale soot fingerprint present after every Falcon 9 recovery.
Question: What is the nature of "the silky black 'highly flame-resistant felt'" on Block 5 Falcon 9's and what is its intended function(s)? What are all of the locations where is it applied? Also, could you point out exactly where is it seen in these photos?
