![Andrew Rader on Twitter: "Space Shuttle tiles were made of silica glass (i.e., sand) more than 90% air by volume, so poor at conducting heat they'd be safe to touch. https://t.co/kRlIfZXK5N" / Andrew Rader on Twitter: "Space Shuttle tiles were made of silica glass (i.e., sand) more than 90% air by volume, so poor at conducting heat they'd be safe to touch. https://t.co/kRlIfZXK5N" /](https://pbs.twimg.com/media/DF3LWptUMAE6A2u.jpg)
Andrew Rader on Twitter: "Space Shuttle tiles were made of silica glass (i.e., sand) more than 90% air by volume, so poor at conducting heat they'd be safe to touch. https://t.co/kRlIfZXK5N" /
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Silica Grey 2x4 Swell Vitrified Floor & Wall Tiles at Rs 55/square feet | Vitrified Floor Tile in Hyderabad | ID: 25981858088
![Dr. Phil Metzger on Twitter: "Another interesting fact: a lot of the darker, new tiles (the replacements) are located over antennas, which we sometimes used as convenient access points for airframe structural Dr. Phil Metzger on Twitter: "Another interesting fact: a lot of the darker, new tiles (the replacements) are located over antennas, which we sometimes used as convenient access points for airframe structural](https://pbs.twimg.com/media/FT2vd-7WAAIlUxv.jpg)
Dr. Phil Metzger on Twitter: "Another interesting fact: a lot of the darker, new tiles (the replacements) are located over antennas, which we sometimes used as convenient access points for airframe structural
![Silica heat tiles glow after being removed from the oven. Temperatures within the cubes can reach 2,000 degrees. Photo Credit: Mike Deep / SpaceFlight Inisder - SpaceFlight Insider Silica heat tiles glow after being removed from the oven. Temperatures within the cubes can reach 2,000 degrees. Photo Credit: Mike Deep / SpaceFlight Inisder - SpaceFlight Insider](https://www.spaceflightinsider.com/wp-content/uploads/2016/11/8352-thermal_protection_system_facility-michael_deep.jpg)