Loving the series so far. Personally, I find your presentation style is great.

I used your backpack filling method in my online video. Works great and I gave you credit in the video. Never saw that method used before. Awesome!

I'm sure you've noticed, but... I imagine filling up the jetpack tank with hot daytime air is likely not doing you any favors. Colder air would let you fit more moles of gas into your tank, leading to longer flight times (at least, that's what I'd expect - constant mol/s rather than kPa/s)...

its red because its the exterior part if you deselect the interior it should become green.