4 posts • joined 5 Sep 2008
As I understand it from reading the NASA article:
As the external tank empties a vacuum is created above the liquid hydrogen left in the tank this cannot be vented to air for obvious reasons. The engines convert some of the liquid hydrogen fuel to gaseous hydrogen and return it to the tank to equalise the pressure.
I believe they are in colour as the images on the site show earth in colour and this image has text indicating that it is in colour:
I'm sure they own a rainforest or two to offset the odd launch here and there
floating eyes, lol