I know is was shown back in 2004 but for those of you that may have missed it, The Scramjet.
Looking through the NASA research content
http://www.nasa.gov/missions/research/x43-main.html I came across loads of info, I cannot believe, 7000mph! Im so amazed.
Ive missed the amount it cost to build, so if anyone comes across it, I would like to know... Hey, I may buy one as I didn't want the Ipad
