I read a book about 10-15 years ago and if I remember correctly the title started with either Red or Blue, but I've been unable to find the rest of the title.
It was about a 'special' guy who invented a way to twist space-time into bubbles and then change the size of the bubble with essentially no effort... then, by untwisting the end, this super compressed matter would generate a rocket of essentially free power.
He works with some other folks, including a (retired?) astronaut.
They test it by putting one out in the Florida Everglades and when it takes off insanely fast the military sees it (thinking it might be an ICBM or something).
Eventually they build what I would best describe as a redneck space ship to rescue a crew en route to Mars who had a ship malfunction and were doomed without this new, free-energy drive.
It ends with them describing a new world where an international organization controls access to these essentially free energy sources, to prevent nations from trying to use them for war.