Btukfyl

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.

This is John Varley's Red Thunder, written in 2003. Description from Wikipdia:

The book's protagonist is Manny Garcia, a teenager who is fascinated by space flight. He, along with his girlfriend Kelly, his best friend Dak, and Dak's girlfriend Alicia, are partying on the beach one night and almost run over a man who has passed out from drinking. The man is Travis Broussard, a former astronaut who was forced to retire in disgrace. Travis lives with his cousin Jubal, who is mentally deficient in some ways, but is also a scientific genius.

Jubal has invented a device called the "squeezer", a spherical impenetrable silver force field that can be formed or have its size changed with no cost of energy. Thus, the squeezer can compress whatever matter is within it to an arbitrarily small volume and then vent the resulting plasma/energy in a controlled way. Travis and the teenagers realize the device has numerous practical uses, but it is also a dangerous weapon. They decide to use the squeezers to power a spaceship and plan to arrive at Mars ahead of the slower traveling American and Chinese missions already in transit, and to be available should Jubal's prediction of problems with the American drive prove true.

So we have Jubal, who has some aspects of being an autistic savant; the 'squeezer' which can enclose and compress matter (air is matter); and squeezer bubbles used as propulsion mechanism for a trip to Mars. In the book one of the other mars missions has technical difficulties and the protagonists provide a rescue.