Ace Hardcover, 2003
The story is set about 20 years in the future (I'd guess), and is told in the first person by Manny Garcia (about 20 years old). He and his friends stumble across (run over, in fact) a drunken ex-NASA spaceship pilot, and discover that he is one of NASA's best pilots ever, and moreover, that he has an idiot savant brother who has discovered a strange new branch of physics, allowing for the production of force fields. By creating a spherical force field and shrinking it down, it's possible to compress mass to the point where it breaks down into its component atoms, or even energetic plasma -- which can than be released at high pressure, resulting in a cheap and compact energy source, or, if you like, propulsion system. Against all scientific logic, the compressed material is also weightless and massless.
This is happening not too long after the first Chinese mission to Mars takes off -- giving them the chance to build a space ship fast enough to overtake the Chinese and maybe save some American astronauts along the way. But for various reasons, they want to keep their discovery a secret until they have actually taken off. And so the adventure begins, building a spaceship out of old railroad tank cars, with a short deadline, and in deepest secrecy.
It's... different. Not different as in a new and original piece of writing, but different as in it isn't what I expected from John Varley. It's set in the near future. It doesn't have any original ideas about future science and societies. It has unrealisticlly magical science popping out of nowhere. It moves slowly. The narrator's voice reminds me of Spider Robinson or Cory Doctorow (both most excellent writers).
It's an okay story idea -- but nothing really interesting happens. It's another story about amateurs building a spaceship from scratch (good), but it has this miraculous new technology that takes most of the challenge out of it (bad). There's more to the story than what I've outlined here, of course, but nothing spectacular. Trouble with the police, trouble with the kids' parents, trouble with each other ... It's well written, interesting, has good characters, and keeps you involved. But it's also deep into well-covered territory, with nothing new to add.
There are a number of Varley books I enjoyed less than this one (the Titan, Wizard, Demon series and Millennium, for example), but if I were introducing Varley to a new reader, I'd suggest nearly any of them rather than Red Thunder. It's a good book, but it doesn't demonstrate why Varley is a good author.
Red Thunder currently has two sequels, Red Lightning and Rolling Thunder.