Saucer - Stephen Coonts

A team of surveyors working in the Sahara happen upon an object buried deep in the rock. The object turns out to be a flying saucer and it is older than the rock it is buried in - 140,000 years old at least.
Rip, a student working with the team is keen to find out as much about the flying saucer as possible. But so are many other people, including the US Military, a team working for a billionaire American businessman and a group of Arabs.
Rip foils their attempts to commandeer the craft with the help of a disillusioned female pilot called Charley. Together they steal the saucer and Charley takes them both into orbit. Rip?s plan is to take the saucer to his uncle?s Missouri farm - but first he has to avoid being tracked down by everyone else.