Hampton expected to spend most of Tuesday undergoing the physical, with a formal announcement, assuming all goes well, arriving Wednesday.
The left-hander pitched for the Astros from 1995-99 and enjoyed a career year in '99, when he won 22 games and finished second in National League Cy Young Award voting, behind Randy Johnson.
Hampton is hoping to recapture some of that magic during his second tour with Houston. He'll also look to focus on contributing a full season of 30-35 starts.
"If I can pitch 200 innings, everything else will fall into place," he said.
Hampton, 36, has battled injuries for the past several years, including a strained left oblique, a torn flexor tendon in his left elbow and a strained hamstring. With the Braves last year, however, he put together a solid late-season run, going 3-4 with a 3.85 ERA over 12 starts.
Hampton's 2009 salary would be based largely on incentives, which protects the Astros in case he is again bitten by the injury bug. Hampton, however, is reveling in the idea of returning "home." Although he's originally from Florida and makes his year-round home in Phoenix, Houston has always been special to him.
"It's a place I want to play, it's closer to my house in Phoenix and [the Astros have] shown an interest in me ever since the GM Meetings," Hampton said. "It's great to have that feeling. The last three years have been tough for not only me but [also] for my family. To be able to come to a place that's comfortable to me and my family makes it all that much more special."
As he left the airport, Hampton was cautiously optimistic.
"Until everything's out of the way, before I sign my name on the paper, it is what it is," he said. "Then I'll have a chance to get excited about it."