In a matter of weeks, the couple will bid farewell to their home, their family and their friends as they take to the open seas aboard the Tahina, a 50-foot long catamaran the Taylors purchased in August 2008.

If all goes according to plan, the Taylors won't set foot on U.S. soil again until at least the fall of 2014.

"I've turned our vacation into more than just a vacation," said Frank Taylor, who describes himself as a serial entrepreneur. "I just have a way of doing that. But it's kind of cool in that I converted our trip into an expedition."

And it's largely born from his love of Google, the popular Internet search engine.

Frank Taylor runs a popular Google Earth blog that explores new features of the interactive, three-dimensional atlas. During the next five years, the Taylors will spend a portion of their travels using both aerial and underwater cameras to take high-resolution photographs of remote parts of the world, both on land and at sea.

Partnerships with Google and VideoRay, a Pennsylvania-based producer of remote-controlled underwater cameras, will allow people to watch the Taylors embark on their five-year journey around the world.

The images will be incorporated into the Google Earth software to help shed light on parts of the world unseen by most people.

The idea for the Taylors' grand adventure began during their days at NASA's Johnson Space Center in Houston, Texas, where the couple met.

Frank spent about eight years developing computer graphics for NASA's three-dimensional visual simulations that prepare astronauts for space travel. Karen worked in software development and design.

The NASA job was a perfect fit for Frank. "It was fantastic because I wanted to be an astronaut and go into space," he said.

The Taylors eventually had twin daughters, and in 1993 they decided it was time for a change of scenery. They moved to Cary to be closer to their North Carolina relatives.

Frank started his own business, an internet consulting company. In 2002, he and Karen decided to take some time off. They packed up the kids and spent the next year sailing in the Caribbean.

That's when the travel bug struck. And it packed a punch.

Karen Taylor liked the sailing lifestyle, and the couple relished the experience of visiting exotic locations. "It's a lot more relaxed," she said. "And you get to see all kinds of different cultural things, the way people live."

Upon their return in 2003, the Taylors began to prepare for their upcoming journey. They promised their children they would wait until the girls finished their freshman year in college, Frank said, "to give them a year to get settled in."

In the meantime, Frank schemed about starting an online publishing company in 2005.

But first, he needed an idea. That's when he stumbled upon Google Earth, and instantly fell in love with it.

Taylor started the Google Earth Blog, gearthblog.com, to discuss new features as they are added to the program.

Taylor said his blog has since become a huge success, drawing up to six million visitors each year and helping him forge a relationship with Google he hopes will advance the product while earning him some money to offset some of the costs of circling the planet.

Karen Taylor said she and her husband hope to document the condition of the world's oceans, focusing on the fragility of coral reefs. They became impassioned about the issue while snorkeling in the Tobago Keys in the eastern Caribbean.

"We've since been back to the Virgin Islands and saw how [the coral reefs] had really declined," she said. "We just thought that was so unfortunate, and decided that anything we could do to help document what's going on would be useful."

The Taylors are excited about the educational element of their journey. But Frank vowed to his wife that their trip wouldn't be all work and no play.

"I'll be spending lot of time blogging and playing with toys," he said. "But I promised her that we'll still have fun."