Microsoft billionaire Charles Simonyi, the leading developer on the Microsoft Word and Excel programs, plans to be the fifth space tourist and the 450th person to orbit the Earth.

Simonyi, now 58, will set off for the International Space Station on 9 March 2007 aboard a Russian-built Soyuz TMA-10 spacecraft.

Speaking at the Museum of Flight in Seattle, Simonyi revealed plans to document his training and experiences on his Charles In Space website.

Part of the Space Adventures project, which most recently sent US entrepreneur Anousheh Ansari on a tour in space, the trip is expected to set Simonyi back around $25m.

According to Space.com, the upcoming flight is the culmination of a lifelong interest for Simonyi who was selected as Junior Astronaut in his native Hungary when aged just 13.

Simonyi is also reported to have racked up more than 2,000 hours piloting jets and helicopters.

He will dedicate the mission towards the advancement of civilian spaceflight while serving as a test subject for biomedical experiments.