When Scott McLennan began his academic career delving into the history of the earth's surface, he never thought he would eventually be joining a Nasa Mars mission.
Now Professor McLennan, from the department of geosciences at Stony Brook State University of New York, is preparing to investigate whether there is life on Mars.
In January 2004, he will join 50 scientists at the Jet Propulsion Laboratory in Pasadena, California. The Mars Exploration Athena Science Team will analyse the data sent back from two robotic rovers that will have been launched towards Mars seven months earlier.
Professor McLennan's interest in the extraterrestrial was sparked by his PhD supervisor in Australia, who was one of the first scientists to study the rocks collected by the 1969 Apollo 11 mission.
He followed the Viking missions to Mars in 1975 and 1976. During 1997's Pathfinder mission, he remembers taking coffee breaks when he and everyone he knew would watch the data coming back on television. "It became clearer that the sort of research I was doing was applicable."
In December 2001, Professor McLennan applied to join the 2004 mission to analyse the surface of the rovers' landing sites.
Among other things, he wants to know the source of Martian water and how the planet's sand dunes developed.
The answers could reveal clues about how Mars changed dramatically billions of years ago.
Next month, he will work with engineers on a secret test mission in several areas of the Earth, mostly deserts.
From the command centre, just as in the eventual Mars mission, Professor McLennan will press the rovers' engineers to look for information.
He said: "There's a good-natured tension between the scientists, who want to push the data, and the engineers, who don't want to break this multimillion-dollar piece of equipment."
After receiving his MSc from the University of Western Ontario in 1977, Professor McLennan earned a PhD from the Australian National University and spent five years there before joining the Stony Brook faculty in 1987.