As you may recall, Harper has been involved in a number of notable projects, including Black Hole for David Fincher, Hansel and Gretel: Witch Hunters and All You Need is Jill.
Although little is yet known about Emmerich's plans for Foundation, the director/screenwriter/producer recently went on record as as saying he wants the sci-fi trilogy to be "very different from other science-fiction movies" without "the burden of too big a budget."
Interestingly enough, Robert Rodat (of Saving Private Ryan fame) was originally brought the first writer on the project.
Emmerich went on record earlier this year saying that "the studio's happy with the script," and as SlashFilm's Germain Lussier points out, either this isn't exactly the case or Harper has been brought on to make the project cheaper.
Either way, Emmerich will be shooting another sci-fi film called Singularity before kicking off the Foundation project.
Foundation is the first book in Isaac Asimov's Foundation Trilogy, which was later expanded into The Foundation Series. The novel tells the story of a group of scientists led by Hari Seldon who attempt to preserve knowledge as civilization - which appears stable in the form of a galactic empire - begins to decay.
Seldon - a mathematician and psychologist - has developed a theory of psychohistory predicting the collapse of the Empire within 500 years, followed by a 30,000-year period of barbarism. He is eventually arrested for treason and offers his accusers an alternative scenario: a collapse followed by a period of dark ages lasting no more than 1,000 years.
The price? The establishment of a Foundation dedicated to condensing all human knowledge in a galactic encyclopedia.
Seldon and his band of "Encyclopedists" are subsequently exiled to a remote planet known as Terminus where they begin compiling the Encyclopedia Galactica under an imperial decree.