I started a book, left it on an airplane, and am trying to remember the title. I believe it was the first book of a trilogy. A main unusual ability of some was to get into a "machine" and send a replicated image of themselves on short ventures out. This gave the person some protection over the real person being harmed. It was not earth.
At the end of the first book a very small group was heading out on their planet to find the truth to some mystery.
Sounds very like Farthest Star, by Frederik Pohl and Jack Williamson. It's the first book of two, rather than three, in a series called The Saga of Cuckoo. The replicator technology duplicates people and transmits the duplicate, so the original stays where he was. The main character, Ben Pertin, is from Earth, but one set of duplicates ends up firstly on a doomed ship rushing to investigate an anomaly, and later on the anomaly itself. Pertin gives himself a new middle name for each new duplicate.
Sounds vaguely like David Brin's Kiln People, published in 2002. The main character is a private detective investigating a mystery, and people can use a machine to create clay duplicates of themselves which expire after about a day.
It is not part of a trilogy, however, and isn't specifically set on a planet other than Earth.
