The Defiant Agents: by Andre Norton

The space race has gone interstellar! Western and Soviet agents vie for control of the strategic alien world of Topaz and the lost technology it conceals.Agent Travis Fox awakens on Topaz after a crash landing, his memories a confusing mix of his own and those of a 19th-century Apache ancestor. His fellow agents have all been subject to the same experiment, some more thoroughly entangled in the past than others. Driven by his present-day memories and aided by a pair of mutant coyotes, he se...