Task: Question Understanding
Input (English): Context : At GenCon 22 in 1989, Erick Wujcik introduced James Wallis to Kevin Siembieda of Palladium; the result was Wallis' entry into the world of RPG supplement publication through Mutants in Avalon (1990) and Mutants in Orbit (1992). 
Question : Which series is Mutants in Orbit apart of?
Output (English): series