During Star Trek TNG's 1st season, Denise Crosby signs up to reprise the role of Tasha Yar for a second season and the producer did not kill Tasha Yar. Gates McFadden decided to leave Star Trek TNG to replaced by Diana Muldaur during season two. After season two, Diana Muldaur signs up to reprise the role of Dr. Pulaski for the third season. Paramount Pictures decided to make additional seasons for TNG until it ended in 1996. Star Trek: Deep Space Nine aired in 1993 with Colm Meaney reprised his role as Chief O'Brien and Ro Laren joining DS9 cast, the pilot episode is about a Cardassian emperor (Miguel Ferrer) seeking help from Commander Sisko and his new crew of the space station to prevent the Cardassia from being destroyed. In 1996, on the United Paramount Network, the new station that