When Nick's conman father suddenly reappears, Jess tries her best to fix the two men's relationship, despite Nick's fears that he's being used.
Howard Wolowitz crosses over into the final frontiers of space…and marriage on the fifth season finale. When Howard and Bernadette decide they want to be married before his NASA space launch, the gang rushes to put on a wedding. NASA Astronaut Mike Massimino guest stars as Himself.
Sheldon intervenes when he learns that Penny is thinking about breaking up with Leonard, but he is hampered by his inability to keep a secret. Meanwhile, in space, Howard is being picked on by the other astronauts.
Howard gets caught in an argument between his mum and Bernadette while at the International Space Station. Meanwhile, Ray is feeling lonely so Sheldon invites him along to his second anniversary date with Amy.
Amy is jealous when Sheldon hires an attractive female assistant named Alex. However, it turns out that Alex is more interested in Leonard, which makes Penny feel threatened.