Season 8, Episode 17 - The Colonization Application
Aired March 5, 2015
As Sheldon and Amy take a step forward in their relationship and choose to buy a pet turtle, Amy is angered to learn that Sheldon has applied for a one-way mission to colonize Mars without discussing it with her.
Meanwhile, Leonard and Penny take a step forward in the bedroom when Leonard makes an adult purchase, while Raj worries about Emily's reaction when she finds out he's been snooping in her apartment.
Season 9, Episode 18 - The Application Deterioration
Aired March 10, 2016
Leonard, Sheldon, and Wolowitz run into problems when they file for a patent for their infinite persistence gyroscope. Also, Penny, Amy and Bernadette give Koothrappali dating advice when Emily reaches out to him after their breakup.