The Monopolar Expedition

Summary
Howard has designed a special toilet for the International Space Station. He realises that it is going to malfunction and asks the guys to help him fix it. Stuart has another date with Penny and asks Leonard for advice. Leonard gives him bad advice and feels terrible about it. He tries to make things right but discovers that Penny said his name while kissing Stuart.

Critics
"This episode sums up the whole of season two of the show. It’s too reliant on Sheldon, not focussed on character development and too static for my tastes. On the flip side it is also funny, consistent and showcases a genuinely strong comic character." - The TV Critic's Review