So in the end the rocket that Walter built is used to send his sister Megan's ashes into space. It is interesting to see how much this affects him for the future. The love between Megan and Sylvester made a long lasting impression on Walter. Her death left him emotionally scarred and he could not comprehend this with his logical reasoning. Would that explain why he is so stuck on Paige, afraid of losing her like his sister?

Side Note: Why is it Walter, and not Sylvester , her husband, taking care of Megan's ashes?