AFS alum Sierra Lanfranco ’13, who is studying mechanical engineering at Boston University, returned to campus to talk with students in Upper and Middle School science and computer classes. In Jordan Burkey’s ninth grade Physics G class, Sierra described projects she had worked on in college and explained some of the basics of engineering design. Then she challenged the students to build the tallest free-standing tower that could hold a marshmallow on top. But they had to do it at the lowest cost.

The building materials included 20 pieces of uncooked pasta, which “cost” $50 a piece, and fettuccini, which is thicker and more expensive, at $75 a strand. Jordan said the students brainstormed, sketched their designs and performed a cost-analysis before building their towers. The winner was the team with the tallest and cheapest tower that carried a marshmallow on top.

Jordan said he remembered Sierra as a top student in his Honors and Advanced Physics classes, who was conscientious, funny and usually pretty quiet. “But that is not who came back to visit,” he said. “She is now a very capable young scientist, a confident public speaker and soon-to-be mechanical engineer.”