How do you write software that needs to perform perfectly a decade from now as it hurtles by an unexplored planet at thirty thousand miles per hour? Welcome to the world --- er, universe :) --- of interplanetary spacecraft flight software, where "launching" your software takes on a whole new meaning. Cosmic rays, constrained memory, execution time limits, and billions of miles between maintainer and program are a few of the challenges we'll explore in this talk. Before running the New Horizons spacecraft as a flight controller for the first-ever reconnaissance of Pluto and Charon, Katie wrote flight software for that spacecraft and one of the scientific instruments aboard a Mercury orbiter. She loves practicing the Way of Tea and mucking about in caves.