The spectacle of a mammoth rocket ‘breaking the surly bonds of Earth’ takes our breath away. Equally amazing are the secrets revealed to us by science missions these rockets have launched – and NASA puts careful thought into what kind of mission will best achieve that science. Sometimes a large, multi-instrumented mission on a giant rocket is the best way to go. But other missions are better suited to a smaller, less expensive rocket as the key to getting a quick answer to a tightly focused science question. Like a sounding rocket. A sounding rocket is an instrument-carrying rocket designed for research, such as taking measurements and performing scientific experiments during a sub-orbital flight.