The environment of zero gravity affords a unique medium for new modalities of musical performance, both in the design of instruments, and human interactions with said instruments. To explore this medium, we have created and flown Telemetron, the first musical instrument specifically designed for and tested in the zero gravity environment. The resultant instrument (leveraging gyroscopes and wireless telemetry transmission) and recorded performance represent an initial exploration of compositions that are unique to the physics and dynamics of outer space. We describe the motivations for this instrument, and the unique constraints involved in designing for this environment. This initial design suggests possibilities for further experiments in musical instrument design for outer space.