We present the concept of a reusable science probe based at the International Space Station (ISS). A wide range of unique scientific and technical investigations will be enabled through the large aperture and high mass capabilities of the platform. The ISS infrastructure is used for servicing the spacecraft and/or scientific instrument, as well as upgrading the scientific payload. During the data gathering phase, envisioned to last six months to two years, the spacecraft will be a free-flyer in the ISS orbit, avoiding operational constraints imposed by the ISS environment and allowing full control of the experiment by the investigation team. Periodic docking with the ISS provides the servicing capability. A limited spare parts cache can be provided by the ISS “mother ship” using excess STS payload capacity to this frequent-flyer destination. By eliminating the need for mission-unique spacecraft and operations infrastructure for a wide range of missions, a tremendous return on investment can be realized