A new radiation measurement system for the realtime measurement of absorbed depth dose and dose-equivalent from space radiation within a phantom is being developed. The head and torso of the “average male” phantom (height 175 cm, weight, 73.5 kg) will be instrumented with active and passive radiation dosimeters and flown as an experiment on a Shuttle mission in 1996. The unique dosimetry system, which utilizes both pulse height analysis and internal data storage, is described. The active systems will be supported with a large number of passive dosimeters (lithium fluoride thermoluminescent detectors and CR-39 plastic nuclear track detectors) distributed throughout the phantom. Previous earlier measurements of space radiation dose distribution within a phantom head are reviewed. Unfortunately, results from both passive and active radiation measurement systems on the head-torso phantom experiment are not yet available.