Miniature Exercise Device (MED)

Current exercise technology requires large mass or bulky equipment (e.g. approximately 2,200 lbs/160 ft3 operational volume for the ISS Treadmill or 1,200 lbs/228 ft3 operational volume for the Advanced Resistive Exercise Device (ARED)) to provide adequate exercise countermeasures for the on-orbit crew.  Some of the greater risks identified in the Human Research Roadmap for Lunar, Mars and Near Earth Asteroid exploration missions have identified the need to prevent the loss of muscle mass, strength and endurance and to maintain adequate aerobic capability through fitness.  The future exploration vehicle and destination will determine the contextual space and mass limitations for any exercise equipment to keep the crew healthy.  Based on previous program requirements assessments which have addressed balancing the competing system priorities, exercise equipment will need to be an order of magnitude (or more) smaller and lighter yet similarly effective as the ISS equipment so as to aid in maintaining crew health during further space exploration.

The Miniature Exercise Device (MED) development approach is to design with the end usage in mind so as to minimize future rework.  During the design, testing and evaluation, the team continues to work closely with the NASA countermeasures and human physiology specialists to ensure appropriate testing criteria, protocol designs and exercise interfaces. With the ISTAR program as an infusion sponsor; ISS authorized the development and evaluation of MED-1 (Proof of Concept Unit) at the 2013 SEATEST2 exploration analog.  This test proved the concept that cable driven exercises could be performed by a small-volume device.  Valuable feedback was received related to noise levels, operational space, and user interfaces that are being incorporated into the design of MED-2. MED-2 is currently being sponsored by JSC as a payload ready to fly to the ISS by the end of 2015.  With ISS funding and the MED-1 prototype evaluation, the team is developing MED-2 as a flight unit leveraging off of existing Robonaut, T61P, and ARED materials, safety and software certification, and the new JSC payload development process to minimize implementation costs and certify MED-2's aerobic (rowing) and concentric resistive exercise capability within the microgravity environment of the ISS.  The results of this evaluation and testing will inform future design trades between vehicle volume and exercise feasibility for exploration vehicles including MPCV. The subsequent plan is to seek Human Research Program (HRP) and ISS funding to continue using MED-2 (Flight Unit) on the ISS to evaluate and certify additional exercises, certify eccentric overload capability, continue extensive exercise data analysis, and design/develop/certify/deliver supporting hardware including force shoes and a bar and/or harness attachment to enable squat and heel raise exercises.  Based on these evaluations further design refinements would be incorporated into MED-3 and available for subsequent exploration use.