TDA Research proposes to develop a computer-controlled lightweight and compact device for aerobic and resistive training (DART) to counteract muscular atrophy and bone loss and to improve the overall wellness of astronauts operating in microgravity. The DART will be able to provide resistive loads up to 350 lbf and will accurately simulate the load profile of a mass in a 1-g environment. It will also be capable of applying custom load profiles such as eccentric overloading. In aerobic training mode, the DART will simulate the loads of a rowing machine with loads up to 175. The system will computer-controlled and can automatically calibrate to a user's range of motion. The total weight of the device will be less than 20 lbs and have a compact form factor to enable integration into a small crew module. By using a regenerative energy recovery system, the average power consumption of the DART will be less than 100 W during an exercise session. TDA is able to build on previous experience building exercise equipment for NASA and develop the DART in a short timeframe. TDA will prove the feasibility of providing effective aerobic and resistive training with a single device that is lightweight and compact in Phase I. At the end of Phase I a prototype will be delivered to NASA for evaluation. In Phase II we will advance the technology and provide the second generation prototype to NASA for testing on the International Space Station.