We propose to design a compact, high-precision, single-axis accelerometer based on atom interferometry that is applicable to operation in space environments. Our design will emphasize reliable operation and minimization of the acceleration noise floor, bias drifts and scale factor instability. Laser system reliability will be a major consideration in the design. The sensor design will be capable of demonstration and testing on a low-dynamics platform under earth gravity. Phase I will result in block diagrams and detailed 3D CAD models of the sensor head, laser system and electronic control system. We will validate the sensor design by developing error models taking into account variations in environmental parameters. Space-based inertial sensors based on atom interferometry are a compelling technology for both technological and scientific applications because of the exceptionally high performance that can be enabled by long interrogation times with cold atoms in a microgravity environment.