Mass memory system based on rewriteable optical disk media are expected to play an important role in meeting the data system requirements for future NASA spaceflight missions. NASA has established a program to develop a high performance (high rate, large capacity) optical disk recorder focused on use aboard unmanned Earth orbiting platforms. An expandable, adaptable system concept is proposed based on disk drive modules and a modular controller. Drive performance goals are 10 gigabyte capacity, 300 megabit per second transfer rate, 10-12 corrected bit error rate, and 150 millisecond access time. This performance is achieved by writing eight data tracks in parallel on both sides of a 14 inch optical disk using two independent heads. System goals are 160 gigabyte capacity, 1.2 gigabits per second data rate with concurrent I/O, 250 millisecond access time, and two to five year operating life on orbit. The system can be configured to meet various applications. This versatility is provided by the controller. The controller provides command processing, multiple drive synchronization, data buffering, basic file management, error processing, and status reporting. Technology developments, design concepts, current status including a computer model of the system and a controller breadboard, and future plans for the drive and controller are presented.