Mass memory systems based on erasable optical disk media are expected to play an important role in the Space Station era of the 1990's and beyond. Substantial work is already underway in both media and disk memory development. NASA has initiated investigation of spaceborne applications, and has begun definition of optical disk mass memory system controller requirements. This work is closely coupled with a multi-agency Government program to develop an erasable optical disk buffer memory1; program goals are one terabit (10 to the 12th bits) capacity, at up to 1.6 gigabits per second transfer rate. Current status of the NASA investigations is reported, including discussions of potential applications and the implications of environmental considerations, self test and reconfiguration philosophy, multi-user network interfaces, and variable (changeable) input/output data rates, all associated with the potentially unique usage in space flight. A baseline optical disk memory system architecture is included as a starting point to indicate interfaces. The role and applicability of interface standards such as SCSI and IPI are addressed. Finally, issues and technologies considered critical to space-flight optical disk usage, and requiring continued research and development, are presented.