The Next Generation Mass Memory Unit (MMU-NXT), developed with funding from ESA’s General Support Technology Programme (GSTP), is a high-performance onboard data storage system designed for future space missions requiring increased storage capacity and data throughput. Aimed at exceeding the capabilities of current mass memory units, MMU-NXT features a modular architecture with two cold-redundant halves. It is comprised of the Mass Memory Module (MMM) and Command and Control Module (CCM).

At the core of MMU-NXT are advanced technologies including the Versal AI Core ACAP XQRVC1902, which acts as a high-speed NAND flash controller and interface hub, and the Microchip RTG4 FPGA, responsible for managing SpaceWire routing and monitoring of the Versal device. A LEON3FT Soft-IP processor provides onboard command and control managed by the CCM.

The system supports up to 53 Tibit (BOL) of non-volatile NAND storage and incorporates 8 GiBytes of DDR4 memory (gross) as a data buffer. It achieves a maximum aggregated data rate of 20 Gbps, with SpaceWire operating up to 200 Mbps and SpaceFibre links supporting up to 6.25 Gbps data signaling rate. Interfaces include multiple SpaceWire and SpaceFibre ports for instrument data and downlink, a WizardLink interface for data input, and a redundant SpaceWire link for command and control and time synchronization.

By integrating state-of-the-art FPGAs and high-speed data links, MMU-NXT will offer a significant advancement in mass memory unit performance, making it a key enabler for data-intensive space applications.