L2-DVT-DIGI CRITICAL PRESERVATION Level 2 · hardware

Digital Server Array

Radiation-Hardened Digital Storage Server Array

The radiation-hardened digital storage server array is a 1,500 kg, 4 m × 3 m × 2 m solid-state platform providing 10 PB of high-speed working storage at 50 GB/s read throughput for active lunar computational systems. Maintaining active solid-state memory on the Moon is complicated by constant exposure to galactic cosmic rays, which trigger single-event upsets and drive long-term total ionizing dose degradation across the hardware's 100-year design lifetime. Furthermore, because the lunar vacuum precludes convective heat transfer, the array must dissipate its 1,200 W thermal load exclusively through structural conduction and thermal radiation while managing distributed triple-parity redundancy across radiation-shielded 3D NAND and MRAM modules.

Active radiation-hardened solid-state server array providing fast random-access to 10 PB of frequently accessed data, serving as the primary working storage for Ark computational systems.

Purpose

Provide high-speed, random-access digital storage for active data operations including knowledge retrieval, system operations, AI processing, and serving as a cache layer between users/systems and the slower 5D quartz archive.

Context

While the 5D quartz archive stores the full 500 PB corpus, the digital server array maintains the 10 PB hot tier of most-accessed data -- operating system images, active databases, frequently queried knowledge, operational logs, and working data. It bridges the gap between computational speed requirements and archival permanence.

Principles

▸Radiation-hardened solid-state storage with hardware ECC and wear leveling
▸RAID-like redundancy with distributed parity across multiple storage nodes
▸Hot-swappable modular storage units for progressive replacement
▸Tiered caching: MRAM/FeRAM for fastest access, rad-hard NAND for bulk
▸Continuous scrubbing and bit-flip correction for long-term data integrity

Typical implementations

▸Radiation-hardened 3D NAND flash arrays (BAE Systems, Microchip heritage)
▸MRAM (Magnetoresistive RAM) for radiation-immune cache layers
▸Triple-modular redundancy (TMR) controllers
▸Custom rad-hard SSD modules with FPGA-based controllers
▸Distributed storage architecture with no single point of failure

Lunar considerations

▸Galactic cosmic rays cause single-event upsets in semiconductor memory
▸Total ionizing dose accumulates over 100-year mission, degrading NAND cells
▸Active cooling required: no convection in vacuum, conduction/radiation only
▸Storage modules must be replaceable by autonomous robotic maintenance
▸Power consumption must be minimized: every watt generates heat that must be radiated
▸10 PB capacity allows full-text search and AI processing of archived knowledge

Specifications

Functional

primary function	Provide fast random-access digital storage for active Ark data operations
inputs	Data write requests from Ark subsystems, Data read requests from L2-DVT-ACC, Integrity check commands from L2-DVT-INTEG, Data migration requests from/to 5D quartz archive
outputs	Requested data at high throughput, Storage health and capacity reports, Error logs and correction statistics
total capacity pb	10
read throughput gb per s	50
write throughput gb per s	20
random access latency us	100
bit error rate	1e-18
scrub cycle days	7
redundancy level	triple parity distributed

Physical

mass kg	1500
dimensions	4m x 3m x 2m (server rack array)
materials	Radiation-hardened 3D NAND flash modules, MRAM cache modules, Aluminum alloy rack structures, Thermal interface materials (graphite sheets, thermal pads), Radiation shielding (tantalum, polyethylene composite)
temperature controlled	True
target temperature c	25
radiation shielding mm al eq	50
vibration isolated	True

Operational

power consumption w	1200
thermal range c	0, 50
lifetime years	100
mtbf hours	300000

Interfaces

Provides

→Data Access InterfaceHigh-speed data accesscritical
Fast random-access reads and writes for knowledge retrieval and system operations
→L1-CTRLSystem storage servicescritical
Operating system, database, and application storage for Ark control systems
→Data Integrity SystemStorage health telemetryessential
Error rates, wear levels, capacity status for integrity monitoring

Requires

←Power Generation SystemElectrical powercritical
1200W continuous regulated power with UPS backup
←L1-THERMActive thermal managementcritical
Heat removal for 1200W thermal load via conductive/radiative cooling
←Data Integrity SystemIntegrity management commandsessential
Scrub scheduling, error correction triggers, and module replacement commands