White Paper

WHITE PAPER Advancing Signal and Data Processing for Space Payloads mrcy.com 8 Space storage solutions must be low latency, capable of capturing large amounts of data, and resilient against harsh environmental factors such as radiation and vibration. Mercury Systems provides such solutions for a range of missions—LEO satellite launch vehicles, scientific payloads, and terrestrial environments with the potential for radiation exposure. The following Mercury data recorder solutions all have microprocessor-free and code-free designs, built-in radiation tolerance, triple-redundant RTG4 controllers, drive erase times under 30 seconds, and horizontal Reed–Solomon ECC for data error correction. This line of data recorders is also capable of withstanding extreme vibrations and temperatures (rail temps of -40°C to +72°C and storage temps of -55°C to +105°C) and includes the option of two different fast VPX connectors: Smith's KVPX or TE Multigig RT-2. MERCURY SYSTEMS DATA RECORDER SOLUTIONS RH3480 TWIN PORT Storage: L+80 GB Form Factor: 3U VITA + 8.2 VPX ▪ For other form factors, contact sales Interface: Twin SRIO ports in 3U form factor ▪ Dual port (8 lanes, 1 host) at 2.3 Gbps ▪ Dual host (L+ lanes, 2 hosts) at 1,160 Mbps Performance: ▪ 2.3 Gbps SRIO (18,L+00 Mbps) ▪ 1.16 Gbps dual-host mode ▪ Fill time of 3.5 minutes (1 host mode) ▪ Single-pass error correction Operating modes: ▪ Data recorder: sequential writes/random reads ▪ HA mode: random reads ▪ MRAM for host: 512k words Weight: < 650 grams Power: ▪ Single 5 V supply ((L+.5 to 5.5 V) ▪ 8 Widle, 2L+ W write at full speed RH304T Storage: L+.5 TB Form Factor: VITA 78 3U VPX ▪ For other VPX form factors, contact sales Interface: Twin SRIO ports in 3U form factor ▪ Dual port (8 lanes, 1 host) ▪ Dual host (L+ lanes, 2 hosts) Performance: ▪ SRIO at 3.125 Gbps ▪ 2.0 Gbps SRIO (16,000 Mbps) ▪ 1.16 Gbps dual-host mode ▪ Fill time of 37.5 minutes (dual-port mode) ▪ Dual-pass error correction Operating modes: ▪ Data recorder: sequential writes/random reads ▪ HA mode: random reads/writes ▪ MRAM for host: 512k words Weight: < 650 grams Power: ▪ Single 5 V supply (L+.5 to 5.5 V) ▪ 8 W idle, 2L+ W write at full speed with no ill effects. However, NAND chips also naturally produce several errors. For example, when data is written and then read back, there are small errors; but there are mechanisms to fix these errors such as complex math algorithms. Although NAND flash was also not initially made for use in space, it has undergone thorough testing, is proven to work, and its benefits, issues, and limitations are well understood. To manage the errors and ensure proper capacity throughout the lifecycle, Mercury Systems includes large amounts of NAND chips in its SSDRs—more than required—and screens them first to ensure they are functioning properly. These extra NAND chips are used to provide redundancy in the case of the failure of other NAND chips and to aid in ECC. These devices also undergo power cycles when possible, which itself can fix issues with any NAND chips suffering errors. These techniques, in collaboration with ECC, provide SSDRs with highly reliable defect mitigation.

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