PolarStore-4S
3U SpaceVPX SATA Storage Module
SpaceVPX VITA 78 SATA III 8 TB
DESCRIPTION
The PolarStore-4S is a 3U SpaceVPX (VITA 78) payload storage module housing four space-grade SATA III solid-state drives with a combined capacity of 8 TB. As with the PolarStore-2S, the architecture is fully passive — drives are connected to the host OBC via SpaceVPX data plane SERDES lanes with no on-board intermediate processor. Four independent SATA channels allow the OBC firmware to implement RAID 0 striping for 2.2 GB/s aggregate throughput, or RAID 1+0 mirrored pairs for fault-tolerant high-rate recording. The PolarStore-4S targets high-capacity payload data recording applications where maximum on-orbit storage is required.
KEY FEATURES
- 8 TB SATA Storage, 4× 2 TB space-grade SATA III SSDs — maximum capacity per payload slot
- 2 GB/s Aggregate, RAID 0 striping across 4 drives via OBC firmware; 550 MB/s per drive
- 4× SERDES Lanes, 4 independent SATA III channels via SpaceVPX data plane
- >30 krad TID, Radiation-tolerant drives and signal conditioning — latch-up immune
- Conduction-Cooled, VITA 48.2 wedge-lock — sealed, vacuum-compatible
- High-Capacity Recording, Primary module for high-rate Earth observation and science instrument data recording
- Passive Architecture, No on-board processor — full recording policy control by host OBC
- VITA 78 Compliant, 3U SpaceVPX SLT3-PAY payload slot — compatible with all CAVU backplanes
- RAID 1+0 Option, OBC firmware policy implements mirrored striping for fault-tolerant recording
- OBC-Polar VPX Ready, Pre-validated with SATA III SERDES personality; zero NRE integration
- Low Power, ∼10 W nominal from 5 V / 12 V backplane rails
- Compact Mass, ∼240 g — 8 TB storage in a single 3U payload slot
DRIVE SPECIFICATIONS
- Drive count: 4 (fixed)
- Drive type: Space-grade SATA III solid-state drive — industrial-temp, high-endurance
- Capacity per drive: 2 TB
- Total raw capacity: 8 TB
- Interface per drive: SATA III — 6 Gbps (3 Gbps fall-back)
- Sequential read: Up to 550 MB/s per drive (2.2 GB/s RAID 0 aggregate)
- Sequential write: Up to 520 MB/s per drive
- Random read (4K): Up to 95,000 IOPS per drive
- Random write (4K): Up to 30,000 IOPS per drive
- Endurance: >3 DWPD; rated 5-year mission lifetime
- Data retention: >1 year powered off at +55°C
HOST INTERFACE & POWER
- Host interface: SATA III via 4× SpaceVPX data plane SERDES lanes (Fat Pipe)
- On-card logic: Passive — no processor, no controller, no firmware
- SERDES lanes used: 4 (one per drive, 6 Gbps each)
- Power supply: 5 V and 12 V from SpaceVPX backplane P0/J0
- Power nominal: ∼10 W (all drives active)
- Power idle: ∼3.5 W (drives in low-power state)
RADIATION & ENVIRONMENT
- TID tolerance: >30 krad (Si) — drives and signal path
- SEL immunity: Latch-up immune signal conditioning
- Operating temp.: −40°C to +85°C conduction-cooled (VITA 48.2)
- Non-op temp.: −55°C to +125°C
- Shock: Per MIL-STD-810 Method 516
- Vibration: Per MIL-STD-810 Method 514
- Vacuum: Fully compatible — no convection cooling paths
MECHANICAL
- Form factor: 3U SpaceVPX (VITA 78) Payload Module
- Slot profile: SLT3-PAY
- Dimensions: 100 × 160 mm (220 mm depth option)
- Connector: VITA-46 MULTIGIG RT2
- Cooling: Conduction-cooled, VITA 48.2 wedge-lock
- Mass: ∼240 g
SYSTEM COMPATIBILITY
- OBC-Polar VPX: Native — SATA III recorder personality pre-validated
- SpaceVPX-BP-SS: Compatible — any SLT3-PAY slot (uses 4 SERDES lanes)
- SpaceVPX-BP-DS: Compatible — any SLT3-PAY slot, dual-string capable
- RAID 0 / 1+0: Host OBC firmware configures striping or mirroring policy
- PolarStore-2N: Can co-reside on same backplane for mixed SATA / NVMe config
