Solar Power System
ROSA-class roll-out solar arrays, power conversion & distribution systems
Solar Generation (ROSA-Class Roll-Out Wings)
Architecture
Two primary solar wings mounted on opposite ends of the main spine. Each wing is a ROSA-class roll-out solar array:
- Flexible blanket stowed on a drum
- Deployed along a lightweight boom once on orbit
Scale
• Total solar area: ~3,000 m² (both wings) for a 1 MW-class node
• Per wing: ~1,500 m², e.g. ~50 m roll-out length × ~30 m effective span
• Effective power density: ~330–350 W/m² (multi-junction cells + derates)
Deployment Sequence
- 1. Sector covers open; blanket + boom released from canister
- 2. Roll-out boom extends, pulling the blanket with it
- 3. Blanket unrolls under tension, guided by edge battens
- 4. Root and tip mechanisms latch, tensioning the array
- 5. Root gimbal enters continuous Sun-tracking mode
Pointing & Control
Single-axis solar array drive per wing at the root. Modes: Sun-tracking, feathered (drag/safe-mode), parked for servicing.
Pointing modes include 'science / power max' and 'astronomy-friendly', following lessons learned from large-array LEO sats like AST's BlueWalker: slight tilts of solar and radiator planes reduce optical brightness while maintaining required power and heat rejection.
Array loads and jitter managed via sensors + attitude control loops, ensuring stable power generation while minimizing structural loads during orbital maneuvers.
Power Conversion & Distribution
Primary DC Bus
~300–600 V class for efficient power transport across the node
Higher voltage reduces current, minimizing I²R losses and enabling lighter power distribution harnesses.
Conversion
• MPPT units near the pod cluster for each string group
• DC/DC converters to 48–60 V rack power and low-voltage avionics rails
Energy Storage (Config-Dependent)
Swappable battery modules in one or more pods. Sized for eclipse operations or run-sun-only, depending on mission. Battery capacity and placement optimized for orbital period and power demand profiles.