# Space Data Network (SDN)

**Type:** Protocol/Architecture  
**Domain:** Space Development  
**Sponsor:** U.S. Space Force, Air Force Research Laboratory  
**Status:** Active development  

## Overview

The Space Data Network (SDN) is the Pentagon's multi-orbit satellite communications architecture designed to provide real-time sensor-to-shooter connectivity for the Golden Dome missile defense system. The SDN is envisioned as "a space-based internet" integrating classified military and unclassified commercial communications satellites with missile warning/tracking sensors, GPS satellites, and distributed data processing capabilities.

## Architecture

The SDN comprises:
- Multi-orbit hybrid satellite constellation (military and commercial)
- Interlinked communications satellites across orbits
- Missile warning and tracking sensors
- Position, navigation, and timing (GPS) satellites
- Distributed on-orbit data processing nodes
- AI-enabled network orchestration

## Relationship to Golden Dome

The SDA's Proliferated Warfighter Space Architecture (PWSA) is described as "a prerequisite for the modern Golden Dome program." The PWSA "would rely on space-based data processing to continuously track targets," establishing orbital compute as a technical requirement rather than a design preference.

## Timeline

- **2026-03** — Breaking Defense reports SDN architecture details; AFRL contracts Aalyria for AI-enabled network orchestration capabilities; Golden Dome budget increases by $10B to $185B to expand space-based sensors and data systems

## Significance

The SDN represents the clearest technical specification of why Golden Dome requires orbital data processing: sensor-to-shooter latency constraints for missile defense make ground-based processing architecturally infeasible. The architecture is structurally identical to commercial orbital data center designs, creating potential for dual-use infrastructure.

## Sources

- Breaking Defense, March 2026: Pentagon's Space Data Network architecture