SpaceLinkOps

An assurance-oriented, offline satellite C3 and TT&C mission-operations demonstrator.

SpaceLinkOps v4 models a LEO spacecraft, three geographically separated ground stations, contact windows, command uplink, telemetry downlink, RF link margin, packet success, retries, ground-station handover, network delay, station outage, engineering risks and Monte Carlo uncertainty.

The seven-view mission-control dashboard combines an interactive 3-D Earth/orbit, dynamic RF margin, contact-aware command state machine, explainable telemetry anomaly detection, graph-cut criticality, ranked FMEA and resilience ensembles.

The operational assurance layer adds role-based command authority, independent approval, hazardous-command dual control, mode and parameter interlocks, global inhibit, telemetry alarm management, deterministic safe-mode FDIR, a digital twin, tamper-evident audit records and generated requirements traceability.

Safety boundary: this repository deliberately contains no interface that can transmit to real spacecraft, radios, antennas or ground equipment.

What it demonstrates

• Orbital access and elevation-mask analysis
• Real TLE/SGP4 propagation with explicit TEME/ECEF handling
• SI-unit link budget: FSPL, received power, C/N0, Eb/N0, SNR and margin
• Deterministic discrete-event command and telemetry simulation
• Availability, latency, success, contact-time and handover metrics
• Station-outage, link-degradation and terrestrial-delay scenarios
• Automated risk/gap flags and Monte Carlo analysis
• Full CREATED → QUEUED → UPLINKED → RECEIVED → EXECUTED → ACKNOWLEDGED lifecycle
• Robust median-absolute-deviation telemetry anomaly detection
• BPSK/QPSK AWGN BER-to-packet-error physics and carrier Doppler prediction
• CRC-16 protected spacecraft/virtual-channel transfer frames
• Graph-cut single-point-of-failure analysis and ranked FMEA
• Automated leave-one-station-out ground-segment trade study
• RBAC command console with two-person approval and flight-director release
• Global command inhibit, spacecraft-mode interlocks and parameter constraints
• Telemetry yellow/red limits, debounce, acknowledgement and stale-data detection
• Digital-twin fault injection with autonomous SAFE-mode transition
• SHA-256 tamper-evident operational audit chain
• Requirements → implementation → verification traceability matrix
• SRS, ICD, V&V plan and preliminary hazard analysis
• Interactive seven-tab Streamlit/Plotly mission-control dashboard with 3-D Earth

Quick start

python -m venv .venv
source .venv/bin/activate        # Windows: .venv\Scripts\activate
pip install -e ".[dashboard,dev]"
spacelinkops scenarios/nominal.yaml --output outputs/nominal.json --monte-carlo 100 --station-ablation
streamlit run dashboard/app.py

The core install (NumPy, Pydantic, PyYAML and SGP4) covers both propagators and the full simulation. The Streamlit/Plotly dashboard is an optional extra.

Scenarios

nominal.yaml is the baseline. resilience.yaml injects a full-day Kourou outage, a terrestrial delay window and a 3 dB margin penalty. Copy a scenario to run your own sensitivity study; validation rejects invalid coordinates, non-positive physical quantities and unknown outage stations.

Validation

pytest -q
ruff check src tests
python -m compileall -q src dashboard

The core tests cover a reference FSPL value, overhead geometry, probability monotonicity, deterministic results and outage availability. Property-based tests (Hypothesis) additionally fuzz the link budget, orbit geometry and transfer-frame codec across their full valid input ranges. See docs/engineering_model.md for equations, assumptions, limitations and authoritative public references. The executed nominal/stress comparison is in docs/validation_report.md.

The TEME-to-ECEF frame conversion on the SGP4 path is validated against the IAU-1982 GMST reference and the neglected-Earth-orientation error is bounded explicitly (~540 m at LEO) in docs/frame_validation.md; run python -m spacelinkops.validation to reproduce the numbers.

Repository map

src/spacelinkops/       physics, configuration, simulation and CLI
scenarios/              nominal and resilience YAML configurations
dashboard/              Streamlit mission-control UI
tests/                  unit and integration validation
docs/                   architecture and engineering model
requirements/           controlled assurance requirements with stable IDs
scripts/                evidence and traceability generation
.github/workflows/      automated quality checks

Propagators

Use model: two_body for transparent synthetic trade studies, or model: sgp4 with two TLE lines for public-catalogue realism. scenarios/tle_sgp4.yaml contains a reproducible public TLE example. TLEs are mean elements tied to SGP4; they must not be treated as osculating elements or extrapolated indefinitely.

Important limitations

The SGP4 path uses a compact GMST TEME-to-ECEF rotation; high-precision Earth orientation requires an IERS-aware frame library. RF error probabilities are uncoded AWGN BPSK/QPSK models rather than a claim about a particular flight modem or coding chain. Results remain for education and early trade studies—not operational planning, licensing or safety-critical decisions.

Responsible scope

SpaceLinkOps does not implement weapon targeting, electronic attack, offensive cyber capabilities, interference procedures or classified/restricted architectures.

Assurance status

The accurate description is flight-software-inspired, assurance-oriented, offline mission-operations demonstrator. It is not flight-qualified. Flight qualification is a mission- and organization-specific evidence process involving controlled requirements, applicable standards, independent verification, representative hardware and formal acceptance—not a repository feature flag.

License

MIT © 2026 Ipek Karaman