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IO.Astrodynamics

IO.Astrodynamics is a .NET astrodynamics framework for orbital mechanics, ephemeris computation, mission analysis, and high-accuracy numerical propagation.

This documentation covers both editions of the framework:

  • Community Edition (IO.Astrodynamics) — open-source core with orbital mechanics, SPICE integration, propagation, maneuvers, attitude control, geometry searches, and CCSDS OMM/OPM support. Available on NuGet and GitHub.
  • Professional Edition (IO.Astrodynamics.Pro) — extends the Community Edition with advanced integrators, conjunction assessment, Monte Carlo analysis, batch propagation, and CDM support. Features exclusive to the Professional Edition are marked (Pro) throughout the documentation.

The Professional Edition includes the full Community API surface. If you install IO.Astrodynamics.Pro, the community package IO.Astrodynamics is pulled in automatically as a dependency.

Community Capabilities

  • Orbital mechanics with Keplerian, equinoctial, Cartesian, and TLE-based workflows
  • SPICE kernel loading, ephemeris access, and frame transforms
  • Lambert transfers, launch windows, and geometry searches
  • Time systems including UTC, TDB, TAI, TDT, GPS, and local time handling
  • Spacecraft, instruments, maneuvers, and event-driven propagation
  • Attitude control: single-vector attitudes, TRIAD fully-constrained pointing, instrument-based pointing
  • Geometry searches such as occultations, eclipses, visibility windows, and distance constraints
  • Atmospheric drag (NRLMSISE-00, U.S. Standard), geopotential (EGM2008), solar radiation pressure, and third-body perturbations
  • Velocity-Verlet fixed-step symplectic integrator
  • CCSDS OMM and OPM reading, writing, and validation

Professional Capabilities

  • CIO-based Earth orientation frames GCRF, CIRS, and TIRS (Pro)
  • Albedo radiation pressure modeling (Pro)
  • Thermal radiation pressure modeling (Pro)
  • Adaptive RK7(8) Prince-Dormand integrator with sub-step event refinement (Pro)
  • Fluent propagator builder for declarative force-model assembly (Pro)
  • Batch propagation with fault isolation and progress reporting (Pro)
  • Monte Carlo dispersion analysis with covariance-based initial-state sampling and per-epoch statistics (Pro)
  • Conjunction screening, conjunction assessment, and simple avoidance trade studies (Pro)
  • CCSDS Conjunction Data Message generation, reading, writing, and schema validation (Pro)

Non-Goals

  • Real-time telemetry processing
  • Hardware control or flight software
  • Detailed thermal, structural, or power subsystem design
  • Closed-loop GNC implementation

Where To Go Next

This documentation is organized into five tabs:

  • Home — you are here
  • Tutorials — step-by-step use cases from ephemeris queries to Monte Carlo
  • API Reference — systematic type and method documentation
  • Guides — cross-cutting best practices (kernels, thread safety, validation)
  • Community & Licensing — editions, contributing to the community project, versioning