ApsisRS

Computational kernels for commercial spaceflight and satellite internet, in Rust.

English | 简体中文

Scope

• Pure Rust, standard library only, no third-party crate dependency
• Clear domain boundaries with a one-way dependency order between layers
• The public facade crate is apsis-rs; its library name is apsis
• Every crate is publish = false at this stage, so none of them is released

Layers

foundation -> physics -> orbit -> rf -> network -> ops -> sim -> apsis-rs

The rules:

• Dependencies flow to the left only. A lower layer may use any layer to its left; a higher layer may not use any layer to its right. So network may use orbit, but orbit may not use network. A leftward dependency may cross as many layers as it needs, because the layers in between need not offer a type that carries the value forward.
• apsis-core in foundation is the global baseline that any crate in any layer may use. apsis-math is the same, because linear algebra is shared across the layers.
• Within a layer, that layer's facade crate (apsis-orbit, apsis-rf, apsis-sim) is the integration point.

scripts/check-layers.sh enforces these rules and CI runs it.

Layer	Responsibility	Crates
foundation	Base types, units, mathematics, macros	apsis-core, apsis-units, apsis-math, apsis-macros
physics	Time, leap seconds, coordinates, datum	apsis-time, apsis-leap, apsis-coord, apsis-geodesy, apsis-frames
orbit	TLE, SGP4, two-body, ephemeris, maneuvers	apsis-tle, apsis-sgp4, apsis-kepler, apsis-ephemeris, apsis-maneuver, apsis-orbit
rf	Radio frequency, antennas, link budget	apsis-rf, apsis-antenna, apsis-doppler, apsis-atmosphere, apsis-noise, apsis-interference, apsis-link
network	Constellations, coverage, access, topology, routing	apsis-constellation, apsis-coverage, apsis-access, apsis-topology, apsis-isl, apsis-routing, apsis-handover, apsis-mesh
ops	Resources, tasks, scheduling, conflicts, schedules	apsis-resource, apsis-task, apsis-scheduler, apsis-conflict, apsis-schedule
sim	Simulation engine, scenarios, events, output	apsis-sim-engine, apsis-scenario, apsis-event, apsis-output, apsis-sim
facade	Public facade	apsis-rs

Building

Run every Rust command from the repository root:

cargo check --workspace
cargo test -p apsis-core -p apsis-units -p apsis-math

The apsis-rs facade selects the layers it needs by feature:

[dependencies]
apsis-rs = { path = "...", features = ["orbit"] }

The features are foundation, physics, orbit, rf, network, ops, sim and full. A layer feature enables the layers below it. full enables everything including sim; ops is every layer except sim, for a project that does not run simulations.

Conventions

• Toolchain stable, edition 2024, rust-version 1.85
• No third-party crate by default, including dev-dependencies and build scripts
• Library code uses no unwrap, expect or panic. A failure on external input is always a Result or an Option. An expect is allowed on an internal invariant that a check just above already guards, such as the element just pushed onto a vector, or a value whose absence the line above ruled out. There are thirteen such sites and each is listed with its guard in docs/design/errors.md.
• Every public item carries a documentation comment, and the comment is self-contained
• Tests live in each crate's tests/ directory, separate from src/. They are integration tests and reach the crate only through its public API; no inline #[cfg(test)] module is used
• Documentation follows the X.md and X.zh.md convention, with English in X.md and Simplified Chinese in X.zh.md

Layout

apsis-rs/
├── Cargo.toml
├── crates/          # Rust workspace members
│   └── apsis-rs/
│       ├── examples/   # validation dumps and cross-layer checks
│       └── ...
├── scripts/         # repository check scripts
├── validation/      # Python cross-checks
└── docs/design/     # design notes

Tests live in each crate's tests/ directory. The cross-layer integration checks and the dependency-free benchmarks are examples of the facade:

# Cross-layer integration checks, which CI runs
cargo run -p apsis-rs --features network --example integrate_network
cargo run -p apsis-rs --features ops --example integrate_ops
cargo run -p apsis-rs --features sim --example integrate_sim

# Hot path benchmark, run in release
cargo run --release -p apsis-rs --features full --example bench

# Scale sweep: the input grows and the cost per unit of work shows the trend
cargo run --release -p apsis-rs --features full --example bench_scale

# Parallel sweep: the same work over 1, 2, 4, 8 and 16 threads
cargo run --release -p apsis-rs --features full --example bench_parallel

Documentation

The design notes record the cross-crate decisions that a reader of a single crate cannot infer:

• Units and coordinates
• Errors and tolerances
• Layer boundaries
• Parallelism
• The simulation layer

Licence

MIT OR Apache-2.0, see LICENSE-MIT and LICENSE-APACHE.