astrodyn_interactions 0.1.1

Aerodynamic drag, SRP, gravity-gradient torque, shadow, and contact for the astrodyn orbital-dynamics pipeline
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51

# astrodyn_interactions

Surface interactions — aerodynamic drag, solar radiation pressure,
gravity-gradient torque, shadow geometry, contact, thermal — for the
[`astrodyn_bevy`](https://github.com/simnaut/astrodyn) workspace.

Ports
[`models/interactions/`](https://github.com/nasa/jeod/blob/jeod_v5.4.0/models/interactions/)
and the surface-model utilities under
[`models/utils/`](https://github.com/nasa/jeod/blob/jeod_v5.4.0/models/utils/)
from [NASA JEOD v5.4.0](https://github.com/nasa/jeod).

## Layered architecture

```
astrodyn_bevy        (Bevy ECS adapter, mission code)
   ↓
astrodyn         (orchestration; sums forces into TotalForce)
   ↓
astrodyn_interactions ←  this crate (pure Rust, zero Bevy)
   ↓
astrodyn_atmosphere, astrodyn_quantities
```

Each module produces a force, torque, or environmental scalar at a
vehicle position. The orchestration that sums them into a body's
`astrodyn_dynamics::TotalForce` lives in `astrodyn`.

## Public surface

- `aero_drag` (scalar-Cd) and `flat_plate_aero` (per-facet) —
  aerodynamic drag.
- `radiation_pressure` — solar flux against a surface model with
  absorption / specular / diffuse coefficients.
- `shadow` — umbra / penumbra geometry. `earth_lighting` extends with
  Earth-albedo and IR contributions.
- `gravity_torque` — cross product of inertia tensor and
  gravity-gradient tensor through body attitude.
- `surface_model` — `SurfaceFacet`, `ArticulatedFacet`, `SurfaceShape`
  — per-facet geometry shared by aero / SRP / contact / thermal.
- `contact` — collision / contact response.
- `thermal_rider` — per-facet power balance.

## See also

- [`docs/JEOD_invariants.md`](https://github.com/simnaut/astrodyn/blob/main/docs/JEOD_invariants.md) — `AE.*`,
  `RP.*`, `GG.*`, `SH.*`, `CT.*`, `TH.*` invariants.
- [Project README](https://github.com/simnaut/astrodyn/blob/main/README.md) and
  [`CLAUDE.md`](https://github.com/simnaut/astrodyn/blob/main/CLAUDE.md) — workspace-level architecture.
- Rendered rustdoc:
  <https://docs.rs/astrodyn_interactions>