Crate kalast

kalast

Next generation thermophysical modelling of asteroids

Using kalast

You will need the last stable build of the rust compiler and the official package manager: cargo.

Simply add the following to your Cargo.toml file:

[dependencies]
// replace * by the latest version of the crates
kalast = "*"
rustool = "*"

Useful functionalities of kalast are grouped in the root module kalast::.

kalast in action

Dimorphos case using HERA kernels.

// Initialize the library.
let mut kalast = kalast::init();

let revolution = 11.92 * kalast::HOUR;
let duration = 192.0 * kalast::DAY;

// System center of mass position.
kalast.set_system_name("DIDYMOS_BARYCENTER");
kalast.set_kernel_system(
    "rsc/kernels/hera_PO_EMA_2024.tm",
    "J2000",
    "SUN",
    "2027-MAR-23 16:00:00",
);

// Add a body to the system without a mesh.
kalast.add_body(
    "DIMORPHOS",           // name
    tool::Vector::zeros(), // relative position to center of mass
    kalast::Properties::new(
        revolution,                  // revolution period
        162.0 * kalast::TAU / 360.0, // obliquity
        500.,                        // thermal inertia
        2146.,                       // density
        600.,                        // heat capacity
        0.07,                        // albedo
        0.9,                         // emissivity
    ),
    Some("rsc/obj/g_08438mm_lgt_obj_didb_0000n00000_v002.obj"), // path to 3D mesh
);

tool::debug!(
    "Barycenter position start: {:.2} AU",
    tool::distance(&kalast.system.position, &kalast.system.sun_position)
        / kalast::ASTRONAUMICAL_UNIT
);

// Some configurations about the system.
kalast.enable_self_heating(false);

// Set simulation duration and time step.
kalast.set_time(duration, 10.0 * kalast::MINUTE);

// Some configuration for exporting before running the simulation.
kalast.export_surface(true);

// Start the simulation.
kalast.start();

// Distance after simulation.
tool::debug!(
    "barycenter position end: {:.2} au",
    tool::distance(&kalast.system.position, &kalast.system.sun_position)
        / kalast::ASTRONAUMICAL_UNIT
);

// Temperatures at the end.
let temp = kalast.get_target().surface_temperatures();
println!(
    "Surface temperatures > max: {:.2} K, min: {:.2} K",
    temp.max(),
    temp.min()
);

kalast.kernel.as_mut().unwrap().unload().unwrap();

You can also read other examples.

Features

kalast is meant for binary system of asteroids surface thermophysical modelling. The physics of this engine includes these features:

• read shape model with Wavefront (.obj) format
• custom shape model by creating vertices & facets
• celestial body revolution around tilted spin axis
• orbital positions using Spice kernels
• surface mask (e.g., to only get equator of asteroid)
• solar flux
• self view factor (for craters and surface roughness)
• self heating
• view factor (for binary systems)
• mutual heating (for binary systems)
• one-dimension conduction (finite difference methods)
• TODO: 3D conduction / finite elemen methods
• TODO: mutual occultations
• TODO: shadowing

Explore

If your want to explore the documentation, you can visite these pages:

• Object3D: parse 3D object file and compute atributes of faces (centers, normals, …)
• Body: the representation for a celestial body
• System: the environment system
• Kalast: the simulation manager
• Properties: all the properties to characterise a body

Re-exports

pub use crate::core::*;
pub use crate::toolbox::*;

Modules

core	Core features.
toolbox	Generic functions for math, physics, matrix operations.

Type Definitions

Matrix10xX	Type alias for Object3D. The matrix has a fixed number of rows (10) and a dynamical number of columns.
MatrixSlice10x1	Type alias for Object3D. The slice matrix has a fixed number of rows (10) and a fixed number of columns (1).
MatrixSliceMut10x1	Type alias for Object3D. The mutable slice matrix has a fixed number of rows (10) and a fixed number of columns (1).