diff --git a/Cargo.toml b/Cargo.toml
index 55f0a64..c85be0c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,5 +8,7 @@ authors = ["thomas"]
 
 [dependencies]
 clap = { version = "4.5.39", features = ["derive"] }
+env_logger = "0.11.8"
+log = "0.4.27"
 serde = { version = "1.0.219", features = ["derive"] }
 serde_json = "1.0.140"
diff --git a/src/config.rs b/src/config.rs
index a244c5c..92c784d 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -3,13 +3,13 @@ use serde::Deserialize;
 
 #[derive(Debug, Deserialize)]
 pub struct Body {
-    name: String,
-    mass: types::Mass,
-    position: types::Position,
-    velocity: types::Velocity,
+    pub name: String,
+    pub mass: types::Mass,
+    pub position: types::Position,
+    pub velocity: types::Velocity,
 }
 
 #[derive(Debug, Deserialize)]
 pub struct ConfigFile {
-    bodies: Vec<Body>,
+    pub bodies: Vec<Body>,
 }
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 6de29c8..6f065cb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,13 +1,20 @@
-use clap::Parser;
-
+// Standard library
 use std::error::Error;
 use std::fs::File;
 use std::io::BufReader;
 use std::path::Path;
 
+// External crates
+use clap::Parser;
+use log::{info, warn, error, debug, trace};
 
+// Internal modules
 mod types;
 mod config;
+mod simulator;
+
+// Specific uses from modules
+use crate::simulator::Simulator;
 
 #[derive(Parser, Debug)]
 #[command(
@@ -37,10 +44,18 @@ fn read_config<P: AsRef<Path>>(path: P) -> Result<config::ConfigFile, Box<dyn Er
 //fn parse_time(arg: &str) 
 
 fn main() {
+    env_logger::init();
     let args = Args::parse();
 
-    println!("Loading initial parameters from {}", args.config);
+    info!("Loading initial parameters from {}", args.config);
 
     let conf = read_config(args.config).unwrap();
-    println!("{:#?}", conf);
+    for body in &conf.bodies {
+        info!("Loaded {} with mass {:.3e} kg", body.name, body.mass);
+        debug!("R_i = {:?}, V_i = {:?}", body.position, body.velocity);
+    }
+
+
+    let mut sim = Simulator::new(conf.bodies, 0.5);
+    sim.run(2);
 }
diff --git a/src/simulator.rs b/src/simulator.rs
new file mode 100644
index 0000000..276b5fa
--- /dev/null
+++ b/src/simulator.rs
@@ -0,0 +1,23 @@
+use log::{info, warn, error, debug, trace};
+
+use crate::config::Body;
+
+pub struct Simulator {
+    bodies: Vec<Body>,
+    step_size: f32,
+}
+
+impl Simulator {
+    pub fn new(bodies: Vec<Body>, step_size: f32) -> Self{
+        Self {bodies, step_size}
+    }
+
+    pub fn run(&mut self, steps: usize){
+        for i in 0..steps {
+            debug!("Step: {}", i);
+            // for b in &self.bodies {
+            //     println!("Body: {}", b.name);
+            // }
+        }
+    }
+}
\ No newline at end of file
