diff --git a/src/cosmic/cosm.rs b/src/cosmic/cosm.rs
index 9024f4cd..958c19aa 100644
--- a/src/cosmic/cosm.rs
+++ b/src/cosmic/cosm.rs
@@ -77,7 +77,7 @@ impl FrameTree {
     /// Seek an ephemeris from its celestial name (e.g. Earth Moon Barycenter)
     fn frame_seek_by_name(
         name: &str,
-        cur_path: &mut [usize],
+        cur_path: &[usize],
         f: &FrameTree,
     ) -> Result<Vec<usize>, NyxError> {
         if f.name == name {
@@ -91,7 +91,7 @@ impl FrameTree {
             for (cno, child) in f.children.iter().enumerate() {
                 let mut this_path = cur_path.to_owned();
                 this_path.push(cno);
-                let child_attempt = Self::frame_seek_by_name(name, &mut this_path, child);
+                let child_attempt = Self::frame_seek_by_name(name, &this_path, child);
                 if let Ok(found_path) = child_attempt {
                     return Ok(found_path);
                 }
@@ -230,15 +230,15 @@ impl Cosm {
             // Return an empty vector (but OK because we're asking for the root)
             Ok(Vec::new())
         } else {
-            let mut path = Vec::new();
-            Self::frame_find_path(name, &mut path, &self.frame_root)
+            let path = Vec::new();
+            Self::frame_find_path(name, &path, &self.frame_root)
         }
     }
 
     /// Seek a frame from its orientation name
     fn frame_find_path(
         frame_name: &str,
-        cur_path: &mut [usize],
+        cur_path: &[usize],
         f: &FrameTree,
     ) -> Result<Vec<usize>, NyxError> {
         if f.name == frame_name {
@@ -250,8 +250,8 @@ impl Cosm {
             ))
         } else {
             for child in &f.children {
-                let mut this_path = cur_path.to_owned();
-                let child_attempt = Self::frame_find_path(frame_name, &mut this_path, child);
+                let this_path = cur_path.to_owned();
+                let child_attempt = Self::frame_find_path(frame_name, &this_path, child);
                 if let Ok(found_path) = child_attempt {
                     return Ok(found_path);
                 }
@@ -565,10 +565,10 @@ impl Cosm {
             // Return an empty vector (but OK because we're asking for the root)
             Ok(self.frame_root.frame)
         } else {
-            let mut path = Vec::new();
+            let path = Vec::new();
             Ok(self.frame_from_frame_path(&FrameTree::frame_seek_by_name(
                 &name,
-                &mut path,
+                &path,
                 &self.frame_root,
             )?))
         }
diff --git a/src/cosmic/mod.rs b/src/cosmic/mod.rs
index d9864c65..4be157fd 100644
--- a/src/cosmic/mod.rs
+++ b/src/cosmic/mod.rs
@@ -25,7 +25,7 @@ use crate::linalg::{DefaultAllocator, DimName, OMatrix, OVector};
 use crate::md::StateParameter;
 use crate::time::{Duration, Epoch, Unit};
 use hifitime::SECONDS_PER_DAY;
-use std::fmt;
+use std::fmt::{self, Write};
 use std::fs::File;
 use std::io::Read;
 #[cfg(not(target_arch = "wasm32"))]
@@ -207,7 +207,10 @@ impl Xb {
                 }
                 for pos in path {
                     if root.children.get(*pos).is_none() {
-                        let hpath: String = path.iter().map(|p| format!("{p}")).collect::<String>();
+                        let hpath = path.iter().fold(String::new(), |mut output, p| {
+                            let _ = write!(output, "{p}");
+                            output
+                        });
                         return Err(NyxError::ObjectNotFound(hpath, self.ephemeris_get_names()));
                     }
                 }
@@ -231,7 +234,7 @@ impl Xb {
     /// Seek an ephemeris from its celestial name (e.g. Earth Moon Barycenter)
     fn ephemeris_seek_by_name(
         name: &str,
-        cur_path: &mut [usize],
+        cur_path: &[usize],
         e: &Ephemeris,
     ) -> Result<Vec<usize>, NyxError> {
         if e.name == name {
@@ -245,7 +248,7 @@ impl Xb {
             for (cno, child) in e.children.iter().enumerate() {
                 let mut this_path = cur_path.to_owned();
                 this_path.push(cno);
-                let child_attempt = Self::ephemeris_seek_by_name(name, &mut this_path, child);
+                let child_attempt = Self::ephemeris_seek_by_name(name, &this_path, child);
                 if let Ok(found_path) = child_attempt {
                     return Ok(found_path);
                 }
@@ -270,8 +273,8 @@ impl Xb {
                     // Return an empty vector (but OK because we're asking for the root)
                     Ok(Vec::new())
                 } else {
-                    let mut path = Vec::new();
-                    Self::ephemeris_seek_by_name(&name, &mut path, root)
+                    let path = Vec::new();
+                    Self::ephemeris_seek_by_name(&name, &path, root)
                 }
             }
         }
diff --git a/src/dynamics/spacecraft.rs b/src/dynamics/spacecraft.rs
index e1206330..6b2ddcfd 100644
--- a/src/dynamics/spacecraft.rs
+++ b/src/dynamics/spacecraft.rs
@@ -30,7 +30,7 @@ pub use crate::md::prelude::SolarPressure;
 use crate::md::prelude::{Harmonics, PointMasses};
 use crate::State;
 
-use std::fmt;
+use std::fmt::{self, Write};
 use std::sync::Arc;
 
 use crate::cosmic::Cosm;
@@ -243,7 +243,12 @@ impl fmt::Display for SpacecraftDynamics {
         let force_models: String = if self.force_models.is_empty() {
             "No force models;".to_string()
         } else {
-            self.force_models.iter().map(|x| format!("{x}; ")).collect()
+            self.force_models
+                .iter()
+                .fold(String::new(), |mut output, x| {
+                    let _ = write!(output, "{x}; ");
+                    output
+                })
         };
         write!(
             f,
diff --git a/src/md/trajectory/orbit_traj.rs b/src/md/trajectory/orbit_traj.rs
index b18d135d..08dab323 100644
--- a/src/md/trajectory/orbit_traj.rs
+++ b/src/md/trajectory/orbit_traj.rs
@@ -238,7 +238,7 @@ impl Traj<Orbit> {
         // Grab the path here before we move stuff.
         let path_buf = cfg.actual_path(path);
 
-        let metadata = cfg.metadata.unwrap_or(HashMap::new());
+        let metadata = cfg.metadata.unwrap_or_default();
 
         let file = File::create(&path_buf)
             .map_err(|e| NyxError::CCSDS(format!("File creation error: {e}")))?;