diff --git a/Source/Addons/RaycastManager.cs b/Source/Addons/RaycastManager.cs
new file mode 100644
index 0000000..a6f14ff
--- /dev/null
+++ b/Source/Addons/RaycastManager.cs
@@ -0,0 +1,241 @@
+
+
+using System;
+using System.Collections.Generic;
+using Unity.Collections;
+using Unity.Jobs;
+using UnityEngine;
+using UnityEngine.Jobs;
+
+namespace SystemHeat.Addons;
+
+[DefaultExecutionOrder(-1)]
+[KSPAddon(KSPAddon.Startup.AllGameScenes, once: false)]
+internal class RaycastManager : MonoBehaviour
+{
+  public static RaycastManager Instance { get; private set; }
+
+  struct RaycastParams
+  {
+    public float range;
+    public int layerMask;
+  }
+
+  const int DefaultCap = 128;
+
+  private TransformAccessArray transforms;
+  private NativeArray<RaycastParams> args;
+  private NativeArray<RaycastHit> hits;
+  private readonly Dictionary<int, int> mapping = [];
+  private readonly Dictionary<int, int> reverse = [];
+  private JobHandle handle = default;
+
+  public void Register(PartModule module, Transform transform, float range, int layerMask = -5)
+  {
+    if (module == null || transform == null || this == null)
+      return;
+
+    handle.Complete();
+
+    if (!enabled)
+      enabled = true;
+
+    var moduleID = module.GetInstanceID();
+    var arg = new RaycastParams
+    {
+      range = range,
+      layerMask = layerMask
+    };
+
+    // If the module is already registered then this overrides its existing
+    // raycast request.
+    if (mapping.TryGetValue(moduleID, out int index))
+    {
+      transforms[index] = transform;
+      args[index] = arg;
+      return;
+    }
+
+    EnsureCapacity();
+
+    index = transforms.length;
+    transforms.Add(transform);
+    args[index] = arg;
+
+    mapping.Add(moduleID, index);
+    reverse.Add(index, moduleID);
+  }
+
+  public void Unregister(PartModule module)
+  {
+    if (module == null)
+      return;
+
+    handle.Complete();
+
+    var moduleID = module.GetInstanceID();
+    if (!mapping.TryGetValue(moduleID, out var index))
+      return;
+
+    mapping.Remove(moduleID);
+    reverse.Remove(index);
+    transforms.RemoveAtSwapBack(index);
+
+    int last = transforms.length;
+    if (reverse.TryGetValue(last, out var swappedID))
+    {
+      args[index] = args[last];
+      if (hits.IsCreated && last < hits.Length)
+        hits[index] = hits[last];
+
+      mapping[swappedID] = index;
+      reverse.Remove(last);
+      reverse[index] = swappedID;
+    }
+  }
+
+  /// <summary>
+  /// Get the precomputed raycast hit for <paramref name="module"/>.
+  /// </summary>
+  /// <param name="module"></param>
+  /// <returns><c>null</c> if there is no hit, and the hit otherwise.</returns>
+  /// <remarks>
+  /// <see cref="RaycastHit.collider" /> will be <c>null</c> if the raycast did
+  /// not hit anything.
+  /// </remarks>
+  public RaycastHit? GetRaycastHit(PartModule module)
+  {
+    var moduleID = module.GetInstanceID();
+    if (!mapping.TryGetValue(moduleID, out var index))
+      return null;
+
+    if ((uint)index >= (uint)hits.Length)
+      return null;
+
+    if (!handle.IsCompleted)
+      handle.Complete();
+
+    return hits[index];
+  }
+
+  void EnsureCapacity()
+  {
+    int length = transforms.length;
+    if (length < transforms.capacity)
+      return;
+
+    var newcap = Math.Max(length * 2, 128);
+    var nt = new TransformAccessArray(newcap, desiredJobCount: 1);
+    var na = new NativeArray<RaycastParams>(newcap, Allocator.Persistent, NativeArrayOptions.UninitializedMemory);
+
+    for (int i = 0; i < length; ++i)
+      nt.Add(transforms[i]);
+    NativeArray<RaycastParams>.Copy(args, na, length);
+
+    transforms.Dispose();
+    args.Dispose();
+
+    transforms = nt;
+    args = na;
+  }
+
+  void Awake()
+  {
+    Instance = this;
+  }
+
+  void OnDestroy()
+  {
+    if (Instance == this)
+      Instance = null;
+  }
+
+  void OnEnable()
+  {
+    transforms = new TransformAccessArray(DefaultCap, desiredJobCount: 1);
+    args = new NativeArray<RaycastParams>(DefaultCap, Allocator.Persistent);
+  }
+
+  void OnDisable()
+  {
+    try
+    {
+      if (!handle.IsCompleted)
+        handle.Complete();
+    }
+    catch (Exception e)
+    {
+      Debug.LogException(e);
+    }
+
+    transforms.Dispose();
+    args.Dispose();
+    if (hits.IsCreated)
+      hits.Dispose();
+
+    transforms = default;
+    args = default;
+    hits = default;
+
+    mapping.Clear();
+    reverse.Clear();
+  }
+
+  void FixedUpdate()
+  {
+    if (!handle.IsCompleted)
+      handle.Complete();
+
+    var count = mapping.Count;
+    if (count == 0)
+    {
+      handle = default;
+      return;
+    }
+
+    var commands = new NativeArray<RaycastCommand>(count, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
+    hits = new NativeArray<RaycastHit>(count, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
+
+    // RaycastCommand.ScheduleBatch reads maxHits immediately but the remaining
+    // fields are not read until the job runs. So we need to initialize maxHits
+    // immediately but the rest can happen in a job.
+    for (int i = 0; i < count; ++i)
+      commands[i] = new() { maxHits = 1 };
+
+    handle = new BuildCommandJob { args = args, commands = commands }
+      .Schedule(transforms, handle);
+    handle = RaycastCommand.ScheduleBatch(commands, hits, 64, handle);
+    JobHandle.ScheduleBatchedJobs();
+  }
+
+  void Update()
+  {
+    handle.Complete();
+
+    if (mapping.Count == 0)
+      enabled = false;
+  }
+
+  struct BuildCommandJob : IJobParallelForTransform
+  {
+    [ReadOnly]
+    public NativeArray<RaycastParams> args;
+    [WriteOnly]
+    public NativeArray<RaycastCommand> commands;
+
+    public void Execute(int index, TransformAccess transform)
+    {
+      var arg = args[index];
+      var command = new RaycastCommand
+      {
+        from = transform.position,
+        direction = transform.rotation * Vector3.forward,
+        distance = arg.range,
+        layerMask = arg.layerMask,
+        maxHits = 1
+      };
+
+      commands[index] = command;
+    }
+  }
+}
\ No newline at end of file
diff --git a/Source/Modules/ModuleSystemHeatAsteroidHarvester.cs b/Source/Modules/ModuleSystemHeatAsteroidHarvester.cs
index 69bf931..ef9b38c 100644
--- a/Source/Modules/ModuleSystemHeatAsteroidHarvester.cs
+++ b/Source/Modules/ModuleSystemHeatAsteroidHarvester.cs
@@ -1,5 +1,6 @@
 using UnityEngine;
 using KSP.Localization;
+using SystemHeat.Addons;
 using Unity.Profiling;
 
 namespace SystemHeat
@@ -39,6 +40,9 @@ public class ModuleSystemHeatAsteroidHarvester : ModuleAsteroidDrill
 
     protected ModuleSystemHeat heatModule;
 
+    // Stock ModuleAsteroidDrill uses Physics.DefaultRaycastLayers (no mask).
+    private const int ImpactLayerMask = -5;
+
     private static readonly ProfilerMarker BaseFixedUpdateMarker = new("ModuleAsteroidDrill.FixedUpdate");
 
     public override string GetInfo()
@@ -63,6 +67,13 @@ public void Start()
 
       Utils.Log("[ModuleSystemHeatAsteroidHarvester] Setup completed", LogType.Modules);
       Fields["HarvesterEfficiency"].guiName = Localizer.Format("#LOC_SystemHeat_ModuleSystemHeatHarvester_Field_Efficiency", ConverterName);
+
+      RegisterImpactRaycast();
+    }
+
+    void OnEnable()
+    {
+      RegisterImpactRaycast();
     }
 
     public override void FixedUpdate()
@@ -92,6 +103,35 @@ void OnDisable()
     {
       heatModule?.AddFlux(moduleID, 0f, 0f, false);
       HarvesterEfficiency = "-";
+      RaycastManager.Instance?.Unregister(this);
+    }
+
+    void RegisterImpactRaycast()
+    {
+      if (!HighLogic.LoadedSceneIsFlight || impactTransformCache == null)
+        return;
+      RaycastManager.Instance?.Register(this, impactTransformCache, ImpactRange, ImpactLayerMask);
+    }
+
+    protected override bool CheckForImpact()
+    {
+      if (string.IsNullOrEmpty(ImpactTransform) || impactTransformCache == null)
+        return true;
+
+      var hit = RaycastManager.Instance?.GetRaycastHit(this);
+      if (hit is not RaycastHit raycastHit)
+      {
+        // If we're not registered for whatever reason then do the raycast ourselves.
+        var origin = impactTransformCache.position;
+        if (!Physics.Raycast(new Ray(origin, impactTransformCache.forward), out raycastHit, ImpactRange, ImpactLayerMask))
+          return false;
+      }
+
+      var collider = raycastHit.collider;
+      if (collider == null)
+        return false;
+
+      return collider.gameObject.GetComponentUpwards<ModuleAsteroid>() != null;
     }
 
     void FixedUpdateFlight()
diff --git a/Source/Modules/ModuleSystemHeatCometHarvester.cs b/Source/Modules/ModuleSystemHeatCometHarvester.cs
index 454a18e..cc8ed75 100644
--- a/Source/Modules/ModuleSystemHeatCometHarvester.cs
+++ b/Source/Modules/ModuleSystemHeatCometHarvester.cs
@@ -1,5 +1,7 @@
 using KSP.Localization;
+using SystemHeat.Addons;
 using Unity.Profiling;
+using UnityEngine;
 
 namespace SystemHeat
 {
@@ -38,6 +40,9 @@ public class ModuleSystemHeatCometHarvester : ModuleCometDrill
 
     protected ModuleSystemHeat heatModule;
 
+    // Stock ModuleCometDrill uses Physics.DefaultRaycastLayers (no mask).
+    private const int ImpactLayerMask = -5;
+
     private static readonly ProfilerMarker BaseFixedUpdateMarker = new("ModuleCometDrill.FixedUpdate");
 
     public override string GetInfo()
@@ -62,6 +67,13 @@ public void Start()
 
       Utils.Log("[ModuleSystemHeatCometHarvester] Setup completed", LogType.Modules);
       Fields["HarvesterEfficiency"].guiName = Localizer.Format("#LOC_SystemHeat_ModuleSystemHeatHarvester_Field_Efficiency", ConverterName);
+
+      RegisterImpactRaycast();
+    }
+
+    void OnEnable()
+    {
+      RegisterImpactRaycast();
     }
 
     public override void FixedUpdate()
@@ -91,6 +103,40 @@ void OnDisable()
     {
       heatModule?.AddFlux(moduleID, 0f, 0f, false);
       HarvesterEfficiency = "-";
+      RaycastManager.Instance?.Unregister(this);
+    }
+
+    void RegisterImpactRaycast()
+    {
+      if (!HighLogic.LoadedSceneIsFlight || impactTransformCache == null)
+        return;
+      RaycastManager.Instance?.Register(this, impactTransformCache, ImpactRange, ImpactLayerMask);
+    }
+
+    protected override bool CheckForImpact()
+    {
+      if (string.IsNullOrEmpty(ImpactTransform) || impactTransformCache == null)
+        return true;
+
+      Collider collider;
+      var hit = RaycastManager.Instance?.GetRaycastHit(this);
+      if (hit != null)
+      {
+        collider = hit.Value.collider;
+      }
+      else
+      {
+        // If we're not registered for whatever reason then do the raycast ourselves.
+        var origin = impactTransformCache.position;
+        if (!Physics.Raycast(new Ray(origin, impactTransformCache.forward), out var fallback, ImpactRange, ImpactLayerMask))
+          return false;
+        collider = fallback.collider;
+      }
+
+      if (collider == null)
+        return false;
+
+      return collider.gameObject.GetComponentUpwards<ModuleComet>() != null;
     }
 
     void FixedUpdateFlight()
diff --git a/Source/Modules/ModuleSystemHeatHarvester.cs b/Source/Modules/ModuleSystemHeatHarvester.cs
index 42d40ee..e986827 100644
--- a/Source/Modules/ModuleSystemHeatHarvester.cs
+++ b/Source/Modules/ModuleSystemHeatHarvester.cs
@@ -4,6 +4,7 @@
 using System.Text;
 using UnityEngine;
 using KSP.Localization;
+using SystemHeat.Addons;
 using Unity.Profiling;
 
 namespace SystemHeat
@@ -52,6 +53,9 @@ public void ToggleEditorThermalSim()
 
     protected ModuleSystemHeat heatModule;
 
+    // Stock ModuleResourceHarvester raycasts against layer 15 only.
+    private const int ImpactLayerMask = 32768;
+
     private static readonly ProfilerMarker BaseFixedUpdateMarker = new("ModuleResourceHarvester.FixedUpdate");
 
     public override string GetInfo()
@@ -77,6 +81,13 @@ public void Start()
       Utils.Log("[ModuleSystemHeatHarvester] Setup completed", LogType.Modules);
       Events["ToggleEditorThermalSim"].guiName = Localizer.Format("#LOC_SystemHeat_ModuleSystemHeatHarvester_Field_SimulateEditor", ConverterName);
       Fields["HarvesterEfficiency"].guiName = Localizer.Format("#LOC_SystemHeat_ModuleSystemHeatHarvester_Field_Efficiency", ConverterName);
+
+      RegisterImpactRaycast();
+    }
+
+    void OnEnable()
+    {
+      RegisterImpactRaycast();
     }
 
     public override void FixedUpdate()
@@ -107,6 +118,31 @@ void OnDisable()
     {
       heatModule?.AddFlux(moduleID, 0f, 0f, false);
       HarvesterEfficiency = "-";
+      RaycastManager.Instance?.Unregister(this);
+    }
+
+    void RegisterImpactRaycast()
+    {
+      if (!HighLogic.LoadedSceneIsFlight || impactTransformCache == null)
+        return;
+      RaycastManager.Instance?.Register(this, impactTransformCache, ImpactRange, ImpactLayerMask);
+    }
+
+    protected override bool CheckForImpact()
+    {
+      if (string.IsNullOrEmpty(ImpactTransform) || impactTransformCache == null)
+        return true;
+
+      var hit = RaycastManager.Instance?.GetRaycastHit(this);
+      if (hit is not RaycastHit raycastHit)
+      {
+        // If we're not registered for whatever reason then do the raycast ourselves.
+        var origin = impactTransformCache.position;
+        if (!Physics.Raycast(new Ray(origin, impactTransformCache.forward), out raycastHit, ImpactRange, ImpactLayerMask))
+          return false;
+      }
+
+      return raycastHit.collider != null;
     }
 
     void FixedUpdateFlight()