diff --git a/app/local/Unit.js b/app/local/Unit.js
index 9214434e..641b2a3c 100644
--- a/app/local/Unit.js
+++ b/app/local/Unit.js
@@ -19,7 +19,8 @@ Unit.parsec = {};
 // Note that, while this exact value is correct, it's larger than
 // Number.MAX_SAFE_INTEGER and will produce bad results in contexts where
 // accuracy is needed.
-Unit.parsec.inMeters = BigInt('30856775814913673');
+Unit.parsec.inMetersBigInt = BigInt('30856775814913673');
+Unit.parsec.inMeters = Number(Unit.parsec.inMetersBigInt);
 // ^^ factors:
 // 1801n, 12269n, 22096469n, 1396457317n
 
@@ -30,6 +31,7 @@ Unit.lightYear = {};
 // Note that, while this exact value is correct, it's larger than
 // Number.MAX_SAFE_INTEGER and will produce bad results in contexts where
 // accuracy is needed (we're accurate up to just over 0.9ly).
-Unit.lightYear.inMeters = BigInt('9460730472580800');
+Unit.lightYear.inMetersBigInt = BigInt('9460730472580800');
+Unit.lightYear.inMeters = Number(Unit.lightYear.inMetersBigInt);
 
 export default Unit;
diff --git a/app/local/core.js b/app/local/core.js
index c5e63857..9adef591 100644
--- a/app/local/core.js
+++ b/app/local/core.js
@@ -78,6 +78,7 @@ window.$game = {
   // TODO: determine if this has become redundant (we're implementing new positioning methods).
   hyperMovement: false,
   event: {
+    offscreenSkyboxReady: new ChangeTracker(),
     skyboxLoaded: new ChangeTracker(),
   }
 };
diff --git a/app/managedWorkers/ManagedWorker.js b/app/managedWorkers/ManagedWorker.js
deleted file mode 100644
index 90226e52..00000000
--- a/app/managedWorkers/ManagedWorker.js
+++ /dev/null
@@ -1,32 +0,0 @@
-// Managed web worker with opt-in/out listeners.
-
-import CbQueue from '../local/CbQueue';
-
-export default class ManagedWorker extends Worker {
-  constructor(url) {
-    super(url, { type: 'module' });
-    super.onmessage = this._onInternalMessage;
-    this._listeners = {};
-  }
-
-  addWorkerListener(message, callback) {
-    if (!this._listeners[message]) {
-      this._listeners[message] = new CbQueue();
-    }
-    this._listeners[message].register(callback);
-  }
-
-  removeWorkerListener(message, callback) {
-    if (!this._listeners[message]) {
-      return;
-    }
-    this._listeners[message].deregister(callback);
-  }
-
-  _onInternalMessage(message) {
-    const payload = message.data;
-    if (this._listeners[payload.key]) {
-      this._listeners[payload.key].notifyAll(payload);
-    }
-  }
-}
diff --git a/app/managedWorkers/OffscreenSkyboxWorker.js b/app/managedWorkers/OffscreenSkyboxWorker.js
index 4d2cedc3..07589fcf 100644
--- a/app/managedWorkers/OffscreenSkyboxWorker.js
+++ b/app/managedWorkers/OffscreenSkyboxWorker.js
@@ -1,15 +1,20 @@
-import ManagedWorker from './ManagedWorker';
 import * as THREE from 'three';
 import Unit from '../local/Unit';
 import { logBootInfo } from '../local/windowLoadListener';
+import ChangeTracker from '../emitters/ChangeTracker';
 
-export default class OffscreenSkyboxWorker extends ManagedWorker {
+// TODO: maybe rename to astrometrics worker? It's become more than just a
+//  skybox machine.
+export default class OffscreenSkyboxWorker extends Worker {
   constructor() {
     // Note: offscreenRenderer.js is made available via Webpack bundling.
-    super('./build/offscreenSkybox.js');
+    super('./build/offscreenSkybox.js', { type: 'module' });
     this.skyboxCube = null;
+    this.initComplete = false;
     // Just a tad bigger than the Milky Way. Yes, we can do that. In meters.
-    this.skyboxSize = Number(Unit.parsec.inMeters * BigInt(32768));
+    this.skyboxSize = Number(Unit.parsec.inMetersBigInt * BigInt(32768));
+    // Used to uniquely identify each web worker request.
+    this.ticketCount = 0;
 
     this._collectedImages = [
       null, null, null, null, null, null,
@@ -19,17 +24,41 @@ export default class OffscreenSkyboxWorker extends ManagedWorker {
   }
 
   prepListeners() {
-    this.addWorkerListener('init', ({ error, value }) => {
+    // Create worker listeners.
+    this.workerListener = {
+      init: new ChangeTracker(),
+      renderFace: new ChangeTracker(),
+      testHeavyPayload: new ChangeTracker(),
+    };
+
+    // Hook listeners into onmessage.
+    this.onmessage = (message) => {
+      const payload = message.data;
+      const listener = this.workerListener[payload.key];
+      if (!listener) {
+        return console.error(
+          '[OffscreenSkyboxWorker] Nothing to receive', payload.key
+        );
+      }
+      listener.setValue(payload);
+    };
+
+    // Define listener responses.
+    this.workerListener.init.getEveryChange(({ error, value }) => {
+      if (this.initComplete) {
+        return console.error('[OffscreenSkyboxWorker] Init received twice.');
+      }
+      this.initComplete = true;
       if (error || !value) {
         console.error(error, '- got:', value);
       }
       else {
-        this.ready = true;
         this.generateSkybox();
+        $game.event.offscreenSkyboxReady.setValue({ when: new Date() });
       }
     });
 
-    this.addWorkerListener('renderFace', ({ value }) => {
+    this.workerListener.renderFace.getEveryChange(({ value }) => {
       const { x, y, z, sideNumber, tag } = value;
       if (tag === 'internal cascade') {
         // Caution: this is request**Post**AnimationFrame, not
@@ -57,7 +86,7 @@ export default class OffscreenSkyboxWorker extends ManagedWorker {
       }
     });
 
-    this.addWorkerListener('testHeavyPayload', ({ error, value }) => {
+    this.workerListener.testHeavyPayload.getEveryChange(({ error, value }) => {
       console.log('testHeavyPayload:', value.length, 'KB transferred. Error:', error);
     });
   }