diff --git a/docs/CODE-BOUNDARIES.md b/docs/CODE-BOUNDARIES.md
index cd3c2bf2c..24cf1491d 100644
--- a/docs/CODE-BOUNDARIES.md
+++ b/docs/CODE-BOUNDARIES.md
@@ -109,13 +109,15 @@ panel carries no Navara or three. There is no blanket exception for layer
 
 The temporary `engineImportExceptions` list in `scripts/package-boundaries.json`
 contains exact file/package pairs with reasons. The checker reports the used
-entries and rejects duplicates, missing reasons and unused entries. Its three
-exceptions are the Bhote Koshi event, locator and embedded-media models in
-`src/data/`, which still construct Cesium property records. Their drawing uses
-shared displays. Exceptions do not relax the portable, contract or cross-engine
-graph checks. Cesium annotation renderers live in `src/globe/cesium/annotations/`;
-wind backend adapters live in their engine folders. Wind's older injected-SDK
-helpers and the remaining annotation migration are separate debt.
+entries and rejects duplicates, missing reasons and unused entries. Its two
+exceptions are the Bhote Koshi event and locator models in `src/data/`, which
+still construct Cesium property records. Their drawing uses shared displays.
+Exceptions do not relax the portable, contract or cross-engine graph checks.
+Cesium annotation renderers live in `src/globe/cesium/annotations/`. Wind's
+Cesium rendering (the particle canvas, its GPU path and the relief shading)
+lives in `src/globe/cesium/`; `src/layers/wind/` keeps the data, model,
+presentation and engine-neutral inspection. The remaining annotation migration
+is separate debt.
 
 Source-only factories use dedicated `layers/<family>/source` exports where
 available, preserving the same factory implementation without loading rendering.
diff --git a/docs/KNOWN-ISSUES.md b/docs/KNOWN-ISSUES.md
index 1ed1f74d9..d4396825f 100644
--- a/docs/KNOWN-ISSUES.md
+++ b/docs/KNOWN-ISSUES.md
@@ -33,14 +33,15 @@ Status: Open (manual map selection)
 Navara does not report tile errors, so a failing map source does not trigger
 fallback to another map. Select another map manually when tiles fail to load.
 
-### Orbital cockpit is unavailable on Navara
+### Orbital imagery look-ahead is unavailable on Navara
 
 Status: Open (Cesium only)
 
-The Navara engine does not offer the satellite cockpit, including sensor
-zoom, ground focus and satellite switching. Satellites can still be selected
-and tracked on the globe. The orbital entry control stays hidden. Switch to
-Cesium to use the orbital cockpit.
+The orbital cockpit works on both engines. On Navara it loads imagery for
+its current view but does not prefetch imagery ahead of the ground track.
+At high optical zoom, imagery can arrive later than on Cesium. Navara's
+package does not expose a raster prefetch operation sharing its tile cache
+and request priorities.
 
 ### Ship bridge waterline uses loaded geometry on Navara
 
diff --git a/scripts/contract-mutants.test.mjs b/scripts/contract-mutants.test.mjs
index 30a197698..49857ab6a 100644
--- a/scripts/contract-mutants.test.mjs
+++ b/scripts/contract-mutants.test.mjs
@@ -15,6 +15,20 @@ const handle = (engine, area, factory, mutate) =>
   });
 
 const mutants = [
+  [
+    'field of view changes are ignored',
+    'camera.setFovy: changes projection',
+    (e) => { e.camera.setFovy = () => {}; },
+  ],
+  [
+    'optical fields below one degree are ignored',
+    'camera.setFovy: changes projection',
+    (e) => {
+      replace(e.camera, 'setFovy', (set) => (radians) => {
+        if (radians >= Math.PI / 180) set(radians);
+      });
+    },
+  ],
   [
     'retarget omits followChanged',
     'camera.following: set, retarget',
diff --git a/scripts/engine-coupling-baseline.json b/scripts/engine-coupling-baseline.json
index defccda2b..b05cf9980 100644
--- a/scripts/engine-coupling-baseline.json
+++ b/scripts/engine-coupling-baseline.json
@@ -6,14 +6,14 @@
     "engineSwitchLayerIds": 3,
     "cesiumLayerRendererLines": 0,
     "navaraLayerRendererLines": 0,
-    "cesiumImportFiles": 3,
-    "viewerLines": 784,
+    "cesiumImportFiles": 2,
+    "viewerLines": 666,
     "navaraKindChecks": 1,
     "engineSniffCalls": 0,
-    "engineExtensionReads": 3,
+    "engineExtensionReads": 2,
     "groundEffectPasses": 0,
     "cesiumSdkLoads": 3,
     "screenSpaceHandlerFiles": 2,
-    "engineNameLines": 21
+    "engineNameLines": 20
   }
 }
diff --git a/scripts/package-boundaries.json b/scripts/package-boundaries.json
index 88ab5fa5a..ecaaa2655 100644
--- a/scripts/package-boundaries.json
+++ b/scripts/package-boundaries.json
@@ -1,10 +1,5 @@
 {
   "engineImportExceptions": [
-    {
-      "file": "src/data/bhoteKoshiEmbeddedMedia.js",
-      "package": "cesium",
-      "reason": "Authored story media still uses Cesium positions and property records."
-    },
     {
       "file": "src/data/bhoteKoshiEvent.js",
       "package": "cesium",
@@ -855,7 +850,8 @@
       "src/globe/cesium/doubleClick.js",
       "src/globe/cesium/orbital.js",
       "src/globe/surfaceDetail.js",
-      "src/globe/surfacePlacement.js"
+      "src/globe/surfacePlacement.js",
+      "src/globe/cesium/orbitalImagery.js"
     ],
     "external": ["cesium"]
   },
@@ -1108,7 +1104,6 @@
       "src/data/detectionCohort.js",
       "src/data/labelArbiter.js",
       "src/globe/cesium/celestial.js",
-      "src/layers/shared/render/engineView.js",
       "src/overlays/worldOverlay.js",
       "src/overlays/worldOverlayDraw.js",
       "src/overlays/worldOverlayTokens.js",
@@ -1116,7 +1111,9 @@
       "src/data/trackedReadout.js",
       "src/ui/releaseTrackers.js",
       "src/globe/cesium/orbital.js",
-      "src/time/clock.js"
+      "src/time/clock.js",
+      "src/globe/cesium/celestialHost.js",
+      "src/globe/cesium/orbitalImagery.js"
     ],
     "external": ["cesium", "vue", "pinia", "vue-i18n"]
   },
@@ -2820,7 +2817,12 @@
       "src/data/geoImportLimits.js",
       "src/data/geoImportPlan.js",
       "src/globe/cesium/qaTileset.js",
-      "src/maps/qaTileset.js"
+      "src/maps/qaTileset.js",
+      "src/globe/cesium/celestialHost.js",
+      "src/globe/cesium/orbitalImagery.js",
+      "src/globe/cesium/windGpuRendering.js",
+      "src/globe/cesium/windRelief.js",
+      "src/globe/cesium/windRendering.js"
     ],
     "external": [
       "hls.js",
@@ -2877,11 +2879,8 @@
       "src/layers/wind/model.js",
       "src/layers/wind/fields.js",
       "src/layers/wind/streamlines.js",
-      "src/layers/wind/gpuRendering.js",
-      "src/layers/wind/relief.js",
       "src/layers/wind/inspection.js",
       "src/layers/wind/presentation.js",
-      "src/layers/wind/rendering.js",
       "src/app/layers/aisLiveVessels.js",
       "src/app/layers/alprCameras.js",
       "src/app/layers/bikeshare.js",
@@ -3260,7 +3259,11 @@
       "src/data/ucsSatellites.js",
       "src/data/imagingSensors.js",
       "src/data/planespottersPhoto.js",
-      "src/data/geoImportLimits.js"
+      "src/data/geoImportLimits.js",
+      "src/globe/cesium/celestialHost.js",
+      "src/globe/cesium/windGpuRendering.js",
+      "src/globe/cesium/windRelief.js",
+      "src/globe/cesium/windRendering.js"
     ],
     "external": [
       "hls.js",
@@ -3882,7 +3885,6 @@
       "src/sources/featureSource.js",
       "src/sources/capability.js",
       "src/i18n/",
-      "src/celestialRing/view.js",
       "src/layers/shared/render/engineView.js",
       "src/globe/cesium/sceneProjection.js",
       "src/layers/shared/color.js",
@@ -3900,7 +3902,8 @@
       "src/data/trackedReadout.js",
       "src/data/trackingGesture.js",
       "src/time/worldClock.js",
-      "src/time/clock.js"
+      "src/time/clock.js",
+      "src/globe/cesium/celestialHost.js"
     ],
     "external": ["cesium", "egm96-universal", "pbf"]
   },
diff --git a/scripts/qa-wind-canvas.mjs b/scripts/qa-wind-canvas.mjs
index dd93cc588..885a52c47 100644
--- a/scripts/qa-wind-canvas.mjs
+++ b/scripts/qa-wind-canvas.mjs
@@ -6,7 +6,7 @@ try {
   const page = await browser.newPage();
   await page.goto(`${process.env.QA_BASE_URL || 'http://localhost:4173'}/`, { waitUntil: 'domcontentloaded' });
   const result = await page.evaluate(async () => {
-    const { createWindRendering } = await import('/src/layers/wind/rendering.js');
+    const { createWindRendering } = await import('/src/globe/cesium/windRendering.js');
     const raf = window.requestAnimationFrame; const caf = window.cancelAnimationFrame;
     const callbacks = new Map(); let sequence = 0;
     window.requestAnimationFrame = callback => { callbacks.set(++sequence, callback); return sequence; };
diff --git a/src/app/tools.js b/src/app/tools.js
index 8533195bc..94fcec1d7 100644
--- a/src/app/tools.js
+++ b/src/app/tools.js
@@ -101,7 +101,7 @@ export async function createApplicationTools({
       // Cesium only for now: it reads Cesium's camera (positionWC, its
       // running flight).
       attachScene(next, { defer: deferScene }) {
-        const viewer = cesiumViewerOf(next.engine);
+        const viewer = next.viewer;
         if (!viewer) return;
         deferScene(
           installGlobeInViewRecovery(viewer, {
@@ -255,12 +255,6 @@ export async function createApplicationTools({
   };
 }
 
-/**
- * The Cesium viewer under an engine, or null on an engine without one: the
- * one place the tools read it.
- */
-const cesiumViewerOf = (engine) => engine?.extensions?.cesium?.viewer ?? null;
-
 /**
  * The tool backend of each engine kind (see attachEngineTools). Cesium's
  * holds the tools that still drive its viewer, so they stay absent on
@@ -273,13 +267,8 @@ const TOOL_BACKENDS = Object.freeze({
 });
 
 /** The Cesium tool backend: the shared tools and its own on the viewer. */
-function cesiumToolBackend({ engine, tileset }) {
-  const viewer = cesiumViewerOf(engine);
-  const {
-    governorRequestRender,
-    holdContinuousRender,
-    releaseContinuousRender,
-  } = renderGovernorFor(engine);
+function cesiumToolBackend({ engine, viewer, tileset }) {
+  const { governorRequestRender } = renderGovernorFor(engine);
   return {
     viewer,
     startupChrome: {},
@@ -300,18 +289,6 @@ function cesiumToolBackend({ engine, tileset }) {
           requestRender: governorRequestRender,
         }),
       );
-      // The follow camera recomputes the tracked target's dead-reckon
-      // position every frame — tracking anything is a per-frame animation.
-      // (perf wave 2)
-      const removeTrackingListener =
-        viewer.trackedEntityChanged.addEventListener(() => {
-          if (viewer.trackedEntity) holdContinuousRender('tracked-entity');
-          else releaseContinuousRender('tracked-entity');
-        });
-      defer(() => {
-        removeTrackingListener();
-        releaseContinuousRender('tracked-entity');
-      });
     },
     // Hidden-state suspension (perf wave 2): when the window/tab is hidden,
     // stop the default render loop outright — a hidden canvas repaints for
@@ -418,6 +395,20 @@ async function attachEngineTools(
   governor.install();
   backend.attach?.({ data, styleManager, dataManager }, { signal, defer });
 
+  // A followed target moves every frame, even while the camera is still.
+  const updateFollow = () => {
+    if (engine.camera.following())
+      governor.holdContinuousRender('tracked-entity');
+    else governor.releaseContinuousRender('tracked-entity');
+  };
+  const removeFollow =
+    engine.camera.followChanged.addEventListener(updateFollow);
+  updateFollow();
+  defer(() => {
+    removeFollow();
+    governor.releaseContinuousRender('tracked-entity');
+  });
+
   // Install the explicit scope mask used by the DISPLAY controls: a canvas
   // in the engine's container, its terminus following the camera's height.
   installScopeMask(engine);
diff --git a/src/celestialRing.js b/src/celestialRing.js
index 887bcc801..5bb9b8f63 100644
--- a/src/celestialRing.js
+++ b/src/celestialRing.js
@@ -1,12 +1,7 @@
 import * as geo from './geo/index.js';
-import { createCelestialView } from './celestialRing/view.js';
-import {
-  cesiumIcrfToFixed,
-  projectCelestialPoint,
-  flyCelestialViewer,
-} from './globe/cesium/celestial.js';
+import { cesiumIcrfToFixed } from './globe/cesium/celestial.js';
 import { createCelestialEphemeris } from './celestialRing/ephemeris.js';
-import { renderGovernorFor } from './renderGovernor.js';
+import { celestialHost } from './globe/cesium/celestialHost.js';
 import { worldClock, worldTimeFor } from './time/worldClock.js';
 
 // The ring shows the sun and moon at the time the sky is drawn.
@@ -154,8 +149,8 @@ export function isCelestialRingStyleSupported(styleName) {
  * is inverted. When the celestial vector points almost directly into/out of the
  * camera, retain the prior stable bearing and fade the marker.
  *
- * @param {number} rightComponent - Dot(direction, camera.rightWC).
- * @param {number} upComponent - Dot(direction, camera.upWC).
+ * @param {number} rightComponent - Dot(direction, camera.right).
+ * @param {number} upComponent - Dot(direction, camera.up).
  * @param {number} lastAngle - Previous stable angle in radians.
  * @returns {{angle:number, opacity:number, stable:boolean}}
  */
@@ -245,29 +240,29 @@ export function earthDiscScreenRadius(cameraDistance, viewportHeight, fovy) {
  * Project the visible Earth disc into viewport coordinates.
  * Shared by full-globe UI treatments that must agree on visual containment.
  *
- * @param {object} viewer - Cesium Viewer-like object.
+ * @param {object} engine - Globe engine or legacy scene host.
  * @param {number} width - Viewport width in CSS pixels.
  * @param {number} height - Viewport height in CSS pixels.
- * @param {object} [scratchCenter] - Reusable Cesium Cartesian2 result.
- * @param {object} [scratchToCenter] - Reusable Cesium Cartesian3 result.
+ * @param {object} [scratchCenter] - Reusable Cartesian2 result.
+ * @param {object} [scratchToCenter] - Reusable Cartesian3 result.
  * @param {import('./globe/contract.js').GlobeProjector | null} [projector] -
  *   The globe engine's projector; without one, Cesium's SceneTransforms
  *   (the same projection on a Cesium scene).
  * @returns {object|null}
  */
 export function projectEarthDiscToViewport(
-  viewer,
+  engine,
   width,
   height,
   scratchCenter = undefined,
   scratchToCenter = undefined,
   projector = null,
 ) {
-  const camera = viewer?.camera;
-  const scene = viewer?.scene;
-  if (!camera || !scene || !(width > 0) || !(height > 0)) return null;
+  if (!engine?.camera || !(width > 0) || !(height > 0)) return null;
+  const host = engine.camera.pose ? engine : celestialHost(engine);
+  const camera = host.camera.pose();
 
-  const distance = geo.cartesian3.magnitude(camera.positionWC);
+  const distance = geo.cartesian3.magnitude(camera.position);
   if (
     !Number.isFinite(distance) ||
     distance <= geo.ellipsoid.WGS84.maximumRadius
@@ -275,22 +270,19 @@ export function projectEarthDiscToViewport(
     return null;
 
   const toCenter = geo.cartesian3.negate(
-    camera.positionWC,
+    camera.position,
     scratchToCenter || geo.cartesian3.create(),
   );
-  if (geo.cartesian3.dot(camera.directionWC, toCenter) <= 0) return null;
+  if (geo.cartesian3.dot(camera.direction, toCenter) <= 0) return null;
 
-  const center = projector
-    ? projector.worldToWindow(geo.cartesian3.ZERO, scratchCenter)
-    : projectCelestialPoint(scene, geo.cartesian3.ZERO, scratchCenter);
+  const center = (projector ?? host.projector).worldToWindow(
+    geo.cartesian3.ZERO,
+    scratchCenter,
+  );
   if (!center || !Number.isFinite(center.x) || !Number.isFinite(center.y))
     return null;
 
-  const earthRadius = earthDiscScreenRadius(
-    distance,
-    height,
-    camera.frustum?.fovy,
-  );
+  const earthRadius = earthDiscScreenRadius(distance, height, camera.fovy);
   if (!earthRadius) return null;
 
   const keyhole = getKeyholeGeometry(width, height);
@@ -401,7 +393,7 @@ let rings = 0;
 /**
  * Screen-space ring and celestial direction overlay for the full-globe view.
  * The overlay is presented to the celestial ring store, whose view renders it
- * inside the viewer's container and hands back the two canvases this paints.
+ * inside the engine's container and hands back the two canvases this paints.
  */
 export class CelestialRing {
   /**
@@ -416,13 +408,7 @@ export class CelestialRing {
     viewer,
     { enabled = true, onAutoDisable = null, store, engine = null } = {},
   ) {
-    this._engine = engine ?? (viewer?.kind ? viewer : null);
-    this._engineView = viewer?.kind ? createCelestialView(viewer) : null;
-    this.viewer = this._engineView?.view ?? viewer;
-    this._projector = engine?.projector ?? null;
-    this._renderGovernor = renderGovernorFor(
-      engine ?? (viewer?.kind ? viewer : null),
-    );
+    this._engine = engine ?? (viewer?.kind ? viewer : celestialHost(viewer));
     this.enabled = !!enabled;
     this.visible = false;
     this._onAutoDisable =
@@ -455,8 +441,8 @@ export class CelestialRing {
     );
 
     this._initView(store);
-    this._removePostRender = this.viewer.scene.postRender.addEventListener(() =>
-      this._draw(),
+    this._removePostRender = this._engine.frames.postRender.addEventListener(
+      () => this._draw(),
     );
     // Pre-existing staleness fix (perf wave 2 review): the ephemeris was
     // sampled once per visible-enable from the FROZEN app clock, so the
@@ -470,7 +456,7 @@ export class CelestialRing {
       // dirty flag up immediately. (review finding)
       this._ephemerisDirty = true;
       if (typeof document !== 'undefined' && document.hidden) return;
-      this._renderGovernor?.governorRequestRender('celestial-ephemeris');
+      this._engine.render.request('celestial-ephemeris');
     }, 60_000);
     // A jump in the world time moves the sun and moon at once.
     // Played through, the sky moves on each minute of world time it passes.
@@ -495,7 +481,7 @@ export class CelestialRing {
     this._view = {
       id: ++rings,
       owner,
-      container: this.viewer.container,
+      container: this._engine.host.container,
       enabled: this.enabled,
       visible: false,
       globeVisible: null,
@@ -548,8 +534,7 @@ export class CelestialRing {
       this._moonCtx = ctx;
       this._moonRenderKey = '';
     } else return;
-    if (canvas && this.enabled)
-      this._renderGovernor?.governorRequestRender('celestial-ring');
+    if (canvas && this.enabled) this._engine.render.request('celestial-ring');
   }
 
   /** Enable or disable the user preference for the effect. */
@@ -563,7 +548,7 @@ export class CelestialRing {
     // all. Camera motion covers every later repaint; the 60 s ephemeris
     // timer requests its own. (perf wave 2 fix — owner playtest finding)
     if (this.enabled !== wasEnabled)
-      this._renderGovernor?.governorRequestRender('celestial-ring');
+      this._engine.render.request('celestial-ring');
     if (!this.enabled) {
       this.visible = false;
       this._clear();
@@ -576,7 +561,7 @@ export class CelestialRing {
 
   /** Whether the current camera already frames the complete globe inside the keyhole. */
   isGlobeFullyVisible() {
-    const canvas = this.viewer.scene.canvas;
+    const canvas = this._engine.host.canvas;
     const width = canvas.clientWidth || canvas.width;
     const height = canvas.clientHeight || canvas.height;
     if (!(width > 0 && height > 0)) return false;
@@ -591,10 +576,10 @@ export class CelestialRing {
    * @returns {boolean} Whether a valid camera flight was started.
    */
   focusFullGlobe({ duration = 2.4 } = {}) {
-    const canvas = this.viewer.scene.canvas;
+    const canvas = this._engine.host.canvas;
     const height = canvas.clientHeight || canvas.height;
-    const cartographic = this.viewer.camera.positionCartographic;
-    const fovy = this.viewer.camera.frustum?.fovy;
+    const pose = this._engine.camera.pose();
+    const { cartographic, fovy } = pose;
     if (
       !(height > 0) ||
       !cartographic ||
@@ -620,7 +605,7 @@ export class CelestialRing {
     this._focusInProgress = true;
     const finishFocus = () => {
       this._focusInProgress = false;
-      this.viewer.scene.requestRender?.();
+      this._engine.render.request('celestial-ring');
     };
     const flight = {
       destination: geo.cartesian3.fromRadians(
@@ -629,7 +614,7 @@ export class CelestialRing {
         altitude,
       ),
       orientation: {
-        heading: this.viewer.camera.heading,
+        heading: pose.heading,
         pitch: -geo.math.PI_OVER_TWO,
         roll: 0,
       },
@@ -640,9 +625,7 @@ export class CelestialRing {
         if (!this.isGlobeFullyVisible()) this._autoDisable();
       },
     };
-    if (this._engine)
-      this._engine.camera.flyTo({ ...flight, easing: 'cubicInOut' });
-    else flyCelestialViewer(this.viewer, flight);
+    this._engine.camera.flyTo({ ...flight, easing: 'cubicInOut' });
     return true;
   }
 
@@ -713,12 +696,11 @@ export class CelestialRing {
   /** Return the projected Earth disc used for the full-globe gate. */
   _projectedEarthDisc(width, height) {
     return projectEarthDiscToViewport(
-      this.viewer,
+      this._engine,
       width,
       height,
       this._screenCenter,
       this._toCenter,
-      this._projector,
     );
   }
 
@@ -795,7 +777,7 @@ export class CelestialRing {
     const now = performance.now();
     if (now < this._nextDrawAt) return;
     this._nextDrawAt = now + 1000 / CELESTIAL_MAX_FRAME_RATE;
-    const canvas = this.viewer.scene.canvas;
+    const canvas = this._engine.host.canvas;
     const width = canvas.clientWidth || canvas.width;
     const height = canvas.clientHeight || canvas.height;
     if (!(width > 0 && height > 0)) return;
@@ -828,15 +810,15 @@ export class CelestialRing {
     const time = skyTime();
     if (!this._updateEphemeris(time)) return;
     this._present({ ephemerisUpdates: String(this._ephemerisUpdateCount) });
-    const camera = this.viewer.camera;
+    const camera = this._engine.camera.pose();
     const sunProjection = celestialScreenAngle(
-      geo.cartesian3.dot(this._sunFixed, camera.rightWC),
-      geo.cartesian3.dot(this._sunFixed, camera.upWC),
+      geo.cartesian3.dot(this._sunFixed, camera.right),
+      geo.cartesian3.dot(this._sunFixed, camera.up),
       this._sunAngle,
     );
     const moonProjection = celestialScreenAngle(
-      geo.cartesian3.dot(this._moonFixed, camera.rightWC),
-      geo.cartesian3.dot(this._moonFixed, camera.upWC),
+      geo.cartesian3.dot(this._moonFixed, camera.right),
+      geo.cartesian3.dot(this._moonFixed, camera.up),
       this._moonAngle,
     );
     if (sunProjection.stable) this._sunAngle = sunProjection.angle;
@@ -923,6 +905,5 @@ export class CelestialRing {
       this._store.publish(null);
     }
     this._sunCanvas = this._sunCtx = this._moonCanvas = this._moonCtx = null;
-    this._engineView?.destroy();
   }
 }
diff --git a/src/celestialRingFocus.test.mjs b/src/celestialRingFocus.test.mjs
index 382d5c8ef..3033bff2c 100644
--- a/src/celestialRingFocus.test.mjs
+++ b/src/celestialRingFocus.test.mjs
@@ -5,25 +5,19 @@ import { CelestialRing } from './celestialRing.js';
 test('full globe focus uses the engine without a Cesium global', () => {
   let flight;
   const engine = {
+    host: { canvas: { clientWidth: 1200, clientHeight: 800 } },
+    render: { request() {} },
     camera: {
-      flyTo: (options) => {
-        flight = options;
-      },
+      pose: () => ({
+        cartographic: { longitude: 0, latitude: 0 },
+        heading: 0,
+        fovy: Math.PI / 3,
+      }),
+      flyTo: (options) => { flight = options; },
     },
   };
   const ring = Object.assign(Object.create(CelestialRing.prototype), {
     _engine: engine,
-    viewer: {
-      scene: {
-        canvas: { clientWidth: 1200, clientHeight: 800 },
-        requestRender() {},
-      },
-      camera: {
-        positionCartographic: { longitude: 0, latitude: 0 },
-        heading: 0,
-        frustum: { fovy: Math.PI / 3 },
-      },
-    },
   });
   assert.equal(globalThis.Cesium, undefined);
   assert.equal(ring.focusFullGlobe(), true);
diff --git a/src/data/bhoteKoshiEmbeddedMedia.js b/src/data/bhoteKoshiEmbeddedMedia.js
index d75bf8612..63ee90c10 100644
--- a/src/data/bhoteKoshiEmbeddedMedia.js
+++ b/src/data/bhoteKoshiEmbeddedMedia.js
@@ -1,4 +1,3 @@
-import * as Cesium from 'cesium';
 import { t, msg, onLocaleChange } from '../i18n/index.js';
 
 const YOUTUBE_HOSTS = new Set([
@@ -538,25 +537,12 @@ function ensureProviderConnections(documentRef, provider) {
   }
 }
 
-function anchorOnScreen(viewer, engine, anchor, root) {
-  if ((!viewer?.scene && !engine) || !anchor || !root) return null;
-  const camera = viewer?.camera;
-  if (engine && !engine.projector.horizonVisible(anchor)) return null;
-  if (camera?.positionWC && camera?.directionWC) {
-    const delta = Cesium.Cartesian3.subtract(
-      anchor,
-      camera.positionWC,
-      new Cesium.Cartesian3(),
-    );
-    if (Cesium.Cartesian3.dot(delta, camera.directionWC) <= 0) return null;
-  }
-  const pixel = engine
-    ? engine.projector.worldToWindow(anchor, {})
-    : Cesium.SceneTransforms.worldToWindowCoordinates(viewer.scene, anchor);
+function anchorOnScreen(engine, anchor, root) {
+  if (!engine || !anchor || !root) return null;
+  if (!engine.projector.horizonVisible(anchor)) return null;
+  const pixel = engine.projector.worldToWindow(anchor, {});
   if (!pixel) return null;
-  const canvasBounds = (
-    engine?.host.canvas ?? viewer?.canvas
-  )?.getBoundingClientRect?.();
+  const canvasBounds = engine.host.canvas?.getBoundingClientRect?.();
   const rootBounds = root.getBoundingClientRect?.();
   if (!canvasBounds || !rootBounds) return null;
   const x = pixel.x + canvasBounds.left - rootBounds.left;
@@ -855,7 +841,7 @@ export function createBhoteKoshiEmbeddedMedia({
 
   const position = () => {
     if (!record) return;
-    const projected = anchorOnScreen(viewer, engine, record.anchor, root);
+    const projected = anchorOnScreen(engine, record.anchor, root);
     record.card.hidden = !projected;
     if (projected) {
       placeCard(record.card, record.leader, projected);
diff --git a/src/data/bhoteKoshiEvent.js b/src/data/bhoteKoshiEvent.js
index 6b9d3cd55..78d3b001a 100644
--- a/src/data/bhoteKoshiEvent.js
+++ b/src/data/bhoteKoshiEvent.js
@@ -885,7 +885,7 @@ function openExternal(url) {
   if (target) target.opener = null;
 }
 
-function focusView(viewer, viewpoint, engine) {
+function focusView(engine, viewpoint) {
   announceNavigationAuthority('bhote-koshi-event-focus');
   const target = Cesium.Cartesian3.fromDegrees(
     viewpoint.lon,
@@ -897,32 +897,20 @@ function focusView(viewer, viewpoint, engine) {
     Cesium.Math.toRadians(viewpoint.pitchDeg),
     viewpoint.rangeM,
   );
-  if (engine) {
-    engine.camera.cancelFlight();
-    engine.camera.flyToSphere(
-      { center: target, radius: 80 },
-      {
-        heading: offset.heading,
-        pitch: offset.pitch,
-        range: offset.range,
-        duration: 2.2,
-        complete: () => {
-          engine.camera.lookAt(target, offset);
-          engine.camera.lookAtTransform(Cesium.Matrix4.IDENTITY);
-        },
+  engine.camera.cancelFlight();
+  engine.camera.flyToSphere(
+    { center: target, radius: 80 },
+    {
+      heading: offset.heading,
+      pitch: offset.pitch,
+      range: offset.range,
+      duration: 2.2,
+      complete: () => {
+        engine.camera.lookAt(target, offset);
+        engine.camera.lookAtTransform(Cesium.Matrix4.IDENTITY);
       },
-    );
-    return;
-  }
-  viewer.camera.cancelFlight?.();
-  viewer.camera.flyToBoundingSphere(new Cesium.BoundingSphere(target, 80), {
-    offset,
-    duration: 2.2,
-    complete: () => {
-      viewer.camera.lookAt(target, offset);
-      viewer.camera.lookAtTransform(Cesium.Matrix4.IDENTITY);
     },
-  });
+  );
 }
 
 function setElementProperty(element, property, value) {
@@ -3524,8 +3512,7 @@ export function createBhoteKoshiEventLayer({
     _embeddedEvidenceIndex = -1;
     _embeddedMedia?.hide?.();
     setSplit(0.5);
-    if (cameraForScene())
-      focusView(_viewer, _event.viewpoints.corridor, _engine);
+    if (_engine) focusView(_engine, _event.viewpoints.corridor);
   }
 
   // Each attachment and release advances this. An attachment that resumes
diff --git a/src/globe/cesium/camera.js b/src/globe/cesium/camera.js
index 516457a5f..142dc5279 100644
--- a/src/globe/cesium/camera.js
+++ b/src/globe/cesium/camera.js
@@ -179,6 +179,14 @@ export function createCesiumCamera(viewer) {
   }
 
   const camera = {
+    setFovy(radians) {
+      if (!Number.isFinite(radians) || radians <= 0 || radians >= Math.PI)
+        throw new RangeError('Field of view must be between 0 and PI');
+      const aspect = cesium.frustum.aspectRatio;
+      cesium.frustum.fov =
+        aspect > 1 ? 2 * Math.atan(Math.tan(radians / 2) * aspect) : radians;
+      viewer.scene.requestRender();
+    },
     pose() {
       const position = toGeo3(cesium.positionWC);
       return {
diff --git a/src/globe/cesium/camera.test.mjs b/src/globe/cesium/camera.test.mjs
index a5dd334d1..8a88a9205 100644
--- a/src/globe/cesium/camera.test.mjs
+++ b/src/globe/cesium/camera.test.mjs
@@ -579,3 +579,47 @@ test('setView ends the engine flight through its cancellation callback', () => {
   assert.deepEqual(outcome, ['cancel']);
   assert.equal(camera.flightActive(), false);
 });
+
+test('completing a sphere flight fires only complete before its look-at', () => {
+  const { scene, engine } = createCameraViewer();
+  scene.tweens = new Cesium.TweenCollection();
+  scene.screenSpaceCameraController = { enableInputs: true };
+  const target = geo.cartesian3.fromDegrees(85.9, 27.9, 2000);
+  const offset = { heading: 0.4, pitch: -0.6, range: 12000 };
+  const outcome = [];
+  engine.camera.flyToSphere(
+    { center: target, radius: 80 },
+    {
+      ...offset,
+      duration: 2.2,
+      complete() {
+        outcome.push('complete');
+        engine.camera.lookAt(target, offset);
+        engine.camera.release();
+      },
+      cancel: () => outcome.push('cancel'),
+    },
+  );
+  engine.camera.completeFlight();
+  engine.camera.completeFlight();
+  assert.deepEqual(outcome, ['complete']);
+  assert.equal(engine.camera.flightActive(), false);
+  assert.ok(
+    Math.abs(
+      geo.cartesian3.distance(engine.camera.pose().position, target) -
+        offset.range,
+    ) < 0.01,
+  );
+  engine.destroy();
+});
+
+test('vertical field of view changes the real Cesium projection and restores it', () => {
+  const { camera, engine } = createCameraViewer();
+  const saved = camera.frustum.fovy;
+  engine.camera.setFovy(0.2);
+  assert.ok(Math.abs(camera.frustum.fovy - 0.2) < 1e-12);
+  assert.ok(Math.abs(engine.camera.pose().fovy - 0.2) < 1e-12);
+  engine.camera.setFovy(saved);
+  assert.ok(Math.abs(camera.frustum.fovy - saved) < 1e-12);
+  engine.destroy();
+});
diff --git a/src/globe/cesium/celestialHost.js b/src/globe/cesium/celestialHost.js
new file mode 100644
index 000000000..079d09286
--- /dev/null
+++ b/src/globe/cesium/celestialHost.js
@@ -0,0 +1,26 @@
+// Compatibility for callers that still construct the ring on a bare viewer.
+import { flyCelestialViewer, projectCelestialPoint } from './celestial.js';
+
+export function celestialHost(viewer) {
+  return {
+    host: { container: viewer.container, canvas: viewer.scene.canvas },
+    frames: { postRender: viewer.scene.postRender },
+    camera: {
+      pose: () => ({
+        position: viewer.camera.positionWC,
+        cartographic: viewer.camera.positionCartographic,
+        direction: viewer.camera.directionWC,
+        up: viewer.camera.upWC,
+        right: viewer.camera.rightWC,
+        heading: viewer.camera.heading,
+        fovy: viewer.camera.frustum?.fovy,
+      }),
+      flyTo: (options) => flyCelestialViewer(viewer, options),
+    },
+    projector: {
+      worldToWindow: (position, result) =>
+        projectCelestialPoint(viewer.scene, position, result),
+    },
+    render: { request: () => viewer.scene.requestRender?.() },
+  };
+}
diff --git a/src/globe/cesium/orbitalImagery.js b/src/globe/cesium/orbitalImagery.js
new file mode 100644
index 000000000..6d31ff366
--- /dev/null
+++ b/src/globe/cesium/orbitalImagery.js
@@ -0,0 +1,128 @@
+import {
+  createOrbitalImageryRequest,
+  isGeographicProjection,
+} from './orbital.js';
+import {
+  centreLinesFirst,
+  ORBITAL_PREFETCH_MAX_TILES,
+  footprintWidthKm,
+  groundTrackAhead,
+  imageryLevelForView,
+  tilesForPoints,
+} from '../../cockpitOrbital.js';
+
+const PREFETCH_MEMORY = 512;
+
+/** Warm the base imagery cache without taking slots from visible tiles. */
+export function prefetchOrbitalImagery(viewer, state, info, fov, aspect) {
+  try {
+    const globe = viewer.scene?.globe;
+    if (!globe || globe.show === false) return 0;
+    const provider = baseImageryProvider(viewer);
+    if (!provider) return 0;
+    // Another base map: its tiles have not been asked for.
+    // A fresh set, so a late failure from the old map's requests cannot
+    // drop a tile the new one has fetched.
+    if (provider !== state.prefetchProvider) {
+      for (const request of state.prefetchRequests) request.cancel?.();
+      state.prefetchRequests = new Set();
+      state.prefetched = new Set();
+      state.prefetchProvider = provider;
+    }
+    const viewKm = footprintWidthKm(info.altitudeM, fov, aspect);
+    // The ground one CSS pixel covers at the nadir point, as Cesium's
+    // screen-space error measures it: the vertical field of view over the
+    // canvas height, at the satellite's altitude.
+    const canvas = viewer.scene?.canvas;
+    const heightPx = canvas?.clientHeight || canvas?.height;
+    const terrain =
+      viewer.terrainProvider ?? viewer.scene?.globe?.terrainProvider;
+    const level = imageryLevelForView(provider.tilingScheme, {
+      metresPerPixel: (info.altitudeM * 2 * Math.tan(fov / 2)) / heightPx,
+      latitudeDeg: info.latitude,
+      geographic: isGeographicProjection(provider.tilingScheme.projection),
+      tileWidthPx: provider.tileWidth,
+      minimumLevel: provider.minimumLevel,
+      maximumLevel: provider.maximumLevel,
+      maximumScreenSpaceError: globe.maximumScreenSpaceError,
+      terrainLevelErrorM:
+        typeof terrain?.getLevelMaximumGeometricError === 'function'
+          ? (terrainLevel) =>
+              terrain.getLevelMaximumGeometricError(terrainLevel)
+          : undefined,
+    });
+    if (level === null) return 0;
+    const memory = state.prefetched;
+    const tiles = tilesForPoints(
+      provider.tilingScheme,
+      centreLinesFirst(groundTrackAhead(info, viewKm)),
+      level,
+      {
+        maxTiles: ORBITAL_PREFETCH_MAX_TILES,
+        skip: (key) => memory.has(key),
+      },
+    );
+    let asked = 0;
+    for (const tile of tiles) {
+      let pending;
+      let request;
+      try {
+        // The tiles on screen keep their slots: Cesium's scheduler declines
+        // this request while the imagery server's slots are taken (shared
+        // with the globe's own tile requests, throttleByServer) or the
+        // scheduler is full, and at the lowest priority it is the first
+        // dropped from the priority heap, never one the screen asked for.
+        pending = provider.requestImage(
+          tile.x,
+          tile.y,
+          tile.level,
+          (request = createOrbitalImageryRequest()),
+        );
+      } catch {
+        continue;
+      }
+      // A provider that declines now (throttled) is asked again later.
+      if (!pending) continue;
+      const requests = state.prefetchRequests;
+      requests.add(request);
+      Promise.resolve(pending).then(
+        () => requests.delete(request),
+        (error) => {
+          requests.delete(request);
+          // Dropped by the scheduler (rejected with no error): asked again
+          // later. A tile that failed to load stays remembered, so one
+          // missing from the map is not asked for every look-ahead.
+          if (error === undefined) memory.delete(tile.key);
+        },
+      );
+      memory.add(tile.key);
+      if (memory.size > PREFETCH_MEMORY)
+        memory.delete(memory.values().next().value);
+      asked += 1;
+    }
+    return asked;
+  } catch {
+    return 0;
+  }
+}
+
+/**
+ * The provider of the lowest shown imagery layer, the base map the globe
+ * drapes, when it can be asked for a tile; else null.
+ */
+function baseImageryProvider(viewer) {
+  const layers = viewer.imageryLayers ?? viewer.scene?.imageryLayers;
+  const count = Number.isInteger(layers?.length) ? layers.length : 0;
+  for (let i = 0; i < count; i += 1) {
+    const layer = layers.get(i);
+    if (!layer || layer.show === false || layer.alpha === 0) continue;
+    const provider = layer.imageryProvider;
+    if (
+      typeof provider?.requestImage === 'function' &&
+      typeof provider.tilingScheme?.positionToTileXY === 'function'
+    )
+      return provider;
+    return null;
+  }
+  return null;
+}
diff --git a/src/globe/cesium/windFlow.js b/src/globe/cesium/windFlow.js
index f14467ca1..10c185287 100644
--- a/src/globe/cesium/windFlow.js
+++ b/src/globe/cesium/windFlow.js
@@ -1,7 +1,7 @@
 // Cesium's backend of the wind display: the wind renderer's streamlines
-// (src/layers/wind/rendering.js) over the viewer, read only once a Cesium globe draws.
+// over the viewer, read only once a Cesium globe draws.
 import * as Cesium from 'cesium';
-import { createWindRendering } from '../../layers/wind/rendering.js';
+import { createWindRendering } from './windRendering.js';
 
 export function createWindCesiumFlow(engine, { onStatusChange } = {}) {
   return createWindRendering({
diff --git a/src/layers/wind/gpuRendering.js b/src/globe/cesium/windGpuRendering.js
similarity index 99%
rename from src/layers/wind/gpuRendering.js
rename to src/globe/cesium/windGpuRendering.js
index 0873fa63b..e6f16d7a5 100644
--- a/src/layers/wind/gpuRendering.js
+++ b/src/globe/cesium/windGpuRendering.js
@@ -4,7 +4,7 @@ import {
   WIND_DISPLAY_HEIGHT_METERS,
   WIND_PATH_LIMIT,
   WIND_NARROW_PATH_LIMIT,
-} from './streamlines.js';
+} from '../../layers/wind/streamlines.js';
 
 const WIND_FADE_LOW_METERS = 15000;
 const WIND_FADE_HIGH_METERS = 60000;
diff --git a/src/layers/wind/relief.js b/src/globe/cesium/windRelief.js
similarity index 100%
rename from src/layers/wind/relief.js
rename to src/globe/cesium/windRelief.js
diff --git a/src/layers/wind/rendering.js b/src/globe/cesium/windRendering.js
similarity index 98%
rename from src/layers/wind/rendering.js
rename to src/globe/cesium/windRendering.js
index 3314e1b9d..f9669181f 100644
--- a/src/layers/wind/rendering.js
+++ b/src/globe/cesium/windRendering.js
@@ -1,7 +1,11 @@
-import { createWindRelief } from './relief.js';
-import { createWindGpuRendering } from './gpuRendering.js';
-import { advectParticle, sampleWind, sameWind } from './model.js';
-import { trailEraseAlpha, windTrailColor } from './fields.js';
+import { createWindRelief } from './windRelief.js';
+import { createWindGpuRendering } from './windGpuRendering.js';
+import {
+  advectParticle,
+  sampleWind,
+  sameWind,
+} from '../../layers/wind/model.js';
+import { trailEraseAlpha, windTrailColor } from '../../layers/wind/fields.js';
 
 /** The wind's streamlines on Cesium (the wind display's flow backend,
  * render/display.js, which draws the colour field): globe-projected surface
diff --git a/src/globe/contract.js b/src/globe/contract.js
index 9db45cea6..9129e30fb 100644
--- a/src/globe/contract.js
+++ b/src/globe/contract.js
@@ -89,6 +89,10 @@
  *   engine-owned object: the same object on every read, holding the current
  *   position (at the latest when read). For per-frame readers, which must not
  *   allocate; read-only, copy it to keep a value.
+ * @property {(radians: number) => void} setFovy Set the vertical field of
+ *   view (finite, strictly between 0 and PI). Resizing retains the angle
+ *   across the wider canvas side, as Cesium does. Does not cancel flights
+ *   or following; pose, projection and picking use the new field of view.
  * @property {() => number} height The camera's height above the WGS84
  *   ellipsoid (the pose's cartographic height), without building a pose.
  * @property {(view: { destination: Cartesian3 | Rectangle, orientation?: Orientation }) => void} setView
@@ -978,6 +982,7 @@ const SHAPE = {
   host: { container: isObject, canvas: isObject, size: isFunction },
   camera: {
     pose: isFunction,
+    setFovy: isFunction,
     livePosition: (value) =>
       value != null &&
       isNumber(value.x) &&
diff --git a/src/globe/navara/cameraModel.js b/src/globe/navara/cameraModel.js
index c3ad4d4f1..fb2c231c1 100644
--- a/src/globe/navara/cameraModel.js
+++ b/src/globe/navara/cameraModel.js
@@ -19,7 +19,6 @@
 import * as geo from '../../geo/index.js';
 import { createEngineEvent } from '../contract.js';
 import {
-  cesiumFovy,
   headingPitchRoll,
   horizonVisible,
   lookAtFrame,
@@ -83,6 +82,7 @@ function posesNear(a, b, distance, angle) {
  *     stop: () => void,
  *     size: () => { width: number, height: number },
  *     requestFrame: () => void,
+ *     setFovy?: (radians: number) => void,
  *     suspendCameraInputs?: () => () => void,
  *   },
  *   clock?: { now: () => number, setTimeout: Function, clearTimeout: Function },
@@ -120,6 +120,13 @@ export function createCameraModel({
           ...orientationVectors(position, 0, -math.PI_OVER_TWO, 0),
         };
       })();
+  let fov = Math.PI / 3;
+  const fovy = () => {
+    const { width, height } = port.size();
+    return width > height
+      ? 2 * Math.atan((Math.tan(fov / 2) * height) / width)
+      : fov;
+  };
   let transform = [...matrix4.IDENTITY];
   let percentageChanged = DEFAULT_PERCENTAGE_CHANGED;
   let flight = null;
@@ -139,7 +146,7 @@ export function createCameraModel({
 
   const view = () => {
     const { width, height } = port.size();
-    return { ...state, fovy: cesiumFovy(width, height), width, height };
+    return { ...state, fovy: fovy(), width, height };
   };
 
   // A programmatic pose: exact here, pushed to Navara for drawing.
@@ -154,11 +161,7 @@ export function createCameraModel({
     const { width, height } = port.size();
     const position =
       'west' in destination
-        ? rectangleViewPosition(
-            destination,
-            cesiumFovy(width, height),
-            width / height,
-          )
+        ? rectangleViewPosition(destination, fovy(), width / height)
         : copy3(destination);
     if (orientation && 'direction' in orientation)
       return {
@@ -311,6 +314,17 @@ export function createCameraModel({
   const livePosition = cartesian3.create();
 
   const camera = {
+    setFovy(radians) {
+      if (!Number.isFinite(radians) || radians <= 0 || radians >= Math.PI)
+        throw new RangeError('Field of view must be between 0 and PI');
+      const { width, height } = port.size();
+      fov =
+        width > height
+          ? 2 * Math.atan((Math.tan(radians / 2) * width) / height)
+          : radians;
+      port.setFovy?.(radians);
+      port.requestFrame();
+    },
     get livePosition() {
       return cartesian3.clone(state.position, livePosition);
     },
@@ -356,8 +370,7 @@ export function createCameraModel({
       transform = [...matrix4.IDENTITY];
       const { width, height } = port.size();
       const range =
-        options.range ||
-        sphereRange(sphere.radius, cesiumFovy(width, height), width / height);
+        options.range || sphereRange(sphere.radius, fovy(), width / height);
       const frame = geo.transforms.eastNorthUpToFixedFrame(
         sphere.center,
         WGS84,
diff --git a/src/globe/navara/createNavaraEngine.js b/src/globe/navara/createNavaraEngine.js
index f5bd521a0..b91a92f97 100644
--- a/src/globe/navara/createNavaraEngine.js
+++ b/src/globe/navara/createNavaraEngine.js
@@ -114,10 +114,13 @@ export function createNavaraEngine(
     width: canvas.clientWidth,
     height: canvas.clientHeight,
   });
+  const applyFovy = (radians) => {
+    if (hooks.setCameraFovy) hooks.setCameraFovy(radians);
+    else view.camera.fov = math.toDegrees(radians);
+  };
   const matchFov = () => {
     const { width, height } = size();
-    if (width > 0 && height > 0)
-      view.camera.fov = math.toDegrees(cesiumFovy(width, height));
+    if (width > 0 && height > 0) applyFovy(cesiumFovy(width, height));
   };
   matchFov();
 
@@ -131,6 +134,7 @@ export function createNavaraEngine(
       stop: () => view.setCamera({}),
       size,
       requestFrame: () => view.forceUpdate(),
+      setFovy: applyFovy,
       suspendCameraInputs: () => input.input.suspendCameraInputs(),
     },
     ...(clock ? { clock } : {}),
@@ -201,7 +205,9 @@ export function createNavaraEngine(
       model.afterFrame();
       frames.postRender.raiseEvent(time);
     },
-    resize: () => matchFov(),
+    resize: () => {
+      applyFovy(model.camera.pose().fovy);
+    },
   };
   for (const [name, handler] of Object.entries(handlers))
     view.on(name, handler);
diff --git a/src/globe/navara/createNavaraEngine.test.mjs b/src/globe/navara/createNavaraEngine.test.mjs
index c95a5642a..1ef45efb5 100644
--- a/src/globe/navara/createNavaraEngine.test.mjs
+++ b/src/globe/navara/createNavaraEngine.test.mjs
@@ -769,3 +769,17 @@ test('a wheel during a flight with the camera inputs suspended does not cancel i
   assert.equal(engine.input.cameraInputsEnabled(), true);
   engine.destroy();
 });
+
+test('optical zoom reaches the drawn camera and survives a resize', () => {
+  const { engine, view } = setup();
+  engine.camera.setFovy(0.2);
+  near(view.camera.fovs.at(-1), geo.math.toDegrees(0.2), 1e-12, 'drawn fovy');
+  near(engine.camera.pose().fovy, 0.2, 1e-12, 'projector fovy');
+  const fov = 2 * Math.atan(Math.tan(0.1) * engine.camera.pose().aspectRatio);
+  view.canvas.clientWidth = 600;
+  view.canvas.clientHeight = 900;
+  view.emit('resize');
+  near(view.camera.fovs.at(-1), geo.math.toDegrees(fov), 1e-12, 'resized fovy');
+  near(engine.camera.pose().fovy, fov, 1e-12, 'resized projector');
+  engine.destroy();
+});
diff --git a/src/globe/navara/internals.js b/src/globe/navara/internals.js
index 0bd314a3d..7003303ad 100644
--- a/src/globe/navara/internals.js
+++ b/src/globe/navara/internals.js
@@ -233,11 +233,25 @@ export function featureChangeQueue(view) {
     : null;
 }
 
+/**
+ * Navara's public camera.fov setter drops angles below one degree, although
+ * the core supports them. Optical zoom needs the same frustum for drawing,
+ * tile selection and picking. Upstream ask: accept every positive FOV.
+ */
+export function setCameraFovy(view, radians) {
+  requireMember(
+    'view._core.setFrustum',
+    typeof view?._core?.setFrustum === 'function',
+  );
+  view._core.setFrustum((radians * 180) / Math.PI, undefined, undefined);
+}
+
 /** The hooks createNavaraEngine takes. */
 export const navaraHooks = (view) => {
   assertNavaraInternals(view);
   return {
     retainTileGeometry,
+    setCameraFovy: (radians) => setCameraFovy(view, radians),
     tileRoots: () => tileRoots(view),
     isIdle: () => isIdle(view),
     dropOrphanFeatureChanges: () =>
diff --git a/src/globe/navara/internals.test.mjs b/src/globe/navara/internals.test.mjs
index 07a06d8ea..8093481d8 100644
--- a/src/globe/navara/internals.test.mjs
+++ b/src/globe/navara/internals.test.mjs
@@ -13,7 +13,8 @@ const loader = registerHooks({
       : next(specifier, context);
   },
 });
-const { navaraHooks, forEachLuminanceUniform } = await import('./internals.js');
+const { navaraHooks, forEachLuminanceUniform, setCameraFovy } =
+  await import('./internals.js');
 loader.deregister();
 const { ModelMesh } = await import(sdkStub);
 
@@ -201,3 +202,31 @@ test('feature changes of a deleted vector layer leave the queue; live ones stay'
     0,
   );
 });
+
+test('optical zoom below one degree reaches the native frustum', async () => {
+  const { initSync, Core } = await import('@navaramap/engine');
+  initSync({
+    module: readFileSync(
+      new URL(
+        '../../../node_modules/@navaramap/engine/navara_wasm_bg.wasm',
+        import.meta.url,
+      ),
+    ),
+  });
+  const core = new Core('optical-zoom-test');
+  core.start();
+  core.resize(1280, 800, 1);
+  core.update(0);
+  try {
+    const view = { _core: core };
+    setCameraFovy(view, 0.0002);
+    core.update(16);
+    assert.ok(Math.abs(core.getCameraFOV() - 0.0002) < 1e-12);
+    setCameraFovy(view, Math.PI / 3);
+    core.update(32);
+    assert.ok(Math.abs(core.getCameraFOV() - Math.PI / 3) < 1e-12);
+    assert.throws(() => setCameraFovy({}, 0.0002), /setFrustum/);
+  } finally {
+    core.free();
+  }
+});
diff --git a/src/globe/testing/contractSuite/camera.mjs b/src/globe/testing/contractSuite/camera.mjs
index a5cd60de4..021225eca 100644
--- a/src/globe/testing/contractSuite/camera.mjs
+++ b/src/globe/testing/contractSuite/camera.mjs
@@ -20,6 +20,61 @@ import { enuOffset } from '../../follow.js';
 export function poseChecks(engine, { settle, until, nadirView }) {
   const { camera } = engine;
   return [
+    [
+      'camera.setFovy: changes projection and rays without moving the camera',
+      async () => {
+        const saved = camera.pose();
+        const size = engine.host.size();
+        const pixel = { x: size.width * 0.65, y: size.height * 0.5 };
+        const ray = camera.pickRay(pixel);
+        const point = cartesian3.add(
+          ray.origin,
+          cartesian3.multiplyByScalar(ray.direction, 1000, cartesian3.create()),
+          cartesian3.create(),
+        );
+        const before = engine.projector.worldToWindow(point);
+        try {
+          camera.setFovy(saved.fovy / 128);
+          await settle();
+          near(
+            camera.pose().fovy,
+            saved.fovy / 128,
+            1e-10,
+            'vertical field of view',
+          );
+          near(
+            cartesian3.distance(camera.pose().position, saved.position),
+            0,
+            0.01,
+            'position unchanged',
+          );
+          const after = engine.projector.worldToWindow(point);
+          ensure(after.x > before.x, 'narrowing the field magnifies the image');
+          const narrower = camera.pickRay(pixel);
+          ensure(
+            cartesian3.distance(narrower.direction, ray.direction) > 1e-3,
+            'pick ray follows the lens',
+          );
+          for (const invalid of [0, -1, Math.PI, NaN, Infinity]) {
+            let rejected = false;
+            try {
+              camera.setFovy(invalid);
+            } catch {
+              rejected = true;
+            }
+            ensure(rejected, 'invalid field of view is rejected');
+          }
+          near(
+            camera.pose().fovy,
+            saved.fovy / 128,
+            1e-10,
+            'invalid input keeps the lens',
+          );
+        } finally {
+          camera.setFovy(saved.fovy);
+        }
+      },
+    ],
     [
       'camera.setView: heading, pitch and roll round-trip through pose',
       async () => {
diff --git a/src/globe/testing/fakeEngine.js b/src/globe/testing/fakeEngine.js
index 78badf667..e4e75fe5c 100644
--- a/src/globe/testing/fakeEngine.js
+++ b/src/globe/testing/fakeEngine.js
@@ -195,7 +195,7 @@ export function createFakeEngine(options = {}) {
   let width = options.width ?? 1024;
   let height = options.height ?? 768;
   // Cesium's default: 60 degrees across the wider canvas dimension.
-  const fovy = options.fovy ?? cesiumFovy(width, height);
+  let fovy = options.fovy ?? cesiumFovy(width, height);
   const state = {
     position: cartesian3.create(),
     direction: cartesian3.create(),
@@ -579,6 +579,13 @@ export function createFakeEngine(options = {}) {
   }
 
   const camera = {
+    setFovy(radians) {
+      if (!Number.isFinite(radians) || radians <= 0 || radians >= Math.PI)
+        throw new RangeError('Field of view must be between 0 and PI');
+      record('camera.setFovy', [radians]);
+      fovy = radians;
+      engine.render.request('camera-fov');
+    },
     pose() {
       const angles = poseAngles();
       return {
@@ -1057,8 +1064,16 @@ export function createFakeEngine(options = {}) {
       );
     },
     setSize(nextWidth, nextHeight) {
+      const fov =
+        width > height
+          ? 2 * Math.atan((Math.tan(fovy / 2) * width) / height)
+          : fovy;
       width = nextWidth;
       height = nextHeight;
+      fovy =
+        width > height
+          ? 2 * Math.atan((Math.tan(fov / 2) * height) / width)
+          : fov;
     },
     callsOf: (method) => fake.calls.filter((call) => call.method === method),
     resetCalls() {
diff --git a/src/layers/wind/edgeCases.test.mjs b/src/layers/wind/edgeCases.test.mjs
index 1b7a0e2ec..2ae1512ae 100644
--- a/src/layers/wind/edgeCases.test.mjs
+++ b/src/layers/wind/edgeCases.test.mjs
@@ -23,13 +23,13 @@ const options = {
   validTime: '2026-09-14 18:00 UTC',
   status: 'Model forecast',
 };
-/** The Cesium path picks the centre itself; Navara hands in the position. */
-const viaViewer = (snapshot, point) =>
+/** Inspect either the current map centre or a captured position. */
+const viaEngine = (snapshot, point) =>
   inspectWindAtCenter(
     snapshot,
     {
       camera: { pickEllipsoid: () => point },
-      scene: { canvas: { clientWidth: 800, clientHeight: 600 } },
+      host: { canvas: { clientWidth: 800, clientHeight: 600 } },
     },
     options,
   );
@@ -42,7 +42,7 @@ test('edge:wind: a fixed grid gives the same direction, speed and legend colour
   // 5 m/s blowing toward the west: the wind comes FROM the east.
   const snapshot = field(-5, 0);
   for (const point of [at(10, 20), at(180, 0), at(-180, 0), at(-45.5, -60)]) {
-    const cesiumReading = viaViewer(snapshot, point);
+    const cesiumReading = viaEngine(snapshot, point);
     const navaraReading = viaPosition(snapshot, point);
     for (const reading of [cesiumReading, navaraReading]) {
       assert.equal(reading.from, 'E');
@@ -76,7 +76,7 @@ test('edge:wind: an empty or unavailable field is not reported as calm, a real 0
   ];
   for (const snapshot of empty) {
     for (const reading of [
-      viaViewer(snapshot, point),
+      viaEngine(snapshot, point),
       viaPosition(snapshot, point),
     ]) {
       assert.equal(reading.speed, undefined, 'no speed is invented');
diff --git a/src/layers/wind/gpuRendering.test.mjs b/src/layers/wind/gpuRendering.test.mjs
index 1a420e23b..9c886b291 100644
--- a/src/layers/wind/gpuRendering.test.mjs
+++ b/src/layers/wind/gpuRendering.test.mjs
@@ -1,6 +1,6 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { createWindGpuRendering } from './gpuRendering.js';
+import { createWindGpuRendering } from '../../globe/cesium/windGpuRendering.js';
 import {
   BoundingSphere,
   Cartesian3,
diff --git a/src/layers/wind/index.js b/src/layers/wind/index.js
index 928573057..3d7b659fd 100644
--- a/src/layers/wind/index.js
+++ b/src/layers/wind/index.js
@@ -82,14 +82,7 @@ export function createWindLayer({
     inspectionMarker?.clear();
   };
   const sample = (position) => {
-    if (!position && engine && !viewer) {
-      const canvas = engine.host.canvas;
-      position = engine.camera.pickEllipsoid({
-        x: canvas.clientWidth / 2,
-        y: canvas.clientHeight / 2,
-      });
-    }
-    reading = inspectWindAtCenter(manifest, viewer, {
+    reading = inspectWindAtCenter(manifest, engine, {
       position,
       units,
       overlay,
@@ -130,7 +123,6 @@ export function createWindLayer({
       rendering?.setOptions?.({ overlay, paused });
       inspectionMarker = createWindInspectionMarker({
         container: engine.host.container,
-        viewer,
         engine,
       });
       if (enabled && manifest && !manifest.unavailable) {
@@ -254,7 +246,7 @@ export function createWindLayer({
         loading = enabled && needsField;
         if (enabled && needsField)
           queueMicrotask(() => {
-            if (enabled && generation === current) void layer.update(viewer);
+            if (enabled && generation === current) void layer.update();
           });
         else if (enabled && manifest && !manifest.unavailable)
           rendering?.start();
diff --git a/src/layers/wind/index.test.mjs b/src/layers/wind/index.test.mjs
index 30ef80423..5ef39e521 100644
--- a/src/layers/wind/index.test.mjs
+++ b/src/layers/wind/index.test.mjs
@@ -365,8 +365,10 @@ test('sample stays fixed across model, field and unit changes; dismissal and dis
     feed: { getSnapshot: async ({ model }) => complete(model) },
     createNativeRendering: () => rendering,
   });
-  // A Cesium page: the viewer samples, the engine projects the marker.
-  layer.init(viewer, { engine: createFakeEngine({ container }) });
+  const engine = createFakeEngine({ container, canvas: viewer.scene.canvas });
+  engine.camera.pickEllipsoid = (point) => viewer.camera.pickEllipsoid(point);
+  engine.frames.postRender = viewer.scene.postRender;
+  layer.init(viewer, { engine });
   layer.enable();
   await layer.update();
   layer.setParams({ inspect: true });
diff --git a/src/layers/wind/inspection.js b/src/layers/wind/inspection.js
index 3459a1df2..8299ddfe1 100644
--- a/src/layers/wind/inspection.js
+++ b/src/layers/wind/inspection.js
@@ -45,20 +45,17 @@ export function formatWindSpeed(speed, units = 'km/h') {
 /** A deliberate snapshot at the map center; does not own pointer input. */
 export function inspectWindAtCenter(
   snapshot,
-  viewer,
+  engine,
   { units, overlay, model, validTime, status, position } = {},
 ) {
-  const scene = viewer?.scene;
-  const canvas = scene?.canvas;
-  // The globe's own ellipsoid, else WGS84 (geo's default).
-  const ellipsoid = scene?.globe?.ellipsoid;
+  const canvas = engine?.host.canvas;
   const point =
     position ||
     (canvas &&
-      viewer.camera?.pickEllipsoid?.(
-        geo.cartesian2.create(canvas.clientWidth / 2, canvas.clientHeight / 2),
-        ellipsoid,
-      ));
+      engine.camera.pickEllipsoid({
+        x: canvas.clientWidth / 2,
+        y: canvas.clientHeight / 2,
+      }));
   const noReading = () => ({
     coordinates: msg('No surface reading'),
     wind: msg('Aim the map center at Earth'),
@@ -70,7 +67,7 @@ export function inspectWindAtCenter(
     ),
   });
   if (!point || !snapshot?.u || !snapshot?.v) return noReading();
-  const location = geo.cartographic.fromCartesian(point, ellipsoid);
+  const location = geo.cartographic.fromCartesian(point);
   const lon = geo.math.toDegrees(location.longitude);
   const lat = geo.math.toDegrees(location.latitude);
   const vector = sampleWind(
diff --git a/src/layers/wind/inspection.test.mjs b/src/layers/wind/inspection.test.mjs
index a19801228..1161c1d76 100644
--- a/src/layers/wind/inspection.test.mjs
+++ b/src/layers/wind/inspection.test.mjs
@@ -27,11 +27,11 @@ test('center inspection uses a fixed forecast reading without double-converting
       values: Float32Array.from([20, 20, 20, 20]),
     },
   };
-  const viewer = {
+  const engine = {
     camera: { pickEllipsoid: () => geo.cartesian3.fromDegrees(0, 0) },
-    scene: { canvas: { clientWidth: 800, clientHeight: 600 } },
+    host: { canvas: { clientWidth: 800, clientHeight: 600 } },
   };
-  const result = inspectWindAtCenter(snapshot, viewer, {
+  const result = inspectWindAtCenter(snapshot, engine, {
     overlay: 'temperature',
     units: 'km/h',
     model: 'GFS',
@@ -42,9 +42,9 @@ test('center inspection uses a fixed forecast reading without double-converting
   assert.equal(result.scalarValue, '20.0 °C');
   assert.equal(result.validTime, 'fixed');
   assert.equal(result.coordinates, '0.00°N · 0.00°E');
-  viewer.camera.pickEllipsoid = () => null;
+  engine.camera.pickEllipsoid = () => null;
   assert.equal(
-    inspectWindAtCenter(snapshot, viewer).coordinates,
+    inspectWindAtCenter(snapshot, engine).coordinates,
     'No surface reading',
   );
 });
diff --git a/src/layers/wind/inspectionMarker.js b/src/layers/wind/inspectionMarker.js
index 7291158bb..028bd7ade 100644
--- a/src/layers/wind/inspectionMarker.js
+++ b/src/layers/wind/inspectionMarker.js
@@ -9,9 +9,7 @@ import { applicationPinia } from '../../ui/vueRuntime.js';
  */
 export function createWindInspectionMarker({
   container,
-  viewer,
   engine,
-  cesium,
   store = useWindInspectionStore(applicationPinia()),
 }) {
   const owner = {};
@@ -28,45 +26,31 @@ export function createWindInspectionMarker({
     removeRender = null;
     if (shown()) store.publish(null);
     marker = null;
-    if (engine) engine.render.request('wind-inspection');
-    else viewer?.scene?.requestRender?.();
+    engine.render.request('wind-inspection');
   };
   return {
     show(position) {
       clear();
-      const scene = viewer?.scene;
-      const canvas = scene?.canvas ?? engine?.host.canvas;
-      const frames = scene?.postRender ?? engine?.frames.postRender;
+      const canvas = engine.host.canvas;
+      const frames = engine.frames.postRender;
       if (
         !position ||
         !container?.ownerDocument ||
         !frames?.addEventListener ||
-        (!engine?.projector && !scene?.cartesianToCanvasCoordinates)
+        !engine.projector
       )
         return;
       present({ owner, container, visible: false, left: 0, top: 0 });
-      const occluder =
-        !engine &&
-        new cesium.EllipsoidalOccluder(
-          scene.globe?.ellipsoid || cesium.Ellipsoid.WGS84,
-          viewer.camera.positionWC,
-        );
       const render = () => {
         if (!shown()) return;
-        if (occluder) occluder.cameraPosition = viewer.camera.positionWC;
-        const point = engine
-          ? engine.projector.worldToWindow(position, {})
-          : scene.cartesianToCanvasCoordinates(position);
+        const point = engine.projector.worldToWindow(position, {});
         const visible =
           point &&
           point.x >= 0 &&
           point.y >= 0 &&
           point.x <= canvas.clientWidth &&
           point.y <= canvas.clientHeight &&
-          (engine
-            ? engine.projector.horizonVisible(position)
-            : scene.mode !== cesium.SceneMode.SCENE3D ||
-              occluder.isPointVisible(position));
+          engine.projector.horizonVisible(position);
         if (!visible) {
           // A hidden marker keeps its last place, as the element did.
           if (marker.visible) present({ visible: false });
@@ -82,8 +66,7 @@ export function createWindInspectionMarker({
       };
       removeRender = frames.addEventListener(render);
       render();
-      if (engine) engine.render.request('wind-inspection');
-      else scene.requestRender?.();
+      engine.render.request('wind-inspection');
     },
     clear,
     destroy: clear,
diff --git a/src/layers/wind/inspectionMarker.test.mjs b/src/layers/wind/inspectionMarker.test.mjs
index 49f0a6574..94d84630d 100644
--- a/src/layers/wind/inspectionMarker.test.mjs
+++ b/src/layers/wind/inspectionMarker.test.mjs
@@ -10,16 +10,7 @@ import { useWindInspectionStore } from '../../ui/stores/windInspection.js';
 import WindInspectionMarker from '../../ui/views/panels/WindInspectionMarker.vue';
 import { createWindInspectionMarker } from './inspectionMarker.js';
 
-const cesium = {
-  SceneMode: { SCENE3D: 3 },
-  Ellipsoid: { WGS84: {} },
-  EllipsoidalOccluder: class {
-    isPointVisible() {
-      return cesium.visible;
-    }
-  },
-  visible: true,
-};
+const visibility = { visible: true };
 
 function fixture(t) {
   document.body.replaceChildren();
@@ -56,18 +47,26 @@ function fixture(t) {
       requestRender() {},
     },
   };
+  const engine = {
+    host: { canvas: viewer.scene.canvas },
+    frames: { postRender: viewer.scene.postRender },
+    projector: {
+      worldToWindow: viewer.scene.cartesianToCanvasCoordinates,
+      horizonVisible: () => visibility.visible,
+    },
+    render: { request() {} },
+  };
   const store = useWindInspectionStore(pinia);
-  cesium.visible = true;
+  visibility.visible = true;
   const owner = createWindInspectionMarker({
     container,
-    viewer,
-    cesium,
+    engine,
     store,
   });
   const nodes = () => [
     ...container.querySelectorAll('.gev-wind-inspection-marker'),
   ];
-  return { owner, viewer, store, frames, projected, nodes, container, cesium };
+  return { owner, viewer, store, frames, projected, nodes, container, engine };
 }
 
 test('the marker follows only its captured point, hides beyond the limb, and releases its listener', async (t) => {
@@ -85,13 +84,13 @@ test('the marker follows only its captured point, hides beyond the limb, and rel
   assert.equal(marker.style.top, '220px');
   assert.equal(marker.hidden, false);
   viewer.camera.positionWC = { moved: true };
-  cesium.visible = false;
+  visibility.visible = false;
   frames.listener();
   await nextTick();
   assert.equal(marker.hidden, true);
   assert.equal(marker.style.left, '110px', 'a hidden marker keeps its place');
   assert.ok(projected.every((value) => value === point));
-  cesium.visible = true;
+  visibility.visible = true;
   frames.listener();
   await nextTick();
   assert.equal(marker.hidden, false);
@@ -111,7 +110,7 @@ test('the marker follows only its captured point, hides beyond the limb, and rel
 });
 
 test('an unchanged frame publishes nothing, and an older owner leaves a newer marker', (t) => {
-  const { owner, viewer, store, frames, container } = fixture(t);
+  const { owner, engine, store, frames, container } = fixture(t);
   owner.show({ x: 1 });
   let publishes = 0;
   const publish = store.publish;
@@ -124,8 +123,7 @@ test('an unchanged frame publishes nothing, and an older owner leaves a newer ma
   frames.listener = null;
   const newer = createWindInspectionMarker({
     container,
-    viewer,
-    cesium,
+    engine,
     store,
   });
   newer.show({ x: 2 });
diff --git a/src/layers/wind/relief.test.mjs b/src/layers/wind/relief.test.mjs
index 9e1b94b33..0258178e2 100644
--- a/src/layers/wind/relief.test.mjs
+++ b/src/layers/wind/relief.test.mjs
@@ -1,6 +1,6 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { createWindRelief } from './relief.js';
+import { createWindRelief } from '../../globe/cesium/windRelief.js';
 
 function fixture({ material = undefined, normals = true } = {}) {
   const materials = [];
diff --git a/src/layers/wind/rendering.test.mjs b/src/layers/wind/rendering.test.mjs
index 9ed0334e5..b1d35d992 100644
--- a/src/layers/wind/rendering.test.mjs
+++ b/src/layers/wind/rendering.test.mjs
@@ -4,7 +4,7 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 
-import { createWindRendering } from './rendering.js';
+import { createWindRendering } from '../../globe/cesium/windRendering.js';
 
 function event() {
   const listeners = new Set();
diff --git a/src/ui/cockpitController.js b/src/ui/cockpitController.js
index f6689538d..07ffd3ddb 100644
--- a/src/ui/cockpitController.js
+++ b/src/ui/cockpitController.js
@@ -137,7 +137,6 @@ export class CockpitViewController {
     } = {},
   ) {
     this.host = cockpitHost(engine, { viewer });
-    // Orbital optics and imagery prefetch still belong to the Cesium viewer.
     this.viewer = viewer;
     this.services = services;
     this.destroyed = false;
@@ -206,7 +205,7 @@ export class CockpitViewController {
         : () => false;
     // Nor a satellite layer to ride without one.
     this.isOrbitEntryAllowed =
-      viewer && typeof isOrbitEntryAllowed === 'function'
+      typeof isOrbitEntryAllowed === 'function'
         ? isOrbitEntryAllowed
         : () => false;
     this.isUtilityDisclosureOpen =
@@ -311,7 +310,7 @@ export class CockpitViewController {
     );
     this._listenerRemovers.push(routeSceneDoubleClick.call(this));
     // In orbit a click on a mapped point keeps the camera on it.
-    if (viewer) this._listenerRemovers.push(routeSceneClick.call(this));
+    this._listenerRemovers.push(routeSceneClick.call(this));
     // In orbit the wheel steps the optical zoom (Cesium's own wheel zoom is
     // off while the Cockpit holds the camera).
     this._listen(
diff --git a/src/ui/cockpitController.test.mjs b/src/ui/cockpitController.test.mjs
index 982827223..4f0e388dd 100644
--- a/src/ui/cockpitController.test.mjs
+++ b/src/ui/cockpitController.test.mjs
@@ -59,7 +59,7 @@ test('Cockpit subscriptions are released once and retained actions cannot restar
   }
 });
 
-test('without a Cesium viewer orbital entry stays hidden and has no side effects', () => {
+test('orbital entry is offered through the engine without a native viewer', () => {
   const env = environment();
   try {
     const owner = new CockpitViewController(env.engine, {
@@ -68,15 +68,15 @@ test('without a Cesium viewer orbital entry stays hidden and has no side effects
         militaryFlightsLayer: { getTrackedInfo: () => null },
         satellitesLayer: {
           getCockpitSubject: () => ({ noradId: 25544, layerId: 'satellites' }),
-          setCockpitSubject: () => assert.fail('no satellite may be hidden'),
+          setCockpitSubject: () => true,
         },
         isTr3b: () => false,
       },
       isOrbitEntryAllowed: () => true,
     });
     owner.syncEntry();
-    assert.equal(owner.presence.entryAvailable, false);
-    assert.equal(owner.enter({ kind: 'satellite' }), false);
+    assert.equal(owner.presence.entryAvailable, true);
+    assert.equal(owner.presence.entryKind, 'satellite');
     assert.equal(owner.orbital, null);
     assert.equal(env.engine.input.cameraInputsEnabled(), true);
     owner.dispose();
diff --git a/src/ui/cockpitHost.js b/src/ui/cockpitHost.js
index 51afc53bb..8431cb171 100644
--- a/src/ui/cockpitHost.js
+++ b/src/ui/cockpitHost.js
@@ -2,6 +2,8 @@ import { readSurface } from '../globe/surfacePlacement.js';
 // Camera and aircraft ownership used by the shared first-person controller,
 // on the globe contract: the ridden aircraft is the engine follow's target,
 // the aircraft display's tracked glyph handle.
+import { routeViewerClick } from '../globe/cesium/orbital.js';
+import { prefetchOrbitalImagery } from '../globe/cesium/orbitalImagery.js';
 import { routeViewerDoubleClick } from '../globe/cesium/doubleClick.js';
 
 /**
@@ -26,6 +28,8 @@ export function cockpitHost(engine, { viewer = null } = {}) {
     release: () => engine.camera.following()?.stop(),
     restore: (target) => target.resumeAircraftFollow(),
     camera: engine.camera,
+    imageryReady: () =>
+      engine.maps.photorealActive() || engine.surface.tilesLoaded(),
     cartographic: () => engine.camera.pose().cartographic,
     terrainHeight: (place) => readSurface(engine, place, { prefer: 'terrain' }),
     surface: engine,
@@ -52,6 +56,12 @@ export function cockpitHost(engine, { viewer = null } = {}) {
         resumeInputs = null;
       } else resumeInputs ??= engine.input.suspendCameraInputs();
     },
+    prefetchImagery: (state, info, fov, aspect) =>
+      viewer ? prefetchOrbitalImagery(viewer, state, info, fov, aspect) : 0,
+    routeClick: (handle) =>
+      viewer
+        ? routeViewerClick(viewer, handle)
+        : engine.input.on('click', (event) => handle(event.position)),
     canvasPosition: (world) => engine.projector.worldToWindow(world) ?? null,
     routeDoubleClick: (handle) =>
       viewer
diff --git a/src/ui/cockpitOrbitalFocus.js b/src/ui/cockpitOrbitalFocus.js
index 5084823cb..2bd23ef2a 100644
--- a/src/ui/cockpitOrbitalFocus.js
+++ b/src/ui/cockpitOrbitalFocus.js
@@ -9,7 +9,6 @@
  * it ends with the session.
  */
 import { cartesian3 } from '../geo/index.js';
-import { routeViewerClick } from '../globe/cesium/orbital.js';
 import { clampOrbitalLook, easeLook } from '../cockpitLook.js';
 import { ORBITAL_EARTH_RADIUS_M } from '../cockpitOrbital.js';
 import {
@@ -264,9 +263,7 @@ export function onOrbitalClick(position) {
  *   (the draw tool borrows it) has replaced ours since.
  */
 export function routeSceneClick() {
-  return routeViewerClick(this.viewer, (position) =>
-    this.onOrbitalClick(position),
-  );
+  return this.host.routeClick((position) => this.onOrbitalClick(position));
 }
 
 /**
diff --git a/src/ui/cockpitOrbitalFocus.test.mjs b/src/ui/cockpitOrbitalFocus.test.mjs
index e4396a212..62e25fd78 100644
--- a/src/ui/cockpitOrbitalFocus.test.mjs
+++ b/src/ui/cockpitOrbitalFocus.test.mjs
@@ -289,6 +289,9 @@ function fixture(t, { reducedMotion = false } = {}) {
   const onMode = (event) => modeEvents.push(event.detail);
   window.addEventListener('gev:cockpit-mode-changed', onMode);
   const engine = createFakeEngine({ kind: 'cesium' });
+  engine.camera.setView = (options) => viewer.camera.setView(options);
+  const following = engine.camera.following;
+  engine.camera.following = () => viewer.trackedEntity ? { stop() { viewer.trackedEntity = undefined; } } : following();
   engine.fake.script('pick', (position) => picks.get(`${position.x},${position.y}`));
   const cockpit = new CockpitViewController(engine, {
     viewer,
diff --git a/src/ui/cockpitOrbitalSatellites.js b/src/ui/cockpitOrbitalSatellites.js
index 43a29c302..c0f656b99 100644
--- a/src/ui/cockpitOrbitalSatellites.js
+++ b/src/ui/cockpitOrbitalSatellites.js
@@ -122,8 +122,8 @@ export function switchOrbitalSatellite(noradId) {
   } catch {
     tracked = false;
   }
-  // Tracking hands the camera to Cesium's follow; the orbital view keeps it.
-  this.viewer.trackedEntity = undefined;
+  // Tracking hands the camera to follow; the orbital view keeps it.
+  this.host.release();
   const info = tracked ? this.readSatelliteInfo() : null;
   if (!info || String(info.noradId) !== String(noradId)) {
     // Nothing changed hands, or the layer could not take it: the view ends
diff --git a/src/ui/cockpitOrbitalView.js b/src/ui/cockpitOrbitalView.js
index a9536d60d..d51479c36 100644
--- a/src/ui/cockpitOrbitalView.js
+++ b/src/ui/cockpitOrbitalView.js
@@ -1,23 +1,14 @@
 /** The orbital (satellite) view of the Cockpit controller: camera, zoom, look and HUD. */
-import {
-  createOrbitalImageryRequest,
-  isGeographicProjection,
-} from '../globe/cesium/orbital.js';
 import { formatNumber, msg, t } from '../i18n/index.js';
 import {
   ORBITAL_DEFAULT_ZOOM,
   ORBITAL_PREFETCH_INTERVAL_MS,
-  centreLinesFirst,
-  ORBITAL_PREFETCH_MAX_TILES,
   ORBITAL_PREFETCH_MIN_ZOOM,
   ORBITAL_SETTLE_BLUR_PX,
   ORBITAL_ZOOM_LADDER,
   ORBITAL_ZOOM_TRANSITION_MS,
-  cesiumFrustumFovRad,
   footprintWidthKm,
   fovForZoom,
-  groundTrackAhead,
-  imageryLevelForView,
   interpolateZoomFov,
   nadirOrientation,
   nextOrbitalZoom,
@@ -30,7 +21,6 @@ import {
   previousOrbitalZoom,
   sensorStripFraction,
   sensorSwathZoom,
-  tilesForPoints,
   wheelZoomStep,
   zoomSettleHolding,
   zoomTransitionState,
@@ -86,7 +76,7 @@ const NADIR_LOOK = Object.freeze({ yawDeg: 0, pitchDeg: 0 });
  * the exit can put it back exactly.
  */
 export function beginOrbital() {
-  const frustum = this.viewer.camera?.frustum;
+  const pose = this.host.camera.pose();
   const state = {
     imagery: acquireOrbitImagery(this.services),
     zoom: ORBITAL_DEFAULT_ZOOM,
@@ -102,7 +92,9 @@ export function beginOrbital() {
     // A zoom step in flight: the magnification it started from and when.
     transition: null,
     previousUp: null,
-    savedFov: Number.isFinite(frustum?.fov) ? frustum.fov : null,
+    savedFov: Number.isFinite(pose.fovy)
+      ? 2 * Math.atan(Math.tan(pose.fovy / 2) * Math.max(1, pose.aspectRatio))
+      : null,
     altitudeM: null,
     verticalFov: null,
     lastBriefMs: 0,
@@ -135,8 +127,12 @@ export function endOrbital() {
   // Pre-loads still queued or in flight are for a view no longer shown.
   for (const request of state.prefetchRequests) request.cancel?.();
   state.prefetchRequests.clear();
-  const frustum = this.viewer.camera?.frustum;
-  if (frustum && state.savedFov !== null) frustum.fov = state.savedFov;
+  if (state.savedFov !== null) {
+    const aspect = Math.max(1, this.host.camera.pose().aspectRatio);
+    this.host.camera.setFovy(
+      2 * Math.atan(Math.tan(state.savedFov / 2) / aspect),
+    );
+  }
   // Back to the map the operator had, unless they picked another meanwhile.
   state.imagery?.release?.()?.catch?.(() => {});
   this.publishOrbital(null);
@@ -153,10 +149,7 @@ function trackPlace(info, nowMs) {
   if (!state?.placeTracker) return;
   let nearKm = null;
   if (Number.isFinite(info.altitudeM)) {
-    const frustum = this.viewer.camera?.frustum;
-    const aspect = Number.isFinite(frustum?.aspectRatio)
-      ? frustum.aspectRatio
-      : canvasAspect(this.viewer);
+    const aspect = viewAspect(this.host);
     const fov = fovForZoom(orbitalBaseFovRad(info.altitudeM), state.zoom);
     // The field of view is vertical: aspect 1 gives the ground height.
     nearKm = nearPlaceRadiusKm(
@@ -241,7 +234,7 @@ function applyFov(state, altitudeM, nowMs) {
     state,
     baseFov,
     nowMs,
-    tilesLoaded(this.viewer),
+    this.host.imageryReady(),
   );
   // The step's last frame (its lock tick over) publishes the idle state.
   if (state.transition && !reading.moving) {
@@ -249,33 +242,11 @@ function applyFov(state, altitudeM, nowMs) {
     reading.transition = IDLE_TRANSITION;
   }
   state.verticalFov = reading.fov;
-  const frustum = this.viewer.camera?.frustum;
-  if (frustum && 'fov' in frustum) {
-    const aspect = Number.isFinite(frustum.aspectRatio)
-      ? frustum.aspectRatio
-      : canvasAspect(this.viewer);
-    frustum.fov = cesiumFrustumFovRad(reading.fov, aspect);
-  }
+  this.host.camera.setFovy(reading.fov);
   return reading;
 }
 
-/**
- * Whether the imagery under the view has loaded. Flat imagery drapes the
- * globe; with the globe hidden (Google 3D kept) there is nothing to wait for.
- */
-function tilesLoaded(viewer) {
-  const globe = viewer.scene?.globe;
-  return !globe?.show || globe.tilesLoaded !== false;
-}
-
-function canvasAspect(viewer) {
-  const canvas = viewer.scene?.canvas;
-  const width = canvas?.clientWidth;
-  const height = canvas?.clientHeight;
-  return width > 0 && height > 0 ? width / height : 1;
-}
-
-/** Copy a plain vector into a Cesium scratch. */
+/** Copy a plain vector into the camera scratch. */
 function intoCartesian(vector, result) {
   result.x = vector.x;
   result.y = vector.y;
@@ -293,8 +264,8 @@ function intoCartesian(vector, result) {
  */
 export function updateOrbital(nowMs) {
   // Tracking anything from orbit (an aircraft, another satellite) ends the
-  // view and leaves Cesium tracking with that target.
-  if (this.host.current() || this.viewer.trackedEntity?.position) {
+  // view and leaves the engine tracking with that target.
+  if (this.host.camera.following()) {
     this.exit({ restoreTracking: false });
     return;
   }
@@ -343,7 +314,7 @@ export function updateOrbital(nowMs) {
   });
   const zoomStepping = Boolean(state.transition);
   const reading = applyFov.call(this, state, info.altitudeM, nowMs);
-  this.viewer.camera.setView({
+  this.host.camera.setView({
     destination: eye,
     orientation: {
       direction: intoCartesian(view.direction, this.scratchForward),
@@ -372,9 +343,6 @@ export function updateOrbital(nowMs) {
   prefetchImageryAhead.call(this, info, nowMs);
 }
 
-/** Tiles remembered as asked for in one orbital session. */
-const PREFETCH_MEMORY = 512;
-
 /** How far the shown time may be from now for the look-ahead to run, ms. */
 const PREFETCH_LIVE_TOLERANCE_MS = 60_000;
 
@@ -388,7 +356,7 @@ const PREFETCH_LIVE_TOLERANCE_MS = 60_000;
  * lowest priority: Cesium's request scheduler declines one while the
  * imagery server's slots are taken by the tiles on screen or the scheduler
  * is full, and a declined tile is asked again on a later look-ahead. At most
- * ORBITAL_PREFETCH_MAX_TILES a time; the last PREFETCH_MEMORY tiles asked
+ * 12 a time; the last 512 tiles asked
  * for are not asked again unless their request failed, and a new base map
  * starts the memory over. Exit cancels the requests still pending. Nothing
  * below 16x, while the view is tilted off nadir (it no longer looks at the
@@ -411,121 +379,8 @@ export function prefetchImageryAhead(info, nowMs) {
   )
     return 0;
   state.prefetchMs = nowMs;
-  try {
-    const globe = this.viewer.scene?.globe;
-    if (!globe || globe.show === false) return 0;
-    const provider = baseImageryProvider(this.viewer);
-    if (!provider) return 0;
-    // Another base map: its tiles have not been asked for.
-    // A fresh set, so a late failure from the old map's requests cannot
-    // drop a tile the new one has fetched.
-    if (provider !== state.prefetchProvider) {
-      for (const request of state.prefetchRequests) request.cancel?.();
-      state.prefetchRequests = new Set();
-      state.prefetched = new Set();
-      state.prefetchProvider = provider;
-    }
-    const fov = fovForZoom(orbitalBaseFovRad(info.altitudeM), state.zoom);
-    const viewKm = footprintWidthKm(
-      info.altitudeM,
-      fov,
-      viewAspect(this.viewer),
-    );
-    // The ground one CSS pixel covers at the nadir point, as Cesium's
-    // screen-space error measures it: the vertical field of view over the
-    // canvas height, at the satellite's altitude.
-    const canvas = this.viewer.scene?.canvas;
-    const heightPx = canvas?.clientHeight || canvas?.height;
-    const terrain =
-      this.viewer.terrainProvider ?? this.viewer.scene?.globe?.terrainProvider;
-    const level = imageryLevelForView(provider.tilingScheme, {
-      metresPerPixel: (info.altitudeM * 2 * Math.tan(fov / 2)) / heightPx,
-      latitudeDeg: info.latitude,
-      geographic: isGeographicProjection(provider.tilingScheme.projection),
-      tileWidthPx: provider.tileWidth,
-      minimumLevel: provider.minimumLevel,
-      maximumLevel: provider.maximumLevel,
-      maximumScreenSpaceError: globe.maximumScreenSpaceError,
-      terrainLevelErrorM:
-        typeof terrain?.getLevelMaximumGeometricError === 'function'
-          ? (terrainLevel) =>
-              terrain.getLevelMaximumGeometricError(terrainLevel)
-          : undefined,
-    });
-    if (level === null) return 0;
-    const memory = state.prefetched;
-    const tiles = tilesForPoints(
-      provider.tilingScheme,
-      centreLinesFirst(groundTrackAhead(info, viewKm)),
-      level,
-      {
-        maxTiles: ORBITAL_PREFETCH_MAX_TILES,
-        skip: (key) => memory.has(key),
-      },
-    );
-    let asked = 0;
-    for (const tile of tiles) {
-      let pending;
-      let request;
-      try {
-        // The tiles on screen keep their slots: Cesium's scheduler declines
-        // this request while the imagery server's slots are taken (shared
-        // with the globe's own tile requests, throttleByServer) or the
-        // scheduler is full, and at the lowest priority it is the first
-        // dropped from the priority heap, never one the screen asked for.
-        pending = provider.requestImage(
-          tile.x,
-          tile.y,
-          tile.level,
-          (request = createOrbitalImageryRequest()),
-        );
-      } catch {
-        continue;
-      }
-      // A provider that declines now (throttled) is asked again later.
-      if (!pending) continue;
-      const requests = state.prefetchRequests;
-      requests.add(request);
-      Promise.resolve(pending).then(
-        () => requests.delete(request),
-        (error) => {
-          requests.delete(request);
-          // Dropped by the scheduler (rejected with no error): asked again
-          // later. A tile that failed to load stays remembered, so one
-          // missing from the map is not asked for every look-ahead.
-          if (error === undefined) memory.delete(tile.key);
-        },
-      );
-      memory.add(tile.key);
-      if (memory.size > PREFETCH_MEMORY)
-        memory.delete(memory.values().next().value);
-      asked += 1;
-    }
-    return asked;
-  } catch {
-    return 0;
-  }
-}
-
-/**
- * The provider of the lowest shown imagery layer, the base map the globe
- * drapes, when it can be asked for a tile; else null.
- */
-function baseImageryProvider(viewer) {
-  const layers = viewer.imageryLayers ?? viewer.scene?.imageryLayers;
-  const count = Number.isInteger(layers?.length) ? layers.length : 0;
-  for (let i = 0; i < count; i += 1) {
-    const layer = layers.get(i);
-    if (!layer || layer.show === false || layer.alpha === 0) continue;
-    const provider = layer.imageryProvider;
-    if (
-      typeof provider?.requestImage === 'function' &&
-      typeof provider.tilingScheme?.positionToTileXY === 'function'
-    )
-      return provider;
-    return null;
-  }
-  return null;
+  const fov = fovForZoom(orbitalBaseFovRad(info.altitudeM), state.zoom);
+  return this.host.prefetchImagery(state, info, fov, viewAspect(this.host));
 }
 
 /**
@@ -623,9 +478,7 @@ export function publishOrbitalView(info, transition = IDLE_TRANSITION) {
   if (!state || !info) return;
   const focus = orbitalFocusReadout.call(this);
   const offset = Boolean(focus) || lookIsOffset(state.lookTarget, 0);
-  const aspect = Number.isFinite(this.viewer.camera?.frustum?.aspectRatio)
-    ? this.viewer.camera.frustum.aspectRatio
-    : canvasAspect(this.viewer);
+  const aspect = viewAspect(this.host);
   const settledFov = fovForZoom(orbitalBaseFovRad(info.altitudeM), state.zoom);
   const footprintKm = footprintWidthKm(info.altitudeM, settledFov, aspect);
   // The strip is drawn over the picture, so it follows the view as a step
@@ -796,7 +649,7 @@ export function jumpToSensorSwath() {
   const zoom = sensorSwathZoom(
     info.altitudeM,
     swathKm,
-    viewAspect(this.viewer),
+    viewAspect(this.host),
     orbitalMaxZoomFor.call(this, info),
   );
   return zoom === null ? false : goToZoom.call(this, zoom);
@@ -840,14 +693,12 @@ function orbitalMaxZoomFor(info) {
   return orbitalMaxZoom(
     info?.altitudeM,
     zoomableSwathKm(info?.sensor),
-    viewAspect(this.viewer),
+    viewAspect(this.host),
   );
 }
 
-function viewAspect(viewer) {
-  return Number.isFinite(viewer.camera?.frustum?.aspectRatio)
-    ? viewer.camera.frustum.aspectRatio
-    : canvasAspect(viewer);
+function viewAspect(host) {
+  return host.camera.pose().aspectRatio;
 }
 
 /**
diff --git a/src/ui/cockpitOrbitalView.test.mjs b/src/ui/cockpitOrbitalView.test.mjs
index f93a62bad..bcd1ce6de 100644
--- a/src/ui/cockpitOrbitalView.test.mjs
+++ b/src/ui/cockpitOrbitalView.test.mjs
@@ -109,6 +109,8 @@ function fixture(
   t,
   {
     satellite = ISS,
+    kind = 'cesium',
+    nativeViewer = true,
     orbitAllowed = true,
     reducedMotion = true,
     aircraftInfo = null,
@@ -136,7 +138,7 @@ function fixture(
   const listeners = () => ({ addEventListener: () => () => {} });
   const shots = [];
   const aircraftPosition = Cesium.Cartesian3.fromDegrees(10.2, 54.5, 3000);
-  const globe = createCockpitEngine({ kind: 'cesium' });
+  const globe = createCockpitEngine({ kind });
   const { engine } = globe;
   const aircraft = globe.aircraft({
     position: aircraftPosition,
@@ -174,7 +176,16 @@ function fixture(
   });
   engine.camera.setView = (options) => viewer.camera.setView(options);
   const pose = engine.camera.pose;
-  engine.camera.pose = () => ({ ...pose(), heading: viewer.camera.heading ?? 0 });
+  engine.camera.pose = () => ({
+    ...pose(),
+    heading: viewer.camera.heading ?? 0,
+    fovy: 2 * Math.atan(Math.tan(viewer.camera.frustum.fov / 2) / Math.max(1, viewer.camera.frustum.aspectRatio)),
+    aspectRatio: viewer.camera.frustum.aspectRatio,
+  });
+  engine.camera.setFovy = (radians) => {
+    viewer.camera.frustum.fov = cesiumFrustumFovRad(radians, viewer.camera.frustum.aspectRatio);
+  };
+  engine.surface.tilesLoaded = () => !viewer.scene.globe?.show || viewer.scene.globe.tilesLoaded !== false;
   engine.projector.worldToWindow = (position) =>
     viewer.scene.cartesianToCanvasCoordinates?.(position, {}) ?? null;
   engine.surface.sampleHeight = (position) => viewer.scene.sampleHeight?.(position);
@@ -186,7 +197,7 @@ function fixture(
     get: () => engine.input.cameraInputsEnabled(),
   });
   const cockpit = new CockpitViewController(engine, {
-    viewer,
+    viewer: nativeViewer ? viewer : null,
     services: {
       flightsLayer: { getTrackedInfo: () => aircraftInfo },
       militaryFlightsLayer: { getTrackedInfo: () => null },
@@ -1649,3 +1660,34 @@ test('back to nadir from past the limb, the sensor waits for the view', async (t
   await settle();
   assert.ok(store.orbital.sensor, 'back on the Earth');
 });
+
+test('Navara orbital entry, zoom, look and exit need only the contract', async (t) => {
+  const { cockpit, engine, shots, satellites } = fixture(t, {
+    kind: 'navara', nativeViewer: false,
+  });
+  const saved = engine.camera.pose().fovy;
+  assert.equal(cockpit.enter({ kind: 'satellite' }), true);
+  cockpit.updateOrbital(performance.now());
+  assert.equal(cockpit.subjectKind, 'satellite');
+  assert.equal(engine.input.cameraInputsEnabled(), false);
+  assert.ok(shots.length > 0);
+  const first = engine.camera.pose().fovy;
+  cockpit.stepOrbitalZoom(1);
+  assert.ok(engine.camera.pose().fovy < first);
+  cockpit.turnOrbitalLook({ axis: 'yaw', sign: 1, stepDeg: 10 });
+  cockpit.updateOrbital(performance.now());
+  assert.ok(cockpit.orbital.lookTarget.yawDeg > 0);
+  cockpit.exit();
+  assert.equal(cockpit.active, false);
+  assert.equal(engine.input.cameraInputsEnabled(), true);
+  near(engine.camera.pose().fovy, saved, 'restored lens');
+  assert.ok(satellites.calls.some(([name, id]) => name === 'subject' && id === ISS.noradId));
+});
+
+test('leaving orbit after a resize restores the wider-side lens angle', async (t) => {
+  const { cockpit, viewer } = await orbitAt(t);
+  viewer.camera.frustum.aspectRatio = 0.75;
+  cockpit.updateOrbital(performance.now());
+  cockpit.exit();
+  near(viewer.camera.frustum.fov, SAVED_FOV, 'restored lens after resize');
+});