diff --git a/CHANGELOG.md b/CHANGELOG.md
index 02a869424..9477ea2fe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+- Catalog source availability no longer modifies layer objects; unavailable
+  tooltips use layer display names.
+
 - Street Level with no providers uses the shared unavailable state and refuses
   activation before initialization, while keeping its layer identity visible.
 
diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index dc460fb3d..4d02c2224 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -3,7 +3,9 @@
 Catalog source contracts and their consuming layers are declared in
 `src/app/sourceComposition.js`. Omitted or null acquisition sources preserve layer
 registration and serialization, report unavailable, and are refused by the existing
-visibility lifecycle before initialization. Invalid supplied methods still fail
+visibility lifecycle before initialization. Availability is held in an explicit
+catalog lookup supplied to the lifecycle, without modifying layer instances;
+unavailable reasons use the layer display name. Invalid supplied methods still fail
 construction. `createStandaloneApplication` and `createStandaloneCatalog` accept
 `sources` overrides; unspecified entries retain
 standalone defaults, and null entries explicitly remove a source. Street Level
diff --git a/src/app/catalog.test.mjs b/src/app/catalog.test.mjs
index fc51c7fcd..ff6d73db5 100644
--- a/src/app/catalog.test.mjs
+++ b/src/app/catalog.test.mjs
@@ -65,13 +65,28 @@ test('data setup seals the caller catalog before controls can restore and drains
         },
       },
     },
-    catalog: createLayerCatalog(layers, metadata(layers)),
+    catalog: {
+      ...createLayerCatalog(layers, metadata(layers)),
+      getSourceAvailability: (id) =>
+        id === 'one'
+          ? {
+              available: false,
+              reason: 'One: data source not configured',
+            }
+          : undefined,
+    },
     defer: (release) => releases.push(release),
     onData: (manager) => {
       observed = manager;
     },
   });
   assert.equal(observed, dataManager);
+  assert.equal(await dataManager.setEnabled('one', true), false);
+  assert.equal(dataManager.layers.get('one').initialized, false);
+  assert.equal(
+    dataManager.getAll().find(({ id }) => id === 'one').stats.error,
+    'One: data source not configured',
+  );
   assert.deepEqual(attached, [['one', 'two']]);
   assert.deepEqual([...dataManager.layers.keys()], ['one', 'two']);
   assert.throws(() => dataManager.register({ id: 'late' }), /finalized/);
diff --git a/src/app/constructCatalog.js b/src/app/constructCatalog.js
index 74cbcf47f..e78a9b249 100644
--- a/src/app/constructCatalog.js
+++ b/src/app/constructCatalog.js
@@ -173,9 +173,11 @@ export function createApplicationCatalog({
       ],
       metadata,
     );
-    sourceComposition.bind(catalog.layers);
     return Object.freeze({
       ...catalog,
+      getSourceAvailability: sourceComposition.createAvailabilityLookup(
+        catalog.layers,
+      ),
       militaryRegistry,
       surface,
       weatherClock,
diff --git a/src/app/data.js b/src/app/data.js
index 85a3183fc..ce3ad0731 100644
--- a/src/app/data.js
+++ b/src/app/data.js
@@ -13,6 +13,7 @@ export function createApplicationData({
   // Initialize data layer manager
   const dataManager = new LayerLifecycle(viewer, {
     allowQaRegistration,
+    getSourceAvailability: catalog?.getSourceAvailability,
   });
   defer(async () => {
     await dataManager.destroyAll();
diff --git a/src/app/sourceComposition.js b/src/app/sourceComposition.js
index 77b3ebe10..b813a83bc 100644
--- a/src/app/sourceComposition.js
+++ b/src/app/sourceComposition.js
@@ -80,22 +80,29 @@ export function resolveCatalogSources(supplied = {}) {
   return {
     sources,
     isConfigured: (name) => !missing.has(name),
-    bind(layers) {
+    createAvailabilityLookup(layers) {
+      const byId = new Map(layers.map((layer) => [layer.id, layer]));
+      const availability = new Map();
       for (const [name, { layers: ids }] of Object.entries(
         CATALOG_SOURCE_CONTRACTS,
       )) {
         for (const id of ids) {
-          const layer = layers.find((entry) => entry.id === id);
+          const layer = byId.get(id);
           if (!layer) throw new Error(`Missing source consumer: ${id}`);
-          layer.getSourceAvailability = () => ({
-            available: !missing.has(name),
-            source: name,
-            reason: missing.has(name)
-              ? `Data source not configured: ${name}`
-              : null,
-          });
+          availability.set(
+            id,
+            Object.freeze({
+              available: !missing.has(name),
+              source: name,
+              reason: missing.has(name)
+                ? `${layer.name || id}: data source not configured`
+                : null,
+            }),
+          );
         }
       }
+      return (id) =>
+        availability.get(id) ?? byId.get(id)?.getSourceAvailability?.();
     },
   };
 }
diff --git a/src/app/sourceComposition.test.mjs b/src/app/sourceComposition.test.mjs
index beafa5c51..44a7c8fa0 100644
--- a/src/app/sourceComposition.test.mjs
+++ b/src/app/sourceComposition.test.mjs
@@ -30,7 +30,7 @@ test('every acquisition source can be omitted without losing catalog membership'
     const actual = catalog(sources, t);
     assert.deepEqual(actual.metadata, baseline.metadata, name);
     for (const id of CATALOG_SOURCE_CONTRACTS[name].layers) {
-      assert.equal(actual.get(id).getSourceAvailability().available, false, id);
+      assert.equal(actual.getSourceAvailability(id).available, false, id);
     }
   }
 });
@@ -38,7 +38,10 @@ test('every acquisition source can be omitted without losing catalog membership'
 test('all acquisition sources may be absent, and enable fails before initializing or fetching', async (t) => {
   const actual = catalog({}, t);
   assert.equal(actual.layers.length, 30);
-  const manager = new LayerLifecycle({});
+  const manager = new LayerLifecycle(
+    {},
+    { getSourceAvailability: actual.getSourceAvailability },
+  );
   for (const layer of actual.layers) manager.register(layer);
   for (const { layers: ids } of Object.values(CATALOG_SOURCE_CONTRACTS)) {
     for (const id of ids) {
@@ -47,7 +50,7 @@ test('all acquisition sources may be absent, and enable fails before initializin
       const row = manager.getAll().find((entry) => entry.id === id);
       assert.equal(row.enabled, false);
       assert.equal(row.stats.status, 'unavailable');
-      assert.match(row.stats.error, /not configured/);
+      assert.match(row.stats.error, /data source not configured/);
     }
   }
 });
@@ -85,7 +88,10 @@ test('standalone defaults allow exact replacements and explicit removal, and rej
 
 test('empty Street Level uses the shared unavailable lifecycle without initialization', async (t) => {
   const actual = catalog({}, t);
-  const manager = new LayerLifecycle({});
+  const manager = new LayerLifecycle(
+    {},
+    { getSourceAvailability: actual.getSourceAvailability },
+  );
   manager.register(actual.get('street-level'));
   assert.equal(await manager.setEnabled('street-level', true), false);
   assert.equal(manager.layers.get('street-level').initialized, false);
@@ -99,3 +105,52 @@ test('empty Street Level uses the shared unavailable lifecycle without initializ
     true,
   );
 });
+
+test('availability lookup accepts frozen layers and uses their display names', () => {
+  const composition = resolveCatalogSources({});
+  const layers = Object.values(CATALOG_SOURCE_CONTRACTS)
+    .flatMap(({ layers }) => layers)
+    .map((id) =>
+      Object.freeze({
+        id,
+        name: id === 'fire-perimeters' ? 'Fire perimeters' : id,
+      }),
+    );
+  const lookup = composition.createAvailabilityLookup(layers);
+  assert.equal(
+    lookup('fire-perimeters').reason,
+    'Fire perimeters: data source not configured',
+  );
+  assert.equal(Object.hasOwn(layers[0], 'getSourceAvailability'), false);
+  const manager = new LayerLifecycle({}, { getSourceAvailability: lookup });
+  manager.register(layers.find(({ id }) => id === 'fire-perimeters'));
+  assert.equal(
+    manager.getAll()[0].stats.error,
+    'Fire perimeters: data source not configured',
+  );
+});
+
+test('absent military acquisition does not poll, suppress flights, or erase supplied classification', async (t) => {
+  let fetches = 0;
+  t.mock.method(globalThis, 'fetch', async () => {
+    fetches++;
+    throw new Error('Unexpected fallback acquisition');
+  });
+  const actual = catalog(createStandaloneLayerSources({ military: null }), t);
+  const registry = actual.militaryRegistry;
+  assert.equal(actual.getSourceAvailability('flights').available, true);
+  assert.equal(registry.isMilitaryLayerActive(), false);
+  assert.equal(registry.isMilitaryIcao('abc123'), false);
+  registry.registerMilitaryIcaos([' ABC123 ']);
+  await registry.refreshMilitaryRegistryIfStale();
+  assert.equal(registry.isMilitaryIcao('abc123'), true);
+  assert.equal(registry.isMilitaryIcao('def456'), false);
+  const manager = new LayerLifecycle(
+    {},
+    { getSourceAvailability: actual.getSourceAvailability },
+  );
+  manager.register(actual.get('military'));
+  assert.equal(await manager.setEnabled('military', true), false);
+  assert.equal(registry.isMilitaryLayerActive(), false);
+  assert.equal(fetches, 0);
+});
diff --git a/src/data/lifecycle.js b/src/data/lifecycle.js
index 6c40b82be..0df5e87a4 100644
--- a/src/data/lifecycle.js
+++ b/src/data/lifecycle.js
@@ -74,7 +74,11 @@ function refreshFailureFromStats(stats, label) {
  * for real-time data overlays on the CesiumJS globe.
  */
 export class LayerLifecycle {
-  constructor(viewer, { allowQaRegistration = false } = {}) {
+  constructor(
+    viewer,
+    { allowQaRegistration = false, getSourceAvailability } = {},
+  ) {
+    this._catalogSourceAvailability = getSourceAvailability;
     this.viewer = viewer;
     this._activityListeners = new Set();
     this.layers = new Map(); // id → { module, enabled, initialized, intervalId, lifecycleState, lifecycleUncertain }
@@ -228,7 +232,7 @@ export class LayerLifecycle {
 
   _normalizedStats(entry) {
     const moduleStats = this._moduleStats(entry);
-    const availability = entry.module.getSourceAvailability?.();
+    const availability = this._sourceAvailability(entry.module.id);
     const lifecycleLoading =
       entry.lifecycleState === 'enabling' ||
       entry.lifecycleState === 'disabling';
@@ -2290,10 +2294,15 @@ export class LayerLifecycle {
     }
   }
 
+  _sourceAvailability(layerId) {
+    return (
+      this._catalogSourceAvailability?.(layerId) ??
+      this.layers.get(layerId)?.module.getSourceAvailability?.()
+    );
+  }
+
   async _visibilityBlockReason(change) {
-    const availability = this.layers
-      .get(change.layerId)
-      ?.module.getSourceAvailability?.();
+    const availability = this._sourceAvailability(change.layerId);
     if (change.enabled && availability?.available === false)
       return availability.reason || 'Data source unavailable';
     for (const callback of this._visibilityGuards) {