diff --git a/DATA_SOURCES.md b/DATA_SOURCES.md
index cac0b5ab7..efee6b9ff 100644
--- a/DATA_SOURCES.md
+++ b/DATA_SOURCES.md
@@ -273,11 +273,12 @@ Bundled OSM-derived data is distributed under [ODbL 1.0](https://opendatacommons
 > We acknowledge the use of data and/or imagery from NASA's Fire Information for Resource Management System (FIRMS) (https://earthdata.nasa.gov/firms), part of NASA's Earth Observing System Data and Information System (EOSDIS).
 
 FIRMS active fires are **fetched live at runtime** (CC0 / U.S. public domain data): the
-`/api/firms` server-side proxy merges the three VIIRS NRT sources (NOAA-20, NOAA-21,
-Suomi-NPP) and MODIS NRT (Terra + Aqua), clamped to the trailing 24 h, cached 30 min to respect the shared MAP_KEY
+`/api/firms` server-side proxy merges the two VIIRS NRT sources (NOAA-20, NOAA-21)
+and MODIS NRT (Terra + Aqua), clamped to the trailing 24 h, cached 30 min to respect the shared MAP_KEY
 transaction quota. Requires a free `FIRMS_MAP_KEY`
 (https://firms.modaps.eosdis.nasa.gov/api/map_key/); the layer is empty without it.
-The former bundled 2026-05-25 snapshot was removed 2026-07-16.
+The former bundled 2026-05-25 snapshot was removed 2026-07-16. Suomi NPP (`VIIRS_SNPP_NRT`)
+is no longer requested: NASA stopped delivering its data on 2026-11-02.
 
 ### Natural Earth physical regions (`natural_earth/`)
 
diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index e868dfc95..102efb997 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -2325,6 +2325,11 @@ accessible name remains "Don't show this again". Control behavior is unchanged.
 
 ## FIRMS source status
 
+The FIRMS proxy requests VIIRS NOAA-20, VIIRS NOAA-21 and MODIS NRT (Terra and
+Aqua). It no longer requests VIIRS Suomi NPP: NASA stopped delivering Suomi NPP
+data on 2026-11-02, and the source returned no rows while still costing one
+MAP_KEY transaction per refresh.
+
 The FIRMS CSV parser rejects impossible acquisition calendar dates before the proxy filters records to the trailing 24 hours, while retaining valid UTC acquisition times.
 The `get_active_fires` tool reports acquisition times as UTC ISO timestamps,
 including zero-padded hours and minutes; missing or invalid dates and times
diff --git a/server/providers/firms.js b/server/providers/firms.js
index 20a2f4bab..51ea4fc56 100644
--- a/server/providers/firms.js
+++ b/server/providers/firms.js
@@ -131,8 +131,8 @@ export async function fetchFirms(
  * NASA FIRMS live active-fire proxy with a memory + disk cache.
  * Upstream: https://firms.modaps.eosdis.nasa.gov/api/area/csv/{KEY}/{SOURCE}/world/2
  *
- * Merges three VIIRS NRT sources (NOAA-20, NOAA-21, Suomi-NPP — independent
- * satellites, no cross-source dedup) plus MODIS_NRT (combined Terra+Aqua,
+ * Merges two VIIRS NRT sources (NOAA-20, NOAA-21 — independent satellites, no
+ * cross-source dedup) plus MODIS_NRT (combined Terra+Aqua,
  * ~1 km, numeric 0-100 confidence), fetched sequentially (quota courtesy)
  * with `days=2` (`days=1` means "current UTC day", nearly empty just after
  * 00:00Z) and clamps to the trailing 24 h via src/data/firmsCsv.js. FIRMS
@@ -141,6 +141,9 @@ export async function fetchFirms(
  * fresh-enough disk cache (.gev-cache/firms.json) prevents ANY upstream
  * fetch across dev-server restarts. Pattern mirrors celestrakProxy.
  *
+ * VIIRS_SNPP_NRT is not requested: NASA stopped delivering Suomi NPP data on
+ * 2026-11-02, so that source only spent a transaction per refresh (#849).
+ *
  * Routes:
  *   GET /api/firms        → {fetchedAt, stale, ttlMs, sources, count, fires}
  *   GET /api/firms/status → {hasKey, lastFetch, count, stale, ttlMs, transactions}
@@ -153,12 +156,7 @@ export async function fetchFirms(
 export function firmsProxy() {
   const TTL_MS = 30 * 60_000;
   const STATUS_TTL_MS = 5 * 60_000;
-  const SOURCES = [
-    'VIIRS_NOAA20_NRT',
-    'VIIRS_NOAA21_NRT',
-    'VIIRS_SNPP_NRT',
-    'MODIS_NRT',
-  ];
+  const SOURCES = ['VIIRS_NOAA20_NRT', 'VIIRS_NOAA21_NRT', 'MODIS_NRT'];
   /**
    * Per-source body cap. A VIIRS world/2 pull is ~130k rows x ~100 B, about
    * 13 MB per satellite in heavy fire season (MODIS runs smaller), so this is a
diff --git a/src/data/firmsProxy.test.mjs b/src/data/firmsProxy.test.mjs
index 14668c825..135002ca7 100644
--- a/src/data/firmsProxy.test.mjs
+++ b/src/data/firmsProxy.test.mjs
@@ -21,7 +21,7 @@ assert.notEqual(start, -1, 'FIRMS refresh function exists');
 const end = config.indexOf('\n  }', start);
 assert.notEqual(end, -1, 'FIRMS refresh function closes');
 const refreshSource = config.slice(start, end + 4);
-const SOURCES = ['VIIRS_NOAA20_NRT', 'VIIRS_NOAA21_NRT', 'VIIRS_SNPP_NRT', 'MODIS_NRT'];
+const SOURCES = ['VIIRS_NOAA20_NRT', 'VIIRS_NOAA21_NRT', 'MODIS_NRT'];
 const NOW = Date.UTC(2026, 8, 11, 12);
 const recent = { acqDate: '2026-09-11', acqTime: '1100' };
 
@@ -63,7 +63,7 @@ test('FIRMS keeps successful sources when another upstream fails', async () => {
     if (source === SOURCES[1]) throw new Error('upstream unavailable');
     return [recent];
   })('fixture');
-  assert.equal(result.fires.length, 3);
+  assert.equal(result.fires.length, SOURCES.length - 1);
   assert.deepEqual(result.sources, SOURCES.map((source, index) => ({
     source, count: index === 1 ? 0 : 1, ok: index !== 1,
   })));
@@ -77,7 +77,7 @@ test('FIRMS reports one failure if consuming a source throws before append', asy
       // Fault injection for aggregation; ordinary parsed CSV returns an array.
       return { length: 1, [Symbol.iterator]() { throw new Error('aggregation failed'); } };
     })('fixture');
-  assert.equal(result.fires.length, 3);
+  assert.equal(result.fires.length, SOURCES.length - 1);
   assert.deepEqual(result.sources, SOURCES.map((source, index) => ({
     source, count: index === 0 ? 0 : 1, ok: index !== 0,
   })));
@@ -107,7 +107,7 @@ function wrappedAddressSelectionFailure() {
     { name: 'ConnectTimeoutError', code: 'UND_ERR_CONNECT_TIMEOUT', cause: inner });
   return new TypeError('fetch failed', { cause });
 }
-const URL_WITH_KEY = 'https://firms.modaps.eosdis.nasa.gov/api/area/csv/SECRET/VIIRS_SNPP_NRT/world/2';
+const URL_WITH_KEY = 'https://firms.modaps.eosdis.nasa.gov/api/area/csv/SECRET/VIIRS_NOAA20_NRT/world/2';
 
 test('FIRMS failures log the socket cause, never the keyed URL', () => {
   const described = describeFetchError(addressSelectionFailure());
@@ -307,3 +307,13 @@ test('every FIRMS upstream request goes through the IPv4 fallback', async () =>
   assert.ok(calls[0][2] instanceof AbortSignal);
   assert.deepEqual(calls[1], ['read', response, calls[0][2]], 'the body read shares the request deadline');
 });
+
+test('FIRMS requests only the satellites NASA still delivers', () => {
+  const listed = config.match(/const SOURCES = \[([^\]]*)\];/);
+  assert.ok(listed, 'FIRMS source list exists');
+  const production = [...listed[1].matchAll(/'([A-Z0-9_]+)'/g)].map((m) => m[1]);
+  assert.deepEqual(production, SOURCES, 'the test mirrors the production source list');
+  // NASA stopped delivering Suomi NPP data on 2026-11-02 (#849): requesting it
+  // returns no rows and still spends a MAP_KEY transaction on every refresh.
+  assert.ok(!production.includes('VIIRS_SNPP_NRT'));
+});
diff --git a/src/tooling/environmentProviders.test.mjs b/src/tooling/environmentProviders.test.mjs
index da3cfc335..feca9432d 100644
--- a/src/tooling/environmentProviders.test.mjs
+++ b/src/tooling/environmentProviders.test.mjs
@@ -313,9 +313,9 @@ test('FIRMS retains a large successful source during partial failure and filters
   const first = json(await request());
   assert.equal(first.count, 130001);
   assert.equal(first.sources.filter((s) => s.ok).length, 1);
-  assert.equal(calls, 4);
+  assert.equal(calls, first.sources.length);
   assert.equal(json(await request()).count, 130001);
-  assert.equal(calls, 4);
+  assert.equal(calls, first.sources.length);
   assert.deepEqual(json(await request('/status')).transactions, {
     used: 3,
     limit: 5000,