Merge pull request #1101 from VG31OP/fix/tle-catalog-matching

fix(satellites): reject TLE pairs with mismatched catalog numbers (#906, #936)

changelog.d/1101-tle-catalog-number-match.md

@@ -0,0 +1,3 @@
+- Skip TLE sets whose line 1 and line 2 carry different catalog numbers, so a
+  spliced catalog cannot pair one satellite's elements with another's; the next
+  valid set still parses (VG31OP, #1101).

docs/CURRENT-STATE.md

@@ -1474,7 +1474,10 @@ access. Callers retain validation, transport and response policy.
 
 The shared TLE text parser skips incomplete named sets and resumes at the next
 complete set. A missing orbital line does not discard the later satellites in
-the catalog; satellite layers and next-pass tools use the same parser.
+the catalog. A set whose two lines carry different catalog numbers, or a
+malformed catalog number, is skipped the same way, so a spliced catalog cannot
+pair one satellite's elements with another's. Satellite layers and next-pass
+tools use the same parser.
 
 ## Build configuration and local provider boundaries
 

src/sources/tle.js

@@ -13,7 +13,14 @@ export function parseTleText(text) {
     const name = lines[i];
     const line1 = lines[i + 1];
     const line2 = lines[i + 2];
-    if (line1.startsWith('1 ') && line2.startsWith('2 ')) {
+    const cat1 = tleCatalogNumber(line1);
+    const cat2 = tleCatalogNumber(line2);
+    if (
+      line1.startsWith('1 ') &&
+      line2.startsWith('2 ') &&
+      cat1 !== null &&
+      cat1 === cat2
+    ) {
       result.push({ name, line1, line2 });
       i += 2;
     }
@@ -60,8 +67,8 @@ export function noradIdFromSatnum(satnum) {
   return decodeCatalogField(String(satnum ?? '').trim()) ?? Number.NaN;
 }
 
-/** The NORAD catalog number from TLE line 1 (columns 3–7), or null. */
+/** The NORAD catalog number from TLE line 1 or 2 (columns 3–7), or null. */
-export function tleCatalogNumber(line1) {
+export function tleCatalogNumber(line) {
-  const field = String(line1).slice(2, 7);
+  const field = String(line).slice(2, 7);
   return decodeCatalogField(field.replace(/^ +/, ''));
 }

src/tools/queries/space.test.mjs

@@ -56,6 +56,55 @@ for (const missingLine of [1, 2]) {
   });
 }
 
+test('TLE parsing rejects pairs with mismatched catalog numbers and resumes', () => {
+  const text = `SAT A
+1 25544U 98067A   24001.50000000  .00016717  00000-0  30270-3 0  9994
+2 48274  41.4697 175.8913 0005643 312.8370 141.6893 15.61287398150000
+SAT B
+1 48274U 21035A   24001.50000000  .00020137  00000-0  24481-3 0  9993
+2 48274  41.4697 175.8913 0005643 312.8370 141.6893 15.61287398150000
+`;
+  const entries = parseTleText(text);
+  assert.deepEqual(
+    entries.map((entry) => entry.name),
+    ['SAT B'],
+  );
+  assert.equal(tleCatalogNumber(entries[0].line1), 48274);
+  assert.equal(tleCatalogNumber(entries[0].line2), 48274);
+});
+
+test('TLE parsing accepts matching Alpha-5 pairs and rejects mismatched Alpha-5 pairs', () => {
+  const text = `SAT MISMATCH
+1 A0000U 98067A   24001.50000000  .00016717  00000-0  30270-3 0  9994
+2 A0001  41.4697 175.8913 0005643 312.8370 141.6893 15.61287398150000
+SAT ALPHA5
+1 A0000U 98067A   24001.50000000  .00016717  00000-0  30270-3 0  9994
+2 A0000  41.4697 175.8913 0005643 312.8370 141.6893 15.61287398150000
+`;
+  const entries = parseTleText(text);
+  assert.deepEqual(
+    entries.map((entry) => entry.name),
+    ['SAT ALPHA5'],
+  );
+  assert.equal(tleCatalogNumber(entries[0].line1), 100000);
+  assert.equal(tleCatalogNumber(entries[0].line2), 100000);
+});
+
+test('TLE parsing rejects a pair whose catalog fields are malformed and resumes', () => {
+  // Read as digits up to the first non-digit, both fields would be 2554.
+  const text = `SAT MALFORMED
+1 2554AU 98067A   24001.50000000  .00016717  00000-0  30270-3 0  9994
+2 2554B  51.6416 247.4627 0006703 130.5360 325.0288 15.50377579432414
+SAT HALF MALFORMED
+1 2554AU 98067A   24001.50000000  .00016717  00000-0  30270-3 0  9994
+2 02554  51.6416 247.4627 0006703 130.5360 325.0288 15.50377579432414
+${TLE}`;
+  assert.deepEqual(
+    parseTleText(text).map((entry) => entry.name),
+    ['ISS (ZARYA)', 'CSS (TIANHE)'],
+  );
+});
+
 test('Alpha-5 catalog numbers decode, skipping I and O', () => {
   for (const [field, id] of [
     ['A0000', 100000],