diff --git a/schedule_single_station.py b/schedule_single_station.py
index 82bfbe6..3378559 100755
--- a/schedule_single_station.py
+++ b/schedule_single_station.py
@@ -167,7 +167,8 @@ if __name__ == "__main__":
 
         # Get NORAD IDs
         norad_cat_ids = sorted(
-            set([transmitter["norad_cat_id"] for transmitter in transmitters.values()]))
+            set([transmitter["norad_cat_id"] for transmitter in transmitters.values()
+                 if transmitter["norad_cat_id"] < settings.MAX_NORAD_CAT_ID ]))
 
         # Store transmitters
         fp = open(
diff --git a/settings.py b/settings.py
index 7ccb2ee..726790b 100644
--- a/settings.py
+++ b/settings.py
@@ -1,3 +1,4 @@
 DB_BASE_URL = 'https://db.satnogs.org'
 NETWORK_BASE_URL = 'https://network.satnogs.org'
 CACHE_AGE = 24
+MAX_NORAD_CAT_ID = 90000