diff --git a/lambda/historic_es_to_s3/__init__.py b/lambda/historic_es_to_s3/__init__.py
index 1f149f2..8098e5d 100644
--- a/lambda/historic_es_to_s3/__init__.py
+++ b/lambda/historic_es_to_s3/__init__.py
@@ -167,7 +167,7 @@ def write_s3(serial, data, launch_sites):
     #get max alt
     append_data = ""
     if serial in launch_sites:
-        append_data = f"\"launch_site\": {launch_sites[serial]['launch_site']}, \"launch_site_range_estimate\": {launch_sites[serial]['launch_site_range_estimate']}"
+        append_data = f"\"launch_site\": \"{launch_sites[serial]['launch_site']}\", \"launch_site_range_estimate\": {launch_sites[serial]['launch_site_range_estimate']}"
     max_alt = sorted(data, key=lambda k: json.loads(k)['alt'])[-1]
     summary = [
         json.loads(data[0]),