diff --git a/package.json b/package.json
index a517b3d..49730b6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "satsim",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "SatSim for JavaScript.",
   "homepage": "https://github.com/ssc-ai/satsimjs/",
   "license": "MIT",
diff --git a/src/index.js b/src/index.js
index 5a70a68..afa1e5a 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,4 +1,4 @@
-globalThis.SATSIM_VERSION = "0.4.0-alpha"
+globalThis.SATSIM_VERSION = "0.5.0-alpha"
 
 export { default as Universe } from './engine/Universe.js'