diff --git a/docs/TODO b/docs/TODO
index fea1caa..3b390a0 100644
--- a/docs/TODO
+++ b/docs/TODO
@@ -6,6 +6,10 @@ If you see modifications to this file in git status, IGNORE them and do not comm
 
 
 === next steps ===
+    - refactor test cases to use strict values in 'REQUIRE' tests
+    - we're working on a generic python simulator to precalculate, but we should
+        also use some actual values from real-world missions or textbooks
+
     - interplanetary transfers
     - SOI boundary testing
         - draw SOI boundry in graphical sim