Header.md

@@ -48,3 +48,9 @@ Header header = new Header(name, clock);
 ```Java
 Header header = new Header(id, name, version, clock);
 ```
+
+# GENERAL VALUES USABLE
+
+**MASTER_CLOCK** - [Clock](Clock) : The clock object used for the simulation
+
+**TIME_SCALE** - [TimeScale](https://www.orekit.org/site-orekit-development/apidocs/org/orekit/time/TimeScale.html) : The time scale used for the simulation.