***** About ***** Introduction ============ **RTSim** is a Python module for simulating the inertial outputs of rotational testbeds (RT). Team ==== RTSim was written and developed by Jason Bingham. Jason is a Principle Member of Technical Staff at Sandia National Laboratories, Albuquerque USA. Acknowledgments =============== Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. Department of Energy or the United States Government.