 The completion of a second round of successful gas generator tests was announced on 21 September 2010.Starting in 2011, the full J-2X engine, derived from heritage and new designs, has undergone hot-fire tests.In October 2013, it was reported that work on the J-2X would pause following development testing in 2014, due to funding limitations, an expected delayed need for the engine's capabilities for piloted missions to Mars, and selection of the RL10 powered Exploration Upper Stage for SLS.