The Cygnus-XL ship launched to the ISS on the Sept. 14 NG-23 mission without a hitch. It entered orbit successfully, then performed a pair of non-sequential burns to bring it into a close orbit with the ISS. However, NASA found that the main thruster shut down prematurely in both cases, prompting a halt to docking plans. It was, in fact, a "conservative safeguard in the software settings" that caused the engines to halt their burns early as a safety precaution. The ship was then cleared to make its docking run, and it all went off without a hitch.