Summary Positions to be filled are in various organizations at the following NASA Centers - Ames Research Center, Armstrong Flight Research Center, Langley Research Center and Glenn Research Center. NASA may fill positions in any of the following series and at any grade level listed in this announcement (GS-801, 861, 850, 830, 854, 855, 806, and 893 at the GS-7/9/11/12/13/14/15 levels). Responsibilities Duties described below are at the highest grade advertised. Duties assigned at lower grade levels will be of more limited scope, performed with less independence and limited complexity; duties will be commensurate with the grade of selected employee. Directs technical efforts across organizational boundaries and provides authoritative guidance to senior officials on highly complex engineering matters. Conducts and oversees advanced engineering analysis, design, test, and evaluation on mission-critical systems. Applies expert judgment to resolve complex technical problems and recommends ...