; and (B) support United States leadership in astrophysics; (2) consistent with annual Government Accountability Office reviews of the James Webb Space Telescope program, the Administrator should continue robust surveillance of the performance of the James Webb Space Telescope project and continue to improve the reliability of cost estimates and contractor performance data and other major space flight projects in order to enhance NASA’s ability to successfully deliver the James Webb Space Telescope on-time and within budget; (3) the on-time and on-budget delivery of the James Webb Space Telescope is a high congressional priority; and (4) the Administrator should ensure that integrated testing is appropriately timed and sufficiently comprehensive to enable potential issues to be identified and addressed early enough to be handled within the James Webb Space Telescope’s development schedule and prior to its launch. 504. Wide-Field Infrared Survey Telescope (a) Sense of Congress It is the sense of Congress that— (1) the Wide-Field Infrared Survey Telescope (referred to in this section as WFIRST ) mission has the potential to enable scientific discoveries that will transform our understanding of the universe; and (2) the Administrator, to the extent practicable, should make progress on the technologies and capabilities needed to position the Administration to meet the objectives, as outlined in the 2010 National Academies’ Astronomy and Astrophysics Decadal Survey, in a way that maximizes the scientific productivity of meeting those objectives for the resources invested. (b) Continuity of development The Administrator shall ensure that the concept definition and pre-formulation activities of the WFIRST mission continue while the James Webb Space Telescope is being completed. 505. Mars 2020 rover It is the sense of Congress that— (1) the Mars 2020 mission, to develop a Mars rover and to enable the return of samples to Earth, should remain a priority for NASA