a point of discussion because FOS below the proof load level would mean the GSE could yield during proof  testing.   In all cases, the goal was to allow GSE to meet its FOS requirements, as this is ultimately a benefit to the  overall program in that it reduces risk of damage to valuable hardware during transportation.   One challenge of two designs working concurrently is that changes to one side of the interface impacts the  other interface. As payload designs evolved and the needs of the interfaces became better understood, the  MPTS design frequently had to adapt. For some component designs of the MPTS, this required up to three  significant redesigns and an unplanned development effort. As a result, design reviews and drawing  releases were regularly adjusted. While program schedule fortunately allowed for these redesigns, planning  them upfront would clarify expectations for affected teams.   Summary and Conclusion  Throughout the development of the MPTS, various methods and tools were used. This included developing  3-D printed models, performing multi-body simulations, and conducting tests. These methods aided in the production of a highly complicated system capable of adapting to the multiple articles it was tasked to support. 3-D printed models provided a means to understand and demonstrate complicated mechanisms inherent in the design. Performing multi-body simulations allowed a means of verifying the released degrees of freedom and the limited range of motion they provide. The use of models and simulated analysis offered a cost-effective means to identify critical locations, features, and tolerances. Testing has also proven to be essential to ensure the MPTS functions appropriately. This aided in assessing specific issues that would have otherwise been overlooked on paper, or with smaller scale modeling. Early communication is key to successfully delivering hardware in a timely manner. All the work performed in developing the MPTS was done in conjunction with the design of the flight hardware. This was accomplished by identifying the interface locations on the vehicle and understanding the MPTS requirements to safely deliver the spaceflight hardware to test locations and the launch platform. References  1. NASA. “KSC-70P-19.”  Apollo 14 Multimedia , scan by J.L. Pickering, 22 Jan. 1970, https://www.hq.nasa.gov/alsj/a14/images14.html#KSC70P19. 2. NASA. “KSC00padig095.”  NASA Image and Video Library , 21 Nov. 2000, https://images.nasa.gov/details-KSC00padig095.html. 3. Wheelift. “nasa2.” NASA Uses Wheelift Transporters for Spacecraft Assembly and Transport , accessed 31 Jan. 2018, http://www.wheelift.com/case-studies/case-study-detail/nasa-uses-wheelifttransporters-for-spacecraft-assembly-and-transport. 4. Bergin, Chris. “Z71.”  SPMT: Providing transport to SLS core stages , NASASpaceFlight.com, 10 Dec. 2013, https://www.nasaspaceflight.com/2013/12/spmt-transport-sls-core-stages. 5. “Crosby® HR-1000CT COLD-TUFF® UNC Heavy Lift Swivel Hoist Rings.” Crosby Catalog . Crosby, 2017. https://www.thecrosbygroup.com/catalog/rigging-accessories/crosby-hr-1000ct-cold-tuff-uncheavy-lift-swivel-hoist-rings/, 31 Jan. 2018. 6. “Timelapse video: Space shuttle Endeavor’s crosstown journey through L.A.”  Los Angeles Times, http://www.latimes.com/local/73406669-132.html, 31 Jan 2018. 7. “KAron Design Guide.”  KAMAN Specialty Bearings & Engineered Products, https://www.kaman.com/sites/default/files/KAronDesignGuide.pdf, 31 Jan. 2018. NASA/CP—2018-219887 469