Ability to Perform First Mode Fundamental Frequency Verification One of the advantages of the air pad system was that it accommodated first mode frequency verification  testing. The Qual –Y Solar Array Wing was configured in the deployed position and a direct measurement of the frequency was able to be performed by placing and releasing side load and examining the  oscillating motion of the wing while supported by the airpads. Since the airpads induce almost zero  friction and the measured value was found to be close to the predict, the analytical model was verified  showing that the Solar Array meets its frequency requirement (Rivera). This test method was found to be  more straightforward than others that required suspending the solar array from a cord and performing a  twang test as has been used for other projects (Jiang and Gahart).  Conclusion In summary, many challenges were overcome developing a system to g-negate the GPM Solar Array  Wings so that their ability to deploy once in orbit could be adequately verified. It was decided to implement heritage design air pads even though this type of system had only been used for solar array  wings much smaller than those of GPM at NASA GSFC. During this process, it was verified that the  facility being used had sufficient air flow and the air pads were optimized to carry the required load. A new support structure was designed in order to capture GSE points on the panels to prevent tipping and allow movement along a flat table surface with the use of air pads. Testing of this design with mass models and full-size mock-ups made it clear that the deployment tables being used, inherited from previous projects,  provided an insufficient surface for deployment due to warping of the table top from previous use. Also, difficulties associated with aligning the large array of tables proved inadequate to accommodate the Solar  Array's full deployment path. Creative solutions were adopted first to align and provide a surface cover to  adequately improve the table surface to allow the Solar Array Wing to deploy. Solutions were also foundto modify the table covering to work in the clean room and to dissipating electrostatic charge due to flow from the air pads. Once the table and surface cover solutions were found, additional testing of Solar Array deployments revealed the sensitivity to both the alignment of the wing in pitch and roll and to the air hose routing. Because of these sensitivities, techniques were developed to normalize these parameters. Finally, it was found that this g-negation system was well suited to support first mode fundamental frequency testing. The result of the work involved in developing this system was that the GPM Solar Array Wings were successfully verified through multiple deployment tests while installed to the flight Spacecraft.   References 1. Rivera, Alejandro, /g42/g51/g48/g16/g54/g36/g39/g39/g54/g16/g53/g51/g55/g16/g19/g20/g23/g23/g3/g16/g3/g54/g82/g79/g68/g85/g3/g36/g85/g85/g68/g92/g3/g41/g88/g81/g71/g68/g80/g72/g81/g87/g68/g79/g3/g41/g85/g72/g84/g88/g72/g81/g70/g92/g3/g55/g72/g86/g87/g3/g53/g72/g86/g88/g79/g87/g86 , https://gpmmis.nasa.gov/ (accessed 1/8/2014) 2. Jiang and Gahart, /g36/g81/g68/g79/g92/g86/g76/g86/g3/g68/g81/g71/g3/g48/g82/g71/g68/g79/g3/g54/g88/g85/g89/g72/g92/g3/g55/g72/g86/g87/g3/g82/g73/g3/g44/g81/g87/g72/g79/g86/g68/g87/g3/g57/g44/g44/g36/g3/g39/g72/g83/g79/g82/g92/g72/g71/g3/g54/g82/g79/g68/g85/g3/g36/g85/g85/g68/g92 , http://web.mscsoftware.com/support/library/conf/wuc94/p02794.pdf (accessed 1/8/2014) Contributors: Majdi Mukhar, Mike Mutaku, Dick McBirney, Jenny Xu, Robbie Robinson, John Tota,  Andrew Scharmann, Chris Matthews, Nick Kwiatkowski, Gary Sheridan, Rodger Farley 348