161 with the presence of wire bending resistance, gravity, and prototype- level workmanship (it should be noted  that many of the com ponents wer e 3D printed or hand machined).  

Lessons Learned  and Forward Work   The preliminary design activities for the NEA  Scout AMT required a significant amount of research and  investigation, but in hindsight, too much time may have been spent creating design options and trade  spaces . As the design process continued from preliminary sizing into component trades and final down  selections, hand calculations and analysis were set aside for bench top testing. This approach proved to  be the best use of time. Once the time was spent to design and build the test bed, the results came quickly  and were easy to discern. In retrospect, testing should have commenced far sooner to save time and  produce hard data. This mindset would have allowed more design iterations and tak en advantage of the  additive manufacturing capabilities available to the AMT designer . Furthermore, this methodology of “test  early and often” would have followed common CubeSat development practices (analysis is less common in CubeSat -sized projects due t o cost and staffing constraints).    Earlier testing would have also allowed the test bed to evolve. Once a design parameter -  such as  the motor  size of thread pitch -  was determined, another parameter could be tested . The test bed was designed with  enough w ork space to test optical sensing and locking mechanisms, but due to “excessive” research and  investigations into space rated components and flight heritage information, time did not allow . This is not to  discredit engineering heritages or workmanship, but  it is intended to reinforce the point t hat CubeSats and  other micro/ nanosatellites have limited heritage . Their comparable mechanical systems are often orders of  magnitude different  from traditional systems in volume, mass, and cost, thus limiting the comparisons . Other  mechanical systems aboard NEA  Scout, such as the solar sail and boom deployers, embraced this mindset  sooner (partially due to age and design maturity) and the number of design iterations was staggering.    As NEA Scout moves into the next  stages  of development, the AMT is scheduled  to deliver an engineering  development unit  in May.  Before that time, positional sensors and locking mechanisms must be designed  and tested. These two subsystems are not trivial and have the potential to greatly  alter the current AMT  design. It would have been beneficial to baseline structural designs for these components, but that is not  the reality . The locking mechanism has numerous single point failure locations . Furthermore, if  positional  knowledge is lost d uring cruise, NEA  Scout could lose its mission. In retrospect, the locking mechanisms  and sensing systems should have been designed and tested in parallel with the linear motion systems.   Moving forward, the AMT design er will have to become more flexible and adapt to the creative environment  common among microsatellite projects . The designers should embrace a mentality to test, learn, and iterate  as often as possible.  

Figure 6.  Current AMT design , and concept wire harnesses   (coax cables in maroon, power and data in blue)