Development of Welded Solar Arrays for DMSP and GPS Satellites

摘要

The integrity of welds used to join solar cells to interconnect materials wasinvestigated in two development programs, one for DMSP and the second for OPS. Previous solar arrays for these programs utilized soldering to join the interconnect to the cells. It is critical to both programs to demonstrate the ability of the welded interconnects to withstand the thermal cycling expected on orbit. Initial test boards for DMSP indicated that additional development was necessary to generate a weld process capable of meeting mission requirements. The Aerospace Corporation was successful in improving the weld survival rates for DMSP, but ultimately recommended that the process be abandoned in favor of an alternate weld design or solder approach. The GPS design was much more successful. Weld evaluations before and after thermal cycling indicated that the GPS design was capable of surpassing mission requirements. An SEM evaluation technique, mechanical fatigue tester, and a rapid thermal-cycle tester were designed in support of these programs. This report relates the findings generated during the two development programs and discusses the reasons behind the failure of the DMSP weld program and the success of the GPS program.