The Applied Physics Laboratory first became involved with the Strategic Defense Initiative Organization (SDIO) in April 1984. Seven programs were initiated, five of which have resulted in launches, another is nearing a launch date. The teamwork between SDIO and APL, along with many other subcontractors, began with the Delta 180 program, the first in a series known as the Delta programs. The Delta series set new standards for accomplishing orbital missions in extremely short periods. Although the seven programs are somewhat diverse, the constant theme throughout was to understand and develop sensors that SDIO could use in a deployed architecture and that could be used from ascent through the midcourse phase of a booster trajectory.
