================================= However, the MA-31 was only an interim solution, because the drone lacked the range and flight path accuracy to fully satisfy the Navy's SSST (Supersonic Sea-Skimming Target) requirement for the simulation of a high-speed anti-ship missile. During the MA-31 evaluation, Boeing had demonstrated an improved variant (sometimes called MA-31PG; PG = "Precision Guidance") with a GPS-based navigation system and the resulting option for a precise flight path after a high-altitude (and therefore longer range) launch, but in the end this variant was not selected for production as the ultimate SSST. Instead, that contract went to Orbital Sciences in June 2000, leading to the GQM-163 Coyote SSST. After the GQM-163 became operational, the remaining MA-31 targets were expended until the end of 2007 and the program terminated.