ROBINS AIR FORCE BASE - Frankly, the future of Joint STARS at Robins Air Force Base is sitting precariously between a rock and a hard place. On one side, the cantankerous, underpowered, 40-year-old JT3D engines that power the ground surveillance jet must be replaced in short order. Heroic -- and very expensive -- maintenance to keep the vital system flying can't continue indefinitely. Degraded aircraft availability, diminished flight efficiency and inadequate onboard power will eventually push the weapon system past the point of viability. On the other hand, the rising cost of re-engining...