The Air Force has long planned to upgrade the radars on the E8 JSTARS ground-surveillance radar planes to enable them to track cruise missiles at 200 miles. But the program is in trouble. Current estimates are $2.2 billion to upgrade only five aircraft, and Air Force chief General Ryan is considering alternative designs. Some include new radars on business-size jets, or long-endurance drones. These might be just as good and cheaper, but they will take longer to field.--Stephen V Cole