Keeping this predator airborne at altitudes as high as 10,000 feet requires a 12-meter wingspan, an accurate guidance system, and near-perfect eyesight.
Skinner's system worked consistently in trials, although the scientists working on the guidance system were hesitant about entrusting pigeon pilots with live bombs.
Then the craft's reentry went wrong. The guidance system failed and they had to steer manually, bumping down in a snowy forest 1,600km from the landing site.