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.
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.
Skinner's system worked consistently in trials, although the scientists working on the guidance system were hesitant about entrusting pigeon pilots with live bombs.