DURING JUNE OF 1979, EARTH RESOURCES TECHNOLOGY had field teams studying uranium deposits in Bolivia, copper deposits in Pakistan, agricultural field utilization in Kashmir, glacier advance in Iceland, timber resources in Malaysia, and diamond deposits in the Congo. This was not unusual for ERTS; they generally had between six and eight groups in the field at any time.

Since their teams were often in hazardous or politically unstable regions, they were vigilant in watching for the first signs of “interference signatures.” (In remote-sensing terminology, a “signature” is the characteristic appearance of an object or geological feature in a photograph or video image.) Most interference signatures were political. In 1977, ERTS had airlifted a team out of Borneo during a local Communist uprising, and again from Nigeria in 1978 during a military coup. Occasionally the signatures were geological; they had pulled a team from Guatemala in 1976 after the earthquake there.

In the opinion of R. B. Travis, called out of bed in the late hours of June 13, 1979, the videotapes from the Congo were “the worst interference signature ever,” but the problem remained mysterious. All they knew was that the camp had been destroyed in a mere six minutes-the time between the signal initiation from Houston and the reception in the Congo. The rapidity was frightening; Travis’s first instruction to his team was to figure out “what the hell happened out there.”

A heavyset man of forty-eight, Travis was accustomed to crises.