 The nuclear yield was reported in most official documents as “less than 20 kilotons.” One report by the U.S. government reported the yield of the "Tightrope" test as 10 kilotons.Seven sounding rockets were launched from Johnston Island in support of the "Tightrope" test, and this was the final American nuclear atmospheric test.The "Fishbowl" series included four failures, all of which were deliberately disrupted by range safety officers when the missiles' systems failed during launch and were aborted.