The people of Rongelap lived on their atoll for hundreds of years. The 61 islands of the atoll have a total land area of just about 20 square kilometres, but it was home to more than 300 people, when the Rainbow Warrior arrived there 1985.
In 1954, the United States detonated a nuclear bomb as part of its Castle Bravo test, knowing that the fallout would cover Rongelap. This bomb was 1,000 times more powerful than those used on Hiroshima and Nagasaki.
Three days after the detonation, the US government evacuated the residents of Rongelap to Kwajalein Atoll. Three years later the government officials claimed that Rongelap Atoll was safe again, and they returned the islanders to their home.
Over the next 30 years, the evidence of radioactive poisoning grew. Rongelap children were still born and many mothers experienced miscarriages. Just under 70% of the Rongelap children who were under 10 in 1954 developed thyroid tumours.
United States scientists continued to monitor the people of Rongelap, believing that the condition of the people of Rongelap afforded an opportunity to observe the effects of prolonged exposure to high radiation levels.
After decades of pleading with the United States government, in 1985 the Rongelap people turned to Greenpeace for help. They asked that Greenpeace send a vessel to evacuate them from their home and move them to nearby Mejato Island.
Greenpeace sent the Rainbow Warrior to Rongelap at the request of its people and in May 1985 moved them to Mejato Island, 180 kilometres away in Kwajalein Atoll. This operation, involving many trips, took 11 days.