Conversation so far:
How is Heyerdahl related to the expedition of Easter Island?
Heyerdahl organized the Norwegian Archaeological Expedition to Rapa Nui (Easter Island).
Who went with him?
The expedition's scientific staff included Arne Skjolsvold, Carlyle Smith, Edwin Ferdon, Gonzalo Figueroa and William Mulloy.
When did they go?
In 1955-1956.
Was the trip a success?
The expedition published two large volumes of scientific reports.

Question: Was this the only expedition to Easter Island?
Self-contained rewrite: Was the Norwegian Archaeological Expedition to Rapa Nui the only expedition to Easter Island?