Kaj Birket-Smith (20 January 1893 – 28 October 1977) was a Danish philologist and anthropologist. He specialized in studying the habits and language of the Inuit and Eyak. He was a member of Knud Rasmussen's 1921 Thule expedition. In 1940, he became director of the Ethnographic Department of the National Museum of Denmark.

Based on the paragraph above can we conclude that "Kaj Birket-Smith was on the Thule expedition."?
Yes