Conversation so far:
What is the Manhattan Project?
atomic bomb project.
When did this project begin?
In February 1944.
Did he work on this with other people?
Rotblat joined the Los Alamos Laboratory as part of Chadwick's British Mission to the Manhattan Project.

Question: What kind of things did they do on this project?
Self-contained rewrite: What kind of things did Chadwick's British Mission do on atomic bomb project?