The UN ultimately created a Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, which was signed by the United States, USSR, and the United Kingdom on January 27, 1967 and went into force the following October 10.

The Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space was signed by three countries on what date?