Home2020 Treaties and Agreements ...Japan (20-1231.4) – Memo of Understanding Concerning Cooperation on the Civil Lunar Gateway hide Japan (20-1231.4) – Memo of Understanding Concerning Cooperation on the Civil Lunar Gateway TIAS Office of Treaty Affairs December 31, 2020 Space Signed at Washington and Tulsa December 28 and 31, 2020; entered into force December 31, 2020. Download Agreement [8 MB] Tags Japan Space Treaties