Historical clue formulations

• U.S./Soviet competition of the 1950s-’60s — 2026-07-20
• Competition with many missions — 2024-09-06
• Contest featuring Apollo — 2023-09-22
• Cold War contest featuring Sputnik and Apollo — 2023-03-27
• Cold War competition — 2019-10-15
• It was launched with Sputnik — 2018-08-10
• Old U.S./Soviet rivalry — 2014-04-23
• Contest with many missions — 2008-05-02
• Event started by 38-Across — 2007-10-04