Space agencies and diplomats in Washington and Moscow this week marked the 50th anniversary of the Apollo–Soyuz Test Project, the first crewed mission jointly conducted by the United States and the Soviet Union and a milestone in Cold-War diplomacy. On 15 July 1975, Soyuz 19 lifted off from Baikonur at 12:20 UTC, followed hours later by Apollo CSM-111 from Cape Canaveral. Forty-four hours later, at 16:19 UTC on 17 July, commanders Alexei Leonov and Thomas Stafford brought their two spacecraft together 225 kilometres above Earth and exchanged a historic handshake. The crews—rounded out by Valery Kubasov, Vance Brand and Donald “Deke” Slayton—shared meals, conducted joint experiments and completed a second docking before separating. Soyuz returned to Kazakhstan on 21 July, while Apollo splashed down in the Pacific on 24 July, closing a mission seen as a precursor to three decades of U.S.–Russian cooperation that now spans the Shuttle-Mir programme and the International Space Station. NASA, Roscosmos and Russia’s Foreign Ministry released archival footage and statements highlighting the mission’s legacy for today’s orbital partnerships. Moscow also linked the anniversary to its proposal to forego the first deployment of weapons in space, while NASA underscored its plans to extend multilateral collaboration through the Artemis lunar programme.