1967
A firsthand debriefing from astronauts James McDivitt and Edward White — the crew of Gemini IV — describing unidentified bright particles observed outside their spacecraft during the 1965 mission. The account sits within a broader experiment debrief, with the relevant UAP observations concentrated on a handful of pages, suggesting the sighting came up organically rather than as a focal point of the mission. What makes this notable is the source: two trained observers in low Earth orbit, one of whom had just completed America's first spacewalk, describing something they couldn't readily explain.
Gemini IV was the second crewed mission of the Gemini series. Astronauts James McDivitt and Edward White successfully completed the four-day flight between June 3 and June 7, 1965. The mission included the first American spacewalk. This collection of documents contains a transcription of the astronauts recounting their observations of bright particles outside the spacecraft, dated circa June 25, 1967, on pages 78-81, and page 101.