Name: Progress-21 — launch
Start: 1984-05-07
Location: NIIP-5, Baykonur, Kazakstan

Launch code: OS. Source references: NK9807-46; XPC.

Jonathan McDowell — General Catalog of Artificial Space Objects (opens in a new tab) — Data from GCAT (J. McDowell, planet4589.org/space/gcat), CC BY 4.0. Adapted into anniversary records. (CC BY 4.0)

1984-01-11 Kosmos-1530 — launch Shares a spacecraft, person or other linked entity
1984-01-13 Kosmos-1532 — launch Shares a spacecraft, person or other linked entity
1984-02-08 Soyuz T-10 — launch Shares a spacecraft, person or other linked entity
1984-01-05 Kosmos-1522/1529 — launch Same organization: Upravleniye Nachalnika Kosmicheskikh Sredstv
1984-01-11 Kosmos-1531 — launch Same organization: Upravleniye Nachalnika Kosmicheskikh Sredstv
1984-01-26 Kosmos-1533 — launch Same organization: Upravleniye Nachalnika Kosmicheskikh Sredstv