Portal:Spaceflight/On This Day/21 April

• 1964 - A Thor-Ablestar fails to launch a Transit satellite.
• 1968 - A Molniya-M launches a Molniya-1 satellite.
• 1972 - A Kosmos-2I launches the Kosmos 487 satellite.
• 1981 - A Tsyklon-2 launches the Kosmos 1266 satellite.
• 1982 - A Kosmos-3M launches the Kosmos 1351 satellite.
• 1982 - A Soyuz-U launches the Kosmos 1352 satellite.
• 1987 - A Soyuz-U2 launches the Progress 29 spacecraft to resupply Mir.
• 1993 - A Molniya-M launches a Molniya-3 satellite.
• 1995 - An Ariane 4 launches the ERS 2 satellite.
• 1997 - A Pegasus-XL launches the Minisat-1 satellite.
• 1999 - The Dnepr makes its maiden flight, launching the UoSAT-12 satellite.
• 2013 - The Antares rocket makes its maiden flight, launching a mass simulator and 4 cubesats.