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April 21 in spaceflight

16 orbital launches flew on April 21, the earliest of them in 1961, and 15 reached orbit. Wikipedia records 2 spaceflight and astronomy events on April 21. Below are the pictures NASA published on April 21 in 6 different years — each one taken or released on this exact date.

DATE

Launches

ON RECORD

16MISSIONS

15 of them reached orbit. The earliest was 1961, the most recent 2026.

Recorded events

IN THE RECORD

2ENTRIES

Spaceflight and astronomy entries from Wikipedia's record of this date, oldest first — from 1964 onward.

Pictures from this date

PUBLISHED

6IMAGES

NASA's Astronomy Picture of the Day for April 21, one per year. Some are public domain and some belong to the photographer — each says which.

Published on April 21

NASA’s Astronomy Picture of the Day, for this calendar date in each of the last several years.

NASA Science

2026

NASA Science

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

NASA · public domain

NASA Science

2025

NASA Science

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

NASA · public domain

NASA Science

2024

NASA Science

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

NASA · public domain

NASA Science

2023

NASA Science

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

© Gwenaël Blanck — used with the credit NASA publishes

NASA Science

2022

NASA Science

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

NASA · public domain

NASA Science

2021

NASA Science

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

NASA · public domain

What happened on April 21

  1. 1964

    A Transit-5bn satellite fails to reach orbit after launch; as it re-enters the atmosphere, 2.1 pounds (0.95 kg) of radioactive plutonium in its SNAP RTG power source is widely dispersed.

    Transit (satellite navigation system) ↗

  2. 1972

    Astronauts John Young and Charles Duke fly Apollo 16's Apollo Lunar Module to the Moon's surface, the fifth NASA Apollo Program crewed lunar landing.

    John Young (astronaut) ↗

Every launch on April 21

16 launches

ONLINE
  1. 2026Falcon 9 Block 5 | GPS III SV10SpXSUCCESS
  2. 2025Falcon 9 Block 5 | Dragon CRS-2 SpX-32SpXSUCCESS
  3. 2022Falcon 9 Block 5 | Starlink Group 4-14SpXSUCCESS
  4. 2013Antares 110 | Cygnus Mass SimulatorOSCSUCCESS
  5. 1999Dnepr | UOSAT-OSCAR-36ISCKSUCCESS
  6. 1997Pegasus XL | Minisat & Celestis Space Burial #1OSCSUCCESS
  7. 1995Ariane 40 | ERS-2ASASUCCESS
  8. 1993Molniya-M | Molniya-3 57LPRSCSUCCESS
  9. 1987Soyuz-U2 | Progress 29CCCPSUCCESS
  10. 1982Soyuz U | Zenit-6U 56CCCPSUCCESS
  11. 1982Kosmos-3M | Taifun-2 12CCCPSUCCESS
  12. 1981Tsiklon-2 | US-A 18CCCPSUCCESS
  13. 1972Kosmos 11K63 | DS-P1-Yu 53CCCPSUCCESS
  14. 1968Molniya-M | Molniya-1 8CCCPSUCCESS
  15. 1964Thor DM-21 Ablestar | Transit-5BN 3USAFFAILURE
  16. 1961Trailblazer 1 | Trailblazer 1gNASASUCCESS

FIELD KIT / LIBRARY

SPONSORED

General-audience astronomy and spaceflight — none of it a textbook.

As an Amazon Associate I earn from qualifying purchases. Links here cost you nothing extra.

  • LISTING

    Cosmos — Carl Sagan

    Still the best single argument for why any of this matters, and it leaves the arithmetic in. For a reader who wants the science, not just the awe.

    VIEW

  • LISTING

    Pale Blue Dot — Carl Sagan

    The case for leaving Earth, written by someone unsentimental about how hard that is. Suits readers who want the argument rather than the poster.

    VIEW

  • LISTING

    Project Hail Mary — Andy Weir

    Hard-SF problem solving in The Martian's key — for anyone who liked the engineering more than the peril. The only novel on this list.

    VIEW

BROWSE opens an Amazon search, not a specific recommendation.

LINKS AMAZON.COM

Sources and licences

Event text and thumbnails come from Wikipedia and are used under CC BY-SA 4.0. Images are drawn only from Wikimedia Commons, which does not accept non-free content — each thumbnail links to its file page, where its licence and author are recorded.

Launch records are from The Space Devs’ Launch Library 2. Pictures are NASA’s Astronomy Picture of the Day; NASA imagery is generally not subject to copyright, but individual APOD entries are frequently the property of the photographer, and each caption says which applies.