Launches
ON RECORD26MISSIONS
24 of them reached orbit. The earliest was 1965, the most recent 2025.
MARKED ON THIS DATE
1997 · 29 years ago today
Cassini-Huygens departs
Cassini launched toward Saturn with the Huygens probe attached, taking seven years and two Venus flybys to get there.
read moreARCHIVE // DAY OF YEAR
26 orbital launches flew on October 15, the earliest of them in 1965, and 24 reached orbit. Wikipedia records 5 spaceflight and astronomy events on October 15. Below are the pictures NASA published on October 15 in 4 different years — each one taken or released on this exact date.
26MISSIONS
24 of them reached orbit. The earliest was 1965, the most recent 2025.
5ENTRIES
Spaceflight and astronomy entries from Wikipedia's record of this date, oldest first — from 1783 onward.
4IMAGES
NASA's Astronomy Picture of the Day for October 15, one per year. Some are public domain and some belong to the photographer — each says which.
NASA’s Astronomy Picture of the Day, for this calendar date in each of the last several years.

2025
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

2024
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

2022
Tidally locked in synchronous rotation, the Moon always presents its familiar nearside to denizens of planet Earth. From lunar orbit, the Moon's farside can become familiar, though. In fact this sharp picture, a mosaic from the Lunar Reconnaissance Orbiter's wide angle camera, is centered on the lunar farside. Part of a global mosaic of over 15,000 images acquired between November 2009 and February 2011, the highest resolution version shows features at a scale of 100 meters per pixel. Surprisingly, the rough and battered surface of the farside looks very different from the nearside covered with smooth dark lunar maria. A likely explanation is that the farside crust is thicker, making it harder for molten material from the interior to flow to the surface and form dark, smooth maria.Tomorrow's picture: Sunday's Childe
NASA · public domain

2021
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.
© Mike Selby — used with the credit NASA publishes
1783
The Montgolfier brothers' hot air balloon makes the first human ascent, piloted by Jean-François Pilâtre de Rozier.
Montgolfier brothers ↗1991
The "Oh-My-God particle", an ultra-high-energy cosmic ray measured at 40,000,000 times that of the highest energy protons produced in a particle accelerator, is observed at the University of Utah HiRes observatory in Dugway Proving Ground, Utah.
Oh-My-God particle ↗2001
NASA's Galileo spacecraft passes within 112 miles (180 km) of Jupiter's moon Io.
Galileo (spacecraft) ↗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
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.
LISTING
The case for leaving Earth, written by someone unsentimental about how hard that is. Suits readers who want the argument rather than the poster.
LISTING
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.
BROWSE opens an Amazon search, not a specific recommendation.
LINKS AMAZON.COM
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.