September 14

Around the Moon and Back

1968 — Zond 5 Begins a Historic Journey

21:42:10 UTC

On September 14, 1968, at approximately 21:42:10 UTC, the Soviet Union launched Zond 5 from Site 81 at the Baikonur Cosmodrome aboard a Proton-K rocket. The spacecraft was placed first into Earth orbit and then sent toward the Moon on a free-return trajectory.

Zond 5 was a version of the Soyuz 7K-L1 spacecraft being developed as part of the Soviet effort to send cosmonauts around the Moon. No people were aboard this flight, but the spacecraft carried an unusual collection of living passengers—including two Russian steppe tortoises, along with insects, plants, microorganisms, and other biological specimens. Scientists hoped to learn more about how living organisms would respond to a journey beyond Earth's immediate environment.

Four days later, on September 18, Zond 5 swept around the Moon, passing approximately 1,950 kilometers (1,210 miles) above its surface. The spacecraft then headed back toward Earth. On September 21, it reentered Earth's atmosphere and splashed down in the Indian Ocean, where Soviet recovery vessels retrieved it. The tortoises and other biological specimens survived the journey.

The mission achieved an extraordinary milestone: living creatures from Earth had traveled around the Moon and returned safely. It also demonstrated important technologies required for human lunar missions, including navigation across hundreds of thousands of kilometers and high-speed atmospheric reentry after returning from the Moon.

The timing was particularly significant. Only three months later, in December 1968, Apollo 8 astronauts Frank Borman, Jim Lovell, and William Anders would become the first humans to travel around the Moon.

Why It Matters: Zond 5 demonstrated that a spacecraft could travel from Earth, pass around the Moon, and return living passengers safely to Earth. It represented an important technological bridge between robotic lunar exploration and human voyages to the Moon.

 

Also on This Day

1712 — Giovanni Domenico Cassini Dies

Time unknown

On September 14, 1712, the influential Italian-born French astronomer Giovanni Domenico Cassini died in Paris.

Cassini was one of the outstanding observational astronomers of the seventeenth century. Among his achievements, he discovered four moons of Saturn—Iapetus, Rhea, Tethys, and Dione—and identified the prominent division between Saturn's A and B rings that still bears his name: the Cassini Division.

He also made important observations of Jupiter and Mars and contributed to efforts to determine the scale of the solar system.

Centuries later, his name would travel to Saturn aboard the Cassini spacecraft, the NASA-European Space Agency-Italian Space Agency mission that entered orbit around Saturn in 2004 and transformed our knowledge of the planet, its rings, and its remarkable family of moons.

Why It Matters: Cassini helped establish planetary astronomy as the careful study of other worlds as physical places with measurable characteristics. His discoveries remain part of the language of astronomy more than three centuries after his death.

1926 — J. L. E. Dreyer Dies

Time unknown

On September 14, 1926, Danish-born astronomer Johan Ludvig Emil Dreyer, usually known as J. L. E. Dreyer, died in Oxford, England, at age 74.

Dreyer's most enduring contribution was the New General Catalogue of Nebulae and Clusters of Stars, published in 1888 and universally known as the NGC. The catalogue contained 7,840 objects, with thousands more subsequently included in Dreyer's supplementary Index Catalogues.

His system remains part of the working vocabulary of astronomy. Familiar objects continue to be identified by their NGC numbers: the Andromeda Galaxy is NGC 224, the Orion Nebula is NGC 1976, and the Whirlpool Galaxy is NGC 5194.

Dreyer was also an important historian of astronomy. He wrote about the development of astronomical thought and devoted considerable scholarly attention to the life and observations of Tycho Brahe.

Why It Matters: Dreyer helped organize the deep sky. His catalogues gave generations of astronomers a common system for identifying thousands of objects beyond the solar system—a system that remains in widespread use today.

1958 — Mohr Sounding Rockets Reach the Upper Atmosphere

Time unknown

On September 14, 1958, three experimental sounding rockets designed by German engineer Ernst Mohr were successfully launched near Cuxhaven, West Germany. Their dart-like payloads reached an altitude of approximately 50 kilometers (31 miles).

The achievement followed unsuccessful launch attempts in June. Mohr's single-stage, solid-fueled rocket accelerated a narrow payload dart that separated after burnout and continued upward because of its more efficient aerodynamic shape. The successful September flights reached their intended altitude.

Fifty kilometers is below the 100-kilometer Kármán line commonly used to define the boundary of space, but sounding rockets occupy an important place in the history of space science. They allow instruments to investigate portions of Earth's atmosphere that are too high for balloons while avoiding the complexity and expense of placing a spacecraft into orbit.

Why It Matters: Mohr's experiments formed part of the postwar development of sounding-rocket technology—an important scientific tool for studying Earth's upper atmosphere and the environment approaching space.

 

The Bigger Picture

September 14 brings together three stages in humanity's effort to understand and eventually travel beyond Earth.

Cassini represents observation. With increasingly capable telescopes, astronomers discovered that the planets were not simply wandering points of light but complex worlds surrounded by rings and moons.

Dreyer represents organization. As telescopes revealed thousands of objects beyond the solar system, astronomy required systematic catalogues so that scientists could identify, compare, and communicate what they observed.

The sounding rockets of 1958 represent experimentation beyond the ground. Astronomical and atmospheric instruments increasingly could be carried above the dense lower atmosphere.

And Zond 5 represents exploration. Only ten years after the Mohr rocket experiments reached 50 kilometers above Earth, another spacecraft departed Earth altogether and began a journey of hundreds of thousands of kilometers around the Moon and back.

The progression captures much of the story at the heart of On This Day in Astronomy and Space: humanity observed the heavens, learned to map and understand them, developed machines capable of rising above Earth, and eventually began sending those machines to other worlds.

At a Glance

1712 — Time unknown — Giovanni Domenico Cassini, pioneering observer of Saturn and its moons, dies in Paris.

1926 — Time unknown — J. L. E. Dreyer, compiler of the New General Catalogue (NGC), dies in Oxford.

1958 — Time unknown — Ernst Mohr's experimental sounding rockets successfully reach approximately 50 kilometers above West Germany.

1968 — 21:42:10 UTC — Zond 5 launches from Baikonur on the historic mission that will carry living organisms around the Moon and safely back to Earth.