September 28

A New Road to Orbit

2008 — Falcon 1 Becomes the First Privately Developed Liquid-Fueled Rocket to Reach Orbit

23:15 UTC

On September 28, 2008, a slender two-stage rocket rose from Omelek Island, part of Kwajalein Atoll in the Pacific Ocean. It was called Falcon 1. The rocket had flown three times before. All three attempts had failed. The fourth would change the history of commercial spaceflight. At 23:15 UTC, Falcon 1 lifted off carrying a 165-kilogram inert payload known as RatSat, or Demosat. Minutes later, the rocket's second stage successfully reached Earth orbit. Falcon 1 had become the first privately developed and funded liquid-fueled rocket to reach orbit. Its builder was Space Exploration Technologies Corporation—SpaceX—a company founded only six years earlier. The achievement had been anything but inevitable. Falcon 1's first flight, in March 2006, ended less than a minute after launch when a fuel leak led to an engine fire. The second attempt, in March 2007, traveled much farther but failed to achieve orbit after problems during the second-stage portion of the flight. The third attempt came on August 3, 2008. This time the first stage performed well, but residual thrust caused it to recontact the second stage after separation. The rocket was lost along with several payloads. The failure was particularly painful because Falcon 1 was no longer simply an experimental vehicle. It was carrying real spacecraft. SpaceX engineers identified the problem and prepared another rocket with remarkable speed. Only 55 days later, Falcon 1 stood ready again. Flight 4 carried no operational satellite. Instead, RatSat served as a payload simulator. The first stage's Merlin engine carried the vehicle through the lower atmosphere. After stage separation, the second-stage Kestrel engine continued the climb. This time, the stages separated cleanly. The second stage reached an initial orbit of approximately 622 by 643 kilometers above Earth. Falcon 1 had succeeded. The payload itself remained attached to the second stage, but that did not change the central achievement: the launch vehicle had reached orbit. NASA's contemporary chronology described Falcon 1 as the first privately developed and funded rocket to do so. The importance of that accomplishment became clearer with time. Falcon 1 flew only once more, successfully, in July 2009. SpaceX then shifted its attention to the much larger Falcon 9 and the Dragon spacecraft.

In 2010, Falcon 9 reached orbit on its first flight.

In 2012, Dragon became the first commercial spacecraft to deliver cargo to the International Space Station.

In 2015, a Falcon 9 first stage returned from an orbital-class mission and landed vertically on land.

In 2016, another landed on a ship at sea.

In 2020, SpaceX's Crew Dragon carried NASA astronauts to the International Space Station, restoring crewed orbital launch capability from the United States.

Falcon 1 therefore occupies a pivotal place in that progression. It was small. Its operational life was brief. But on September 28, 2008, it demonstrated that a privately developed liquid-fueled launch vehicle could reach orbit.

Why It Matters: Falcon 1's fourth flight marked a turning point in commercial spaceflight. The achievement demonstrated that a comparatively young private company could develop and operate an orbital launch vehicle, helping open a path toward the commercial launch, cargo, and human-spaceflight systems that would become increasingly important during the following decades.

 

Also on This Day

1951 — Seth Nicholson Discovers Ananke, a Moon of Jupiter

Observation time not established

On September 28, 1951, American astronomer Seth Barnes Nicholson discovered another member of Jupiter's growing family of moons. The discovery was made photographically using the 100-inch Hooker Telescope at Mount Wilson Observatory in California. The object would eventually receive the name Ananke. By the middle of the twentieth century, astronomers had learned that Jupiter possessed two very different kinds of satellites. The four large moons discovered by Galileo in 1610—Io, Europa, Ganymede, and Callisto—travel in relatively regular orbits close to the planet's equatorial plane. Farther away are much smaller irregular satellites. Ananke belongs to this second population. It travels around Jupiter in a distant, eccentric, highly inclined retrograde orbit, meaning that it moves in the direction opposite Jupiter's rotation. Those characteristics provide clues to its origin. Rather than forming alongside Jupiter in the disk of material surrounding the young planet, Ananke was probably associated with an object captured by Jupiter's gravity. Today astronomers recognize an entire Ananke group of small retrograde moons with similar orbital characteristics. One leading explanation is that they are fragments produced when a larger captured body was broken apart by a collision. Ananke itself has a mean radius of only about 14 kilometers. Nicholson was particularly skilled at discovering faint planetary satellites. During his career at Mount Wilson, he discovered several moons of Jupiter, greatly expanding the known architecture of the Jovian system. The contrast with modern planetary exploration is striking. Nicholson discovered Ananke as a tiny point recorded on a photographic plate. Decades later, spacecraft would transform other Jovian moons from points of light into complex worlds containing volcanoes, oceans, magnetic fields, mountains, craters, and icy terrain. Yet distant irregular moons such as Ananke remain reminders that even the planetary systems closest to us still contain populations whose histories must be reconstructed largely through careful astronomical observation.

Why It Matters: Ananke's discovery expanded the known Jovian satellite system and contributed to recognition that giant planets possess families of small irregular moons very different from their large regular satellites. Their unusual orbits preserve clues to capture, collision, and the violent early history of the solar system.

1953 — Edwin Hubble Dies

Time unknown

On September 28, 1953, American astronomer Edwin Powell Hubble died in San Marino, California. Few astronomers had done more to enlarge humanity's conception of the universe. When Hubble began his most important work, astronomers were still debating the nature of the faint spiral objects visible through telescopes. Were they relatively small clouds located within the Milky Way? Or were they enormous systems of stars lying far beyond it? Using the 100-inch Hooker Telescope at Mount Wilson—the same instrument Seth Nicholson used in discovering Ananke—Hubble identified Cepheid variable stars in the Andromeda Nebula. Cepheids were enormously valuable because their pulsation periods could be used to estimate their intrinsic luminosities. By comparing their actual luminosities with how faint they appeared from Earth, astronomers could calculate their distances. Hubble's measurements demonstrated that Andromeda was far too distant to lie within the Milky Way. The universe was suddenly much larger. The Milky Way was not the universe. It was one galaxy among many. Hubble then helped develop a system for classifying galaxies according to their appearance—spirals, barred spirals, ellipticals, and irregular systems. His work soon contributed to an even more profound discovery. Astronomers had measured the spectra of galaxies and found that many were redshifted, indicating recession. Combining galaxy-distance measurements with recession velocities, Hubble published in 1929 the relationship between distance and recession velocity that became fundamental to observational cosmology. The interpretation developed into one of the central pieces of evidence that the universe is expanding. The history deserves an important qualification. Hubble did not accomplish this alone. Vesto Slipher had already performed the difficult spectroscopic work that established the large radial velocities of spiral nebulae. Belgian astronomer and physicist Georges Lemaître had derived an expanding-universe solution from general relativity and, in 1927, published a relationship between distance and recession velocity before Hubble's famous 1929 paper. Modern historical treatments therefore place Hubble's achievements within a larger community of theoretical and observational work. His importance nevertheless remains immense. The Hubble Space Telescope, launched in 1990, was named in his honor. Its observations would extend the kind of extragalactic astronomy Hubble helped establish into realms he could scarcely have imagined.

Why It Matters: Edwin Hubble helped demonstrate that the Milky Way is only one galaxy among an enormous population of galaxies and provided crucial observational evidence associated with the expansion of the universe. His work was central to the transformation of astronomy into modern observational cosmology.

1971 — Luna 19 Launches to Map the Moon

Launch time not established

On September 28, 1971, the Soviet Union launched Luna 19, continuing an increasingly sophisticated program of robotic lunar exploration. By this point, Soviet spacecraft had already accomplished several historic lunar firsts. Luna 2 had become the first human-made object to reach another celestial body. Luna 3 had photographed the Moon's far side. Luna 9 had achieved the first successful soft landing. Luna 10 had become the first artificial satellite of the Moon. Luna 16 had returned lunar material robotically to Earth. And Lunokhod 1 was operating as the first successful remotely controlled rover on another world. Luna 19 represented another kind of investigation. Rather than landing, the spacecraft entered lunar orbit in early October and began systematically studying the Moon from above. Its scientific program included investigations of the Moon's gravitational field, surface environment, radiation conditions, and other properties. Orbital tracking was particularly useful for improving knowledge of variations in lunar gravity. Those variations were not merely academic. Earlier lunar spacecraft had revealed gravitational concentrations known as **mascons—mass concentrations—**beneath some of the Moon's great impact basins. Their gravitational pull could perturb the orbit of a spacecraft. Understanding the lunar gravity field was therefore important both scientifically and operationally. Luna 19 continued returning information from lunar orbit into 1972.

Why It Matters: Luna 19 formed part of the Soviet Union's broad robotic investigation of the Moon. Its orbital observations helped refine understanding of the lunar environment and gravity field, demonstrating that exploration required not merely reaching or landing on the Moon but systematically mapping and measuring it.

 

The Bigger Picture

September 28 gives us two very different telescopic views of the universe—and then shows what happened when humanity began building machines capable of leaving Earth altogether. In 1951, Seth Nicholson used Mount Wilson's 100-inch Hooker Telescope to identify a tiny new moon orbiting Jupiter. Two years later, Edwin Hubble died, leaving behind a scientific legacy built in large part with that very same telescope. That coincidence is particularly evocative. Nicholson used the Hooker Telescope to enlarge our knowledge of a planetary system. Hubble used it to enlarge our conception of the universe. One instrument could reveal a faint moon accompanying a nearby planet and help demonstrate that apparently faint patches of light were actually enormous galaxies far beyond our own. Then came the Space Age. Luna 19 no longer needed to examine the Moon from Earth. Humanity could send an observatory into orbit around the Moon itself.

And Falcon 1 represents another transformation. For most of the Space Age, the ability to place substantial objects into orbit had belonged principally to national governments and the large industrial organizations working for them. Falcon 1 suggested another model. Private companies might develop their own orbital launch systems and sell transportation to governments, scientists, businesses, and other customers. The consequences became increasingly visible during the following decades. The progression across September 28 is therefore remarkable: look through a telescope → discover new worlds → discover a universe of galaxies → send machines to another world → broaden who can build the machines that reach space. There is another lesson in Falcon 1's story. The rocket that reached orbit on September 28 was Flight 4. Flights 1, 2, and 3 had failed. Had the history ended with any one of those attempts, Falcon 1 might have been remembered as an unsuccessful experiment. Instead, engineers examined what had gone wrong, changed the vehicle, and tried again. Fifty-five days after the third failure, Falcon 1 reached orbit. September 28 therefore illustrates something we have encountered repeatedly in the history of astronomy and space exploration: progress is not the absence of failure. Very often, progress is what happens when people understand a failure well enough to make the next attempt different.

At a Glance

1951 — Observation time not established — Seth Barnes Nicholson discovers Ananke, an irregular moon of Jupiter, on a photograph obtained with Mount Wilson's 100-inch Hooker Telescope.

1953 — Time unknown — Edwin Hubble dies in California, leaving a legacy that helped establish extragalactic astronomy and modern observational cosmology.

1971 — Launch time not established — The Soviet Union launches Luna 19, beginning a mission to study the Moon from orbit.

2008 — 23:15 UTC — Falcon 1 lifts off from Omelek Island and becomes the first privately developed and funded liquid-fueled rocket to reach Earth orbit.