Learning to Live in Space
1973 — Skylab 3 Returns After a Record 59 Days in Space
Splashdown time approximately 22:20 UTC
On September 25, 1973, astronauts Alan Bean, Owen Garriott, and Jack Lousma splashed down in the Pacific Ocean, ending a 59-day stay aboard Skylab and completing what was then the longest human spaceflight in history.
Their mission had begun on July 28.
Skylab, America's first space station, represented a fundamental change in the purpose of human spaceflight. Mercury had demonstrated that a person could survive in space. Gemini developed the rendezvous, docking, spacewalking, and endurance skills necessary for Apollo. Apollo carried astronauts to the Moon.
Skylab asked a different question:
Could people actually live and work productively in space for months at a time?
The second Skylab crew would provide an important part of the answer.
Their 59½-day mission more than doubled the previous human spaceflight endurance record of approximately 28 days, established only months earlier by the first Skylab crew. The astronauts completed 858 orbits of Earth and accomplished substantially more scientific work than originally planned. NASA later assessed the crew as completing about 150 percent of its mission objectives.
Much of the research focused on the human body.
Extended weightlessness produces physiological changes that cannot be adequately studied during missions lasting only a few days. Skylab's medical experiments investigated cardiovascular function, metabolism, blood, muscles, balance, nutrition, sleep, and other effects of prolonged spaceflight.
Lessons from the first Skylab crew had already demonstrated the importance of exercise and adequate nutrition. Bean, Garriott, and Lousma followed improved exercise routines, and despite spending more than twice as long in space as their predecessors, they returned in comparatively good physical condition.
The astronauts also conducted extensive observations of the Sun using Skylab's Apollo Telescope Mount. Its instruments observed the Sun in wavelengths largely inaccessible from Earth's surface and provided new information about solar flares, coronal activity, and other phenomena.
Earth itself became a scientific target. The crew used Skylab's Earth Resources Experiment Package to photograph and measure features of the planet's surface, atmosphere, oceans, agriculture, and geology.
The mission even included experiments conceived by students. One of the most memorable involved two spiders, Arabella and Anita, sent into orbit to determine whether spiders could construct webs in weightlessness.
At first, their webs were irregular. With experience, however, the spiders adapted and produced more normal structures—an unexpectedly vivid demonstration that living organisms could adjust their behavior to an environment unlike anything encountered on Earth.
The crew also performed three spacewalks, carrying out maintenance and repairs and servicing scientific equipment.
Inside Skylab's spacious workshop, they tested the Astronaut Maneuvering Unit, an experimental backpack that allowed an astronaut to maneuver independently. Experience with such systems contributed to the later development of the Manned Maneuvering Unit used during Space Shuttle missions.
On September 25, the astronauts boarded their Apollo command module and departed Skylab.
After 59 days, 11 hours, and 9 minutes in space, they splashed down approximately 230 miles southwest of San Diego and were recovered by the USS New Orleans.
Their record would not last long. The third Skylab crew would remain aboard the station for 84 days.
But the implications of Skylab 3 reached much farther.
Why It Matters: Skylab 3 demonstrated that people could remain healthy, scientifically productive, and operationally effective during months rather than days in space. Its biomedical research, exercise experience, maintenance work, and long-duration living lessons became part of the foundation for later programs such as Shuttle-Mir and the International Space Station.
Also on This Day
1960 — Pioneer P-30 Fails on Its Journey to the Moon—but Achieves a Rocketry First
15:13 UTC
On September 25, 1960, the United States launched Pioneer P-30, also known as Able 5A, from Cape Canaveral.
Its destination was the Moon.
NASA intended the 175.5-kilogram spacecraft to enter lunar orbit and investigate radiation, magnetic fields, micrometeorites, and the plasma environment surrounding Earth and the Moon.
It never got there.
The Atlas first stage operated normally, but the Able second stage suffered an oxidizer-system failure. It ignited abnormally and shut down prematurely.
The spacecraft could no longer achieve the velocity required for its lunar journey.
Mission controllers nevertheless commanded the vehicle's third-stage engine to ignite.
It did.
That seemingly minor event represented a significant technological milestone: according to NASA's mission history, the small third-stage engine became the first rocket engine successfully fired in space.
The achievement could not save the mission. Pioneer P-30 lacked sufficient velocity, reentered Earth's atmosphere, and burned up approximately 17 minutes after launch.
Yet its brief flight illustrates an important reality of early space exploration. A mission could fail in its primary objective while still demonstrating a technology that would become essential.
Restarting or igniting rocket engines after reaching space is fundamental to modern spaceflight. Upper stages perform burns to place satellites into precise orbits or send planetary spacecraft toward their destinations. Spacecraft engines change orbits, rendezvous with other vehicles, enter orbit around distant worlds, and begin journeys home.
Why It Matters: Pioneer P-30 failed to reach the Moon, but its third stage achieved the first successful firing of a rocket engine in space. The mission demonstrates why the history of exploration cannot be divided neatly into successes and failures: even an unsuccessful mission can advance a technology on which later successes depend.
1992 — Mars Observer Begins America's Return to Mars
17:05:01 UTC
On September 25, 1992, at 17:05:01 UTC, NASA launched Mars Observer from Cape Canaveral aboard a Titan III rocket.
It was America's first mission to Mars in 17 years.
NASA's Viking 1 and Viking 2 spacecraft had reached Mars in 1976, placing orbiters around the planet and landers on its surface. Their achievements were extraordinary, but after Viking the United States entered a long pause in Martian exploration.
Mars Observer was intended to begin a new era.
Rather than conduct a short reconnaissance mission, the spacecraft was designed to systematically map Mars from a near-polar orbit for an entire Martian year—approximately 687 Earth days.
Its instruments would investigate the planet's surface composition, topography, gravitational and magnetic fields, atmosphere, climate, and geological history.
Among its instruments were the Mars Observer Camera, Thermal Emission Spectrometer, Gamma Ray Spectrometer, Magnetometer/Electron Reflectometer, and a laser altimeter intended to map the planet's topography with unprecedented precision.
The spacecraft began its approximately 725-million-kilometer journey normally.
Eleven months later, it was almost there.
On August 21–22, 1993, only days before the spacecraft was scheduled to enter Mars orbit, controllers lost contact.
They never heard from Mars Observer again.
Investigators could not determine the cause with certainty. One possible explanation involved a rupture or leak associated with the spacecraft's propulsion system during pressurization, potentially causing the vehicle to lose control.
The loss was a major disappointment.
Yet Mars Observer's scientific ambitions did not disappear with the spacecraft. Several of its instrument concepts were subsequently rebuilt or adapted for later missions. The Mars Orbiter Camera flew on Mars Global Surveyor, as did a laser altimeter and other instruments derived from Mars Observer's planned payload.
Mars Global Surveyor reached Mars successfully in 1997 and helped inaugurate the sustained era of Martian exploration that continues today.
Why It Matters: Mars Observer marked America's return to Mars after a 17-year absence. Although the spacecraft was lost before reaching its scientific orbit, its mission design and instrumentation influenced the successful Mars exploration program that followed. Failure did not end the scientific questions—it changed the way NASA returned to answer them.
2008 — Shenzhou 7 Launches China's First Spacewalking Mission
13:10:04 UTC
On September 25, 2008, at 13:10:04 UTC, China's Shenzhou 7 spacecraft lifted off from the Jiuquan Satellite Launch Center aboard a Long March 2F rocket.
Aboard were three taikonauts: Zhai Zhigang, Liu Boming, and Jing Haipeng.
The mission's most important objective would occur two days later: China's first extravehicular activity, or spacewalk.
China had become the third nation to independently launch people into orbit with Shenzhou 5 in 2003. Shenzhou 6 followed in 2005 with a two-person crew and a mission lasting nearly five days.
Shenzhou 7 represented another step in increasing complexity.
The spacecraft had been modified to support EVA operations, and the crew carried two different spacesuits. Zhai would wear the Chinese-developed Feitian suit, while Liu assisted him wearing a Russian-derived Orlan suit.
On September 27, Zhai emerged from the spacecraft and floated outside while Liu partially exited the orbital module to assist him.
The excursion was brief, but its significance was considerable.
A spacewalk requires much more than opening a hatch. The spacecraft must be capable of depressurization and repressurization. The spacesuit must function as an independent miniature spacecraft, providing oxygen, pressure, temperature regulation, communications, and protection from the vacuum of space. Astronauts must also be trained to work safely when even a simple task can become difficult in weightlessness.
The mission therefore demonstrated technologies and procedures China would later need to construct and maintain space stations.
Those capabilities eventually contributed to China's Tiangong space station, whose assembly required repeated spacewalks.
Why It Matters: Shenzhou 7 began the mission that gave China its first independent spacewalking capability. EVA was a necessary technological step toward China's later ability to assemble, maintain, and operate a permanently crewed space station.
The Bigger Picture
September 25 is a day about learning what comes next.
Pioneer P-30 failed to reach the Moon, yet during its short life engineers successfully fired a rocket engine in space—a capability essential to countless missions that followed.
Skylab 3 asked what came after simply proving that humans could reach space.
Could they live there?
For nearly two months, Bean, Garriott, and Lousma demonstrated that astronauts could conduct science, repair equipment, exercise, adapt their routines, and remain productive while living in weightlessness.
Mars Observer asked what came after the pioneering reconnaissance of Mars.
Could spacecraft begin a sustained, systematic scientific investigation of the planet?
Mars Observer itself did not survive to answer that question. But its scientific objectives and instrument heritage helped shape the missions that followed.
Shenzhou 7 represents the same progression within China's human spaceflight program.
First, send a person into orbit.
Then send multiple crew members.
Then learn to leave the spacecraft and work outside it.
Eventually, use those skills to build and maintain a space station.
There is a pattern running through all four events:
attempt → learn → improve → attempt something more difficult.
That progression is easy to overlook when the history of spaceflight is reduced to famous firsts.
The first satellite, first person in space, first Moon landing, or first spacewalk makes an obvious historical marker.
But exploration advances through what happens after the first.
Someone must turn an experimental capability into a dependable one.
Someone must discover why a spacecraft failed.
Someone must remain in orbit long enough to learn what the human body needs.
Someone must develop the procedures that allow tomorrow's mission to attempt something yesterday's could not.
September 25 therefore reminds us that the history of space exploration is not simply the history of reaching new destinations.
It is the history of learning how to stay, work, recover from failure, and go farther the next time.
At a Glance
1960 — 15:13 UTC — Pioneer P-30 launches toward the Moon. The mission fails, but its third-stage engine achieves the first successful firing of a rocket engine in space.
1973 — Approximately 22:20 UTC — Alan Bean, Owen Garriott, and Jack Lousma splash down after Skylab 3, completing a then-record 59½-day human spaceflight.
1992 — 17:05:01 UTC — Mars Observer launches from Cape Canaveral, beginning the first American mission to Mars in 17 years.
2008 — 13:10:04 UTC — Shenzhou 7 launches with Zhai Zhigang, Liu Boming, and Jing Haipeng, beginning the mission that will conduct China's first spacewalk.
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