September 29

Return to Flight

1988 — Discovery Returns the Space Shuttle to Flight

15:37:00 UTC

On September 29, 1988, the three main engines of Space Shuttle Discovery ignited at Kennedy Space Center. Seconds later, its two solid rocket boosters came alive. At 15:37:00 UTC, Discovery lifted away from Launch Pad 39B carrying five astronauts into orbit. The moment was unlike any previous Shuttle launch. For 32 months, no Space Shuttle had flown. On January 28, 1986, Space Shuttle Challenger had broken apart 73 seconds after liftoff, killing all seven members of the STS-51L crew: Francis “Dick” Scobee, Michael Smith, Ellison Onizuka, Judith Resnik, Ronald McNair, Gregory Jarvis, and Christa McAuliffe. The accident brought Shuttle operations to an immediate halt. Investigators traced the physical cause of the disaster to the failure of seals in a joint of the right solid rocket booster. Hot gases escaped through the joint, eventually contributing to the catastrophic destruction of the vehicle. But the investigation went beyond hardware. The Presidential Commission examining the accident also identified serious problems in decision-making, communication, and NASA's organizational culture. Returning to flight therefore required more than replacing a defective component. NASA redesigned the solid rocket booster field joints, made numerous modifications to Shuttle hardware and procedures, strengthened safety oversight, and reconsidered how risks were evaluated and communicated. Discovery itself underwent more than 200 modifications before STS-26. The crew chosen to make the return was deliberately experienced. Commander Frederick “Rick” Hauck, pilot Richard Covey, and mission specialists John Lounge, George “Pinky” Nelson, and David Hilmers had all flown in space before. They became the first all-veteran American spaceflight crew since Apollo 11. Their spacecraft also reflected lessons learned from Challenger. During launch and landing, the astronauts wore newly introduced Launch and Entry Suits, providing greater protection than the clothing worn by Shuttle crews immediately before the accident. Discovery also carried equipment for a new emergency escape system that could allow astronauts, under certain circumstances, to leave a disabled orbiter during controlled gliding flight. But first the spacecraft had to launch. More than a million spectators reportedly gathered along Florida's Space Coast. After weather caused a delay of approximately an hour and a half, the countdown resumed. Discovery rose from the pad. About two minutes later came one of the flight's most closely watched moments. The redesigned solid rocket boosters completed their burns normally and separated. Discovery continued toward orbit. NASA's flight controllers, engineers, astronauts, and spectators had just watched the Shuttle safely pass the point at which Challenger had been lost. Approximately eight and a half minutes after liftoff, Discovery's main engines shut down normally. About 40 minutes into the mission, the astronauts fired the Orbital Maneuvering System engines to circularize their orbit. Hauck radioed Mission Control: “It's nice to be in orbit.” STS-26 was intentionally conservative. Its principal objective was to demonstrate that the redesigned Shuttle system could operate safely. But the mission also had important work to do. Approximately six hours after launch, the crew deployed TDRS-3, a Tracking and Data Relay Satellite. A similar satellite had been lost aboard Challenger. The TDRS network allowed spacecraft in low Earth orbit to communicate with Earth through satellites in much higher geosynchronous orbits, greatly increasing the amount of each orbit during which astronauts and spacecraft could remain in contact with ground controllers. Discovery remained in space for four days. On October 3, it landed safely at Edwards Air Force Base in California. The Shuttle program had returned.

Why It Matters: STS-26 restored American human spaceflight after the Challenger disaster, but its significance was greater than simply resuming launches. The mission tested redesigned hardware and new safety procedures developed after one of NASA's darkest moments. It demonstrated that returning from catastrophe requires understanding not only what hardware failed, but also the human and organizational systems that allowed failure to occur.

 

Also on This Day

1962 — Alouette I Places Canada Among the Spacefaring Nations

UTC launch time uncertain; approximately 05:30–07:06 UTC in surviving official accounts

On September 29, 1962 UTC, a Thor-Agena rocket lifted off from California carrying a small Canadian spacecraft named Alouette I. The satellite marked Canada's arrival in the Space Age. Only the Soviet Union and the United States had previously designed and built their own artificial Earth satellites. Canada became the third nation to do so. Alouette I emerged from an invitation NASA issued in 1958 for international participation in its new satellite program. Canadian scientists John Chapman and Eldin Warren, working at the Defence Research Telecommunications Establishment, proposed building a satellite that could investigate the ionosphere from above. The ionosphere is a region of Earth's upper atmosphere containing electrically charged particles. It has enormous practical importance because it affects the propagation of radio waves and therefore long-distance communications. Scientists had studied the ionosphere from the ground by transmitting radio signals upward and examining their reflections. Alouette would reverse the geometry. Orbiting above much of the ionosphere, it could transmit radio signals downward and investigate the structure of the region from the top. The challenge was formidable. Canada had never built a satellite. Engineers incorporated technologies that were still relatively new, including transistors, solar cells, and ingenious deployable antennas. The spacecraft's long antennas were designed to unroll after reaching orbit. Alouette I weighed approximately 145 kilograms and entered an orbit roughly 1,000 kilometers above Earth. It worked extraordinarily well. The spacecraft had been designed for a lifetime of about one year. Instead, it returned useful scientific data for more than ten years and produced more than one million ionospheric images. Its success led to further Canadian-American cooperation through the International Satellites for Ionospheric Studies program, including Alouette II, ISIS I, and ISIS II. It also helped establish Canadian expertise in spacecraft engineering that would later contribute to communications satellites, robotic systems such as the Canadarm, and Canada's continuing role in international space exploration. The name itself was distinctly Canadian. “Alouette”—French for meadowlark—evoked flight while also acknowledging Canada's French-language heritage.

Why It Matters: Alouette I made Canada the first country after the Soviet Union and United States to design and build its own satellite. Its extraordinary ten-year scientific lifetime demonstrated that important space science need not be confined to the two Cold War superpowers and helped establish Canada as a significant participant in space research.

1977 — Salyut 6 Begins a New Era of Space-Station Operations

Launch time not established

On September 29, 1977, the Soviet Union launched Salyut 6, a space station whose design would fundamentally change how humans lived and worked in orbit. Earlier Salyut stations had already demonstrated that crews could occupy orbital laboratories for extended periods. But they had an important limitation. A station with only one docking port could accommodate only one Soyuz spacecraft at a time. Because the crew needed its Soyuz to return home, another spacecraft could not easily dock while the resident crew was aboard. Salyut 6 had two docking ports. That seemingly straightforward change transformed space-station operations. A resident crew could remain aboard with its Soyuz docked at one end while another vehicle arrived at the other. Visiting crews could come aboard. Replacement spacecraft could be delivered. Most importantly, uncrewed Progress cargo spacecraft could bring food, water, equipment, scientific supplies, and propellant. For the first time, an inhabited space station could be resupplied routinely while its crew remained aboard. That capability made progressively longer missions practical. Salyut 6 would host numerous Soviet and international crews. Its cosmonauts repeatedly broke human-spaceflight endurance records, eventually remaining aboard for missions lasting roughly six months. The station also became an important venue for the Soviet Intercosmos program, through which cosmonauts from several allied countries flew in space. The operational model established aboard Salyut 6—resident crews, visiting crews, multiple docking ports, cargo deliveries, orbital refueling, repairs, and long-duration habitation—would be developed further aboard Salyut 7 and Mir. Today those practices are routine aboard modern space stations.

Why It Matters: Salyut 6 helped transform a space station from a laboratory visited for a single expedition into an orbital facility capable of sustained operations. Its second docking port and Progress resupply system established an operational model that ultimately led toward continuously inhabited stations such as Mir and the International Space Station.

2011 — China Launches Tiangong-1

13:16 UTC

On September 29, 2011, China launched Tiangong-1, an experimental orbital laboratory that represented another major step in the development of the country's human-spaceflight program. Its name meant “Heavenly Palace.” Tiangong-1 was not a large permanently inhabited space station comparable with Mir or the International Space Station. It was something more transitional: a laboratory in which China could learn and demonstrate technologies required to build such a station. One capability was particularly important: rendezvous and docking. Reaching orbit is one challenge. Bringing two spacecraft traveling thousands of meters per second around Earth into the same orbit, guiding them toward one another, and joining them safely is another. Without dependable rendezvous and docking, constructing a modular space station is effectively impossible. Tiangong-1 provided the target. In November 2011, the uncrewed Shenzhou 8 spacecraft successfully rendezvoused and docked with it, demonstrating China's first orbital docking. Human crews followed. Shenzhou 9 docked with Tiangong-1 in 2012, carrying China's first woman in space, Liu Yang. Shenzhou 10 visited in 2013 for another crewed mission. The small laboratory thus served as a technological bridge between China's early Shenzhou missions and its much more ambitious plans for long-term human habitation in orbit. Those plans eventually produced the modular Tiangong space station, assembled in orbit beginning with the Tianhe core module in 2021.

Why It Matters: Tiangong-1 gave China practical experience in rendezvous, docking, orbital habitation, and station operations. It was an essential stepping-stone from independent crewed spaceflight toward China's construction and operation of a permanently crewed modular space station.

 

The Bigger Picture

September 29 tells a story about how spaceflight grows from an extraordinary achievement into a sustainable capability. Alouette I demonstrates that progression at the national level. In 1962, the ability to build a satellite was still associated overwhelmingly with the two Cold War superpowers. Canada demonstrated that another nation could design a sophisticated scientific spacecraft, place it in orbit through international cooperation, and produce important research for more than a decade. Salyut 6 addressed sustainability differently. Putting people aboard a space station was no longer enough. If humans were truly going to remain in orbit, they needed a way to receive supplies, replace equipment, welcome other crews, and keep the station operating. Two docking ports helped make that possible. Tiangong-1 represents another nation climbing a similar technological ladder. China had learned to launch astronauts. Then it learned to conduct a spacewalk. With Tiangong-1, it began mastering rendezvous, docking, and orbital habitation—the capabilities required to construct a larger station. And Discovery's return to flight reminds us that maintaining a capability also means confronting what happens when the system fails catastrophically. The Challenger disaster demonstrated that technological maturity can never be assumed. Spaceflight remains unforgiving. The lesson of STS-26 was therefore not simply: We can fly again. The deeper question was: What have we changed because of what happened? That question belongs not only to NASA but to the entire history of exploration. Alouette I required Canada to develop capabilities it had never possessed. Salyut 6 required engineers to rethink how a station could be supported. Tiangong-1 required China to master techniques needed for a future station. STS-26 required NASA to examine a system that had failed and determine how—and whether—it could safely return to flight. September 29 therefore illustrates that exploration does not advance through achievement alone. It advances when institutions learn. Build → operate → discover weaknesses → adapt → build something better. That cycle has carried spaceflight from small experimental satellites to spacecraft that can operate for decades and stations that can remain inhabited year after year.

At a Glance

1962 — Approximately 05:30–07:06 UTC; exact time uncertain — Alouette I launches from California, making Canada the third nation to design and build its own artificial Earth satellite.

1977 — Launch time not established — The Soviet Union launches Salyut 6, whose two docking ports and ability to receive Progress resupply spacecraft transform long-duration space-station operations.

1988 — 15:37:00 UTC — Space Shuttle Discovery launches on STS-26, returning the Shuttle program to flight 32 months after the Challenger disaster.

2011 — 13:16 UTC — China launches Tiangong-1, an experimental orbital laboratory that will help establish rendezvous, docking, and habitation capabilities needed for a future modular space station.