A History of Significant Incidents and Close Calls in Human Spaceflight

Since the dawn of the Space Age in the early 1960s, NASA and other space agencies have made remarkable achievements in human spaceflight. From the first flights of Project Mercury to the Apollo missions to the Moon, the Space Shuttle program, and the International Space Station, astronauts have pushed the boundaries of exploration and expanded our knowledge of the universe. However, the history of human spaceflight has also been marked by significant incidents, close calls, and tragic accidents that have demonstrated the inherent risks and challenges of venturing into the hostile environment of space.

The Early Years: Mercury, Gemini and Apollo

The first major incident in the U.S. human spaceflight program occurred during a ground test for the first crewed Apollo mission. On January 27, 1967, a fire broke out in the command module during a “plugs-out” test on the launch pad, trapping the crew inside. The three astronauts – Virgil “Gus” Grissom, Ed White, and Roger Chaffee – perished in the blaze, which was fueled by the pure oxygen atmosphere inside the capsule. The tragedy was a stark reminder of the dangers of spaceflight and led to major safety improvements for future missions.

Despite this setback, NASA pushed forward with the Apollo program, determined to meet President Kennedy’s challenge to land a man on the Moon by the end of the 1960s. The agency achieved this historic goal with Apollo 11 in July 1969. However, the subsequent Apollo missions also faced their share of incidents and close calls.

Apollo 12, the second lunar landing mission, was struck by lightning shortly after liftoff, temporarily knocking out power and telemetry. The quick thinking of the crew and ground controllers saved the mission. Apollo 13 famously suffered an explosion in its oxygen tank en route to the Moon, forcing the crew to use their lunar module as a “lifeboat” to return safely to Earth. And on Apollo 16, a malfunction in the main propulsion system of the command and service module almost led to an abort of the lunar landing.

The Space Shuttle Era

The Space Shuttle was conceived as a reusable spacecraft that would make access to low Earth orbit routine and economical. However, the complexity of the shuttle system also introduced new risks and failure modes.

On January 28, 1986, the Space Shuttle Challenger broke apart 73 seconds into its 10th flight, killing all seven crew members. The cause was traced to the failure of an O-ring seal in the right solid rocket booster, which allowed hot gases to escape and impinge on the external tank, leading to its rupture. The accident grounded the shuttle fleet for nearly three years while NASA worked to redesign the boosters and implement other safety improvements.

Tragedy struck the shuttle program again on February 1, 2003, when the Space Shuttle Columbia disintegrated during reentry at the end of its 28th mission. A piece of foam insulation had broken off the external tank during launch and struck the leading edge of the orbiter’s left wing, damaging the thermal protection system. This created a breach that allowed superheated gases to enter and destroy the wing structure upon reentry. The accident claimed the lives of all seven astronauts on board.

In the aftermath of the Columbia accident, the shuttle fleet was grounded for over two years. NASA worked to eliminate the foam shedding problem and developed in-flight repair techniques for the thermal protection system. The agency also implemented a program to inspect and reinforce the leading edge panels on the remaining orbiters. The Space Shuttle flew its final mission in July 2011, marking the end of an era in human spaceflight.

The International Space Station

The International Space Station (ISS) is a remarkable example of global cooperation in space, but it too has faced its share of incidents and close calls over the years.

In 1997, a fire broke out on the Russian Mir space station, filling the modules with smoke and forcing the crew to don respirators. The fire was eventually extinguished, but it underscored the dangers of living and working in space for extended periods.

In 2009, the ISS crew had to shelter in the Soyuz spacecraft when a piece of space debris passed uncomfortably close to the station. And in 2015, an unmanned Progress resupply ship spun out of control shortly after launch and was unable to dock with the ISS, disrupting the crew’s supply chain.

Perhaps the most harrowing incident on the ISS occurred in 2013, when Italian astronaut Luca Parmitano’s helmet began filling with water during a spacewalk. The leak was later traced to his spacesuit’s cooling system. Parmitano was able to safely return to the airlock, but the incident highlighted the risks of extravehicular activity and the importance of robust contingency procedures.

Commercial Spaceflight

In recent years, commercial companies like SpaceX and Boeing have entered the human spaceflight arena, offering new capabilities and challenges.

In 2015, a SpaceX Falcon 9 rocket carrying cargo to the ISS exploded shortly after launch. The cause was traced to a faulty strut in the second stage liquid oxygen tank. SpaceX worked to identify and fix the problem, and has since flown numerous successful missions to the ISS.

During a 2019 uncrewed test flight of Boeing’s Starliner spacecraft, multiple software issues caused the vehicle to miss its planned rendezvous with the ISS. The spacecraft was able to return safely to Earth, but the incident delayed Boeing’s plans to fly astronauts and prompted a major review of the company’s software development and testing processes.

Lessons Learned

Each of these incidents and close calls has provided valuable lessons that have helped make spaceflight safer and more reliable. Some key takeaways include:

• The importance of robust design, with multiple layers of redundancy and fault tolerance
• The need for thorough testing and simulation to identify potential failure modes
• The value of crew training and real-time problem solving skills
• The criticality of open communication and information sharing, both within the crew and with mission control
• The necessity of having well-defined contingency procedures in place for a wide range of scenarios

NASA and its partners have worked hard to institutionalize these lessons across their human spaceflight programs. Today, astronauts undergo rigorous training to handle a variety of emergency situations, from fires to depressurization to medical issues. Spacecraft are designed with multiple backup systems and escape mechanisms. And mission control maintains constant communication with the crew to monitor vehicle health and respond quickly to any anomalies.

Looking to the Future

As NASA and other space agencies set their sights on returning humans to the Moon and eventually sending astronauts to Mars, the lessons of the past will be more important than ever. Venturing beyond low Earth orbit introduces new risks and challenges, from increased radiation exposure to communication delays to the psychological effects of long-duration spaceflight.

To mitigate these risks, NASA is developing new technologies like advanced life support systems, in-situ resource utilization, and improved radiation shielding. The agency is also investing in research to better understand the effects of spaceflight on human health and performance.

At the same time, NASA is embracing a new era of commercial partnerships and international collaboration. By working with a diverse range of partners, the agency hopes to increase access to space while sharing the risks and rewards of exploration.

As we reflect on the significant incidents and close calls in the history of human spaceflight, it is important to remember the bravery and dedication of the astronauts, engineers, and support personnel who have made these incredible journeys possible. Their efforts have expanded the boundaries of human knowledge and capability, and inspired generations to reach for the stars.

While the risks of spaceflight can never be eliminated entirely, by learning from the past and continuing to innovate for the future, we can ensure that the benefits of human spaceflight far outweigh the costs. As we embark on a new era of exploration, we honor the legacy of those who have come before and recommit ourselves to the noble pursuit of expanding human presence in the cosmos.

Summary

The history of human spaceflight is one of triumphs and tragedies, breakthroughs and setbacks. Through it all, the significant incidents and close calls have served as stark reminders of the dangers inherent in this incredible endeavor.

But they have also demonstrated the resilience, ingenuity, and courage of the human spirit. By learning from these experiences and applying their hard-won lessons, we can continue to push the boundaries of exploration while keeping our astronauts safe.