Spacecraft is an inherently dangerous business: launching into orbit atop a massive explosive reaction, hurtling through orbit at tens of thousands of miles per hour protected from the vacuum of space and the heat of the Sun only by the thin metal skin of the spacecraft, and then plunging back to Earth, protected only by a specially designed shield from heat and friction which could be fatal after only a moment's exposure (as occurred, tragically, to the Space Shuttle Columbia in 2003). As a result, it is not surprising, though no less tragic, that twenty-two men and women have lost their lives in the quest for space. Overall, there is a roughly one-in-fifty chance that a given manned space mission will suffer a fatal accident at some point during its flight.
There are also, it should be noted, rumours that a number of other Soviet cosmonauts lost their lives during secret, unpublicized flight experiments during the late 1950s and 1960s. To date, none of these deaths has been publicly confirmed.
VALENTIN BONDARENKO - In a 1961 test of a high-oxygen, contained environment in Moscow, intended to be similar to the conditions inside a spacecraft, Soviet would-be cosmonaut Valentin Bondarenko was killed after a fire broke out when he inadvertently tossed a cloth drenched in alcohol onto an active hotplate. Bondarenko was not the first casualty on a spaceflight, but he was the first casualty in training for space flights. The lesson of tragedy in a high-oxygen environment was not learned in America until after another, equally devastating fire occurred aboard Apollo 1 several years later.
THEODORE FREEMAN - Would-be American astronaut Theodore Freeman was killed in 1964 after a birdstrike disabled his T-38 training aircraft while in flight. At the time, ejection seats could not provide protection at low altitudes; had Freeman's aircraft possessed a modern military-grade ejection seat, he might have survived.
GEMINI 9 - In 1966, the Gemini 9 flight crew was conducting a similar T-38 training flight when they crashed during an attempted landing in poor weather conditions. Both men, Elliott See and Charles Bassett, were killed. Gemini 9 was ultimately flown by their backup crew, Thomas Stafford and Eugene Cernan.
APOLLO 1 - In January 1967, Gus Grissom, Ed White, and Roger Chaffee were testing the power systems aboard the Apollo 1 command module in advance of the first flight of the ambitious Project Apollo. Apollo 1 was a simple test flight to Earth orbit; upcoming missions would extend the spacecraft's range to the Moon, and then make several landings there. Unexpectedly, while the astronauts were undergoing a checklist procedure, they noticed a fire in the cockpit. In the pure-oxygen atmosphere of the spacecraft, the fire grew horrifyingly quickly, and the astronauts were unable to open the complex hatch quickly enough to escape. Within a minute, all three had been killed by the flames and by smoke inhalation.
The fatal accident was devastating to NASA and to the other Apollo astronauts, as it was the first fatality on an actual American spacecraft. However, the Apollo project survived, after some design tweaks, and Neil Armstrong and Buzz Aldrin stepped onto the Moon just two years later. Thanks to the Soviet and American tragedies, it is now unthinkable that a spacecraft would launch with a pure-oxygen atmosphere, or with a hatch that lacked an emergency escape option for astronauts who needed to leave the vehicle quickly.
SOYUZ 1 - In April 1967, the Soviets launched the first of what would become a long-lived series of space missions, Soyuz 1. Today, Soyuz spacecraft are regarded as among the safest and most proven technologies available in manned space flight. Their beginnings were quite different, however. The lone occupant, Vladimir Komarov, died during re-entry when his ship's parachute failed to deploy on schedule. Soyuz 1 struck the ground at 90 miles per hour and exploded. Mercifully, Komarov probably would have been killed on impact rather than in the ensuing fire.
APOLLO 9 (BACKUP CREW) - In another T-38 jet failure during training, would-be Apollo 9 backup pilot and Apollo 12 lunar module pilot Clifton Williams crashed and was killed in October 1967.
X-15-3 - In November 1967, an experimental American spaceplane, the X-15, was being test-flown by Michael Adams when it developed an electrical problem and then went into a spin at perilous hypersonic speeds (about five times the speed of sound). Adams was unable to recover out of the spin, and his spaceplane broke apart in the air. He was killed, and posthumously decorated as an astronaut. The X-15 program was, overall, a great success, with 199 flights being made on three separate airplanes by a team of test pilots including future astronauts like Neil Armstrong. It flew only eight more times after Adams's tragic death.
MOBILE ORBITING LABORATORY - The first African-American astronaut, Robert Henry Lawrence, Jr., was killed in December 1967 on a training flight in an F-104 Starfighter. He would have been launched into space as part of the Manned Orbiting Laboratory space program, initiated by the U.S. Air Force. Ultimately, the program was cancelled before any manned flights occurred, and those men who had completed their astronaut training were given slots in NASA's astronaut corps as an alternative.
SOYUZ 3 - In 1968, the first publicly confirmed Soviet flight training accident occurred, when Yuri Gagarin, the man who had been the first human in space several years before, on Vostok 1, crashed during a training flight in a MiG-15 jet. Initially the crash was blamed on either a birdstrike or sudden maneuvers in excess of the aircraft's capabilities, but after the Cold War it was admitted that a secret investigation blamed inaccurate weather reports from ground personnel.
SOYUZ 11 - In June 1971, Soyuz 11 was returning from a mission to the Salyut 1 space station with a crew of three, Georgi Dobrovolski, Viktor Patsayev, and Vladislav Volkov. A valve was inadvertently left open and exposed to vacuum as the ship separated from the space station, and the crew were killed. Technically, these men were the only men who ever died in space rather than while leaving or re-entering Earth's atmosphere. The year before, the crew of Apollo 13 had also nearly met their ends while in space after an explosion in the service module of their spacecraft, but were saved through heroic efforts on the part of themselves and the NASA ground crew.
The Soyuz 11 tragedy rattled the Soviet space program's confidence. Since then, all space crews have been required to wear pressure suits during potentially risky activities, in case of another exposure to vacuum. Since 1971, there has never been another fatal accident aboard any Soyuz spacecraft.
CHALLENGER - The loss of the Space Shuttle Challenger in 1986 was perhaps even more tragic than the loss of Soyuz 11 in 1971. Just over a minute after lifting off, the Challenger shuttle was engulfed in a fireball caused by a faulty O-ring. The massive external fuel tank disintegrated, and then threw Challenger sideways out of its flight path, breaking the massive shuttle to pieces. Seven astronauts were tragically killed: Ellison Onizuka, Greg Jarvis, Dick Scobee, Judith Resnick, Michael Smith, Christa McAuliffe, and Ronald McNair. This was the first American loss of multiple astronauts in flight.
The deaths aboard the Challenger resulted in a massive investigation into needed reforms within NASA (although some might still argue the inquiry was not soul-searching enough). The Rogers Commission, which included astronauts Neil Armstrong and Sally Ride, pinpointed the failed O-ring but also criticized administrative failures in not properly identifying and responding to potential malfunctions. The surviving Space Shuttles did not fly again for three years, as the inquiry completed its investigation and engineers redesigned the rocket boosters to prevent further failures.
COLUMBIA - In 2003, the Space Shuttle Columbia disintegrated over Texas while making its re-entry at the end of the two-week long STS-107 space mission. Once again, all seven astronauts on board - Rick Husband, William McCool, Kalpana Chawla, Ilan Ramon, Laurel Clark, David Brown, and Michael Anderson - lost their lives. Once again, a subsequent investigation found that the actual accident had occurred during launch (but went unnoticed at the time): a large chunk of insulation broke off the external fuel tank and slammed into the Space Shuttle's wing, puncturing its heat shield. During re-entry, the chink in the spacecraft's protective armour was enough to cause fatal damage to the vehicle.
Once again, the shuttles were grounded for a substantial period of time during the result of the investigation. For the final Space Shuttle flights (as of 2010, the Shuttles are due to be retired shortly after a thirty-year lifespan), there were careful investigations of the wing surfaces while in orbit to ensure that similar damage had not occurred again.
In addition to those astronauts who lost their lives in tragedies either training for or flying space missions, there have of course been a large number of ground crew who also tragically lost their lives in the quest for space, usually through accidents and explosions during launch operations. Two of the deadliest launch catastrophes were the 1960 Nedelin disaster at Baikonur, USSR, when at least 90 were killed in an explosion (unofficial estimates place the number much higher), and the crash of the Intelsat 708 launch rocket in Xichang, China, in 1996, which careened into a nearby town. Official Communist government estimates claimed only six had lost their lives, but outside sources agree that the true scale of the tragedy was far greater.
Overall, the quest for space has not come without its tragic cost in human lives. However, for those astronauts involved, so far the resounding answer seems to be that the benefits justify the risks. All they ask is that a proper institutional culture of safety be maintained, so that all-too-predictable failures are properly identified and corrected well in advance. Space flight is inherently dangerous, but it should never be foolhardy.