destroyed the space shuttle and killed its seven astronauts.
   cold in Florida on the day of
   On Soyuz 11, a Soviet spacecraft, three cosmonauts died the Challenger launch on
   when a valve failed in 1971. The valve opened at the
   January 28, 1986. Even the
   wrong time. All the air escaped from the spacecraft. The launch pad had icicles
   cosmonauts couldn’t breathe.
   (below). The cold weather
   caused Challenger’s rockets
   HUMAN ERRORS
   }to leak hot gases.
   People design and build
   spacecraft, and people can make
   mistakes. In 1996 scientists fed
   the wrong instructions into the
   computer on board Ariane 5, a
   European rocket. That error
   caused the rocket to tip over after
   takeoff. The rocket cracked and
   exploded.
   Bad decisions are another kind
   of human error. For instance,
   officials at NASA decided to
   launch Challenger on a cold
   morning in 1986. Some NASA
   workers warned that the cold air
   could cause the shuttle’s rockets to
   leak hot gases. But NASA
   launched the shuttle anyway. The
   rockets leaked, and Challenger
   exploded.
   16
   A flame can be seen near the
   } external fuel tank as Challenger
   takes off in 1986. Seconds later,
   the shuttle exploded.
   “We will never forget them,
   “We will never forget them
   nor the last time we saw them, this morning, as the
   nor the last tim
   y
   e we saw them, this morning, as the
   prepared for their journey and wa
   prepared for their journe
   v
   y and wa ed g
   v
   oodbye and
   ed g
   slipped the surly bonds of Earth
   to touch the fa
   to tou
   ce of God.
   —U.S. president Ronald Reagan, quoting from a poem by John Gille ”
   —U.S. president Ronald Reagan, quoting from a poem by John Gillespie Magee Jr.
   while honoring the Challenger
   Challenge astronauts who died during takeoff in 1986
   SPACE JUNK
   Space junk is another ingredient for disaster. Junk in space? You might think that space is empty. But it’s not. Thousands of human-made objects orbit Earth in space.
   Space junk includes hundreds of old artificial (human-made) satellites.
   Artificial satellites are spacecraft that hold electronic equipment. Some satellites pass along signals used for television, telephones, and the Internet.
   Others hold cameras that help scientists study and predict the weather.
   People started sending satellites into space in the 1950s. But when the satellites get old or break down, people don’t bring them back to Earth.
   Instead, they leave the satellites in orbit.
   A tracking device called radar allows space workers to locate old satellites. The workers can then make sure that spacecraft steer around the satellites. More dangerous, however, are smaller pieces of space junk.
   These objects include paint chips from old spacecraft and small pieces of metal from old satellites. Billions of these small pieces also orbit Earth.
   TINY DANGERS
   Even a bit of metal as small as a pencil eraser could cause a disaster. How?
   Space junk orbits Earth very fast. Some of it flies at 6 miles (10 km) per second. At that speed, a tiny bit of metal is like a bullet. It could crack a window. It could poke a hole in the craft. Then air
   would escape, and people inside the spacecraft
   might die. If a piece of metal punctured a fuel
   tank, the tank could explode. The explosion would
   blow the spacecraft to pieces.
   So far, space junk hasn’t caused a space
   disaster. But in 2006, the space shuttle Atlantis hit a meteoroid. Meteoroids are small pieces of rock
   }
   that zoom through space. The meteoroid that hit
   This hole on the space shuttle
   Atlantis left a 0.1-inch (2.5-millimeter) hole in the
   Atlantis is from a small meteoroid
   spacecraft. Luckily, the hole did not cause serious
   hitting the shuttle in space in 2006.
   damage to the shuttle.
   18
   This satellite image from NASA shows all the
   space junk orbiting Earth. The pieces are much,
   }
   much smaller than they appear in this image.
   “Hatch not...sealed?
   “Hatch not...
   What’
   W
   s happening?
   hat’
   What’
   W
   s g
   hat’
   oing on?
   s g
   —Soyuz 11
   ”
   —Soyuz 11 cosmonaut Vladislav V
   cosmonaut Vladisla
   o
   v V lkov
   o
   } A Soviet Soyuz
   spacecraft ready
   to launch.
   Everything seemed to be going wrong The cosmonauts climbed into the for Soyuz 11, a Soviet spacecraft. The
   space station. They planned to stay
   problems began before the launch. One
   for thirty days. However, the
   of the cosmonauts scheduled to fly the
   problems continued.
   spacecraft got sick. Officials worried that
   The cosmonauts planned to use a
   he might have infected his crewmates.
   large telescope to study objects in
   So a substitute crew took over. The new
   space. But the cover on the telescope
   cosmonauts were Georgy Dobrovolsky,
   got stuck. The cosmonauts could not
   Vladislav Volkov, and Viktor Patsayev.
   get it off. They could not do their study.
   Soyuz carried the cosmonauts into
   Then a small fire broke out on the
   space on June 6, 1971. In space,
   space station. After twenty-four days,
   Soyuz docked (connected) with the
   Soviet space officials decided to bring
   Soviet Union’s Salyut space station.
   the cosmonauts home early. The crew
   20
   got back into their Soyuz spacecraft.
   Before the craft disconnected from
   Salyut, however, a warning light
   flashed on. The Soyuz hatch had not
   closed properly. “Hatch
   not . . . sealed?” said Vladislav Volkov to mission control over the radio.
   “What’s happening? What’s going on?”
   “Don’t panic,” mission control
   answered. “Open the hatch, and move
   }
   the wheel to the left to open. Close
   (Left to right) Cosmonauts Georgy
   the hatch, and then move the wheel to
   Dobrovolsky, Vladislav Volkov, and Viktor
   the right six turns with full force.”
   Patsayev pose in the cabin of Soyuz 11.
   The instructions worked. The hatch
   closed properly. Soyuz disconnected
   parachute slowed the craft down. The
   from Salyut and headed back to Earth.
   space capsule made a gentle landing
   As Soyuz commander Georgy
   on June 30. When space workers
   Dobrovolsky prepared the craft for
   arrived at the touchdown, they
   landing, he radioed mission control,
   breathed a sigh of
 relief. The Soyuz
   “Landing sequence proceeding
   looked perfectly normal.
   excellent, all OK, crew is excellent.”
   When workers opened the hatch,
   Seconds later, however, the crew
   however, they found that all three
   heard a hissing sound. It sounded like
   cosmonauts were dead. Something else
   air escaping from a tire. They thought
   had gone wrong on this jinxed mission.
   the hatch had come unsealed. But the
   When the spacecraft reached 2.5 miles
   hatch was fine. The crew searched
   (4 km) above Earth, a valve was
   frantically for a leak. To hear better,
   supposed to open to let in fresh air.
   they turned off their radios. Mission
   However, the valve opened earlier,
   control waited to hear from the crew.
   when the craft was still in space. When
   But with the radios off, mission control
   the valve opened, all the air rushed out
   heard only silence. Mission control
   of the spacecraft. The cosmonauts
   thought that Soyuz’s radios had broken.
   weren’t wearing space suits, which
   Soyuz approached Earth normally.
   would have given them backup air
   As it neared the ground, a parachute
   supplies. The three men suffocated
   attached to the spacecraft opened. The
   (died from lack of air).
   21
   A LAYER OF AIR SITS BETWEEN EARTH AND SPACE. THIS LAYER IS CALLED
   THE ATMOSPHERE. IT CONTAINS GASES SUCH AS OXYGEN. THE ATMOSPHERE
   IS THICKEST—CONTAINS THE MOST GASES—
   AT GROUND LEVEL. THE HIGHER YOU GO
   ABOVE THE GROUND, THE THINNER THE AIR
   BECOMES. EVENTUALLY, ABOUT 62 MILES
   (100 KM) ABOVE THE GROUND, THE AIR
   DISAPPEARS AND SPACE BEGINS.
   Spacecraft are designed to take off from
   Earth, fly through the atmosphere, and then fly
   through space. Some spacecraft, such as space
   shuttles, are also designed to return to Earth,
   passing back through the atmosphere to land
   on the ground. Space disasters can happen
   during any part of this process: on the ground,
   in the atmosphere, or in space.
   Super Slurper
   DISASTROUS UPS
   During launch, a space
   Some of the worst space disasters have
   shuttle’s main engines slurp
   occurred during launch. During launch, a
   up fuel quickly. Imagine a
   spacecraft must work at full power to reach
   backyard swimming pool
   space. As it zooms through the atmosphere,
   filled with rocket fuel. During
   its mechanical parts are under great stress. If a
   launch, the shuttle’s engines
   mechanical problem occurs during launch,
   would drain the pool in about
   astronauts and space workers have little time
   twenty-five seconds.
   to solve it. Before they find the problem and
   22
   fix it, the craft could come crashing down to the ground.
   Rockets are engines that propel spacecraft into space. Workers load rockets with fuel during launch. A full load of rocket fuel makes a spacecraft very heavy. The rockets must work perfectly to lift all that weight. Even a small problem with the rockets can cause a crash during launch.
   DANGEROUS DOWNS
   The trip back home is another
   danger zone. Spacecraft reenter
   Earth’s atmosphere at about
   17,000 miles (27,000 km) per
   hour. At that speed, friction
   against the spacecraft heats it up.
   The sides of the spacecraft glow
   red hot. Temperatures reach
   nearly 3,000°F (1,649°C).
   Normally, insulation protects
   }
   spacecraft from the heat. But if
   The space shuttle Columbia touches
   the insulation has cracks or holes, as
   down in May 1998. The shuttle’s
   Columbia’s did, the vehicle will burn up.
   parachute helps slow it down.
   GROUND ZERO
   Even on the ground, spacecraft are not safe from disasters. The Apollo 1
   astronauts died when fire broke out in their spacecraft during a practice session on the ground.
   Space workers face danger on the ground too. For instance, in 1964
   three workers were putting together a satellite inside a building in Cape Canaveral, Florida. The satellite’s engine started by accident. Hot gases filled the room and burned the workers to death. In 2003 the nation of Brazil prepared to launch satellites into space. But a few days before the launch, the rocket for carrying the satellites exploded on the ground. The explosion killed twenty-one space workers and scientists.
   23
   Danger Zones
   Space disasters can happen anywhere spacecraft travel—
   on Earth, in orbit around Earth, near the International Space Station or Hubble Space Telescope, or near
   satellites, and even farther out in space.
   Hubble Space
   Telescope
   International
   Space Station
   24
   MOON
   Weather and
   Communications
   Satellites
   SPACE
   SPACE JUNK
   ATMOSPHERE
   EARTH
   25
   “We felt the grief
   “Wand shock over this
   and shock ov
   side of the world too
   [in Dublin, Ireland].
   I think I was too
   stunned to cry. ”
   —Noel O’Neill, who watched the
   Challenger disaster on television
   January 28, 1986, was an unusual
   McAuliffe taught social studies at
   day for many American
   Concord High School in New
   schoolchildren. On that day, millions
   Hampshire. All twelve hundred
   of children got to watch TV in school.
   students from her school gathered in
   They gathered around TV sets to
   the auditorium to watch their teacher
   watch the launch of the space shuttle
   fly into space. McAuliffe’s husband
   Challenger. Every shuttle launch is
   and two children watched the launch
   exciting. But this launch was special.
   at the Kennedy Space Center in
   One of Challenger’ s seven astronauts
   Florida. Her parents were there too.
   was a schoolteacher. Her name was
   Everyone cheered at 11:38 A.M.
   Christa McAuliffe. She was going to
   when Challenger rose into the air. At
   be the world’s first teacher in space.
   first, the launch seemed fine.
   26
   Challenger flew normally. The
   shuttle rose higher and higher
   into the bright blue sky.
   About seventy-three seconds
   after launch, Challenger was
   48,000 feet (14,630 m) above
   the ground. Then mission control
   got a radio message from
   Challenger. “Uh-oh!” said
   astronaut Michael Smith. That
   }
   was the last message from Challenger.
   Christa McAuliffe and other astronauts
   People watching on TV and at the
   train in a zero-gravity aircraft for their
   Kennedy Space Center could not
/>   shuttle mission in 1986.
   believe their eyes. As they watched,
   Challenger exploded. Pieces of the
   a high school student in Conway,
   spacecraft fell into the Atlantic Ocean.
   South Carolina, about forty-five
   Ryan Loskarn was watching the
   minutes from the home of Challenger
   launch with his elementary schoolmates.
   astronaut Ronald McNair. “When I saw
   “I remember cheering, watching the
   that explosion I felt like someone
   split screen [TV] show of lift-off and
   really close to me had just died right
   Christa’s class observing the launch,”
   before my eyes,” Lipscomb said. “Ron
   Loskarn said. “Then I remember white
   was a hero to a lot of us.”
   smoke. A teacher screamed and
   All seven astronauts died in the
   students began to cry.”
   disaster. Some may have died during
   “I’ll never forget that day as long
   the explosion. The rest certainly died
   as I live,” said Alisa Lipscomb. She was when the shuttle’s crew compartment
   slammed into the Atlantic Ocean. It
   took recovery workers several weeks
   of searching the Atlantic to find the
   bodies.
   Students at Framingham High School
   } in Massachusetts watch as Challenger
   explodes after takeoff on January 28,
   1986. Christa McAuliffe graduated
   from Framingham High School.
   27
   WHEN DISASTER STRIKES IN SPACE,
   PEOPLE ASK THE SAME QUESTIONS THEY
   ASK ABOUT DISASTERS ON EARTH.
   HOW SERIOUS WAS THE DISASTER?
   HOW MANY PEOPLE WERE KILLED?
   HOW MANY PEOPLE WERE HURT?
   }
   As with other disasters, measuring
   The crew of the 1986 space shuttle Challenger
   space disasters involves counting
   injuries and deaths. The Challenger
   at last—
   disaster and the Columbia disaster
   Another Teacher in space
   each killed seven astronauts. The
   Apollo 1 and the Soyuz 11 disasters
   In 2007 a teacher finally made it into
   each killed three astronauts.
   space. The teacher, Barbara Morgan, had
   The loss of human life is always
   been Christa McAuliffe’s backup in
   sad, especially for the friends and
   
 
 Space Disasters Page 2