It was April 19, 1971.
The Soviet Union had just launched the world’s first space station into low Earth orbit,
named Salyut-1 [Sal-yoot].
Two months later, on June 6, 1971, the Soyuz 11 [Soy-ooz] would make a trip to the orbiting
space station with cosmonauts Georgi Dobrovolski,[Ghee-ohr-ghee Dough-bro-vole-skee] Vladislav Volkov [Vol-cove],
and Viktor Patsayev [Pat-sigh-yev] aboard the spacecraft.
The Soyuz 11 launched into space, and the three cosmonauts boarded the Salyut-1 space
station on June 7, 1971, without any trouble, and were there to carry out three weeks of
experiments, such as growing Chinese cabbage and bulb onions, taking spectrograms of stars,
and snapping some ‘from orbit’ photos of the snow and ice on the River Volga.
They were now heroes, famous, and plastered all over Soviet evening television.
On June 29th, 1971, with the cosmonaut's primary mission complete, the Soyuz 11 finally undocked
from the Salyut-1, and three hours later, the spacemen fired their ship’s engine to
return to Earth.
Vladislav Volkov joked with flight control and asked them to make sure their traditional
welcome-home gift of cognac would be waiting for them at the landing site.
At twenty-nine minutes before touchdown, and at an altitude of 160 kilometers [100 miles],
explosive charges fired as planned to separate the Soyuz 11’s orbital bell-shaped capsule
and instrument modules.
The space capsule was now the cosmonaut's only defense against the fiery furnace of
re-entry.
But then something unexpected happened…
As soon as the other modules were jettisoned, the pressure inside the crew capsule quickly
fell, and all the air inside began escaping into the vacuum of space.
Meanwhile, mission control was unaware of the situation.
Attempts to contact the cosmonauts over VHF radio were met with an unnerving silence,
and a sense of nervous unease crept into the room.
Twenty-two minutes before touchdown, the capsule was picked up on radar entering Soviet airspace.
Mission controllers knew that because the spacecraft was still re-entering the atmosphere,
it would be covered in a cocoon of plasma, and therefore communication would be impossible
during this time.
As the minutes went by, hopes for a happy ending were rekindled when the space capsule’s
drogue parachute automatically deployed, and then the larger main parachute canopy followed.
However, there was still no word from the crew, and ten minutes before touchdown, helicopter
crews spotted the undamaged Soyuz 11 gently swinging back and forth under the perfect
looking parachute.
Mission control was elated when the helicopter commander radioed that the capsule had landed
safely.
The recovery team was setting down nearby, and they were just minutes from opening the
hatch and treating the cosmonauts to their cognac and other comforts of home after being
in space for three long weeks.
Within just two minutes of touchdown, the search and rescue team of two men reached
the Soyuz 11, and then hammered on the ship’s hull to let them know they were there.
But there was no reply from inside…
When they opened the hatch, a look of troubled uncertainty creased the face of one of the
rescuers.
Inside the capsule, the recovery team saw all three cosmonauts slumped over and motionless.
Their faces were covered with dark spots that looked like bruises, and blood was coming
from their noses and ears.
One of the spacemen, Dobrovolski, was still warm, but attempts to revive him were unsuccessful.
The first contact between the recovery crew and mission control took the form of three
numbers: 1-1-1.
This was a code that represented the health of the cosmonauts.
The number 5 stood for excellent condition, 4 was good condition, 3 meant there were injuries,
2 meant they were seriously injured, and 1 meant the injuries were fatal.
So what happened?
Based on the positions of the three cosmonauts’ bodies upon their discovery, investigators
came to the conclusion that Dobrovolski and Volkov had unstrapped themselves from their
seats to try to find the leak that was allowing air to escape from the capsule.
Health trackers showed their heart rates soared as they searched.
But time was not on their side, as within just 50 seconds, Patsayev’s pulse dropped
as his body became starved for oxygen, and within 110 seconds, all three cosmonauts had
perished.
Investigators had learned that a faulty valve was the cause of the space accident.
Their funeral was epic on a grand scale, and the whole country mourned their passing.
The Soviets halted all human spaceflights, while engineers redesigned the Soyuz spacecraft.
All cosmonauts are now required to wear spacesuits during launches and landings.
But Russia is not the only country to have a space disaster that cost the lives of brave
astronauts.
The United States was leading the world in space travel with the ingenious engineering
of the reusable Space Shuttle.
But even the most advanced spacecraft can have problems.
By January 1986, the United States seemed bored with spaceflight since the first space
shuttle launch on April 12, 1981, and Americans were already used to the sight of the space
shuttle launching.
The program had experienced no trouble since its debut flight.
But everything would quickly change.
On the morning of January 28, 1986, the crew of mission STS-51L boarded the orbiter Challenger.
It was a sunny, but chilly Tuesday morning.
All across the USA, people were a little more excited with this launch, because the crew
of seven astronauts included payload specialist Christa McAuliffe, who was a civilian, school
teacher, and mother of two children.
She was part of the ‘Teacher in Space’ project, and proof that space was now wide
open, not just to top gun fighter pilots, but also the average American.
The Challenger shuttle was commanded by Dick Scobee with Michael Smith as the pilot, along
with mission specialists Ellison Onizuka, Judith Resnik, and Ronald McNair.
The other payload specialist with Christa McAuliffe was Gregory Jarvis.
At 11:38 a.m., the space shuttle Challenger lifted off from Cape Canaveral, Florida, with
Christa McAullife on her way to becoming the first ordinary American to travel into space.
But after just 73 seconds, and with hundreds of people on the ground watching, including
Christa’s family and a group of students, plus millions of viewers watching the launch
on television, the space shuttle exploded into a ball of fire and smoke and disintegrated.
So what happened?
We mentioned it was a cold morning.
In fact, there was ice on the tower two hours before the launch.
An overnight measurement taken by the ice team recorded temperatures on the left solid
rocket booster at -4 degrees Celsius [25 °F] and the right SRB was -13 degrees Celsius
[8 °F].
However, these measurements were recorded for engineering data only and not reported,
as the temperatures of the solid rocket boosters were not part of the Launch Commit Criteria.
Before we go on, it’s important to know that the shuttle solid rocket boosters are
made up of four segments bolted together at three O-ring joints.
These O-rings are in place to maintain internal pressure of the SRB, and any failure of these
O-rings would create a ‘burn through’, causing a catastrophic failure.
This is exactly what happened to the right solid rocket booster.
There was a puff of black smoke from the right SRB at liftoff, showing that the O-ring had
already failed.
By the time the shuttle was in the air, flames started to come from the failed O-ring, and
the sideways flame cut through the SRB like a cutting torch.
The 1.2 billion dollar spacecraft, its satellite payload, and the seven astronauts were lost
instantly.
The biggest factor in the accident was the cold.
The launch itself was performed in -3 degrees Celsius [26 °F] weather, and engineers knew
of the dangers posed to the O-rings at such low temperatures.
However, despite the many warnings from engineers, the shuttle was cleared for launch.
NASA shut down the space shuttle program for two years after this terrible tragedy, as
its engineers redesigned many components of the shuttle.
But it would not be the last space shuttle disaster.
The Space Shuttle Columbia was the first shuttle to be launched into space in April 1981.
The shuttle launched again twenty-seven more times after its maiden voyage, and on January
16, 2003 it was on its 28th flight.
The seven member crew of mission STS-107 were mission commander Rick D. Husband, pilot William
C. McCool, payload commander Michael P. Anderson, Israeli astronaut Ilan Ramon [Elon Ra-moan]
serving as payload specialist, flight engineer Kalpana Chawla who had previously flown on
mission STS-87, and U.S. Navy captains flying as mission specialists’ David M. Brown and
Laurel Blair Salton Clark.
The launch seemed to go well and without problems.
The astronauts were on a 16-day mission, and successfully conducted around 80 science and
research experiments, working 24 hours a day in two alternating shifts.
It was now time for the crew to return home, and the space shuttle Columbia was scheduled
to reenter the atmosphere and land on February 1, 2003.
At 2:30 am Eastern Standard Time, the Entry Flight Control Team started its shift at Mission
Control.
Aboard the orbiter, the crew put away loose items and prepared for re-entry.
Husband and McCool began working through the entry checklist.
And at 1:10 pm, the Columbia crew was approved to conduct their deorbit burn, which lasted
2 minutes and 38 seconds.
At 1:44 pm, Columbia reentered the atmosphere at an altitude of 120 kilometers [400,000
feet] Four and a half minutes later, a sensor began recording a greater than normal amount
of stress on the left wing.
But the sensor's data was sent to an internal recorder, and the crew or ground controllers
didn’t see it.
The orbiter began to yaw to the left because of the increased drag.
However, the orbiter's flight control system corrected the problem, and the crew never
noticed the drag, or what was happening.
This was followed by sensors indicating problems in the left wing hydraulic systems, and a
loss of tire pressure on the left side landing gear.
Columbia was flying at 60 kilometers [38 miles] above Earth at a speed of 20,120 kilometers
per hour [12.500 mph] when flight controllers received their last communications from the
shuttle.
Video from many witnesses watched in horror as the orbiter broke up and disintegrated.
So what happened to Columbia and its crew?
NASA’s Intercenter Photo Working Group was looking over videos of the launch after Columbia
entered orbit as a routine review.
It wasn’t until the second day that they discovered a piece of foam had broken off
from the large external tank and impacted the left wing as the shuttle was climbing
into orbit.
The Debris Management Team was unable to determine the damage caused to the left wing, and multiple
requests for images were made to the US Department of Defense.
A request was relayed to the US Strategic Command, which began identifying assets that
could snap images of the orbiter.
However, the image request was denied by NASA Mission Management Team Chair Linda Ham after
she discovered where the request came from.
She asked a flight director about the imaging requirement, but not the Debris Assessment
Team.
Moving the orbiter into a position to be imaged would have disrupted ongoing science operations,
and Ham dismissed the Department of Defense's imaging capabilities as insufficient to assess
damage to Columbia’s left wing.
Now here is where things get more interesting.
Mission management downplayed the risk of the debris strike in communications with the
Columbia crew, and flight director Steve Stich sent an email to Husband and McCool telling
them of the strike and that there was no concern about damage since foam strikes occurred on
previous flights.
They also got a 15-second video of the debris strike, but were reassured there was no danger.
Obviously, they were wrong.
No one knows the true extent of the damage to the wing, but members of the Columbia Accident
Investigation Board performed a test using a space shuttle wing part, and fired a chunk
of foam at high speed at the same spot a chunk of foam hit Columbia’s wing…and this is
what happened.
To the amazement of onlookers, the investigators blew a gaping 60-centimeter [2 foot] gaping
hole in the shuttle wing after firing a chunk of foam insulation at it.
This was the smoking gun that proved that the damage from the debris strike led to Columbia’s
destruction, and the loss of her crew.
It was the last space shuttle launch, and the space shuttle program was permanently
retired after this.
Since then, astronauts have been getting into space with Russia’s Soyuz program, and now
SpaceX’s rockets.
That’s all the time we have for now.
We hope you found the video interesting, and learned how brave our men and women who go
into space are.
Stay tuned here for more incredible space stuff, and thank you for watching.