It was at best a make-work mission.
The 80 experiments on the agenda for Columbia's 28th flight had no urgency. Many were high school student projects.
In truth, it was a mission meant to maintain momentum. After 13 delays in two years, shuttle planners were impatient to clear the mission from the agency's manifest on Jan. 16.
Like a sideshow performer juggling chain saws, NASA could not afford to break its rhythm of launch and recovery.
In the third-floor crew quarters several miles from Launch Pad 39A at Kennedy Space Center, seven men and women sat in chairs while technicians helped them don orange pressure suits.
Air Force Col. Rick Husband, 45, the crew commander, gave a thumbs-up with both hands.
With him were Navy Capt. William McCool, 41, the shuttle's pilot; Air Force Lt. Col. Michael Anderson, 43, payload commander; Navy Cmdr. Laurel Clark, 41; Navy Capt. David Brown, 46; and Israeli Air Force Col. Ilan Ramon, 48, his country's first astronaut.
Kalpana Chawla, 41, was the only civilian in the crew. It was her second flight. She could not stop smiling.
As they disappeared into the bulky flight emergency suits, seven individuals became a regulation space shuttle crew — living components of the vehicle that awaited them.
They had a last meal and a last walk and last waves before disappearing into a hatch high on the streamlined white leviathan.
Technicians locked the hatch.
After 112 flights, the aim of the space shuttle was no longer so compelling, nor was its place in the American imagination so sharply defined.
The shuttle had been upstaged by science's maturing vision of space and time.
In the decades since Columbia was on the drawing boards, scientists had discovered the universe to be much more exotic than anyone had known.
Doug Stevens / LATTHE ASTRONAUTS: The shuttle crew had a last meal and last waves before disappearing" into a hatch high on the streamlined white leviathan."
Wormholes pierced its fabric. Black holes drank light and consumed galaxies. Space had been sliced into so many dimensions that theoretical physicists had trouble counting them all.
Instead of only one solar system with planets, astronomers had discovered dozens.
Dwarfed by such mysteries, the shuttle became a measure not of mankind's mastery of space, but of its limitations.
At the dawn of the 21st century, humanity was marooned on the shore of an ethereal ocean too broad to cross.
Columbia rose that winter morning on plumes of fire and steam.
Gathered in bleachers along the Banana River at the Kennedy Space Center in Florida, spectators whispered prayers and cheered.
"My God. Oh, my God."
"There they go."
"Go! Go! Go!"
At 81.9 seconds into the flight, a large block of foam and two smaller ones broke off the left side of the external tank.
Columbia was at an altitude of 65,860 feet, traveling at 1,668 mph.
The largest block, tumbling at 18 times a second, smashed a hole in the spacecraft's left wing.
A pair of pressure sensors on the underside of the wing registered an unusual strain along the leading edge between panels No. 6 and No. 8 immediately after the impact.
The warning spooled onto the tape of the shuttle's flight data recorder under a crew seat but was not transmitted to the crew or Mission Control.
Two video cameras on the ground captured the strike. One was about 17 miles from the launch site at the Cape Canaveral Air Force Station, the other 26 miles away at Cocoa Beach.
Photo analysts worried. They asked permission to seek clearer images of the wing to inspect for possible damage.
Permission was denied.
Weightless above the planet, Laurel Clark videotaped pink roses and rice flowers in an experiment to develop space-based perfumes.
Ilan Ramon monitored dust storms over the Middle East and searched for lightning sprites.
In a series of combustion experiments for USC, the crew tried to determine the smallest amount of fuel that would ignite in a fire and the smallest amount of water that would extinguish it.
They conjured up the smallest flame ever seen.
David Brown filmed the tiny flame balls in a combustion chamber.
To pass the time, Brown and the others named one of the flames Howard. Two other fireballs moved in a spiral reminiscent of DNA's double helix. Those were christened Crick and Watson.
On the morning of their second day in orbit, a fragment of the left wing drifted away from the spacecraft.
It trailed behind them for two days, then burned up in the atmosphere.
No one noticed.
For eight days, different groups of debris analysts lobbied shuttle managers for permission to inspect Columbia's wings using Defense Department satellites.
Although the space agency prided itself on outspoken openness, the organization was actually run from the top down. Shuttle managers blocked or ignored the requests.
Worried engineers could not bring themselves to break the chain of command. In an agony of indecision, they pushed only so far and no further.
Had they detected the wing damage in time, agency engineers might have improvised a repair in orbit or a rescue mission. Either would have been a long shot.
All the crew heard about the arguments over the debris came in an e-mail message from flight director Steve Stitch eight days into the mission.
Concerned that reporters might ask the astronauts about the foam at a news conference, Stitch told them the foam striking the wing was otherwise "not even worth mentioning."
"We have seen this same phenomenon on several other flights, and there is absolutely no concern for entry," Stitch told them.
"Thanks a million, Steve," shuttle commander Husband replied in an e-mail on Jan. 25. "And thanks for the great work on your part."
Within the shuttle's white eggshell of thermal tiles, the crew members were exhilarated.
During a lull in the routine, Kalpana Chawla floated gently over the flight deck.
She watched the sun set.
In the overhead windows, she could see her reflection along with the day and night sides of Earth.
"I called all the crew members one by one and they saw it," she said during a news conference on Jan. 29. "Everybody said, 'Oh, wow!' "
Three days later, it was time for them to come home.
At 8:18 a.m. EST, the shuttle fired its engines to leave orbit.
There was no turning back. Columbia was a glider. Once it entered the atmosphere, it flew by force of gravity alone in an artful computer-controlled fall.
Just after 8:44 a.m., the orbiter skimmed into the upper reaches of the atmosphere over the central Pacific at 24 times the speed of sound.
Normally, the ship was protected by a smooth aerodynamic flow that swept dangerous gases around it, with a thin boundary layer insulating it from the most severe heat.
The hole in the wing disrupted that layer. It exposed the wing to extreme superheated gases that could melt a 5-inch hole in an aluminum plate in 13 seconds.
Columbia inhaled a blowtorch.
The first imperceptible signs of trouble came quickly.
A gauge about 15 inches from the spot where the foam debris had struck 16 days earlier registered the earliest signs of stress. The information went no further than the flight data recorder.
Twenty seconds later, a well-insulated temperature sensor nearby started to detect an unusual rise in heat. But no one knew.
Inside the crew compartment, the astronauts stowed the trash and worked through pre-landing checklists.
Columbia began the first in a series of computer-controlled rolls designed to slow it for a safe landing.
Almost immediately, the blazing plume blew through the hollow behind the left wing's heat shielding and began spraying gas out through a thin vent that ran the length of the wing's leading edge.
The wing was burning from the inside out.
Five times in quick succession, beginning at 8:50 a.m. EST, communications between Columbia and Mission Control in Houston flickered on and off rapidly, as if someone were fanning his fingers in front of a light.
Sprays of molten metal erupted from the wing and enveloped the fuselage, interfering with electronic transmissions, like handfuls of metallic chaff dumped from a fighter jet to confuse enemy radar.
Over the next three minutes, the aluminum spars supporting the wing softened and began to sag.
Flight control responses were still normal. Telemetry measurements received at Mission Control were normal.
In the tumult of reentry, the crew sensed nothing amiss.
There was a small but noticeable increase in the temperature of a hydraulic brake line running through the left wheel well.
That signal was relayed to Mission Control. It was too small to cause alarm.
Nine and a half minutes after leaving orbit, Columbia streaked over California, trailing flashes of sparks.
Thermal tiles and pieces of the upper side of the wing were peeling away like shingles in a hurricane.
Ten times in 10 seconds, bright bursts of glowing particles flashed in Columbia's wake.
Passing over Texas, Columbia was wobbling enough that all four of its maneuvering jets fired automatically in an effort to stabilize it.
The shuttle rolled violently to the right. It yawed violently to the left.
At Mission Control, Marine Lt. Col. Charles Hobaugh, the astronaut in charge of communications, radioed the crew about the telemetry data.
"Columbia, Houston. We see your tire pressure messages and we did not copy your last call."
"Roger," replied shuttle commander Husband. "Uh, buh .... "
His transmission ended in mid-word.
Gyrating wildly, Columbia was traveling at 12,738 mph.
A large piece of the spacecraft ripped off. Five more pieces wrenched free during the next 30 seconds.
Half of the left wing broke away.
A final burst of telemetry data suggested that the autopilot toggled off and on.
Seconds after 9 a.m. EST, the onboard recorder stopped.
Several hundred miles later, the remaining root of the left wing ripped away.
Pulled around like a shuttlecock by the weight of its heavy main engines, the craft started flying tail first.
Almost immediately, the tail structure and engines snapped off.
Seconds later, the right wing broke away.
The crew compartment briefly continued to fly on its own, then was torn apart.
At Lake Toledo Bend along the Texas-Louisiana border that Saturday, the bass fishermen got an early start, eager for the prize money from the Bass N' Bucks tournament.
By 9 a.m., dozens of anglers had launched skiffs, baited hooks and cast lines in the water.
The fog lay like smoke across the lake. Competing boats were no more than muffled shadows.
When the wreckage started falling through the mist, the fishermen were terrified.
They heard the singing noise of shrapnel ripping the air. They heard the splashes as it hit the water. They felt the ripples rock their boats.
Columbia rained down around them.
It was a long, troubled summer.
War continued in such faraway places as Fallouja and Kabul. A heat wave gripped Europe and killed thousands of people. North America's worst power blackout darkened cities across the United States and Canada.
On Aug. 26 — seven months after Columbia fell from the sky — the independent Accident Investigation Board released its final report.
So open had the board been all along that its final report contained no surprises.
Without reservation, the board members agreed: It was the foam. They fixed blame squarely on NASA's complacent management.
In all, 11 managers involved in the ill-fated mission were demoted or reassigned. A few took early retirement.
Investigation board members returned to their families and careers, leaving NASA to fix its own problems.
As summer drifted into autumn, the space agency pledged to reform itself and began planning to return the three remaining shuttles to space, perhaps by next September.
Nothing could be done to make the wings stronger or to stop debris from striking the spacecraft.
Engineers worked on a repair kit that astronauts could use in orbit. They installed extra sensors in the wings to detect damage more readily. NASA managers vowed a renewed commitment to safety.
The world was moving on.
In October, technicians at the Kennedy Space Center packed away the 83,900 pieces of wreckage. They stored them on the 16th floor of the Vehicle Assembly Building — the same building where the next shuttle was being readied for launch.
A mystery can transform those who pursue it. The people involved in the Columbia inquest may never be free of it. Memories have a life of their own. Regrets linger.
Should they start to fade, there will be reminders.
Just a few weeks ago near Chireno, Texas, a farmer feeding his cattle discovered a jagged piece of alloy about the size of a fountain pen jammed in a bale of hay.
He took it to the county sheriff, who duly sent it by overnight express to NASA.
It was another piece of Columbia.
They turn up about once a week.
Kalpana Chawla was the only civilian in the crew of seven. It was her second flight. She could not stop smiling.
This six-part series is the product of six months of reporting, encompassing 130 interviews with accident investigators, scientists and NASA employees across the United States.Staff writer Robert Lee Hotz reviewed dozens of government reports and public hearing transcripts spanning the quarter-century of the space shuttle program. He met at length with members of the Columbia Accident Investigation Board.Hotz covered the 1986 Challenger accident and has reported on other manned spaceflight issues for 20 years.The illustrations are based on photographs, video images and eyewitness descriptions. They were drawn by staff artist Doug Stevens in The Times' Washington bureau.Hotz can be contacted at firstname.lastname@example.org.