After disaster the quest for answers: in the wake of the columbia tragedy, what will become of America' romance with space?

When the space shuttle Columbia broke, up on re-entry into the Earth's atmosphere, killing all seven astronauts aboard, America's space program cycled again from triumph to tragedy.

Few under 25 have any memory of a time when space travel meant the crossing of a new frontier, the drama of man's first steps on the moon--or the last time American astronauts died.

It was in 1986 that Columbia's sister ship, the Challenger, blew apart during liftoff, killing all seven aboard, including Christa McAuliffe, the first "teacher/astronaut," who was supposed to conduct lessons from orbit.

After the Challenger disaster, America's manned space program was grounded for 32 months. NASA, the National Aeronautics and Space Administration, spent $2.4 billion on redesign and testing, and made several hundred alterations.

The Columbia crash is all but certain to bring further changes, though specifics won't be known for months. Even before the disaster, critics had raised questions about the age and safety of the shuttle fleet. All but one of the orbiters were built during the 1980s. A government panel studying shuttle safety concluded last year that federal budget cuts over the past decade were endangering future missions.

SAFETY AND COST

"I have never been as worried for space shuttle safety as I am right now," Richard D. Blomberg, the panel's chairman, told a congressional committee last spring. "All of my instincts suggest that the current approach is planting the seeds for future danger." He added that his concern was not for current missions, but that "nobody will know for sure when the safety margin has been eroded too far."

NASA has sought to make safety paramount, but critics said it has fostered a conservatism causing delays and cost overruns.

It is no secret that NASA has had major difficulties. "They have been under a lot of scrutiny because of some high-profile screwups and the enormous cost overruns in the space station," says one senior Washington official, referring to the International Space Station, which is serviced by the shuttles.

A HISTORY OF TROUBLES

NASA, in fact, has had a string of problems, but the ones not involving loss of life attract less attention. In September 1999, the Mars Climate Orbiter was destroyed when it flew too close to the planet. It went off course due to confusion between two teams of engineers, one using measurements in feet and the other using meters. Three months later, the Mars Polar Lander was destroyed when its engines shut down 132 feet before it reached the planet's surface. A wiring mistake during a test had prevented engineers from detecting a false sensor reading.

But the underlying problem, two review panels said, was the pressure of NASA's so-called "faster, cheaper, better" approach to space missions. "People were trying to do too much with too little, and not adequately conveying their concerns to others, particularly upper management," Thomas Young, a former NASA official, said after heading one of the reviews.

SOME WARNINGS UNHEEDED

To be sure, such seemingly elementary mistakes have not been evident in the shuttle program. After Challenger, "there was a rededication to safety," says NASA spokesman Robert Jacobs, an idea sure to be re-examined in coming weeks.

The Challenger's scheduled liftoff had been delayed for days, leaving the spacecraft and its giant boosters on the launch pad during an unusual cold snap. The cold reduced the flexibility of rubber gaskets called O-rings in the booster rockets. During the launch, a plume of flame leaked through one of the gaskets and ignited the huge external fuel tank. Some engineers had asked that the launch be delayed because of the cold, but they were overruled, and their warning had never reached key NASA officials.

Now, Jacobs says, if any employee has any questions, they are discussed thoroughly and launches are delayed for "anything that is deemed to be abnormal on any level."

Early last year, for instance, a shuttle launch was delayed because a technician dropped a four-inch-long pin, which fell "where it shouldn't be," says Jacobs. "Would it have caused a problem? Maybe, maybe not, but it was something that shouldn't be there and so the launch was scrubbed."

Regardless of such assurances, the Columbia accident has reopened debate on the need for both the shuttle program and manned space flight. Anticipating the objections, the families of the crew members issued a statement imploring the country not to turn back, despite the deaths.

Columbia's 16-day mission of scientific discovery was a great success, cut short by mere minutes--yet it will live on forever in our memories," they said. "Although we grieve deeply, as do the families of Apollo 1 and Challenger before us, the bold exploration of space must go on."

The Columbia Lesson: Space Travel Is Never Routine, Never Entirely Safe

DISCUSSION QUESTIONS

* What was your first reaction when you learned about the Columbia?

* Were you aware of the Columbia mission before the accident?

* Why do you think so many young people regard space travel as routine?

TEACHING OBJECTIVES

To help students understand serious questions raised in the wake of the Columbia disaster, specifically whether the NASA experts and the general public fully understand all of the dangers of space travel.

CLASSROOM STRATEGIES

CRITICAL THINKING/DISCUSSION: A key point made in the article concerns the huge expenditure--$2.4 billion spent on redesign and testing and hundreds of alterations following the 1986 explosion of the Challenger. Tell students that after the Challenger disaster, NASA had no internal review board to investigate the accident. Compare this with the routine investigations carried out by police departments following traffic accidents. Ask students what the fact that NASA had no accident-review plan reveals about the mind-set of NASA officials before the Challenger accident. Were they dangerously overconfident?

Continue with the safety changes made after Challenger. Does it seem to take a terrible accident to provide people with a clearer view of life? Have students ever experienced a traffic or other dangerous accident? If so, how did the experience change their thinking about dangerous activities?

FINDING ANSWERS:

Write "Who's to Blame?" on the board. Ask if that is a fair question. Remind students that although many saw space travel as routine, the shuttle was perhaps the most complicated machine ever built. Did success lull experts and average people into a sense of complacency? Does that explain the decade of budget cuts--and concerns that that would endanger future missions? Should the budget cutters be disciplined?

Note the 1999 accident resulting from engineers' mix-up of feet and meters. Is this the type of error that would earn a student an "F" from a math teacher? What does the experience reveal about human frailty? About the combustible mix of humans and space? Is it reasonable to expect that other astronauts will be killed or injured in future accidents? DEBATE: Ask students to take sides on this statement: The Columbia shuttle disaster teaches us that humans should not travel in space.

During a Normal Re-entry

PERIOD   First Contact with     Speed-Reducing    Maximum Heating and
         Atmosphere             Turns             Communications
                                                  Blackout

         The shuttle first      As the shuttle    At the point of
         comes into contact     passess through   maximum heating,
         with the atmosphere    the atmosphere,   the thermal tiles can
         about 76 miles above   it rolls over by  reach temperatures
         the earth's surface.   as much as 80     of up to 3,000 degrees
         Its nose is lifted     degrees, causing  Fahrenheit. The air
         about 40 degrees to    it to sweep       around the shuttle is
         absorb heat safely.    through two       ionized, ususally
                                broad S-turns     preventing radio
                                that further      contact for about 13
                                slow it down.     minutes.

PERIOD   Return to Fight

         As the air pressure
         increases, the shuttle
         can be controlled with
         flaps and rudders
         instead of jets. As it
         slows, the shuttle's
         nose is lowered, and it
         files more like an
         airplane.

Milestones and Grief in the U.S. Space Program

OCTOBER 1, 1958

One year after the Soviet Union launched Sputnik, the first space satellite, the National Aeronautics and Space Administration (NASA) begins operations in the U.S., and the "space race" is born.

MAY 5, 1961

Astronaut Alan B. Shepard Jr., In a one-man Mercury capsule, becomes the first American to travel in space. He stays there for five minutes, declaring "What a beautiful view!"

FEBRUARY 20, 1962

Astronaut John Glenn is the first American to orbit Earth, circling the globe three times. Russian cosmonaut Yuri Gagarin had orbited Earth nearly a year earlier, in April 1961.

JANUARY 27,1967

Astronauts Virgil "Gus" Grissom, Edward White, and Roger Chaffee are killed when fire sweeps through their capsule during a rehearsal for the first Apollo mission. They are the first U.S. astronauts to die.

JULY 20, 1969

Neil Armstrong and Buzz Aldrin touch down on the moon in Apollo 11's lander. Setting foot on the surface, Armstrong tells a worldwide TV audience, "That's one small step for a man, one giant leap for mankind."

The Search for Clues

Early in the investigation of the Columbia disaster, NASA officials were focusing on problems involving the left wing of the spacecraft.

NOVEMBER 1969

As Apollo 13 hurtles toward the moon, an onboard explosion cripples its power, electrical and life-support systems. Astronauts use the lunar landing module as a lifeboat to return to Earth.

APRIL 12, 1981

The world's first reusable, piloted spacecraft, Columbia, inaugurates the space shuttle program.

JANUARY 28, 1986

The space shuttle Challenger explodes 73 seconds after launch, killing all seven on board. Among them is teacher Christa McAuliffe, the first civilian scheduled to fly into space.

NOVEMBER 20, 1998

The first piece of the International Space Station is launched. Scheduled for completion in 2008, its internal volume eventually will be roughly equal to that of a 747 jumbo jet.

FEBRUARY 1, 2003

After completing its 28th mission, Columbia disintegrates 16 minutes before it is to land in Florida. Three of the original five shuttles remain--Atlantis, Discovery, and Endeavour.

The Search for Clues

Early in the investigation of the Columbia disaster, NASA officials were focusing on problems involving the left wing of the spacecraft.

Rising Temperatures

(1) 8:53 a.m.

Over California

Hydraulic and braking measurements are lost to flight control. Temperature readings in part of the left wing wheel well rise 30 to 40 degrees in five minutes.

(2) 8:54 a.m.

Over eastern California And Nevada

Temperature readings above left wing rise 60 degrees in five minutes.

(3) 8:58 a.m.

Over New Mexico

Drag on the left wing of the orbiter causes it to roll left, possibly a result of missing tiles. The shuttle's flight control system attempts to counteract the roll. Three left wing temperature sensor readings are lost.

(4) 8:59 a.m.

Over western Texas

One minute before communication with shuttle is lost, drag on the left wing again causes the shuttle to bank left. The computer system activates yaw rockets to counteract the roll. Eight tire and temperature readings are lost.

RELATED ARTICLE: Anything but routine.

By Peter Vilbig

Though its regular flights have grown routine for many Americans, the space shuttle is a wonder of modern technology, perhaps the most complicated machine ever built.

Launched atop an inferno of exploding hydrogen and chemicals that develop 7.3 million pounds of thrust, the spacecraft undergoes unearthly extremes of heat and cold, then streaks back to Earth at more than 12,000 miles per hour--five times faster than a rifle bullet--as air friction heats its skin to more than 2,000 degrees.

FLIGHTS ON HOLD

Investigators will likely spend months analyzing why the Columbia spacecraft broke up over Texas, killing its seven astronauts. Flights of the three remaining shuttles won't be authorized until the problems are identified and, if necessary, changes are made in the rest of the shuttle fleet.

The grounding of the shuttle could have serious consequences for human space exploration and science. Though Columbia's last mission focused on science experiments, the shuttle has more commonly been a workhorse in recent years, launching satellites and scientific instruments, and helping build and supply the orbiting International Space Station, a joint U.S.-Russian project, and the key site for space research.

While the space station's crew--two Americans and one Russian--are safe, officials say, the station itself requires regular pushes from the space shuttle to keep it from falling back to Earth.

NASA has no plans to build new shuttles. Each shuttle was designed for 100 flights, and the space agency planned to continue operating the current fleet through at least 2015--a plan that may now be questioned.

REPLACEMENT VEHICLES?

A new high-tech replacement has been studied, but NASA, faced with technical hurdles, postponed a decision last November. The agency has also proposed building an orbital space plane that would be launched atop a conventional rocket, and then land on a runway. But conventional rockets are expensive, and the space plane would be only a temporary measure.

Despite the routine veneer of shuttle missions, the Columbia disaster reinforces how dangerous space travel is. "This is inherently a risky business," says George Lewis, associate director of the security-studies program at the Massachusetts Institute of Technology. "This is not like a commercial flight."

MATTHEW L. WALD covers transportation for The New York Times.