- Education and Science
Space Shuttle Columbia
On the morning of April 12, a revolutionary new spaceship stood loaded with fuel on the launching pad at the John F. Kennedy Space Center in Cape Canaveral, Fla. Nothing like it had flown before in the 24 eventful years of the young space age. Indeed, during the nine years in which it was developed and constructed, at a cost of nearly $10 billion, many people wondered if the spaceship would ever fly and, if it did, whether it could perform its job successfully.
The craft was the space shuttle Columbia, the first of the winged space planes designed to ferry people and satellites to and from earth orbit time and time again. Unlike the Mercury, Gemini, and Apollo craft that bore earlier astronauts, the Columbia and its sister ships to follow would not be discarded after only one flight, but would be capable of making 100 or more round trips each.
In the cockpit of Columbia were John W. Young and Robert L. Crippen, the astronauts who had trained three years for this moment of testing. It would be Young's fifth journey into space, one of which had taken him to a landing on the moon; it would be Crippen's first. Hundreds of thousands of people gathered on the perimeter of the launching base, and millions more sat by television screens. It had been nearly six years since U.S. astronauts had last ventured into space.
What viewers saw was a kind of hybrid vehicle. It could climb into space on the power of rockets, cruise through orbit like a conventional spacecraft, and then plunge back into the earth's atmosphere, gliding to a runway landing like a powerless airplane. A design taking into account these diverse functions dictated the shuttle's rather ungainly appearance on the launching pad. Instead of the streamlined shaft of the Saturn 5 rocket topped with the neatly conical Apollo, the shuttle is a trident-shaped cluster of machinery of various shapes and sizes.
The most prominent component, the external fuel tank, looks more like a farm silo than something intended for flight. This white insulated aluminum vessel, 154 feet tall and 271/2 feet in diameter, contains in separate chambers the supercold propellants (liquid hydrogen and liquid oxygen) for the shuttle's main engines. The tank is the only non-reusable part of the system.
Structurally, the tank serves as the backbone for the .other major components. To each side of the tank is attached a solid-fuel booster rocket, 149 feet tall and 12 feet in diameter. The job of these two rockets is to provide extra thrust in the initial two minutes of flight, to get the huge tank as well as the winged spaceship itself off the ground and up into the thinner, less resistant upper atmosphere.
Riding the back of the tank, as if hanging on for dear life, is the spaceship carrying the astronauts and cargo. This boxy vehicle, 122 feet long with stubby wings spanning 78 feet, about the size of a DC-9 airliner, is called the orbiter or, more commonly, the shuttle - Columbia being the first of at least four by the mid-1980's.
At the forward end of the orbiter's fuselage is the flight deck, with a cockpit resembling those in large jet aircraft. Below the flight deck are the crew quarters, which on later missions will eventually include a galley, toilet, and sleeping compartments for up to seven people. (Though Crippen and Young had an electric food warmer and - sometimes - a working, zero-gravity toilet, they slept in the cockpit chairs to leave more room for flight instrumentation.) Back in the mid-fuselage is the cargo bay, an unpressurized, 60-foot-by-15-foot area for hauling satellites, scientific laboratories, or other payloads. The tail section houses the three main rocket engines and two smaller orbital maneuvering engines.
The lift-off and ascent for the first test flight of Columbia followed the script almost to the letter. First, the three main engines of the orbiter ignited and in three seconds roared to 90 percent of their full 1.1 million pounds of thrust. At that instant, the two booster rockets exploded with the force of another 5.3 million pounds of thrust. The entire 4.5-million-pound vehicle - tank, rockets, and orbiter - rose, cleared the tower, and climbed out over the Atlantic Ocean.
In two minutes the boosters burned out, as planned, and were jettisoned, parachuting into the ocean, where recovery ships waited. The spent rocket casings were brought back for refurbishment and reuse on a later flight. The three orbiter engines continued to fire for more than six minutes, taking Columbia to the outer reaches of the atmosphere. When those engines shut down, Mission Control announced, "Columbia, the gem of this new ocean, now in space, not yet in orbit."
Nine minutes into ascent, the external tank, now almost empty of its propellants, separated from the orbiter and plunged toward earth, its fragments falling into the Indian Ocean. After coasting for a minute and a half, Columbia's two orbiting maneuvering rockets fired to nudge the ship into a low orbit. Three successive firings over the next seven hours put Columbia into its cruising orbit 170 miles above earth. After almost a decade of test failures and accidents, redesigns and postponements, congressional criticism and growing public perceptions of the shuttle as an expensive lemon, the ship was flying at last.
The concept of the space shuttle was first officially proposed by the National Aeronautics and Space Administration in 1969. Originally, NASA engineers conceived of a completely reusable shuttle. The orbiter was to be carried aloft on the back of a winged booster, which would have a crew to fly it back to a landing. The orbiter would also have had jet engines, enabling it to land under power. Ordered to cut in half the estimated development costs, however, NASA had to forsake the reusable booster and eliminate the landing engines. The decision had the long-term effect of reducing the shuttle's efficiency and increasing its per-flight operational costs, thus puncturing two of the most convincing arguments - efficiency and economy - in favor of building the shuttle in the first place.
In January 1972, President Richard M. Nixon announced his decision to let NASA proceed with construction of the scaled-down version. But there would be no more Apollo-like largesse. NASA was told that it must build and test the first shuttle at a cost of $5.15 billion in 1971 dollars. The first test flight was to be in 1978.
As they began work, NASA and its prime contractor, Rockwell International, acknowledged three areas of greatest concern: the orbiter engines, the flight-control computers, and the thermal protection system.
The orbiter's three main rocket engines had to be smaller and more efficient and durable than anything flown before, for they were going to be used not once, but many times over. To achieve maximum efficiency, the engines were to operate at pressures three times greater than on Apollo's Saturn 5 rocket and at combustion temperatures of 6,000 degrees Fahrenheit. At times, it seemed an impossible challenge. Seals broke in testing and had to be redesigned. There were bearing failures, bad welds, stuck valves, and several fires and explosions. The engines did not pass their preflight tests until late in 1980, long after the original scheduled launching date had come and gone.
The computers, on the other hand, sailed through development and testing. More than any previous manned spaceship, the orbiter is critically dependent on computers for every phase of its operations. Four identical machines operate simultaneously, checking each other's performance; a fifth is held in reserve for emergencies, and a sixth can be turned on if additional back-up is needed. With their links to all important subsystems, the computers plot course, fire rockets, check for leaks, and keep an inventory of fuel, oxygen, and water.
But it was the computer system, seemingly tripping over the wires of its own complexity, that forced the postponement of the shuttle lift-off from April 10 to 12. Less than half an hour before ignition, as part of a routine check, the fifth computer attempted to "talk" to the other four. Getting no response and thus suspecting a failure, the fifth computer shut down, as it was supposed to do, and this caused the entire countdown to come to a halt. A 40-millisecond timing skew, it turned out, had left the two systems slightly out of synchronization. The problem, once diagnosed, was easily corrected.
There was more foreboding, as the day of launch approached, concerning the orbiter's thermal protection system, which had given engineers their most visible and embarrassing headaches. Earlier spacecraft were coated with a shielding material that dissipated the heat of ascent and reentry by charring and flaking off, but this approach was rejected for the shuttle because the shielding had to survive numerous reentries. Instead, the orbiter's aluminum-alloy skin was covered with over 30,000 lightweight tiles of varying shapes and thicknesses. Gluing on these silica-fiber tiles and making sure they would hold under flight stress proved to be a more challenging task than anyone had anticipated. As late as the fall of 1980, technicians were still removing, modifying, and regluing tiles on Columbia.
These technical problems and delays escalated costs and provoked deep concern in Washington. Reviews of the project, ordered by the Carter administration, led to a general shake-up of top government and contractor management. In November 1979, President Jimmy Carter declared his full support of the shuttle and a willingness to pump additional money into the project to see it to completion as soon as possible. Crucial to his decision was the shuttle's intended role for the Department of Defense.
In selling the concept to the White House and Congress, NASA had contended that a fleet of reusable shuttles would eventually replace all expendable launching rockets, presumably reducing launch costs. As an all-purpose vehicle, the shuttle would be used to deploy scientific, weather, and earth-resources satellites for civilian agencies, communications satellites for commercial concerns, and communications, navigation, and surveillance satellites for the Pentagon. To win Pentagon support NASA redesigned the shuttle to include a much larger cargo bay and more maneuvering capability. The Pentagon, in turn, became an advocate of the shuttle and pressed for the necessary financial transfusions, not only to complete preparations for Columbia's first test flight but also to push production of the sister ships, Challenger, Discovery, and Atlantis. If it had not been for timely Pentagon pressure, in the opinion of many observers, the shuttle project might well have foundered several years ago.
But the project survived, and for 54 1/2 hours Young and Crippen orbited the earth, getting the feel of this new space plane and testing the performance of its engines, computers, thermal tiles, and many subsystems. From the flight deck on the first day the astronauts operated controls to unlatch and open the clamshell doors to the cargo bay, allowing excess heat to escape. Televised pictures showed a flawless maneuver - and a possible problem: a small number of Columbia's protective tiles were missing. Fortunately, the damage was to one of the least vulnerable sections of the vehicle, the pods housing the two maneuvering rockets. After a review of lift-off movies and other data, NASA engineers felt confident that the tiles in other areas were firmly in place.
The only other potentially serious problem was not detected until after the mission. A few seconds after ignition, when the two boosters fired at full thrust, the heat-induced atmospheric pressure rose several times higher than expected, buckling some struts on the vehicle and pushing other structures close to their limits. For the second shuttle launch, engineers devised a method of pumping a massive spray of water into the base of the pad to dampen the heat pressures.
On the morning of April 14, Young and Crippen prepared Columbia for its return to earth, a maneuver that one project official called the foremost "unknown unknown" of the mission. There would be no splashdown, as in the past. Columbia would have to slow down from a velocity of 17,500 miles an hour by firing the two maneuvering rockets, drop out of orbit, and glide to a touchdown on a runway. A desert strip at Edwards Air Force Base in California was the target, giving the astronauts plenty of room in the event of navigational errors. (In an emergency, however, the shuttle could land at just about any large runway for jets.)
Over the Indian Ocean, 59 minutes until touchdown, the two maneuvering rockets fired on computer command. Twenty-five minutes later, its nose pointed 40 degrees above the horizon so that the underbelly would bear the brunt of reentry heat, Columbia entered the atmosphere over Wake Island in the Pacific. Columbia glowed red from frictional heat, which disrupted radio communications for 16 minutes, as expected. Slowed by the friction, the ship reached the coast of California with communications restored
The computers had been doing all the flying up to then, moving control surfaces on the wing and vertical tail. Now, Young took over manual control twice to line up the ship for its final approach and landing. Columbia swept over Edwards, made a U-turn, and glided smoothly to a touchdown in the wash of a desert mirage. The tiles had held.
The success of Columbia inspired a surge of national pride and hope, dispelling for a time at least self-doubts born of unremitting crises in international and domestic affairs. "The space shuttle did more than prove our technological abilities," President Ronald Reagan said. "It raised our expectations once more; it started us dreaming again."
Among the dreams for the space shuttle, once Columbia clears all of its testing hurdles, is the creation of a transportation system that would make space a frontier not just for exploration but for a growing human presence. More than 30 shuttle missions were tentatively scheduled before the end of 1985, and by 1990 there could be 40 flights a year, with each craft going and coming about once a month. In time the fleet may expand from four shuttles to a dozen
Tucked into the cargo bay on these flights would be a wide range of satellites and experiments On some flights the orbiter might deploy two or three satellites and pick up an old one to bring back for refurbishment. Other flights would be devoted entirely to the European Space Agency's Spacelab, a self-contained laboratory that would fill up the cargo bay and provide living and working quarters for international teams of scientists. NASA has also sold hundreds of "getaway specials": for as little as $3,000 anyone can rent space for a small experiment.
In 1985 the shuttle was scheduled to place in orbit a large remote-controlled telescope which, unhampered by earth's atmosphere, should be able to make observations to vastly greater distances than any instrument on earth. Also, even though the shuttle is restricted to low earth orbit, payloads with attached rockets could be launched from the shuttle for outer destinations, including the planets. However, in the struggle to develop the shuttle, NASA was forced to sacrifice , nearly all other projects, leaving it with only one approved planetary venture - the Galileo mission, scheduled for the mid-1980's, to orbit Jupiter and probe its atmosphere.
Commercial customers have already lined up for space on the shuttle flights, taking advantage of its lower cost compared to the expendable rockets. Most of these clients are in the booming space telecommunications business, which was expected to account for at least one-third of all shuttle activity in this decade. In addition, some industries were planning modest experiments in processing materials such as biological substances, where ultra-high purity is required, or computer chips, where a weightless environment is an advantage. Toward the end of the decade NASA hopes to take steps toward the permanent occupancy of space. On the drawing board are plans for the shuttle to ferry components that would be assembled in orbit, creating a large space station which would serve as a base for earth observations, experimentation, and perhaps materials processing plants. Clusters of such stations could form a space community that would operate solar power stations or communications relay platforms.
Roughly one-third of the shuttle flights planned for the next few years were slated for defense missions, most of them related to such conventional satellite functions as surveillance and communications. Already, two of the next three orbiters being built or planned are intended primarily for use by the Pentagon, whose space activities spending will have outpaced NASA's by 1982. By the late 1980's the Department of Defense plans to have its own mission control center in Colorado, as well as the shuttle launch and landing facilities now being built at Vandenberg Air Force Base in California. Among the fairly concrete ideas for the shuttle's military use is the testing of a new type of sensor, code-named Teal Ruby, which would be able to detect strategic bombers as well as satellites. Shuttles might conceivably be used to help create manned military space stations or to launch laser weapons or kamikaze satellites capable of destroying enemy spacecraft. Such uses are controversial, being opposed by those who want to preserve the shuttle for nonmilitary research or who fear a space-age escalation of the arms race.
Columbia successfully completed 27 missions when on its 28th mission on February 1, 2003 a tragic mishap occurred during re-entry destroying the shuttle and all seven crew members lost their lives.