Ho trovato un articolo molto interessante sulla storia del programma spaziale americano negli sciagurati anni dell’amministrazione Nixon. http://126.96.36.199:8081/moonshot/ssb.htm A proposito dello Shuttle,e dei compromessi che la NASA dovette accettare nello sviluppo dell’Orbiter,è detto come a causa dei requisiti imposti per le missioni militari dello Shuttle,lanciate da Vandemberg,la originaria configurazione ad ala dritta dello Shuttle venisse rigettata in favore di una configurazione con ali a delta.Questo comportò un rientro nell’atmosfera con un angolo ripido ed a una velocità considerevolmente più alta,esponendo l’Orbiter a temperature molto più alte rispetto a quelle previste nella configurazione ad ala dritta.Da ciò la necessità di una protezione termica maggiore ed il ricorso alle famigerate “mattonelle”.Oltre agli altri ben noti problemi,le mattonelle resero più pesante l’Orbiter (già scalato più grande per le esigenze dei militari).Per compensare il peso i progettisti dovettero eliminare i propulsori che avrebbero permesso un atterraggio come quello di un aereo,e UDITE,UDITE,UN SISTEMA DI SALVATAGGIO PER L’EQUIPAGGIO CONSISTENTE NELLA SEPARAZIONE DELLA CABINA DAL RESTO DELL’ ORBITER (“The crew escape system that could have saved the Challenger crew by pulling the crew cabin away from the disintegrating shuttle stack was eliminated”;quindi originariamente un sistema del genere era previsto)!!!
Posto quì l’articolo in originale. da notare che è stato scritto PRIMA della tragedia del Columbia:
"Millions of newspaper and web page readers, TV and radio audiences as well as the very astronauts whose job it is to work on America’s space shuttle have read or heard the following sentences time and time again over the past two decades: “The space shuttle launch has been delayed due to cloud cover around the launch pad.” “The entire space shuttle fleet is grounded indefinitely due to a potential systems safety issue.” The space shuttle landing has been put off again due to weather issues in Florida and California.” “The seven member crew of Challenger was killed due to a catastrophic failure occurred during the launch.” “The space shuttle did not return to duty for more than two and a half years while the design flaw was corrected.”
The quoted statements above elicit some painful questions that nobody at NASA really wants to hear, much less answer. Problems and delays continue to plague the space shuttle after more than twenty years into its operational life. An inspection of the interior of the space shuttle rocket engine flow lines in the summer of 2002 revealed numerous tiny cracks. These cracks forced NASA to postpone all shuttle lunches for months while the problem was assessed and a resolution sought.
The launch operations team at Kennedy Space Center deserves a medal every time the shuttle launches successfully. The shuttle is one of the most complex and cantankerous machines ever built. The space shuttle is a “fair-weather” vehicle. In fact, the record of space shuttle launch operations show that predicting the weather can be more accurate than predicting shuttle launches. Thirty-one successful shuttle launches from Kennedy Space Center have been executed since launch operations contractor United Space Alliance assumed launch operations in 1996. The overall “on-time launch rate” for those 31 missions was only 62 percent. Excluding weather delays, the on-time launch rate is 81.6 percent.
The longest gap in shuttle operations came following the Challenger explosion in 1986. For two years and eight months, the entire shuttle fleet was grounded while investigations and engineering revisions were executed. Two other space shuttles, Columbia and Endeavor have been grounded for periods of at least three months on four separate occasions over the years since Challenger while various issues had to be addressed. One of those delays lasted for five months, but that grounding was due to a delay in the International Space Station rather than technical problems with the shuttle.
Major STS launch schedule delays:
Mission Orbiter Launch date Issue Next Launch Time between launches
STS-93 Columbia 7/22/1999 electrical short/wiring STS-103 on 12/19/99 ~ 4 months
STS-88 Endeavour 12/4/1998 ISS program STS-96 on 5/27/99 ~ 5 months
STS-78 Columbia 6/20/1996 hot gas through joint on SRB, but not past O-ring STS-79 on 9/16/96 ~ 3 months
STS-35 Columbia 12/20/1990 Hydrogen leak STS-37 on 4/05/91 ~ 4 months
STS-51L Challenger 1/28/1986 O-ring hot gas blowby; explosion STS-26 on 9/29/88 ~ 2 years 8 months
Each delay in the shuttle program is expensive. The cost of each postponement varies according to the specific circumstances of each delay, but the net effect is a substantial increase in costs per launch. Recycling a launch involves thousands of personnel and the resetting of numerous sophisticated systems whenever a postponement comes deep into the countdown. Such a launch delay can result in unloading the shuttles huge cryogenic propellant tanks, an expensive and delicate operation. Some “perishable” research experiments in the shuttle might have to be unloaded or secured by a crew of technicians. The vital members of the launch team have to remain on the job during extended launch schedule delays. They have to be paid or NASA and United Space Alliance risks losing rare, highly trained people to competitors in the job market. The repairs and redesigns that have to be done during the delays also cost a great deal of money.
The space business has always seen delays and setbacks, but the Space Shuttle was supposed to provide NASA with a revolutionary vehicle that would offer reliability and quick turnaround times in the launch schedule. Something went terribly wrong with those optimistic plans. Challenger stands out as the worst day in the history of the shuttle but the reputation of NASA has also suffered with each of the frequent disappointing delays or setbacks in the program. What happened to the “good old NASA” that made Americans cheer back in the early 1960s? Why is America‘s only means of human access to space so plagued by disappointing delays, endless technical problems and only fair-weather reliability? Is the shuttle just a massive NASA boondoggle? Are these problems exclusively the National Aeronautics and Space Administration’s fault? Can we blame this faulty space program on the Republicans or the Democrats?
NASA actually has a remarkable safety record despite a couple of very dark days. In more than forty years of human spaceflight, there have only been two fatal incidents directly involving a spacecraft. The first fatalities came in 1967 when the three member Apollo 1 crew died in a fire that consumed their spacecraft during a pre-launch ground test. Spaceflight was considered an especially dangerous business in 1967 and former NBC television reporter Roy Neal recalls that all of the early astronauts gave an “obit” interview in the event that they ended up getting killed in the line of duty. Each astronaut sat in front of a camera and gave his personal version of “this is a very dangerous profession and the space program must not be halted or delayed just because astronauts might be lost.”
An exhaustive official investigation and thorough journalistic inquiry revealed that the fire was basically caused by negligent work from the NASA contractor who built the spacecraft combined with overbearing schedule pressure imposed by NASA. Apollo was on a strict deadline to meet the late President John F. Kennedy’s vow for America to reach the moon by the end of the decade. The pressure to deliver before the deadline arrived imposed almost unrealistic wartime like pressures on the space contractors. The Apollo 1 tragedy did not come as a total surprise to many knowledgeable observers despite the shocking nature of the accident.
It was a different kind of time pressure that worked against the astronauts who died in the next US space tragedy. The space shuttle was already “operational” and had been flying for years. The space shuttle was having a hard time meeting hoped for expectations as far as mission turnaround time as well as in making designated launch dates. Launch delays were expensive and shuttle managers were under pressure to explain why they weren’t meeting the stated goals of the shuttle program. Otherwise, spaceflight appeared to be so easy and safe by 1980s that the United States decided it was time to start giving some “regular folks” like Congressional politicians, a Saudi prince and even a schoolteacher a ride on the space shuttle. Since shuttle launches were no longer regularly broadcast on live network television by 1986, most Americans were probably not aware of the shuttle’s inability to keep true to the designated launch schedule due to repeated delays caused by weather and technical issues. Most of the sordid details of a legacy of bad management and political favoritism in the shuttle program came out after the shuttle Challenger killed America’s “Teacher in Space” along with the other six members of the crew on a unusually cold Florida morning in January of 1986. A poorly designed solid-rocket booster (SRB) combined with NASA management’s “Go Fever!” determination to make the shuttle look more reliable than it actually was, resulted in those fatalities.
NASA literally had put all of its eggs in the space shuttle “basket”. The space shuttle was officially designated as the space agency’s sole means of access to space. No new unmanned boosters were to be built or developed on behalf of NASA. All satellites and NASA space missions were to be launched from the space shuttle cargo bay. The United States was basically blown out of the satellite delivery market when Challenger exploded. The European Space agency, Soviet Union and other global competitors in the multi-billion dollar satellite delivery business quickly filled the market vacuum left in the wake of Challenger. The space shuttle is still “out of business” as far as commercial satellite delivery is concerned. NASA was forced to return to the old Deltas, Atlases and Titan rockets that served as satellite delivery workhorses in the pre-shuttle era.
The space shuttle was once considered a key part of the American vision of a future world where space would help bring peace, freedom, prosperity and wealth to all the people of earth. The original space shuttle concept was probably conceived in the mind of Dr. Wernher von Braun back in the 1950’s when he worked with an artist to depict his vision of America’s future in space. The artist and the late director of NASA’s Marshall Space Flight center in Huntsville were working on a series of magazine articles that seized the imagination of the general public as well as the future leaders of America’s space program.
The original space vision of von Braun and his colleagues was comprised of three major components. Component number one, a “fully reusable” space shuttle would ferry cargo and passengers to component number two, an orbiting space station. Scientific research would be carried out on this space station in addition to its serving as a possible space tourism destination and host to commercial activities. The third component was a “space port” function for the station. Space “ferries” to the Moon, Mars and other space destinations would launch from the space station. The ferry service would be much less expensive than launching directly to those exotic destinations directly from the surface of earth. In the late 1960s, von Braun’s three-part concept was still very much alive in the future projects offices at NASA centers. The scheme made perfect sense to those who saw the ultimate human destiny in space exploration. Supporters of the concept felt that America needed all three parts of the system if NASA was going to have any kind of a decent future in the grand scheme of things. This article will examine the details of the troubled birth of America’s Space Transportation System.
APOLLO SATURN: RELIABILITY AND CREW SAFETY RULE
Building a space shuttle was never an absolute necessity for US space exploration. The shuttle was intended to replace the Apollo Saturn rocket that sent American astronauts to the moon and launched the first US space station, Skylab into orbit. The mighty Apollo Saturn V moon rocket had been originally designed to serve all US space needs to the end of the twentieth century. The German and American rocket team led by Dr. Wernher von Braun at NASA’s Marshall Space Flight center in Huntsville had conceived and managed the Saturn program from it’s inception. The Saturn had a remarkable 100% success rate through all of the unmanned and manned missions that it flew. Saturn was exemplary of what unfettered science and engineering could achieve. The Marshall engineers were essentially given a blank check to spend on the Saturn program.
The Apollo Saturn came with a Launch Escape System that was designed to separate the astronaut crew cabin from the huge rocket in the event of a cataclysmic explosion or malfunction. A parachute system would then assure a soft landing for the astronauts in the event of a launch emergency. That safety system never had to be used.
Safe completion of the mission was built into the Apollo Saturn program. The Apollo Saturn launches and missions were divided up into a series of so-called “modes”. Each mode offered a distinct method for safely delivering the crew in the event of an emergency or failure. The modes gave Saturn versatility and robustness from the crew safety point of view. These modes extended beyond the launch booster. The use of the Lunar Module as a “lifeboat” during the “successful failure” of Apollo 13 is illustrative of the Apollo program’s emphasis on “crew survivability”.
CHANGES SWEEP AWAY OLD DREAMS AND IDEALS
The summer of 1969 was a turning point in American history. In Houston, Texas and Cape Kennedy, Florida an army of young men and women under the guidance of a collection of some “Greatest Generation” managers were set to pull off a miraculous event- the first human expedition to the moon. Elsewhere, plans were being finalized for a festival of “Love, Peace and Rock & Roll” at a place called Woodstock in New York state. America was in a period of painful reevaluation. The war in Vietnam seemed both endless and pointless to the younger generation. Poverty and civil rights issues were the new banner issues of the day. The Space Race between the USA and the USSR was increasingly perceived as just another part of the “Military Industrial Complex” conspiracy against peace and social improvement by the growing “movement”.
NASA employees and families were not unaffected by these unsettling societal changes. A former student who attended Cocoa Beach High School, where many children of NASA and Kennedy Space Center workers attended in 1969, reported that drug use among students was widespread. She reported that her peers in the student body frowned upon personal values such as “ambition”.
Nationwide, NASA was facing an unprecedented “upstream” battle for public support. The dismal mood of the younger generation was beginning to bleed into the mainstream fabric of American political thought, particularly in the Northeastern and West coast centers of academia and “sophistication”. Both the media and the general public were rapidly losing interest in NASA and space exploration. Television networks were no longer interrupting soap operas with breaking space news. NASA was so good at pulling off space spectaculars, that space travel was beginning to look routine. Television audience ratings for space coverage steadily dropped after the first moon landing.
Meanwhile, first year U.S. President Richard Nixon was busily putting his personal imprint on the face of government and public policy. Nixon transformed the old Bureau of the Budget into the Office of Management and budget, now known as the OMB. The OMB examiner charged with oversight of the NASA budget was a man named Donald Rice. Rice was Nixon’s NASA axe-man. Rice immediately targeted NASA’s Saturn rocket program. Critics of NASA claimed that the Saturn was too expensive to build and operate.
The agonizing war in Southeast Asia was draining America’s spirit as well as the federal budget. The burgeoning “Great Society” entitlement programs created by the Lyndon Johnson devoured a larger and larger portion of the public treasure as the federal bureaucracy mushroomed. Some young activists went so far as to demand a “guaranteed national income” for every citizen of the USA. Idealistic socialists issued the unrealistic demand that government solve all of America’s social ills before resuming space exploration. Saying that space exploration should be grounded until the planet becomes a Utopia was the same thing as saying that humans should never explore space. NASA’s usual response to anti-space sentiment was (and still is) to point out the value of “ space spin-offs” created by NASA research. The press was given long lists of household, hospital/medical, industrial, transportation, and commercial products and services enabled by NASA research. The media and the public yawned.
Most of the world and the majority of Americans had enthusiastically cheered as they watched the Apollo 11 expedition expand the domain of humanity into another world. Not everybody on earth was pleased with what President Nixon called, “The greatest day since the Creation.” Not everybody was “proud and happy” that America had realized President Kennedy’s fantastic goal. The moon landing news on July 20, 1969 was roundly booed by many young activists even as Neil Armstrong proclaimed that America came to the moon, “in peace for all mankind” to the largest TV and radio audience in history. Young radicals saw the space program as just another a militaristic Cold War offensive. The splendid space vision of John F. Kennedy and the traditional spirit of pioneering exploration were becoming just as unmarketable as patriotism and the Pledge of Allegiance were with the disgruntled Baby Boomers. Young people were more interested in questioning authority, “mind expansion” or deeply esoteric matters than they were in a bunch of “fascist” astronauts.
Politicians in Washington were grumbling about the NASA budget. A Democrat controlled Congress confronted Republican President Nixon. Some powerful Democrats wanted to divert NASA’s funding to social welfare programs. Space funding was a particularly easy target for politicians from states that had few companies or employees working in the space program. NASA funding was never actually more than several percent of the federal budget, but the erroneous public perception was that space spending was causing children to go without food and medicine in poor places like rural Mississippi. Regardless of the reality of the situation, von Braun’s old three-part vision for space was about to go on the federal chopping block as NASA was demoted to the status of a “political football”.
The legacy of the space naysayers of 1969 still tints the public perception of America’s space program. NASA funding is less that one percent of the federal budget in the year 2002, but the general public apparently still perceives NASA as a very costly, major federal program. In 1969, NASA administrators viewed the threat of a space-funding cut in human terms as much as they saw it as a curtailment of an era of bold exploration. Thousands of hard working engineers, technicians, laborers and managers would be out of a job. Families would suffer. The tax bases of cities like Titusville, Florida and Houston, Texas would suffer as payrolls dwindled in the former “space boomtowns”.
COPING WITH CHANGE: A MAJOR MISCALCULATION
The final years of Apollo brought a change in leadership at the top of the agency as well as in the White House. Thomas O. Paine was the new NASA administrator who replaced the brilliant James Webb as the leader of America’s space program. Paine was a Democrat, appointed by Lyndon Johnson and retained by Richard Nixon when he assumed the Oval office. Paine was willing to compromise and deal with the new President to save as many of those endangered NASA jobs as he could. Nixon’s Vice-President, Spiro Agnew came across as an enthusiastic supporter of NASA. Nixon himself, grabbed as much Apollo glory and afterglow as he could by telephoning the Apollo moonwalkers while they were walking on the moon and later greeting the astronauts when their spacecraft returned to earth. It certainly appeared that Nixon admired, even adored America’s space pioneers. Paine had no inkling of how devious Nixon was when it came to his “space vision”. Nixon actually wanted to end the entire U.S. human spaceflight program before he left office. To be fair to Republicans, Nixon had some strong allies in the Democrat party. NASA eventually found a way to “buy off” two of those Democrat naysayers, William Proxmire (D-Wisconsin) and Walter Mondale (D-Minnesota) by awarding lucrative contracts to businesses in the Senator’s home states. Nixon could not be bought.
President Nixon appointed Vice-President Spiro Agnew to head his Space Task Group (STG). NASA Administrator Paine, Air Force Secretary Robert C. Seamans and presidential Science Advisor Lee A. Dubridge also served in the STG. The group was assigned the mission of investigating the future possibilities for America’s space efforts and to present president Nixon with a list of possible future courses for action.
The final recommendations that were submitted to the President by the STG gave Nixon some rather dramatic, if not extreme options:
OPTION A- An expensive and comprehensive space effort that included a manned mission to Mars, orbiting space stations around the earth and the moon and a robust space shuttle.
OPTION B- Terminate NASA manned spaceflight operations by 1974 and place NASA on a subsistence budget of just three billion dollars annually for future development. This level of funding was spartan for an agency the size and scope of NASA. Option B would essentially mean the end of NASA as America had come to know it.
OPTION C- Institute moderate levels of funding for NASA that would allow the agency to build a makeshift space station from leftover Apollo hardware and fly a few earth orbit missions while initiating development of a ten billion dollar space shuttle.
Nixon shocked the Space task group by choosing OPTION B! Paine felt that the President had deceived him. Agnew probably felt even more foolish as he had previously gone on TV promising Americans that Nixon was going to give his stamp of approval to a Mars landing mission. Rumors soon began to spread that Nixon actually despised the space program since many people associated space exploration with his late nemesis, John F. Kennedy. NASA had finally and totally lost the support from the top that it previously enjoyed during the Kennedy and Johnson administrations. NASA has been on it’s own during the budget battles ever since. NASA quickly discovered that it had to compete with the Pentagon and other federal agencies for every single dollar of funding. The agency began looking for new alliances to help keep the agency funded. Unfortunately, NASA sought the wrong ally to help sustain funding for the space shuttle.
Administrator Paine had vainly hoped that Nixon would come around and fully support the development of a new space transportation system after he had offered up a savings of six billion dollars by canceling the last four Apollo missions to the moon. After all, Nixon’s Vice-President was a tremendous space enthusiast. Paine was banking on the possibility that Nixon would agree to apply some or all of the six billion dollars to the proposed space shuttle. He could not have been more wrong.
Nixon and Vice-President Agnew had extremely different views about the future of America’s space program. United States Senate historian Mark O. Hatfield documented those differences:
“After Agnew publicly advocated a space shot to Mars, Nixon’s chief domestic advisor, John Ehrlichman, tried to explain to him the facts of fiscal life:
Look, Mr. Vice President, we have to be practical. There is no money for a Mars trip. The President has already decided that. So the President does not want such a trip in the [Space Council’s] recommendations. It’s your job . . . to make absolutely certain that the Mars trip is not in there (in the Space Task Group recommendations).”
Paine’s miscalculation of Nixon had devastating results. NASA had voluntarily sacrificed the final phase of it’s Apollo lunar exploration program in the vain hope that Washington would back the development of a cost-efficient, safe and reliable space shuttle. As events developed, the loss of the Apollo-Saturn program left NASA with no “real” place to go for decades.
Feeling like an outsider in the Nixon government, Thomas Paine resigned his administrator’s post on September 15, 1970. Engineer George M. Low was appointed as acting NASA administrator. Low loved NASA and space exploration, but he was unable to stop the transformation of NASA from an earnest, cutting-edge scientific/engineering agency, into a typical, politically directed bureaucracy. Low, inexperienced in the ways of Washington politics, agreed to an dangerously low Space Shuttle development budget.
President Nixon next appointed a new NASA administrator, James C. Fletcher, in the spring of 1971. The space agency needed a powerful new political partner to help push the shuttle program in Washington. NASA did not have to look very far for a partner. There was another powerful entity that dreamed about having its own space stations and shuttles. The United States Air Force was waiting in the wings.
The top minds at NASA originally proposed a completely reusable, efficient and reliable shuttle concept based on the original vision from the 1950s. The hoped for space shuttle would be initially expensive to build but very cheap to operate since it would be able to fly repeatedly with a minimum of maintenance and reconfiguration. They proposed a shuttle booster powered by conventional liquid fuel rocket engines and air-breathing jet engines. The booster would lift the airliner sized shuttle orbiter to high altitude where the shuttle would separate from the booster and climb into orbit under the power of its own liquid rocket engines. This shuttle would return to earth and would fly back to the launch site powered by jet engines. The logic behind this well thought out concept was solid.
Nixon and the Congress did not care if the shuttle concept was a sound and logical concept. The president balked at the proposed ten billion dollar budget for the project. The stated goal was to build a fully reusable spaceship that would operate in a manner very similar to a commercial airliner. The space shuttle was supposed to eventually put huge payloads into orbit for a cost of just five-dollars a pound and launch every couple of weeks. The small Space Shuttle development budget (8 billion dollars) guaranteed that the NASA Space Shuttle concepts of economic reusability and a high priority for crew safety would be unattainable. What looked like a bargain for the taxpayers in the beginning would actually turn out to be a source of continuing frustration, disappointments and national tragedy.
The United States Air Force already had big plans for it’s own manned space station when Nixon first assumed office in January of 1969. The Air Force was pushing a concept called Manned Orbiting Laboratory (MOL). This military space station would essentially serve as a surveillance outpost in earth orbit. Nixon shut down the Air Force space station program during the summer of 1969. That cancellation was very disappointing to the Air Force as it left them totally out of the manned spaceflight arena.
America’s space agency turned to the United States Air Force for help in selling the shuttle concept to the White House and Congress. The shuttle would be touted as a solution for both civilian and military space needs. The planned shuttle would actually “make money” for NASA by delivering commercial satellites to orbit. Various planners working on proposed commercial and scientific space ventures were informed that their satellites, space telescopes and other experiments would have to be designed for compatibility with the shuttle cargo bay. It was optimistically anticipated that the space shuttle would render the “expendable” launch vehicle hopelessly obsolete.
Essentially, NASA and the USAF had conflicting missions and objectives that made for an unhealthy alliance. The result of their “collaboration” was ultimately bad for both institutions. NASA is largely civilian science entity. The Air Force is an arm of the military with a very tightly defined role. The Air Force needed to dictate major shuttle design characteristics and stipulate performance capabilities. In the end, there simply wasn’t enough money in the final shuttle budget to meet the Air Force requirements and keep true to the original NASA vision of a safe and efficient design. The expensive military shuttle requirements effectively cast aside NASA’s traditionally stringent crew safety requirements and ignored the lower-cost of space access goal in the original program concept. NASA was never able to recover as much as half of the costs of a shuttle mission from its commercial shuttle launch operations before Challenger finally knocked the shuttle out of the commercial space business.
The new “military grade” shuttle system looked like a bizarre combination of farm silo, airliner and fireworks rockets. The Air Force planned to launch its proposed space shuttle missions from Vandenberg Air force Base in California. The military shuttle would fly in a circumpolar, or north-south orbit as opposed to the near earth equatorial, or west to east orbits used by NASA when they a lunched from Florida.
The proposed military shuttle missions presented unique problems for shuttle designers. The shape, size, weight and payload capacity for the “civilian space shuttle” had to be tossed into the trash bin after the Air Force stated it’s desires to NASA.
Since the earth rotates about it’s polar axis, the shuttle launch pad and landing strip in California would move one thousand miles toward the east during every orbit the military shuttle made around the earth. The military shuttle would have to have the capability to fly across this vast displacement. The Air Force insisted that the shuttle have a one thousand mile “cross-range” landing capability to compensate for the rotation of the earth. This cross-range requirement was the nail in the final coffin as far as “cheap, fully reusable access to space” was concerned. NASA was forced to dump the original slow, straight wing shuttle for a delta-wing shape. The delta-wing design meant that the shuttle would drop at a very steep angle and high speed after it reentered the earth’s atmosphere on the way back from space.
The higher reentry speed imposed by the delta wing also meant that the shuttle would be exposed to extremely high temperatures as it raced back into earth’s atmosphere at sub-orbital speed. A heavy heat shield solution had to be added to the shuttle. This gave rise to the infamous “heat shield tile” concept that made the shuttle so fragile that it could not be launched during the slightest drizzle of rain. The tiles had to be glued to the exterior of the shuttle. It was soon discovered that the tiles could be dislodged from the shuttle fuselage by falling raindrops as the shuttle rocketed upward at high speed.
The heat-shield tiles also added a lot of weight to the orbiter. The new military grade shuttle concept became too heavy to fly, so designers had to start eliminating some of the original features. The crew escape system that could have saved the Challenger crew by pulling the crew cabin away from the disintegrating shuttle stack was eliminated. The jet engines that would have allowed the shuttle to make a powered landing and “go around” in the event of an errant approach was eliminated. Without jet engines, the shuttle had to make a perfect high angle of attack, high speed dead stick landing every time it returned to earth. No second chance landings were allowed. The net effect was that safety itself was largely eliminated from the original shuttle design. The dangerous take off and landing maneuvers had to be executed with split second precision and near perfect systems performance or the entire vehicle and crew would be lost.
Launching the shuttle into a circumpolar orbit also required more fuel and power than was required for NASA’s civilian shuttle launches at Kennedy Space Center (KSC). One of the main reasons that Cape Canaveral was chosen as a space launch center is that rockets launched toward the east can take advantage of earth’s several hundred thousand miles per hour rotational velocity. This is equivalent to racing with the wind at your back. All KSC launches benefit from that speed boost provided by our spinning planet. Launching into a circumpolar orbit requires that the booster engines provide all of the speed required to reach orbit. The Air Force also expected the shuttle to have a payload capacity of twenty-two tons and have enough cargo space for payloads as large as sixty-feet by fifteen-feet. The payload requirements of the Air Force requirement imposed further major changes to NASA’s original shuttle design.
It became apparent that the rocket booster component of the revised shuttle concept required massive changes in the propulsion system if the shuttle was going to be able to meet the rapid launch turnaround requirement and heavy lift capability. The equivalent power of twenty-three Hoover dams would be required from the three upgraded shuttle engines. Expensive and complex new Space Shuttle Main Engines (SSME) had to be developed. Total thrust from these engines totaled about 400,000 pounds. The new, powerful liquid fuel engines would use a liquid oxygen-liquid hydrogen propellant combination as opposed to the liquid oxygen-kerosene propellants in the original NASA shuttle concept. The new propellant combination was a staggering engineering challenge that required totally new tankage and propellant plumbing system to accommodate the super cold liquid hydrogen. Liquid hydrogen is the most difficult to handle rocket propellant ever used and this powerful fuel will leak from seemingly airtight pipes and tanks. The SSMEs required a lot of fuel. Designers added a huge disposable, external fuel tank to the exterior of the orbiter. This tank would be ejected after the shuttle achieved orbit and it would gradually fall back to earth. The tanks were not recoverable. The space shuttle was no longer a fully reusable spacecraft after the external tank was added to the design. A new tank had to be constructed for each launch. The propellant tank added another significant expense to the per-mission costs.
The three new SSMEs still did not provide the entire rocket thrust required to lift the space shuttle off of the launch pad. The NASA/USAF shuttle design was therefore was additionally altered to include two large “reusable” solid rocket boosters (SRB) to help power the heavy shuttle. The SRBs provided the majority of thrust for shuttle liftoff with 6.6 million pounds of lifting power. The solid rocket boosters would drop into the ocean under huge parachutes after expending their fuel during the first couple of minutes of the boost phase. NASA would then recover those boosters by ship and return them to a contractor for refurbishment and refueling. It was an expensive proposition to purchase and equip the booster recovery ships and then hire and train the crew, scuba divers and infrastructure for the SRB recovery operations. Per-mission costs continued to climb. The growing gap between reality and budget constraints was either ignored or not perceived by anybody with a voice powerful enough to influence the decision makers.
The new shuttle design was finally agreed upon and the plan submitted to the White House. NASA Administrator Fletcher obtained Nixon’s endorsement of the final shuttle concept on January 5, 1972. Nixon approved the joint shuttle design with a proposed five and one half billion-dollar budget. That was a little more than one-half of the original NASA shuttle budget request. What once appeared to be a great victory for NASA and the USAF is now an event that both parties would like to forget. The alliance with the USAF was a fateful decision that haunts the shuttle program to this day.
NASA still has to live with the shuttle design changes imposed by the pact with the USAF. The military shuttle never flew from the California launch complex, although military shuttle missions have been launched from Kennedy Space Center. The expensive cross-range capability turned out to be totally unnecessary. The Air Force cancelled its California based manned space program following the Challenger disaster.
FORCING THE SHUTTLE TO FIT
The damage to America’s overall space effort caused by “putting all of our eggs in the shuttle basket” is staggering. Progress has been stalled and the promise of space has been compromised by a reduced capability to conduct truly robust operations. The obvious shortcomings with the shuttle had a major impact on other space research and commercial projects long before the first shuttle flew in 1981.
What NASA finally built to serve as a “space shuttle” has never been cost-efficient, safe, reliable or even fully reusable. NASA promoted the “unique” capability of the shuttle to deliver and maintain earth-orbiting satellites. The ability to service satellites was truly unique. However, the ability to deliver satellites was neither unique nor particularly special. NASA scrambled to find “important” payloads and missions for the shuttle as part of a public relations and political effort to keep the federal funds coming.
Perhaps the most significant impact was on another major U.S. Space project- The Hubble Space telescope (HST). The original plan for HST called for the telescope to be launched into a high earth orbit well beyond the range of the shuttle. The huge telescope would be launched on a powerful unmanned rocket. NASA saw the opportunity to combine HST with the shuttle program and have the shuttle deliver the telescope to orbit. Scientist had originally conceived a space telescope equipped with a powerful ten-foot diameter mirror to give HST incredible capability to magnify extremely faint objects in the cosmos. That ten-foot design meant that HST would not fit into the shuttle cargo bay. Scientists were disappointed when NASA shrunk the mirror to eight-feet so that it would fit into the cargo bay. Shuttle lacked the ability to reach the high altitude orbit desired by space telescope planners. The low earth orbit required for a shuttle serviced HST was an additional disappointment since the earth would take up a huge portion of the HST’s field of view. The low orbit meant that HST would also be turning in a tighter, faster orbit than it would with a higher orbit. That increased motion rate was yet another downside as it would negatively impact the precise aiming required for HST imaging.
The original HST concept was altered to fit a shuttle maintenance mission regimen. A lot of easily replaceable parts were put into the design. It was anticipated that these parts could be frequently replaced or repaired during the anticipated frequent shuttle HST maintenance missions. The shuttle’s lack of reliability thus forced another change to HST design. HST program managers were forced to redesign the orbiting telescope to accommodate for both fewer and less frequent shuttle HST maintenance missions. These forced changes resulted in further cost overruns to the troubled space telescope.
HST was plagued by it’s own “shoestring budget” limitations. The contractor who won the HST optical mirror construction contract, Perkin-Elmer seriously “underbid” the project in order to wrest the job away from industry giant, Eastman Kodak. Perkin-Elmer did not accurately perceive the reality of NASA’s weakened political clout in the 1970s when they won the HST mirror contract. The company assumed that NASA would be able to increase HST project funding as easily as they had been able to “size up” monetary allocations during the boom years of the 1960s. The under funded company could not afford to do extensive pre-delivery testing and evaluation on the critical mirror. The result was that HST was seriously flawed before it was carried into orbit inside the space shuttle cargo bay. The mirror grinding error that made HST nearly blind was never detected until the instrument was activated in orbit.
THE LESSON LEARNED AND THE PATH TO THE FUTURE
The United States government began to fund major scientific and technological projects in the first half of the twentieth century. The early results were spectacular. The harnessing of the power of the atom, the first human to fly faster than the speed of sound, the first US space satellite, first American in space and ultimately the first human to walk on the surface of another world were all made possible by intensive, federally funded projects. In each of those spectacular success stories, the scientists and engineers were allowed to take charge of the research and development activities. Nothing was done without assured and honest funding. An “arsenal” mentality and management style meant that the scientists and engineers could focus on solving the identified challenges. An executive officer, administrator or project manager took care of the housekeeping, Washington liaison duties and general infrastructure requirements in that environment. The United States Army missile program located at Huntsville, Alabama was such a program.
NASA was created in 1958 with the intent of consolidating and coordinating a number of widely geographically distributed centers that were previously under civilian or military control. Many of those early NASA project people had worked in highly successful and efficient programs that helped give America unprecedented global prestige and almost impervious self-confidence. It was a merging of diverse cultures and management styles that wrought many great successes.
The changing environment of the 1960-1970 saw the end of NASA’s “Golden Age of Space Exploration” and the beginning of a long series of disappointments and faulty starts from NASA and other under funded federal programs. The Golden Age of Space Exploration was over and the blossoms of spectacular achievements withered in the minds of the public and the media. The devotees of space exploration still look back on that golden past and somberly wonder what went wrong. Where is that bright future that glorious Apollo pointed us toward back in 1969?
THE FUTURE AND THE PAST MERGE BUT THE QUESTIONS LINGER
Is the shuttle safer now after more than twenty years of flying? NASA says that it really is. The space shuttle support team at Kennedy Space Center works tirelessly to keep the shuttle flying safely. Those technicians, mechanics, electricians and engineers are miracle workers. Each successful launch of the shuttle is a tribute to their dedication and hard work.
Several years ago, the epitome of an “All American Hero”, John Glenn retuned to space aboard the space shuttle after a 36-year layoff from spaceflight. In 1962, President John F. Kennedy discouraged NASA from “risking” the life of America’s greatest space icon, Glenn, by giving him another space mission following his groundbreaking orbital flight on February 20, 1962. Glenn finally flew another space mission on October 29,1998 when he went back into orbit aboard U.S. space shuttle Discovery. Glenn may have come closer to death than he ever did in his old one-man Mercury spacecraft when Discovery drogue parachute hatch fell off of the spacecraft and barely missed the engine exhaust bells of the space shuttle main engines. Fortunately, Discovery was not consumed in a huge explosion that could have happened if that loose hatch had struck and penetrated one of the liquid hydrogen cooling lines on the engine assembly.
The shuttle fleet is much younger than John Glenn but it is showing the wear and tear of years much more than Glenn was showing in 1998. It is past time to take the hard earned lessons from the space shuttle program and build a better space transportation system. America cannot shy away from its space challenge. The United States cannot retain a position of global leadership if it relies on other nations to carry the human quest beyond the earthly cradle. People must lead our journey into the Final Frontier, not robots and unmanned probes. We also cannot depend on remote machines to do our work for us. Sending an unmanned probe to Mars can be compared to shipping you camcorder to Hawaii with instructions for someone there to tape the sights for you. It’s not the same thing as going on a real Hawaiian vacation. We must take the small steps and the giant leaps".
By Jim McDade