Colonies in Space
by T. A. Heppenheimer
Copyright 1977, 2007 by T. A. Heppenheimer, reproduced with permission
Chapter 5: First of the Great Ships
The summer of 1969 was a halcyon time for NASA. It was not only the time of Apollo 11, which drew such enormous acclaim with its successful lunar landing. It was the time when NASA's administrators began to plan seriously for the post-Apollo future. In retrospect, it appears as a last summer of innocence, a last time before NASA would face the limitations of budget.
While launch crews prepared the next Apollo flights and astronauts intensified their training, a group of high-level Administration officials was charting the future of NASA's activities. This was the Space Task Group, chaired by Spiro Agnew. Agnew, who would later step down from the office of vice-president, came to Cape Canaveral on the morning of the Apollo 11 launch to announce that NASA's future goal would be to land men on Mars. Back in Washington, he led the Space Task Group in proposing a space program to exceed the Apollo program both in scope and in expense.
Its report, published in September 1969, listed three main program options for the 1970s and 1980s. All three called for the development of a small 12-man space station, a reusable space shuttle, a 100-man space base, and lunar orbiting stations as well as a station on the lunar surface. Two of the three called for the first manned expedition to Mars in the mid-1980s and projected funding levels of $8 to $10 billion per year for NASA by the late 1970s. The third option was less ambitious, giving no date for the first Mars landing but calling for simultaneous development of the space station and shuttle. This budget peaked at $6 billion for fiscal year 1977. By contrast, the peak NASA budget in the Apollo years had been $5.9 billion in 1966.
These optimistic projections seemed reasonable to a NASA elated with the success of Apollo. NASA officials believed they had an ally in President Nixon, who had often welcomed astronauts to the White House. This enthusiasm was not shared by the president's political and budgetary advisors, who argued that the nation's political climate and the competition for federal dollars would rule out such an ambitious space program. It was not long before NASA's hopes were put to the test. The agency had become accustomed during the Apollo years to receiving virtual carte blanche treatment of its budget requests. In the wake of the Space Task Group report, NASA was shocked when its fiscal 1971 budget proposal was rejected out of hand. The Office of Management and Budget slashed over $1 billion from it.
As the fall and the winter deepened and the decade of the 1960s came to an end, NASA officials began to lower their sights. In the Administration's judgment such projects as the space base, the lunar stations, and the manned Mars flight appeared too expensive to undertake in the foreseeable future. That left the space station and the shuttle.
Of these two, the space station was by far the more advanced in design. It was planned as the next step after the three-man Skylab program (Skylab flew in 1973-74), to fly in the latter part of the 1970s, carrying twelve astronauts who would conduct various programs of scientific study and Earth observations. In the course of the space-station design studies, NASA discovered that it needed a low-cost, reusable launch system. The launch vehicle to be used for Skylab would be the Saturn I-B, each flight of which cost $120 million. For Skylab only three flights would be needed, but the space station would require so many that much of the budget would be used up simply supplying the station. NASA proposed to develop the shuttle simultaneously with the station, at a cost of about $5 billion for each project. Agency officials described the shuttle and station as a single interdependent project. The space agency did suggest other uses for the shuttle: the launching and servicing of unmanned satellites, Earth observation studies, military reconnaissance, rescues in space. These were clearly secondary to its role in support of the space station and as a springboard to new manned adventures in space.
The "shuttle/station" concept was forthright enough, but it nearly killed both projects. Congressman Joseph Karth (D-Minn.) of the House committee on science and astronautics, usually an ardent supporter of the space program, claimed that NASA was seeking to extract from Congress a piecemeal commitment to what he called "its ultimate objective" of sending men to Mars. In the late spring of 1970, Karth introduced an amendment to block appropriations for the "shuttle/station." The amendment failed by the narrowest possible margin: a 53-53 tie. Early in July, Senator Walter Mondale introduced a similar amendment, which failed to pass by 32 to 28.
As a result, NASA quickly did an about-face on its justification for the shuttle. Instead of describing its use for new manned flights, it asserted that the shuttle could be justified in economic terms by the savings it would provide to an unmanned space program. NASA officials also "decoupled" the shuttle from the space station project, giving it a separate project staff and separate designation in the budget. The shuttle was now Shuttle, with a capital S. And they went shopping for other customers to use it.
They soon found that the Air Force could use it. The Air Force found itself in an unusual and quite fortunate situation: NASA needed Air Force business even more than the Air Force needed a new launch vehicle. As the secretary of the Air Force, Robert Seamans (later to head the Energy Research and Development Administration) told a 1971 Congressional hearing, "I cannot sit here today and say that the space transportation system is an essential military requirement." As NASA and the Air Force ultimately agreed, the Air Force would contribute its political support and its payloads, but would not put up money for Shuttle's development. The space agency, in its turn, agreed to design the shuttle to meet Air Force requirements. It would have a delta wing to permit increased maneuverability during re-entry and it would be designed to carry 65,000 pounds of payload to orbit in a cargo bay 60 feet long by 15 feet wide.
By late 1970, it was clear that this plan would succeed. Congress accepted NASA's new justifications for the program and the program was not again seriously challenged in the House of Representatives. In the Senate, Walter Mondale and a few others continued for some time to grumble that Shuttle was "a project in search of a mission." But on recorded votes, Mondale's motions to delete Shuttle funding went down to defeat in subsequent years by votes of 50 to 26, 61 to 20, and 64 to 22. In the spring of 1973, Senate opposition to the shuttle collapsed, Mondale declined to again offer his amendment to delete funding, and NASA's appropriation swept through to passage.
This did not mean, however, that NASA had a free hand in Shuttle's design and construction. Shuttle, born of compromise, would throughout its life be a creature of politics. The evolution of its design would ultimately depend as much upon budgetary considerations as upon technical requirements.
The shuttle has its roots in the dreams of the rocket pioneers of the 1930s. They foresaw the development of spaceships which would lift off from Earth, perform a mission in space, and return intact to Earth to be used for further missions. They scarcely imagined the actual situation of three or four decades later, when a rocket costing perhaps $100 million would lift off, perform a mission, and be destroyed either by falling into the ocean or by burning up reentering the atmosphere. Arthur Clarke said of those days, "We were not that imaginative."
From 1940 to 1970, nearly all rocket development involved expendable boosters, either for use as ballistic missiles of war or for the first generation of space launch vehicles. Nor was there any sharp distinction between these uses. The United States found, following World War II, that after scraping the Nazi swastikas off the tailfins of the V-2, they could have a fine rocket for upper-air research. A generation later, NASA found that by scraping the Air Force insignia off the Titan III, it would have precisely the right launch vehicle to send its Viking spacecraft to Mars. But a few projects pointed to the future.
In the years after the war, the Air Force built the X series of rocket-powered research aircraft: the X-1, X-1A, X-2, and X-15. In the 1960s, the X-15 explored many of the aerodynamic and control problems to face a returning shuttle, carrying pilots to altitudes as great as 67 miles and at speeds above 4000 miles per hour. There was an active program of research in hypersonic wind tunnels which in the middle 1960s culminated in the programs of ASSET and PRIME. These involved aerodynamically controllable re-entry vehicles with stubby wings or with shapes capable of providing lift during atmosphere entry. Boosted by Atlas rockets, they were launched on suborbital flights to enter the atmosphere at 12,000 miles per hour and give data on flight at speeds and altitudes which the X-15 could not reach.
In January 1969, NASA awarded contracts for initial (Phase A) design studies of space shuttles. These studies were intended to demonstrate the feasibility of developing such vehicles; the contracts went to General Dynamics, Lockheed, North American Rockwell, and McDonnell Douglas. For all four companies the Phase A studies meant an opportunity to explore a world once reserved only to the science-fiction writers.
In June 1970, NASA awarded contracts for Phase B work, detailed design, to teams of companies headed by North American Rockwell and by McDonnell Douglas. This work was intended to produce specific, thorough designs of a two-stage fully reusable shuttle. But at the same time, the space agency took two other actions, which in time would lead to the shuttle as we know it today. It extended its Phase A feasibility study contract with Lockheed and gave new Phase A contracts to Grumman and to the Chrysler Corporation, directing these companies to investigate simpler, less costly design concepts. It also negotiated a contract with Mathematica, Inc., an economics research company in Princeton, New Jersey, to provide for a one-year study of the economic merits of the fully reusable space shuttle.
In late spring and early summer of 1971, the contractors presented their reports—and the roof fell in. It started on May 31, when Mathematica presented its economic study. On the surface, it seemed to justify the fully reusable design. Actually, it amounted to a strong warning against proceeding with it. Its calculations showed that any cost overruns would mean the design would fail to meet its economic goals. The question of overruns was tied closely to the risks involved in developing what in 1971 was a very advanced system. Both in NASA and in the aerospace industry, there were nagging doubts about the prospect of building the fully reusable design without encountering costly technical problems. The principal problem was the lack of flexibility in the design. If either the booster or the orbiter proved heavier than originally planned the extra weight could not be accommodated by a simple expedient such as increasing the length of a propellant tank. Instead, much of the system would require redesign.
NASA had also discovered in discussions with the Office of Management and Budget that the White House had no intention of allowing a space budget adequate for development of the two-stage fully reusable design. The contractors had found that its development would require peak funding of over $2 billion. The Administration would permit a budget allowing only $1 billion for peak funding. With that discovery, it was back to the drawing boards for all NASA's contractors. As one aerospace executive put it, "Some people saw it coming and some didn't, but whatever the case we all knew by July that the whole damned system had suddenly gone up for grabs."
Seeking cost reductions, the contractors studied the possibility of developing the shuttle second stage (the orbiter) and flying it for a term of years atop some interim booster, a first stage already in use. They also tried the approach of using existing engines and avionics (flight instrumentation). These approaches offered some hope, but not enough. It was then in the fall of 1971 that the Boeing design teams had an attack of sheer inspiration.
These teams had designed the S-IC, the first stage of the Saturn V moon rocket. They had studied the possibility of using the S-IC as an interim booster. They proposed that the S-IC should be converted into the much-sought fully reusable booster instead of being an interim project. They proposed to attach large delta wings and a vertical fin to that first stage, to add a nose section with a pilot compartment and add landing gear and ten large jet engines. The jets would be placed together in a pod under the fuselage. They proposed to use the same engines being built for use in the B-1 bomber. When they completed their studies, they found they had a design with peak funding nearly a billion dollars lower than that of the two-stage fully reusable shuttle, yet with all the growth potential of the more advanced design and with far less risk in development. The peak funding was some $1.2 billion, only $200 million above the target. Once again President Nixon's budget officials said: Good, but not good enough.
Because it would fly back to Cape Canaveral after launch and because it used the same set of five F-1 rocket engines used in the S-IC, the booster was called the Flyback F-1. It attracted a great deal of support within NASA but the relentless requirements of the budget left it no hope. When NASA reluctantly abandoned the Flyback F-1, it also abandoned its last hope for a manned booster. As 1971 drew to a close, NASA and its contractors were studying unmanned boosters which would fall into the Atlantic and be fished out for reuse. There were both solid- and liquid-propellant designs to consider. Some years earlier, in the 1960s, NASA had built experimental solid rockets with diameters of 120, 156, and 260 inches. The 120- inchers found use with the Air Force's Titan III. The larger designs were kept around in case they might someday be needed. Various contractors had proposed to build simple, rugged, liquid-propelled "big dumb boosters," lacking guidance systems or complex pumps and plumbing. It was to this body of research that NASA now turned.
That was the situation in early 1972. On March 15 of that year the top administrators of NASA announced their decision on the choice of a booster for the shuttle in the U.S. Senate chamber. James Fletcher described the choice: the use of large solid motors, against the liquid-propelled big dumb booster. The problem, he said, was the booster would have to come down in the ocean and float until a tugboat could come to tow it back. The booster might sink. If it were the steel case of a solid motor, it would mean a loss of only $2 million, but if it were the liquid booster, it would be $75 million.
With that decision, the shuttle assumed its final form, except for rather minor changes (though they were not at all minor to the engineers who worked on them). The configuration
In a sense, the first major contract had already been awarded, a year earlier in July 1971. This contract had been won by Rocketdyne of Canoga Park, California. Rocketdyne was (and is) the nation's leading manufacturer of rocket engines, having built the engines for all three stages of the Saturn V as well as for most of the nation's other launch vehicles. The contract was for the space shuttle main engine (SSME), an advanced rocket motor burning hydrogen and oxygen at the unusually high pressure of 3000 pounds per square inch. High pressure was the key feature of the engine design since it would permit improved performance from a smaller motor.
In July 1972 the main shuttle contract went to North American Rockwell, now a part of Rockwell International, the automotive conglomerate. Perhaps the greatest irony is the world's first true spaceship will be built by what is now the Space Division of Rockwell International. This is no sleek, modern aerospace company full of Ph.D.'s and looking like a college campus. Its major plant facilities were built for aircraft production during World War II. Hundreds of engineers sit at desks in rows filling huge indoor work areas larger than a basketball court. There was a time when it was full of young scientists. In the years just after the war, North American was yeasty with new ideas—rocket propulsion, ramjets, inertial guidance, high-speed flight. Today many of these same scientists are at Stanford or MIT or the Jet Propulsion Laboratory, where they will cheerfully tell you that North American is a great place to be from. It is certainly remarkable that spaceships can now be designed and built as if they were new commercial airliners, that out of old airplane factories can come the stuff of long-held dreams. Chaucer would have understood:
In 1976, as the construction of the space shuttle approached completion, the question of a name for it arose. NASA officials preferred to call it Constitution. But Dick Hoagland, erstwhile science adviser to Walter Cronkite, had a different suggestion: Enterprise, after the "Star Trek" ship. He had a sufficiently close relation with one of the White House aides to have the idea put before President Ford. Further, through his contacts with the community of "Star Trek" fans, 100,000 letters were sent to the president, urging that the name Enterprise be chosen. Ford acceded.
The Enterprise underwent final assembly in a plant at Palmdale in California's Mojave Desert. When complete, it was rolled out before the press and TV on September 17, 1976, to the accompaniment of a band playing the "Star Trek" theme. At the time of writing, plans called for it to be moved to Edwards Air Force Base for initial flight tests to begin early in 1977. In these, the orbiter will ride piggyback aboard a modified Boeing 747, being released to glide down to a landing at 200 knots on Edwards' 15,000-foot runway. Meanwhile, the second orbiter will be assembled and prepared for flight from Cape Canaveral. The first flight is scheduled for March 1, 1979.
The liftoff of a shuttle flight will be at least as spectacular as that of the Saturn V, which used to draw up to a million people to the Florida beaches to watch. There were only about a dozen flights, but in the decade of the 1980s there will be about five hundred shuttle flights. The shuttle will lift off with all five engines burning. The three liquid-fueled SSME's in the orbiter will burn with a pale yellow flame, as excess hydrogen in the exhaust flames in the air. The two large solid boosters will leave a smoky trail from the launch pad, extending far into the sky.
At 126 seconds into the mission, the spacecraft is at 142,000 feet. The solid boosters fall away, having propelled the shuttle to a speed of 4,715 feet per second. As the empty booster casings fall, parachutes open, and the casings fall into the Atlantic 150 miles downrange, seven and a half minutes after liftoff. There they will float until collected by a tugboat, which will tow them back to Port Canaveral. The orbiter with its external tank continues its ascent. At 66 miles it enters a preliminary orbit at 25,786 feet per second. The external tank falls away to burn up in the atmosphere upon re-entry, and the orbiter is on its own. A short burst from its onboard orbital maneuvering engines places it in circular orbit at 110 miles. These engines also serve to maneuver the craft to any desired orbit, as high as 700 miles. There, the crew may launch or recover a satellite, using long manipulator arms carried in the payload bay.
The crew may stay up as long as thirty days. At mission's end, they use the orbital maneuvering engines to decrease the craft's velocity slightly. They enter the atmosphere with the nose held high, absorbing the heat of re-entry on the belly and the underside of the wings. These are covered with silica-fiber insulation. The leading edges of the nose and wing, exposed to temperatures as high as 3000°, are protected with carbon-fiber coverings. During re-entry, the crew may maneuver the craft as much as 1100 miles to the right or left of its orbital path. The landing is a critical time. Without power, the orbiter must land successfully on the first try and it is provided with a very advanced system for automated landing. It approaches the 15,000-foot runway at Cape Canaveral and glides in to land.
The orbiter is removed to the Vehicle Assembly Building, where the Saturn V rockets once were assembled. In two weeks it will be made ready for another flight. Like an airliner between flights, it will receive the attentions of a swarm of attendants, making minor repairs, overhauling or replacing its rocket engines, installing new payload, and replacing stores of food or oxygen used by the crew. Then it will be prepared for another flight. Cranes will lift it to a vertical position and a new external tank will be attached. Two solid motors, their casings filled with new propellant, will complete the assembly. The ship will move to the launch pad aboard one of NASA's huge crawler-transporters—the same ones used to carry Saturn V's to Pads 39 A and B. From one of these launch pads the shuttle will be fueled, counted down, and sent on its next flight. All will be routine, a matter of standard practice, and happening before 1980.
The shuttle will stand as the foundation for any space colonization effort. It will be used directly whenever it is necessary to return people or goods from the colony to Earth. Over a hundred passengers may squeeze into the payload bay for the return flight through the atmosphere. But most of the traffic will be outward bound, from the earth to the colony. Especially during the colony's construction, it will be necessary to lift 10,000 tons or more of payloads per year. The shuttle will lift over thirty tons on each flight at a cost of $10.5 million, or $160 per pound as the freight rate to orbit. While this is eminently suitable for a NASA program based upon the launching of more Landsats and Seasats, it is not adequate for colonization. The payload capacity is too low, the freight costs too high.
There is irony in this, recalling the situation late in the 1950s. At that time NASA was developing the rocket engine which would later be the F-1—a single motor with thrust of 1,500,000 pounds. Critics said, "You'll never use one of those, it's so large." And in a way they were right. When NASA began planning the manned lunar mission, it needed not one but five of these engines for the first stage of the Saturn V. Similarly, the shuttle as it exists today must be extended to carry five times its present payload.
The road to this result, however, turns out to be both short and simple. The shuttle, after all, is a collection of components: propellant tanks, engines, payload compartment, solid boosters and the like. These components will serve to create heavy lift launch vehicles (HLLV's). The process begins with a simple development. The SSME engines of the orbiter, instead of being mounted within the orbiter for return to Earth, must be packaged along with the avionics inside a heat shield so as to survive atmosphere entry on their own. This will provide a recoverable propulsion package which will re-enter the atmosphere following a launch and float to the ground with parachutes. Next the airplane-like orbiter must be replaced with a simple payload fairing to enclose the cargo on its trip up through the atmosphere. These simple engineering steps will produce an HLLV with two solid motors. Payload will increase to 150,000 pounds from the shuttle's 65,000. The freight rate will drop to $90 a pound.
This is not the end, however. The payload compartment, instead of riding piggyback on the propellant tank, can be mounted at the front of the tank. The tank then must be 70 strengthened in structure to support the added loads. The number of solid motors is increased from two to four and the number of SSME's increases from three to four. These are encapsulated in their recoverable propulsion packages and mounted at the base of the propellant tank. Propellant feed lines are relocated. What results then is an HLLV with payload of 300,000 pounds and a freight rate of only $67 per pound. This is the launch system which the NASA study on space colonization, in the summer of 1975, recommended as the basic vehicle for use in space colonization.
Its use would put Cape Canaveral on an assembly-line basis. Two or three launches a week would be the standard. The four main assembly bays of the Vehicle Assembly Building would be in use round the clock as teams of rocketmen erected the propellant tanks, attached the solid motors, installed the cargo, and sent their handiwork to Pad 39 aboard the crawler-transporters. The tugboat operators out of Port Canaveral would expand their fleet to recover their hauls of spent booster casings at sea. Specialized Air Force flight crews would be on frequent call to perform aerial catches of the returning propulsion packages. All of this could be happening by 1982. A budget of half a billion dollars, less than 10 percent of the cost of the shuttle itself, will do to build the four-solid-motor HLLV.
The colonization effort will call for so much cargo to be lifted, so many HLLV flights, that it will be worthwhile to seek even further cost savings. Each use of a solid motor costs $2 million, or $8 million for the set of four. Much money can be saved replacing the solids with a fully reusable liquid booster. The Flyback F-1, rejected for budgetary reasons in 1971, will be quite appropriate. It will cost perhaps $5 billion and will take seven years to develop; it will not be available before 1985. But the combination of the Flyback F-1 and the main core of the HLLV, with its propellant tank and four SSME engines, will lift 400,000 pounds. The freight rate: a near-rock-bottom $25 per pound. The use of the Flyback F-1 will cut over $80 billion from what would otherwise be the cost of the colonization effort. Even this may not be the end. When it is again proposed to build a fully reusable liquid booster NASA will once again look at the designs submitted in 1971 by North American Rockwell and by McDonnell Douglas. One of these may give even greater economy than the Flyback F-1. The resulting launch vehicle could serve the colonization effort until well into the next century.
The payload compartment will be 27 feet in diameter and nearly 100 feet long. It will be suitable for a wide-body spaceliner to carry passengers and workers on their way to the colony. A partition down the center line of the compartment will produce two large passenger cabins, each with room for 100 or more people. Each passenger can be provided with a couch, on which to lie during the accelerations of launch, and a set of curtains to draw around the couch as in old Pullman railway sleepers. This will give everyone an enclosed cubicle in which to sleep during the three-day trip to the colony. The baggage allowances will be generous. A family of four will take at least a ton of personal belongings. There will be meals served aboard the spaceliner, which hopefully will be better than those served aboard airliners. There will also be rows of windows along the sides and the opportunity for passengers to experience weightlessness.
These projections illustrate the requirements for space colonization. Yet all these requirements can be met with launch vehicles derived from elements of the space shuttle or with vehicles such as the Flyback F-1 of 1971. It is for this reason that advocates of space colonization speak with such confidence. Any space project must necessarily rest upon the available rocket transport. This is as true for space colonization as it was, only twenty years ago, when scientists were planning the first Earth satellites. Rocket transport stands as a rock upon which space colonization may begin.
Arthur Clarke said: "If man survives for as long as the least successful of the dinosaurs—those creatures whom we often deride as nature's failures—then we may be certain of this: For all but a vanishingly brief instant near the dawn of history, the word 'ship' will mean—'spaceship.'"