The new system delayed the arrival of the second Gemini spacecraft at the Cape. There the curse set in. Once on the pad the spacecraft was struck by lightning, threatened by not one but two hurricanes, and forced to undergo check after check. And when launch day finally came in December, the engines ignited and then shut down. More rework. Finally on 19 January 1965, Gemini 2 rose from the launch pad on the tail of almost colorless flame from Titan II's hypergolic propellants, and in a 19-minute flight confirmed the readiness of a fully equipped Gemini spacecraft and the integrity of the heatshield during reentry. Gemini was man-rated.
The final test flight, a manned, three-orbit qualification flight, was conducted on 23 March without incident. Now the diversified flight program could continue. One program objective was to orbit men in space for at least the week that it would take an Apollo flight to go to the Moon, land, and return. Gemini 4 (3-7 June) stayed aloft four days; Gemini 5 (21-29 August) doubled that time and surpassed the Soviet long-duration record; Gemini 7 (4-18 December) provided the clincher with 14 days (330 hours, 35 minutes). Of more lasting importance than the durability of the equipment was the encouraging medical news that no harmful effects were found from several weeks exposure to weightlessness. There were temporary effects, of course: heartbeat slowed down, blood tended to pool in the legs, the bones lost calcium, and other conditions appeared, but things seemed to stabilize after a few days in weightlessness and to return to normal after a few days back on Earth. So far there seemed to be no physiological time limit for humans living in space.
A crucial question for Apollo was whether the three rendezvous and docking maneuvers planned for every lunar flight were feasible. Gemini 3 made the tentative beginning by testing the new thruster rockets with shortburst firings that changed the height and shape of orbit, and one maneuver that for the first time shifted the plane of the flight path of a spacecraft. Gemini 4 tried to rejoin its discarded second-stage booster but faulty techniques burned up too much maneuvering fuel and the pursuit had to be abandoned --a valuable lesson; back to the computers for better techniques! Gemini 5 tested out the techniques and verified the performance of the rendezvous radar and rendezvous display in the cockpit.
Then came what is still referred to by NASA control room people with pride but also with slight shudders as "Gemini 76." The original mission plan called for a target Agena stage to be placed in orbit and for Gemini to launch in pursuit of it. But the Agena fell short of orbit and splashed into the Atlantic. The Gemini spacecraft suddenly had no mission. Round-the-clock debate and recomputation produced a seemingly bizarre solution, which within three days of the Agena failure was approved by Administrator Webb and President Johnson: remove the Gemini 6 spacecraft-launch vehicle combination intact from the launch pad and store it carefully to preserve the integrity of checkout; erect Gemini 7 on the launch pad, check it out and launch it; bring Gemini 6 out and launch it to rendezvous with the long-duration Gemini 7. It happened. Gemini 7 was launched 4 December 1965; Gemini 6 was back on the pad for launch by 12 December. On launch day the engines ignited, burned for four seconds, and shut off automatically when a trouble light lit up. On top of the fueled booster Astronaut Walter M. Schirra, Jr., sat with his hand on the lanyard of the ejection seat while the control checked out the condition of the fueled booster. But the potential bomb did not explode. On 15 December Gemini 6 lifted off to join its sister ship in orbit. On his fourth orbit Schirra caught up to Gemini 7 and maneuvered to within 33 feet; in subsequent maneuvers he moved to within six inches. Rendezvous was feasible; was docking?
On 16 March 1966, Gemini 8 on its third orbit docked with its Agena target. Docking too was feasible, though in this case not for long. Less than half an hour after docking for an intended full night in the docked position, the two spacecraft unaccountably began to spin, faster and faster. Astronaut Neil A. Armstrong could not stabilize the joined spacecraft, so he fired his Gemini thrusters to undock and maneuver away from the Agena. Still he could not control his single spacecraft with the thrusters; lives seemed in jeopardy. Finally he fired the reentry rockets, which did the job. By then ground control had figured out that one thruster had stuck in the firing position. Armstrong made an emergency landing off Okinawa. Despite hardware problems, docking had been established as feasible.
Rendezvous was new and difficult, so experimentation continued. Gemini 9 (3-6 June 1966) tried three kinds of rendezvous maneuvers with a special target stage as its passive partner, but docking was not possible because the shroud covering the target's docking mechanism had not separated. The shroud did not prevent simulation of an Apollo lunar orbit rendezvous. Gemini 10 (18-21 July 1966) did dock with its Agena target and used the powerful Agena engine to soar to a height of 474 miles, the highest in space man had ventured. It rendezvoused with the derelict Agena left in orbit by Gemini 8 four months earlier, using only optical methods and thereby demonstrating the feasibility of rendezvous with passive satellites for purpose of repairing them. On the next flight Gemini 11 caught up with its target in its first orbit, demonstrating the possibility of quick rendezvous if necessary for rescue or other reasons. Each astronaut practiced docking twice. Using Agena propulsion, they rocketed out to 850 miles above the Earth, another record. The final Gemini flight, Gemini 12 (11 November 1966), rendezvoused with its target Agena on the third orbit and kept station with it.
Would astronauts be able to perform useful work outside their spacecraft
when in orbit or on the Moon? This was the question extravehicular activity
(EVA) was designed to answer. The answers proved to be various and more
difficult than had been envisioned.
|The view from Gemini 11's window of the Agena rocket with which the Gemini crew is practicing rendezvous and tethered station keeping.|
Gemini 4 began EVA when Edward H. White II floated outside his
spacecraft for 23 minutes. Protected by his spacesuit and attached to Gemini
by a 26 foot umbilical cord, White used a handheld maneuvering unit to
move about, took photographs, and in general had such an exhilarating experience
that he had to be ordered back into the spacecraft. Because he had no specific
work tasks to perform, his EVA seemed deceptively easy.
|America's first space walk. Astronaut Edward H. White II fired short birsts with his hand-held maneuvering gun to move around in the zero gravity of space before returning to the Gemini 4 spacecraft.|
That illusion was rudely shattered by the experience of Gemini 9, when Eugene A. Cernan spent 2 hours in EVA; he had tasks to perform in several areas on the spacecraft. His major assignment was to go behind the spacecraft into the adapter area, put on the 165-pound astronaut maneuvering unit --a more powerful individual flight propulsion system the Air Force had built-- and try it out. The effort to get the unit harnessed to his back was so intense that excessive perspiration within his spacesuit overtaxed the system and fogged his visor. The experiment was abandoned and he was ordered back into the spacecraft.
Much more pleasant was the experience of Michael Collins on Gemini 10. He tried two kinds of EVA: the first time he stood in the open hatch for 45 minutes and made visual observations and took pictures; the second time he went out on a 33-foot long tether, maneuvering for 55 minutes with the handheld maneuvering unit and even propelled himself over to the station-keeping Agena and removed a micrometeoroid-impact experiment which had been in space for four months. But reality raised its ugly head again during Gemini 11 when Richard F. Gordon, Jr., was assigned a full schedule of work tasks along the spacecraft but had to terminate after 33 minutes because of fatigue. He had battled himself to exhaustion trying to control his bodily movements and fight against the opposite torque that any simple motion set in train. It was Isaac Newton's Third Law of Motion in pure form.
NASA had learned its lesson. When Gemini 12 went up, many additional body restraints and hand and footholds had been added. Astronauts had trained for the strange floating sensation by doing the same assignments in water tanks on Earth. Results were gratifying; in a 2 hour 6 minute tethered EVA (aside from two standup EVAs) Edwin E. Aldrin, Jr., successfully performed 19 separate tasks. Total EVA on this flight added up to 5 hours 28 minutes.
On the last seven flights, Gemini experimented with the aerodynamic lift of the spacecraft to ensure pinpoint landings on Earth's surface; with the dispersions possible when Apollo came in from 230,000 miles away, tired astronauts would need this. The inertial guidance system provided inputs to the computer, which solved the guidance equations. On flights 6-10 the reentry was controlled by the crew. On the last two flights the data were fed into the automatic system. Results were promising. The average navigational accuracy of the seven flights was within 2 miles of the aiming point, much better than previous flights.
Gemini was primarily a technological learning experience. So it is not surprising that of the 52 experiments in the program, more than half (27) were technological, exploring the limits of the equipment. But there were also 17 scientific experiments and 8 medical ones. An important one was the 1400 color photographs taken of Earth from various altitudes. This provided the investigators the first large corpus of color photographs from which to learn more about the planet on which we live.
Probably the most valuable management payoff from Gemini was the operational one: how to live and maneuver in space; next was how to handle a variety of situations in space by exploiting the versatility and depth of the vast NASA-contractor team that stood by during flights. Finally there were valuable fiscal lessons: an advanced technology program had a "best path" between too slow and too fast. Deviation on either side, as had occurred in the early days of Gemini, could cost appalling amounts of money. But once on track, even economies were possible. Once Gemini flights were on track, for example, associate administrator for Manned Space Flight George E. Mueller (successor to Holmes) had won agreement from his principal contractors to cut the three-month period between launches to two months. This was primarily to get Gemini out of the way before Apollo launches started, but it paid off financially, too; where total program costs for Gemini were estimated in 1964 to be $1.35 billion, the actual cost closed out at $1.29 billion.
This, then, was Gemini, a versatile, flexible spacecraft system that wound up exploring many more nooks and crannies of spaceflight than its originators ever foresaw--which is as it should be. Major lessons were transmitted to Apollo; rendezvous, yes; docking, yes; EVA, yes; manned flights up to two weeks in duration, yes. Equally important, there was now a big experience factor for the astronauts and for the people on the ground, in the control room, around the tracking network, in industry. The system had proved itself in the pit; it had evolved a total team that had solved realtime problems in space with men's lives at stake. This was no mean legacy to Apollo.
Some of the technological payoff had come too late. With the increasing sophistication of Gemini and the consequent slippage of both financial and engineering schedules, the Apollo designers and engineers sometimes had to invent their own wheel. But the state of the art had been advanced: thrusters, fuel cells, environmental control systems, space navigation, spacesuits, and other equipment. In the development stage of Apollo the bank of knowledge from Gemini paid off in hundreds of subtle ways. The bridge had been built.
Boosters and Spacecraft for Apollo
Throughout Gemini's operational period, Apollo was slogging along toward completed stages and completed spacecraft. Saturn I, the booster almost overtaken by events, finished its 10-flight program in 1964 and 1965 with six launches featuring a liquid-hydrogen second stage. Not only was it proved out; the clustered-engine concept was demonstrated and an early form of Apollo guidance was tested. The last four flights were considered operational; one (18 September 1964) tested a boilerplate Apollo spacecraft. The last three carried Pegasus meteoroid-detection satellites into orbit. The last two Saturn I boosters were fabricated entirely by industry, making a transition from the Army-arsenal in-house concept that had previously characterized the Marshall Space Flight Center. Ten launches, ten successes.
Meanwhile the larger brother, the Saturn IB, was being born. Its first stage was to generate 1.6 million pounds of thrust, from eight of the H-1 engines that had powered Atlas and Saturn I, but uprated to 200,000 pounds each. The second stage was to feature the new J-2 liquid hydrogen engine, generating 200,000 pounds of thrust. It was a crucial element of the forthcoming Saturn V vehicle, since in a five-engine cluster it would power the second stage and a single J-2 would power the third stage.
Saturn IB was the first launch vehicle to be affected by a new concept, "all-up" testing. Associate Administrator Mueller, pressed by budgetary constraints and relying on his industry experience in the Air Force's Minuteman ballistic missile program, pressed NASA to abandon its stage-by-stage testing. With intensive ground testing of components, he argued, NASA could with reasonable confidence test the entire stack of stages in flight from the beginning, at great savings to budget and schedule. Marshall engineers had built their splendid success record by being conservative; they vigorously opposed the new concept. But eventually Mueller triumphed. On 26 February 1966, the complete Saturn IB flew with the Apollo command and service module in suborbital flight; the payload was recovered in good condition. On 5 July the IB second stage, the instrument unit--which would house the electronic and guidance brains of the Saturn V--and the nose cone were propelled into orbit. The total payload was 62,000 pounds, the heaviest the U.S. had yet orbited. On 26 August a suborbital launch qualified the Apollo command module for manned flight; the attached service module fired its engine four times; and an accelerated reentry trajectory tested the Apollo heatshield at the 25,000-MPH velocity of a spacecraft returning from lunar distance.
The largest brother, Saturn V, was still being pieced together. Developed
by three different contractors, the three stages of Saturn V had individual
histories and problems. The first stage, although the largest, had a long
lead-time and was on schedule. The third stage, though enlarged and sophisticated
from the version flown on Saturn IB, had a previous history. It was the
second stage that was the newest beast--five J2 engines burning liquid
hydrogen. It became the pacing item of the Saturn V and would remain so
almost until the first launch.
|As manned space launches became more frequent, logistics became a major problem. Oversized cargoes like the Apollo instrument unit segment, as well as command modules and upper stages were carried by the Super Guppy, a dramatically modified Boeing Stratoliner.|
Of the three spacecraft, the lunar module was, early and late, the problem child. For one thing, it was begun late--a whole year late. For another, it differed radically from previous spacecraft. There were two discrete spacecraft within the lunar module; one would descend to the lunar surface from lunar orbit; the other would separate from the descent stage and leap off the lunar surface into lunar orbit and rendezvous with the command module. The engine for each stage would have to work perfectly for that one time it fired. Both had teething troubles. The descent engine was particularly troublesome, to the point that a second contract was let for a backup engine of different design. Weight was a never-ending problem with the lunar module. Each small change in a system, each substitution of one material for another, had to be considered as much in terms of pounds added or saved as in any gain in system efficiency. By the end of 1966, the Saturn 1B and the block 1 Apollo command and service module were considered man-rated.
On 27 January 1967, AS-204, to be the first manned spaceflight, was on the launch pad at Cape Kennedy, moving through preflight tests. Astronauts Virgil I. Grissom, Edward H. White II, and Roger B. Chaffee were suited up in the command module, moving through the countdown toward a simulated launch. At T minus 10 minutes tragedy struck without warning. As Major General Samuel C. Phillips, Apollo program director, described it the next day: "The facts briefly are: at 6:31 p.m. (EST) the observers heard a report which originated from one of the crewmen that there was a fire aboard the spacecraft . . . ." Ground crew members saw a flash fire break through the spacecraft shell and envelop the spacecraft in smoke, Phillips said. Rescue attempts failed. It took a tortuous five minutes to get the hatch open from the outside. Long before that the three astronauts were dead from asphyxiation. It was the first fatal accident in the American spaceflight program.
Shock swept across the nation and the world. In the White House, President Johnson had just presided over the signing of an international space law treaty when Administrator Webb phoned with the crushing news. Webb said the next day: "We've always known that something like this would happen sooner or later....who would have thought the first tragedy would be on the ground?"
Who, indeed? What had happened? How had it happened? Could it happen again? Was someone at fault? If so, who? There were many questions, few answers. The day following the fire, Deputy Administrator Seamans appointed an eight-member review board to investigate the accident. As chairman he chose Floyd L. Thompson, the veteran director of the Langley Research Center. For months the board probed the evidence, heard witnesses, studied documentation. On 10 April, Webb, Seamans, Mueller, and Thompson briefed the House space committee on the findings: the fire had apparently been started by an electrical short circuit which ignited the oxygen- rich atmosphere and fed on combustible materials in the spacecraft. The precise wire at fault could probably never be determined. Like most accidents it should not have happened. There had been errors in design, faults in testing procedures. But the basic spacecraft design was sound. A thorough review of spacecraft design, wiring, combustible materials, test procedures, and a dozen more items was underway. Congress was not satisfied. Hearings in both houses continued, gradually eroding Webb's support on Capitol Hill.
The block I spacecraft would not be used for any manned flights. The hatch on the block II spacecraft would be redesigned for quick opening. The hundreds of miles of wiring in the spacecraft were checked for fire-proofing, protecting against damage, and other problems. An intensive materials research program devised substitute materials for combustible ones. In effect, the block II spacecraft was completely redesigned and rebuilt. The cost: 18 months delay in the manned flight schedule and at least $50 million. The gain: a sounder, safer spacecraft.
Well before men flew in Apollo spacecraft the question had been raised as to what, if anything, NASA proposed to do with men in space after Apollo was over. With the long lead-times and heavy costs inherent in manned space programs, advance planning was essential. President Johnson proposed the question to Webb in a letter on 30 January 1964. NASA's first-look answer surfaced in congressional hearings on the fiscal 1965 budget. Funds were requested for study contracts that would investigate a variety of ideas for doing new things in space with the expensively acquired Apollo hardware. Possibilities: long-duration Earth-orbital operations, lunar surface exploration operating out of an unmanned Apollo lunar module landed on the Moon, long-duration lunar orbital missions to survey and map the Moon, Earth-orbital operations leading to space stations.
Through 1965 and 1966 the studies intensified and options were fleshed out. The Woods Hole conference in the summer of 1965 brought together a broad spectrum of the American science community and identified some 150 scientific experiments that were candidates for such missions. By 1966 there was a sense of urgency in NASA planning; the Apollo production line was peaking and would begin to decline in a year or two. Unless firm requirements for additional boosters, spacecraft, and other systems could be delineated and funded soon, the production lines would shut down and the hard-won Apollo skills dispersed. In the fiscal 1967 congressional hearings, NASA presented further details and fixed the next fiscal year as the latest that hardware commitments could be deferred if the Apollo production line was to be used.
NASA went into the fiscal 1968 budget cycle with a fairly ambitious Apollo Applications proposal. It asked for an appropriation of $626 million as the down payment on six Saturn 1Bs, six Saturn Vs, and eight Apollo spacecraft per year. The Bureau of the Budget approved a budget request of $454 million. This cut the program by one-third. Congress appropriated only $253 million, so by mid-1968 the plan was down to only two additional Saturn 1Bs and one orbital workshop, with it and its Apollo telescope mount being deferred to 1971.
Spacecraft for Space Science
Manned spaceflight, with its overwhelming priority, had had both direct and indirect impact on the NASA space science program. From 1958 to 1963, scientific satellites had made impressive discoveries: the van Allen radiation belts, Earth's magnetosphere, the existence of the solar wind. Much of the space science effort in the next four years had been directed toward finding more detailed data on these extensive phenomena. The radiation belts were found to be indeed plural, with definite, if shifting, altitudes. The magnetosphere was found to have an elongated tail reaching out beyond the Moon and through which the Moon periodically passes. The solar wind was shown to vary greatly in intensity with solar activity.
All of these were momentous discoveries about our nearby space environment. The first wave of discoveries said one thing to NASA: if you put up bigger, more sophisticated, more versatile satellites than those of the first generation, you will find many other unsuspected phenomena that might help unravel the history of the solar system, the universe, and the cosmic mystery of how it all works. So a second generation of spacecraft was planned and developed; they were called observatory class --five to ten times as heavy as early satellites, built around a standard bus instrumented for a specific scientific discipline, but designed to support up to 20 discrete experimental instruments that could be varied from one flight to the next-- solar observatories, astronomical observatories, geophysical observatories. As these complex spacecraft were developed and launched in the mid-1960s, the first results were on the whole disappointing. The promise was confirmed by fleeting results, but their very complexity inflicted them with short lifetimes and electrical failures. There were solid expectations that these could be worked out for subsequent launches. But by the late 1960s the impingement of manned spaceflight budgets on space science budgets reduced or eliminated many of these promising starts. Smaller satellites, such as the Pioneer series, survived and made valuable observations, measuring the solar wind, solar plasma tongues, and the interplanetary magnetic field.
Lunar programs faired somewhat better but did not come away unscathed. The lunar missions were now in support of Apollo, so they were allowed to run their course. Surveyor softlanded six out of its seven spacecraft on the Moon from 1966 through 1968. Its television cameras gave Earthlings their first limited previews of ghostly lunar landscapes seen from the surface level. Its instruments showed that lunar soil was the consistency of wet sand, firm enough to support lunar landings by the lunar module. Lunar Orbiter put mapping cameras in orbit around the Moon in all of its five missions, photographed over 90 percent of the lunar surface, including the invisible back side, and surveyed potential Apollo landing sites.
Planetary programs suffered heavy cuts. The Mariner series was cut back, but its two flights provided exciting new glimpses into the history of the solar system. Mariner 4 flew past Mars on 14 July 1965 and gave us our first closeup view of Earth's fabled neighbor. At first glance the view was disappointing. Mars was battered by meteor impacts almost as much as the Moon. While there were no magnetic fields or radiation belts, there was a thin atmosphere. Mariner 5 flew past Venus on 19 October 1967; this second pass at mysterious Venus found no magnetic field but an ionosphere that deflected the solar wind. The atmosphere was dense and very hot; temperatures were recorded as high as 700 K, with 80 percent of the atmosphere being carbon dioxide. But the immediate future of more sophisticated planetary exploration seemed bleak. The ambitious Voyager program was curtailed in 1966 and finally dropped in 1968; it envisioned large planetary spacecraft launched on Saturn V which would deploy Mars entry capsules weighing up to 7000 pounds.
The applications satellites had been a crowning achievement for NASA in the early 1960s. The NASA policy of bringing a satellite system along through the research and development stages to flight demonstration of the system and then turning it over to someone else to convert into an operational system received its acid test in 1962. With the demonstration of Syncom performance, the commercial potential of communications satellites became obvious and immediate. NASA's R&D role seemed over, but how should the valuable potential be transferred to private ownership without favoritism? The Kennedy administration's answer was the Communications Satellite Corporation, a unique government-industry-international combination. The board of directors would be made up of six named by the communications industry, six by public stockholders, and three named by the President of the United States. The corporation would be empowered to invite other nations to share the investment, the services, and the profits. This precedent-setting proposal stirred strong political emotions, especially in the Senate. A 20-day debate ensued, including a filibuster, the time-honored last resort in cases of deeply divisive issues, before the administration proposal was approved. On 31 August 1962, President Kennedy signed the bill into law. ComSat Corp, as it came to be called, set up in business. On 6 April 1965, its first satellite, Early Bird I was launched into synchronous orbit by NASA on a reimbursable basis. By the end of 1968, there was an Intelsat network of five communications satellites in synchronous orbits, some 20 of an expected 40 ground stations in operation, and 48 member nations participating. The Soviets had mounted a competitive system of Molniya satellites with first launch in 1965. They too had sought international partnership, but only France outside of the Iron Curtain countries signed up. By 1968 they had launched 10 Molniya satellites into their standard elliptical orbit. On the American side, the question of government-sponsored research on communications satellites was not completely solved by the creation of ComSat Corp. Congress continued to worry over the thorny question of whether the government should carry on advanced research on communications satellites versus the prospect that a government-sponsored monopoly would profit from the results.
Weather satellites were simpler in the sense that the relationship was confined to two government agencies. The highly successful Tiros was seized on by the Weather Bureau as the model for its operational satellite series. NASA had high hopes for its follow-on Nimbus satellite, bigger, with more instruments measuring more parameters. The Weather Bureau, however, felt that unless NASA could guarantee a long operational lifetime for Nimbus, it was too expensive for routine use. So NASA continued Nimbus as a test bed for advanced sensors that could provide better measurements of the vertical structure of the atmosphere and global collection of weather data.
Navigational satellites, one of the early bright possibilities of space, continued to be intractable. But there was a new entry, the Earth resources satellite. Impressed by the Tiros photographs and even more by the Gemini photographs, the Department of Interior suggested an Earth resources satellite program in 1966. Early NASA investigation envisioned a small, low-altitude satellite in Sun-synchronous orbit. What could be effectively measured with existing sensors, to what degree, with what frequency, in what priority? These questions involved an increasing number of government agencies. Then there was the complex question of what trade-off was best between aircraft-borne sensors and satellite-borne ones. It was a new kind of program for NASA, involving many more government agencies and many more political sensitivities than the uncluttered researches in space.
Aspects of Flight Research
The advanced research activities of NASA also became more subtle and difficult to track. An interlocking network of basic and applied research, advanced research was designed to feed new ideas and options into the planning process. The most visible portion was flight research, which sometimes supported work in the space program.
Although ballistic reentry from space had become familiar by the 1960s, there was a group of engineers who argued in favor of "lifting" reentry. The idea was to build a spacecraft with aerodynamic characteristics so that a crew could fly back through the Earth's atmosphere and land at an airfield. The X-20A Dyna-Soar proposed by the Air Force was one such example.
But the Dyna-Soar never flew, a victim of budget constraints and new technology. The NACA became involved in a smaller series of lifting body aircraft that helped pave the way for the Space Shuttle design. At Ames, a series of exploratory studies during the 1950s culminated in a design known as the M2, a modified half-cone (it was flat on the top) and a rounded nose to reduce heating. NASA engineers at Edwards kept up with much of the theoretical ideas percolating out of Ames, and Robert Reed became fascinated by the M2, by now called the "Cadillac" for the two small fins emerging at the blunt tail. He built a successful flying model, which led to authorization for a manned glider.
In many ways, the local authorization was more typical of the early NACA, since Headquarters did not know about it --nor did Langley, for that matter. But it seemed promising and it could be done cheaply. One aircraft company later estimated it would have cost at least $150,000 to build the M2, but the Edwards crew did it for less than $50,000. A nearby sailplane company built the laminated wooden shell (Reed was also an avid sailplane pilot); a considerable amount of other fabrication work was done by NASA personnel who were practiced hobbyists in the art of homebuilt aircraft. The landing gear was scrounged from a Cessna 150. By 1963, the M2-F1, as it was now called, had been completed.
Initial flight tests required a ground vehicle to tow the M2-F1 above
the dry lake bed, but none of NASA's trucks or vans was fast enough for
the task. The Edwards team had to shop around for a hopped-up Pontiac convertible,
further modified by a custom car shop in Long Beach to include rollbars,
radio equipment, and special seats for observers. Results from the ground
tow tests were good, so the next step involved aerial tow tests behind
a C-47. By the time these flights concluded in 1964, the lifting-body concept,
despite its oddball history, seemed to be worth pursuing. NASA Headquarters
and congressional people were both impressed. News reporters loved the
lifting-body saga, and there was keen interest in the more advanced lifting-body
designs already under consideration.
|Three ligting body configurations grouped on the dry lake bed at Flight Research Center. Left to right: the X-24, M-2, and HL-10.|
The M2-F1 showed the way, but far more work was needed, involving high-speed descent and landing approach tests. By this time, the Air Force was interested, and a joint lifting-body program was formalized in 1965. Generally speaking, NASA, through the Flight Research Center at Edwards, held responsibility for design, contracting, and instrumentation, while the Air Force supplied the launch aircraft for drop tests, assorted support aircraft, medical personnel, and the rocket power plant to be used in the advanced designs.
Northrop became the prime contractor for the aluminum "Heavyweights" sponsored by NASA. The M2-F2 was a similar, but refined version of the M2-F1; Northrop also delivered the HL-10, which had a very short, angled delta wing and a different fuselage shape. There was progress as well as disappointment; a landing accident destroyed the M2-F2 and cost the pilot the sight of one eye. The plane was rebuilt as the M2-F3 with an additional vertical fin. The HL-10,with a flat bottom and rounded top fuselage became the most successful, capable of Mach 1.86 speeds and altitudes of 90,000 feet. At a time when arguments over a "deadstick" shuttle reentry became hottest, some crucial HL-10 landing tests convinced planners that a shuttle without special landing engines could successfully complete reentry, approach, and landing. A final confirmation came during tests of the Martin X-24A (based on an Air Force project), whose shape was similar to a laundry iron. By the time that the X-24A test flights ended (1969-71), designers had complete confidence in the ability of the space shuttle to land on a conventional runway at the end of a space mission. The lifting-body tests made an important contribution.
In other projects, explicit aeronautical research continued. At the
Flight Research Center, another exotic plane captured the attention of
flight aficionados --the Rockwell XB-70 Valkyrie, a Mach 3 high-altitude
bomber. The Air Force began plans for the XB-70 in 1955, but by the time
of its rollout ceremonies in 1964, plans for a fleet of such large bombers
had given way to reliance on advanced ICBMs with more powerful warheads.
In the meantime, the Kennedy administration had endorsed studies for a
supersonic transport (SST) for airline use, and the configuration of the
XB-70 made it an excellent candidate for flight tests in support of the
|The North American XB-70 yielded valuable data on flight characteristics of large, supersonic aircraft. This photo of a test flight shows shock waves and vortices forming on the fuselage and wings.|
The XB-70 Valkyrie took to the air for the first time in the autumn of 1964. With a fuselage length of 189 feet and a large delta wing measuring 105 feet from tip to tip, its size, operating characteristics, and construction features made it an excellent SST prototype. The Air Force and NASA began a cooperative test program with the XB-70 in the spring of 1966, the first airline-sized aircraft in the world able to make sustained, long-range supersonic flights. The flight requirements for a Mach 3 airliner similar to the XB-70 were far more complicated than those for a Mach 2 aircraft, such as the Anglo-French Concorde SST. A Mach 3 airliner's structure required more exotic alloys, such as titanium, because the conventional aluminum airframe of a plane like the Concorde could not survive the aerodynamic heating at greater speeds. Integrating a Mach 3 aircraft into the existing airway traffic system became a special problem, because it made turns that required hundreds of miles to complete. Working with the XB-70 uncovered a number of operational and maintenance problems.
Despite the loss of one XB-70 in a midair collision, killing two test pilots, the NASA test program generated invaluable data on sustained supersonic flight. On one hand, XB-70 tests conclusively demonstrated that shock waves from SST airliners would prohibit supersonic routes over the continental United States. These tests helped fuel the opposition to the American SST program. On the other hand, the knowledge accumulated about handing qualities and structural dynamics represented basic data for use in future supersonic military aircraft and in high-speed airliners. But the test program was too expensive to sustain indefinitely. Early in 1969, the XB-70 Valkyrie made its last flight, to the Air Force Museum in Dayton, Ohio.
When the political question arose as to whether the United States should enter the international competition for a supersonic commercial transport aircraft --a sweepstakes already begun by Great Britain and France jointly with their Concorde and by the Soviet Union with its TU-144-- NASA already had a solid data base to contribute. It also had the laboratories and the contracting base to manage the program. But wise counsel from Deputy Administrator Dryden led to NASA's retreat into a supportive R&D role; he argued that with Apollo underway, NASA could not politically sponsor another high-technology, enormously expensive program during the same budget years without one of them being sacrificed to the other or killing each other off in competition for funds. The subsequent history of the SST program, including its eventual demise, was eloquent testimonial to the wisdom of his judgment. His death in December 1965 was a loss to the nation's aerospace program.
Other research efforts paid big dividends within the space program. Lewis Research Center had become involved in the use of liquid hydrogen as a rocket fuel in 1955. Although liquid hydrogen offered very attractive increases in thrust per pound as compared to previous fuels, hydrogen had a bad reputation left over from dirigible days and the Hindenburg disaster. But by 1957 Lewis was successfully and routinely firing a 20,000-pound thrust engine using liquid hydrogen as fuel. It was these tests that gave NASA the confidence in 1959 to decide that the upper stages of the lunar rocket should be fueled with liquid hydrogen. Without this additional rocket power, it might have been impossible (or at least much more expensive) to put men on the Moon.
Long-range prospects of manned planetary exploration depended heavily on more efficient thrust per pound of fuel propulsion. To this end NASA had continued the long-range program inherited from the Air Force to develop a nuclear-propelled upper stage for a rocket. Engineering down to a compact package the enormous weight, size, and shielding of the kind of reactor used in nuclear electric power plants was a severe challenge. The inevitable intensification of radiation density and temperatures defeated existing materials that would contain and transmit the heat to an engine. Time after time over the years, test firings of promising configurations had to be stopped prematurely when radiation corrosion took its toll. Finally in December 1967 the NRX-A6 reactor ran for one hour at full power, twice the time achieved before. Improvements in reactor fuel elements cut radiation control in half. The SNAP program of radioisotope thermoelectric generators also progressed. The SNAP-27 was the longlife power source for the Apollo science experiments to be left on the lunar surface.
Apollo to the Moon
Although the tragic fire of January 1967 delayed plans for manned spaceflight in Apollo hardware for approximately 18 months, the versatility of the system came to the rescue. The burden of checking out the major components of the system was quickly shifted to unmanned flights while a quick-opening hatch was designed and tested, combustibles were sought out and replaced, and the wiring design was completely reworked. After a nine-month delay, flight tests resumed. On 9 November 1967, Apollo 4 became the first unmanned launch of the awesome Saturn V. A 160-foot high stack of three-stage launch vehicle and spacecraft, weighing 2824 tons, slowly lifted off Launch Complex 39, propelled by a first- stage thrust of 7.5 million pounds. A record 278,000 pounds of payload and upper stage were put into Earth orbit. Later the third stage fired to simulate lunar trajectory, lifting the spacecraft combination to over 10,000 miles. With the third stage discarded, the service module fired its engine to raise the apogee to 11,000 miles, then burned again to propel the spacecraft toward Earth reentry at the 25,000 MPH return speed from the Moon. All systems performed well; the third stage could restart in the vacuum of space; the automated Launch Complex 39 functioned beautifully. The once-controversial concept of "all-up" testing had been vindicated.
Next came the unmanned flight test of the laggard lunar module. On 22 January 1968, a Saturn 1B launched a 32,000-pound lunar module into Earth orbit. It separated, and tested its ascent and descent engines. The lunar module passed its first flight test.
Now to man-rate the huge Saturn V. Apollo 6, on 4 April 1968, put the launch vehicle through its paces--the stages, the guidance system, the electrical systems. Four of five test objectives were met; Saturn V was manrated. The scene was set for the first manned spaceflight in Apollo since the tragic fire. Apollo 7 would test the crew and command module for the 10 days in space that would later be needed to fly to the Moon, land, and return.
But beyond Apollo 7, the schedule was in real difficulty. It was the summer of 1968; only a year and a half remained of the decade within which this nation had committed itself to land astronauts on the Moon. Somehow the flight schedule ought to be accelerated. Gemini's answer had been to launch missions closer together, but the size and complexity of Apollo hardware severely limited that option. The only other possibility was to get more done on each flight. For a time, however, it seemed that the next flight, Apollo 8, would accomplish even less than had been planned. It had been scheduled as the first manned test of the lunar module in Earth orbit, but the lunar module had a lengthy test-and-fix roadblock ahead of it and could not be ready before the end of the year, and perhaps not then. So a repeat of Apollo 7 was considered, another test of the command module in Earth orbit without the tardy lunar module but this time on the giant Saturn V. Eight years earlier that would have been considered a big bite; now, was it big enough, given Apollo's gargantuan task?
In Houston, George Low didn't think it was. After all, he reasoned, even this test-flight hardware was built to go to the Moon; why not use it that way? The advantages of early experience at lunar distances would be enormous. On 9 August he broached the idea to Gilruth, who was enthusiastic. Within days the senior managers of the program had been polled and had checked for problems that might inhibit a circumlunar flight. All problems proved to be fixable, assuming the Apollo 7 went well. The trick then became to build enough flexibility into the Apollo 8 mission so that it could go either way, Earth-orbital or lunar-orbital.
Apollo 7 was launched on 11 October 1968. A Saturn IB put three astronauts into Earth orbit, where they stayed for 11 days, testing particularly the command module environmental system, fuel cells, communications. All came through with flying colors. On 12 November, NASA announced that Apollo 8 had been reconfigured to focus on lunar orbit. It was a bold jump.
On 21 December a Saturn V lifted the manned Apollo 8 off Launch
Complex 39 at the Cape. The familiar phases were repeated: Earth orbit,
circularizing the orbit, all as rehearsed. But then the Saturn third stage
fired again and added the speed necessary for the spacecraft to escape
Earth's gravity on a trajectory to the Moon. All the rehearsed or simulated
steps went well. On 23 December the three-man crew became the first human
beings to pass out of Earth's gravitational control and into that of another
body in the solar system. No longer were humans shackled to the near environs
of Earth. The TV camera looked back at a small, round, rapidly receding
ball, warmly laced with a mix of blue oceans, brown continents, and white
clouds that was startling against the blackness of space.
|As Apollo 8 came around the backside of the Moon after going into lunar orbit, the crew was greeted with this haunting view of the earth rising above the desolate lunar horizon.|
On Christmas Eve Apollo 8 disappeared behind the Moon and out of radio communication with Earth. Not only were the astronauts the first humans to see the mysterious back side of the Moon; while there they had to fire the service module engine to reduce their speed enough to be captured into lunar orbit --irrevocably, unless the engine would restart later and boost them back toward Earth.
Another engine burn regularized their lunar orbit at 70 miles above the surface. Television shared the breathtaking bird's eye view of the battered lunar landscape with hundreds of millions on Earth. The crew members read the creation story from Genesis and wished viewers a Merry Christmas. On Christmas Day they fired the service module engine once again, acquired the 3280 feet per second additional speed needed to escape lunar gravity, and triumphantly headed back to Earth. They had at close range verified the lunar landing sites as feasible and proved out the hardware and communications at lunar distance, except for the all-important last link, the lunar module.
That last link, the lunar module, was still of major concern to NASA. Two more flights were expended to confirm its readiness for lunar landing. The Apollo 9 flight (3-13 March 1969) was the first manned test of the lunar module. The big Saturn V boosted the spacecraft combination into Earth orbit. The lunar flight drill was carefully rehearsed; the command and service modules separated from the third stage of the Saturn V, turned around, and docked with the lunar module. The lunar module fired up and moved away to 113 miles; then the spacecraft rendezvoused and docked.
A final test --was anything different at lunar distance? On 18 May 1969,
10 took off on a Saturn V to find out. The entire lunar landing combination
blasted out to lunar distance. Once in lunar orbit, the crew separated
the lunar module from the command module, descended to within 9 miles of
the surface, fired the ascent system, and docked with the command module.
Now all systems were "go."
|Astronaut Neil A. Armstrong took this photograph of Edwin E. Aldrin, Jr., deploying the passive seismic experiments at tranquility base, while the ungainly lunar module crouches in the background.|
On 16 July 1969, Apollo 11 lifted off for the ultimate mission of Apollo. Saturn V performed beautifully. The spacecraft combination got off to the Moon. Once in lunar orbit, the crew checked out their precarious second home, the lunar module. On 20 July the lunar module separated and descended to the lunar surface. At 4:18 P.M. (EST) came the word from Astronaut Neil A. Armstrong: "Houston,--Tranquility Base here. --The Eagle has landed." After checkout, Armstrong set foot on the lunar surface: "one small step for a man --one giant leap for mankind." The eight- year national commitment had been fulfilled; humans were on the Moon. Armstrong set up the TV camera and watched his fellow astronaut Edwin E. Aldrin, Jr., join him on the lunar surface, as Michael Collins circled the Moon in the Columbia command module overhead. More than one-fifth of the Earth's population watched ghostly TV pictures of two spacesuited men plodding around gingerly in an unlikely world of gray surface, boulders, and rounded hills in the background. The astronauts implanted the U.S. flag, deployed the scientific experiments to be left on the Moon, collected their rock samples, and clambered back into the lunar module. The next day they blasted off in the ascent module and rendezvoused with the command module.
The astronauts returned to an ecstatic reception. For a brief moment, people's day-to-day divisions had been suspended; the world watched and took joint pride in this achievement in exploration. Astronauts and their families made a triumphant world tour which restated world pride in this new plateau of humanity's conquest of the cosmos.