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Introduction

For a while during the summer of 1969, NASA basked in the afterglow of two major successes. Within a few days of the return of the first men from the moon, two unmanned spacecraft, Mariner 6 and 7, flew by Mars and transmitted hundreds of closeup photographs - the first since Mariner 4 in 1965 and the most detailed ever.1 _{Some continuity in manned space flight was assured when several years of} difficult planning culminated in the decision - made while Apollo 11 was on its way back to earth - on a configuration and mission plans for the first post-Apollo project, Skylab.2

Successes notwithstanding, the future of manned space flight was far from settled. The Nixon admin- istration, just eight months in office, had not adopted a policy on space and was waiting far recommen- dations from a special Space Task Group appointed in January 1969. Early indications were that the new administration was more strongly committed to reductions in government spending than to ambi- tious space programs.3

The national enthusiasm generated by Apollo 11 was soon spent. In the words of a journalist who had followed the program from its early days,

The people who in 1961 said, 'yessir, let's go to the moon and beat the Russians' had become a different people by 1969. . . . There was the feeling: 'we won the war, now bring the boys home.' . . . no one wanted a big space program any more. * 4

* "Bring the boys home" was a cry raised throughout the country as soon as World War II ended in August 1945. As a result, the U.S. hastily - some thought unwisely - discharged millions of draftees from the armed services and dismantled its military forces around the world.

"No one" is an exaggeration - there were many who believed in continuing manned space flight at an ambitious pace, particularly NASA Administrator Thomas O. Paine - but certainly the public's enthu- siasm for space flight waned rapidly after Apollo 11. Apollo would not suffer the full effects of this change in public opinion, but neither would it escape them entirely.

Until the first lunar landing was accomplished, George Mueller intended to launch missions as fre- quently as possible. At the end of June 1969 three Saturn/Apollo vehicles were in preparation at Kennedy Space Center: Apollo 11 on the launch pad, Apollo 12 in the Vehicle Assembly Building, and Apollo 13 components being readied for stacking. Headquarters' launch forecast issued in June projected flights only two months apart, in July, September, and November - essentially the same schedule that had existed for more than a year.5 _{After the first successful landing the interval between missions was} extended to four months: Apollo 12 was rescheduled for November 14 and Apollo 13 was targeted for earliest launch readiness by March 9, 1970.6

On With Lunar Exploration

Pleased by the results of Apollo 11, scientists called for scientific goals to take priority on subsequent missions. Those goals, stated by the Santa Cruz summer study in 1967, included extending the Apollo landing zone to cover more of the moon's surface, increasing the time the astronauts could remain on the lunar surface, and providing mobility aids to enable the astronauts to cover more ground in the time available. [see Chapter 7 and Appendix 3] The scientists also noted the desirability of gathering data from lunar orbit, either by deploying an independent lunar satellite from the command and service module or by using sensors mounted in the CSM. Four working groups had found good reasons to use the moon-orbiting CSM for scientific purposes.* 7

As soon as Apollo 11 was safely down in the Pacific, Mueller directed the manned space flight centers to shift their efforts to lunar exploration. The manned space flight organization had long agreed in a general way that the scientists' goals were the primary justification for continuing the lunar landing program and had, in fact, begun studying the changes implied in those goals as soon as the Santa Cruz conference was over. Improved mobility was the most urgent need for the scientific missions. The conferees at Santa Cruz had called for both a lunar flying unit and a surface-traversing vehicle. Since both vehicles were likely to require extensive development, the Manned Spacecraft Center's Lunar Exploration Project Office had begun technical discussions with several contractors in the fall of 1967.8 After a year spent in defining requirements, MSC awarded two seven-month preliminary definition contracts for a flying unit in January 1969. Marshall Space Flight Center let study contracts in April for a dual-mode surface vehicle, which could be remotely controlled from earth after the astronauts left the moon.9

Equally high on the priority list for exploration missions was extending the time astronauts could stay on the moon. Grumman Aircraft Engineering Company, the lunar module contractor, had made some preliminary studies on modification of the lander for that purpose in 1967.10 _{Life-support systems and}

* This option had been available since 1964, when engineers defining the Block II service module had arranged its systems so that one sector was left empty to accommodate scientific instruments. Courtney G. Brooks, James M. Grimwood, and Loyd S. Swenson, Jr., Chariots for Apollo: A History of Manned Lunar Spacecraft, NASA SP-4205 (Washington, 1979), p. 140. The Santa Cruz planners had envisioned one or two lunar-orbit missions devoted entirely to photography and remote sensing, as then-current plans for Apollo Applications provided.

electrical power were enough for only 36 hours on the surface; longer stays would require hardware changes. Propulsion systems would have to be upgraded to carry the scientific equipment and mobility module to be taken on exploration missions. In March 1969, MSC directed Grumman to define the changes necessary to allow the lunar module to stay three to six days on the moon, with their cost and schedule impacts.11

Planning for lunar-orbital science began in May of 1968, when Wilmot Hess, acting on a request from the Lunar Exploration Office in Headquarters, asked the Apollo spacecraft program office to look into the question of placing a scientific payload in the service module.12 _{MSC commissioned North Ameri-} can Rockwell, the spacecraft contractor, to study the effects on cost and schedule of adding scientific instrumentation to the spacecraft as early as Apollo 14.13 _{As that study drew toward a dose without} discovering any major difficulties, MSC established a panel to review the operational implications of making scientific observations in lunar orbit and to identify the scientific activities that could be con- ducted during a lunar exploration mission.14

By early 1969 MSC had concluded that a package could be developed in time to fly on Apollo 14 in the last half of 1970 and had compiled a tentative list of instruments for evaluation by the Space Science and Applications Steering Committee. Director Robert Gilruth sent Headquarters the center's procure- ment plan, which provided for MSC to procure the instruments and deliver them as government-fur- nished equipment to North American to be integrated into the service module. Early approval and provision of the necessary funds by Headquarters were essential to meeting the projected schedule.15 In early April the Office of Space Science and Applications approved a group of experiments for the first phase of the lunar-orbit science project.16 _{Apollo Program Manager Sam Phillips wanted more} specific information before granting final approval and releasing funds, however.17 _{The proposal was} discussed in detail by Mueller's Management Council on May 7, after which Mueller gave MSC the authority to proceed - but on Apollo 16 rather than Apollo 14. Details of integrating the experiments into the service module remained to be settled, as did the exact mode of operation of each experiment, and this would take time.18

On June 30 Headquarters sent Houston a list of lunar-orbital experiments for Apollo 16 through 20, with authority to continue North American's integration effort and begin procurement of experiments. Assignment of experiments to specific flights could not yet be made, because the list was subject to revision during the summer. Total cost of the project was not to exceed $55 million.19

The manned space flight organization worked steadily from 1967 onward to lay the foundations for scientific exploitation of the Apollo systems, but the effort was often overshadowed by preparations for the first lunar landing. With NASA's encouragement, the Santa Cruz conference that summer had called for a maximum effort. The scientists' recommendations had been carefully considered, and by mid-1969 many of the most important ones were on their way to realization. It seems clear that if manned space flight had enjoyed the assurance of a high level of support, the lunar scientists would have gotten more. As it was, lunar exploration had to proceed with little more than had been projected by mid-1969: limited extension of the duration of exploration missions, a limited increase in the range of operations on the lunar surface, and a few lunar-orbital sensors.

Selecting Sites for Exploration

Since its primary objective was to land on the moon and return, Apollo 11 had been targeted for the least hazardous site. When the emphasis shifted to exploration, however, scientific considerations car- ried much greater weight in the choice of a landing site.20 _{Even so, every landing was as risky as the} first, and if MSC vetoed a site or expressed strong reservations about its feasibility on operational grounds, Headquarters and the Apollo Site Selection Board were reluctant to override the center's recommendations for the sake of enhanced scientific return.21

During 1968 and early 1969 the Apollo Site Selection Board necessarily concentrated on choosing landing areas for the first two missions. Five prime candidates had been chosen by December 1967, from which three - an eastern, a central, and a western, to allow for possible delays in the launch - were picked for the first landing. [see Chapter 8] It was more or less taken for granted that if the first landing

Table 1.

Lunar Landing Sites Recommended for Consideration as of June 1969.*

mission should succeed, then the second would be sent to another of those five sites, since much of the necessary planning would already have been done. If the first mission landed in an eastern mare, the second would be sent to a western one, and vice versa.

The Board's advisory groups continued to evaluate Lunar Orbiter photographs and by June of 1969 had produced a list of 22 sites for lunar exploration missions [see Table 1].

These were chosen for their apparent value in contributing to answers to one or more of the 15 ques- tions in lunar exploration. [Appendix 3] For most of these sites, changes in operational philosophy would be required. Only one site, not three, would be available at each launch opportunity; point landings (within 1 kilometer, 0.62 miles) would be necessary, to place the landing module as near the features of interest as possible; approach paths might be rough or undulating rather than smooth; free- return trajectories could not be used; and the high-resolution photography required to certify a site was generally not available.22

With more than twice as many interesting locations to visit as there were missions planned, site selec- tion would be a complex process at best. Scientists' priorities might change as the results of early missions became known and as NASA developed more precise landing techniques and extended the area where the spacecraft could land. Reconciling the goals of science with the constraints of mission operations required an early start and continuing tradeoffs as the project progressed.

At the June 3 meeting of the Apollo Site Selection Board, chairman Sam Phillips, anticipating heavy work loads if the board was to accomplish its task within tight schedules, requested that the board meet monthly if possible. He directed Lee Scherer to prepare a thorough briefing on the scientific objectives of lunar exploration and suggested that the Group for Lunar Exploration Planning propose a sequence of missions that would accomplish those objectives. Board members agreed a that to make sensible choices between sites they needed a better understanding of the rationale of lunar exploration and the operational improvements being planned.23

The meeting then turned to the question of a site for the second mission. Scientists reiterated their preference for a western (younger) mare if the first mission landed safely at an eastern (older) site. Two western sites were on the short list of preferred sites compiled in 1968: one just below the equator some 450 kilometers (280 miles) south and slightly east of crater Kepler and the other about 250 kilometers (155 miles) northwest of the first. Benjamin Milwitzky of the Lunar Exploration Office then suggested that Apollo 12 land near a Surveyor spacecraft. As early as January 1969 Milwitzky, formerly the Headquarters program manager for Surveyor, had suggested visiting a landed Surveyor and returning some spacecraft parts and nearby surface samples to earth for study. This could yield valuable engi- neering information on the effects of the space environment on materials, besides allowing postmission verification of Surveyor's scientific results.24

MSC representatives then presented a rationale for considering two other western sites. Although these had been eliminated in selecting the final five sites, they met MSC's criteria for operational suitability and offered certain advantages over the first two. Both sites were near Surveyor spacecraft.25 _The Board reacted unfavorably to these suggestions, pointing out that the site where Surveyor III was lo- cated was in a younger mare that was not much different from those in the eastern sites, whereas the scientists' first two choices were in typical older regions. Examining the Surveyor would detract from the other objectives of the mission. Furthermore, if returning Surveyor parts were set as a goal for the

mission, failure to accomplish the necessary precision in landing could be interpreted as failure - which would not, in fact, be the case. Chairman Sam Phillips was reluctant to add any more sites to the list for the second mission. He did not favor either of MSC's choices and instead directed Houston to examine two sites considered highly desirable by the scientists, Hipparchus and Fra Mauro, and report On their suitability.26

MSC analyzed the data available for these two sites and found them unacceptable for the second land- ing mission. Hipparchus had only about half as much good landing area as the average Apollo 11 site and Fra Mauro was worse. Photographic coverage in both cases was marginal. Houston recommended that the site selection board give no further consideration to these two locations, but that it reexamine the Surveyor III site, which met all the criteria for the first landing and was in some respects better than the two western sites under consideration.27 _{Phillips concurred and directed the Group for Lunar Ex-} ploration Planning to assess the scientific merit of the site.28

On June 17 the Site Selection Subgroup of the Group for Lunar Exploration Planning met at Houston to try to reduce the complexity of lunar exploration planning. MSC's operations planners needed definite recommendations as to scientific objectives and priorities rather than the unstructured group of sites currently being considered. A short list of high-priority sites was desired, which would not subse- quently be changed except through formal change procedures. MSC engineers briefed the subgroup on the increased capabilities that might be expected for the exploration missions. After Apollo 11, four "H" missions were planned, each of which would be able to carry a complete Apollo lunar surface experiments package (ALSEP), could support two periods of surface activity by the astronauts, and would be targeted for a smaller landing zone than the first mission.** On the later "H" missions engi- neers expected to be able to land within a 1-kilometer (0.62-mile) circle. After the "H" missions, six "J" missions would be flown. These could land with considerably improved accuracy, stay on the surface for three days and allow four excursions to the surface, and carry scientific equipment in the service module for lunar- orbital experiments. Starting with the second or third "J" mission, a powered surface vehicle would extend the astronauts' radius of operations to about 5 kilometers (3 miles).29

With these developments in mind, the subgroup reduced the list of candidate sites to 10, ordering them in a sequence that would produce the best scientific return, and added five more representing lunar features of scientific interest not covered by the existing fist. It recommended systematic photography from the orbiting command and service module to provide the necessary planning data for later mis- sions. Finally, the subgroup recommended that Surveyor III be deleted from further consideration for the second landing because its location was not expected to yield data significantly different from the two eastern sites already picked for Apollo 11.30

The Site Selection Board met again on July 10 for a briefing on the aims of lunar exploration. Donald Wise of the Lunar Exploration Office discussed the types of information the scientists hoped to get from the lunar exploration program: the ages of lunar materials, their chemical composition, clues to the processes that have created lunar landforms, the interior structure of the moon, and the rate of flow of heat from its interior. Farouk El-Baz of Bellcomm described the general areas that should be sampled in the first phase (10 missions) of lunar exploration: two types of mare material ("older" or "eastern" and "younger" or "western"); regional stratigraphic units such as deposits around mare basins; impact

** The landing zone for Apollo 11 was about 19 kilometers long and 5 kilometers wide (12 by 3 miles) as a result of uncertainties in the determination of the spacecraft's position and velocity in lunar orbit before landing.

* Surveyor III landed on April 20, 1967, and transmitted 6,326 television pictures and large amounts of scientific data for 14 days.

craters in both maria and highlands; morphological manifestations of volcanic activity in both mafia and highlands; and areas that might give clues as to the nature and extent of processes other than impact and volcanism which may have acted on the lunar surface. He then enumerated the characteristics of each of the 10 landing sites proposed by the Group for Lunar Exploration Planning, relating each to the scientific goals of the program and tying the sequence to expected improvements in spacecraft capa- bilities and flight operations planning.

Chairman Phillips remarked that the list seemed well thought out and that a short list of desirable science sites must soon be stabilized. After considerable discussion, the Board approved the 10 candi- date sites for planning purposes. Phillips directed MSC to study these sites and report on their suitabil- ity.

Houston had already taken a quick look at the sites and determined that all would require additional