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On Mars: Exploration of the Red Planet. 1958-1978
 
 
LANGLEY ENTERS THE MARS BUSINESS
 
 
 
[121] By early 1964, it was widely recognized within NASA that Mars was the next likely major target for exploration following Apollo's expeditions to the moon. Leonard Roberts, head of the Mathematical Physics Branch in the Dynamics Load Division at the Langley Research Center, became interested in the technological problems associated with vehicles passing through the Martian atmosphere. 1 Langley, by virtue of its extended research into the behavior of airplanes arid spacecraft operating in Earth's atmosphere, was generally recognized as the leading NASA center for the study of the aerodynamic and heat-load aspects of the entry design of such vehicles. Pursuing the Langley tradition of researcher-generated study projects, Roberts brought together an informal group of center personnel to [122] examine the possible application of its expertise to the problems associated with landing vehicles on Mars. From that group, he selected William D. Mace, Flight Instrumentation Division; Roger A. Anderson, Structures Research Division: and Edwin C. Kilgore, chief of the Flight Vehicle Systems Division, for a team * that would determine how Langley personnel could best contribute their talents to the investigations of the Red Planet.
 
Starting from "near zero in knowledge pertaining to....interplanetary missions," the Roberts group decided to concentrate on the area in which Langley had talent-vehicle entry aerodynamics. It would work on devising the optimum entry vehicle for landing payloads on Mars. The decision had been influenced by an early look at what other NASA organizations were doing. In Pasadena, the Jet Propulsion Laboratory was the lead "center" for planetary missions. Both Ames Research Center and Goddard Space Flight Center were studying probes that would obtain information about the Martian environment. Langley would examine the specific class of problems related to a vehicle from the time it was released by its transporting craft (orbiter or flyby) until it came to rest on the planet's surface.
 
After a few weeks of study during which they exchanged telephone calls, cryptic notes, and other informal communications, Roberts and his specialists chose to focus their efforts on the design of a basic, or "baseline," entry vehicle. About two and a half meters in diameter (to fit the Mariner launch shroud), it would weigh 136 kilograms (compatible with Atlas-Centaur capacities). The Langley Mars probe would contain instruments that would make direct measurements of the Martian atmosphere while the vehicle was descending on a parachute deployed from the protective heatshield. About 20 persons in scattered locations at Langley participated in this preliminary planning activity, with the engineering office of the Flight Vehicles and Systems Division becoming the focal point for coordinating all the work. Finding volunteers for the project was no problem, since the Langley people realized that they might be getting in on the "ground floor'' of something big. As James McNulty subsequently recorded, during the early period "no sophisticated analyses were made, designs were broad based, and most work was done on scratch paper." 2 Primarily, the Langley team wanted to get a feel for ideas; "a lot of work and concepts were turned out, analyzed, modified, or discarded...."Langley researchers were taking the same kind of initial course that their counterparts at JPL had followed with Mariner B and Voyager.
 
Two major problems considered by the Roberts group were optimum designs of a heatshield and a descent television experiment. Descent television was considered useful and a "glamorous" idea but it was scrapped because of weight and the long time lag for transmission and processing of video images. The heatshield also raised the issue of weight allowances. [123] Roberts' team looked at heatshields for several different landers-from a simple spherical probe (hard-landing) that would enter the atmosphere at an angle and travel a long tangential path to the surface, to a series of much larger, complex craft (soft-landing). But hard or soft, the landers would need a heatshield to overcome aerodynamic heating and assist in slowing down the craft before touchdown. Writing in the fall of 1964, Roberts noted that during the past decade considerable research had been applied to the design of ICBM and manned entry vehicles for use in Earth's atmosphere, and much of that technology could be adapted for planetary exploration. However, there were some significant differences," primarily because we face different planetary atmospheres and higher entry velocities."
 
Although it became obvious that existing heatshield technology would not meet payload weight limitations for the large landers, a solution did appear to exist for the smaller probes. Roger Anderson's Structures Research Division at Langley was working on a new heatshield-a "tension shell" with a peaked cap-in which the payload would be placed below the main ring of the heatshield structure. The membrane, stretched between the payload and the ring, would deflect the entry heat pulse and provide the necessary drag. For the thin Martian atmosphere, this new shield promised to be more efficient than those used for Earth reentry. 3 Concurrently, Langely researchers under William Mace examined the problems posed by sterilizing hardware using intense heat over long periods of time.
 
In the summer of 1964, Roberts asked the center management to fund a $500 000 industry study of a Mars probe with a tension-shell heatshield. After a vigorous selling job by Roberts, NASA Headquarters allocated the requested funds, half from the Office of Advanced Research and Technology and half from the Office of Space Sciences and Applications. It was December before the request for proposals (RFP) was released, and the six months gave the Virginia team time to define the contractor's tasks.
 
Preparing a statement of work for the contract proved a challenge. In Langley's first plunge into the interplanetary realm, Roberts and his colleagues discovered it was a difficult task to define on paper exactly what needed to be done. In addition to the probe, NASA Headquarters was urging Langley to examine the lander in more detail. Since the lander had been considered thus far only as it affected the design of the heatshield, this study gave the men at Langley new opportunities. Despite the extra work required, the team was enthusiastic about working on a new lander, since it enlarged the scope and importance of the study. It also gave Langley a chance to enter a domain previously dominated by JPL. A shift away from the Atlas-Centaur launch vehicle to the Saturn IB-Centaur permitted a more realistic examination of larger landing craft. As McNulty said,"....it was a new and bigger project-and it was Langley's responsibility."
 
As it finally evolved, the Langley statement of work for the contractor study contained some familiar ideas and some new ones. While planning in [124] detail for a 1971 probe mission, the contractors would also examine larger, more complex landers for 1973 and 1975. Unlike earlier proposals, Langley's proposal recommended separating the landing probe from the spacecraft before the spacecraft's encounter with Mars. The main part of the craft would subsequently fly by the planet after relaying a short transmission from the probe. 4 Released in December 1964, the request for proposals generated eight responses from industry, which were evaluated in March 1965. A contract was awarded to the Research and Advanced Development Division of AVCO.
 
This $600 000, seven-month examination was one of three Mars-related studies being funded by NASA in the summer of 1965. First-and foremost-was the Voyager phase IA under the direction of JPL, with Boeing, General Electric, and TRW as contractors. Second, Ames Research Center had contracted with AVCO for a six-month, $300 000 study of a lightweight (11-kilogram), nonsurviving probe. And third was Langley's new contract with AVCO to develop an entry system and survivable lander. 5 The three contracts, two of them managed by Office of Advanced Research and Technology (OART) centers-Langley and Ames-raised many issues that had to be resolved at NASA Headquarters.
 
Basic to all other concerns was a management problem-how to integrate the Office of Advanced Research and Technology centers into the activities of the Office of Space Sciences and Applications. Langley had no Voyager office as such at this time, but with the increased tempo of Mars activities the Virginia center set up a Planetary Mission Technology Steering Committee, chaired by Leonard Roberts. Through this committee, the center's staff could bring members of Langley into planetary activities without taking them away from their primary responsibilities in their technical divisions. Charles J. Donlan, Langley deputy director, outlined three tasks for the steering committee-guiding the AVCO study, beginning a Langley research program in support of Voyager, and preparing a working agreement defining relations between JPL and Langley.
 
In the process of overseeing AVCO's work, the steering committee discarded one of its pet ideas, the tension-shell heatshield. The concept had given Langley a foot in the door, but the heatshield had failed to prove out in the wind-tunnel tests. The Apollo and blunt-body heatshields were its equal in performance without some of its structural weaknesses. As one participant noted, "Thus, one of Langley's main selling points-its unique knowledge of tension shell technology-was quietly discarded without notice." 6 Langley's attention shifted to a blunt cone for entry, because it was easier to package than the bigger Apollo heatshield.
 
In defining the research program, the Langley team demonstrated its bias toward research and technology development rather than the conduct of flight projects. Since the creation of its first facilities shortly before World War I, Langley had been dedicated to applied research. In the NASA era, flight projects were viewed as status symbols, good for public relations and [125] as a source of funding, but the center's managers sought a careful mix of missions and research and strove to keep flight projects subordinate to the research program. At Langley, Voyager-related research in 1965 called for a wind-tunnel test program ($330 000), capsule-heatshield development ($400 000), and parachute development ($865 000). Parachute technology was an important area to be studied, because no parachute then in existence would survive deployment at the extremely high speeds (mach 1.2) needed for a Mars mission. 7
 
Defining Langley-JPL working relations was no simple task, because of JPL's unique position in the NASA organization. 8 In July 1965, when the California laboratory was selected as the capsule system manager for Voyager, Homer Newell told JPL Director William Pickering that Langley would act "in a capsule technical support role relating to design, development and testing of the entry system." 9 With management charter in hand, 12 representatives from JPL visited Langley to work out the details of Langley's support, and it was quickly apparent, according to McNulty, that JPL and Langley had some diverse view as to Langley's role. From the Tidewater perspective, it appeared that "JPL was interested in getting Langley out of the 'systems' area which JPL wanted to control and into narrow specific technology tasks (i.e., type of heat shield material) which would support its mission concept." The Langley people, on the other hand, took a broader view. To them, support in the area of entry technology included entry concepts, design, methodology, materials testing, and the like. JPL, in addition, was miffed over the AVCO probe contract with Langley, believing that it might lead to "preferential treatment [of] AVCO in subsequent Voyager capsule procurement." 10 McNulty later wrote that there was much "free discussion but few agreements" between Langley and JPL. Headquarters would have to help define the roles the centers played.11
 
The specialists in Virginia spent the late summer months of 1966 working with the AVCO study and making occasional trips to Voyager capsule advisory group meetings. Like everyone else, the Langley group was surprised at the October shift to the Saturn V launch vehicle. AVCO was redirected to consider the implications of the adoption of the giant booster.12 More significant, Langley Deputy Director Donlan told the Planetary Mission Technology Steering Committee that the center management wanted to use Voyager as a focus for its research programs, since it was the only major approved NASA activity after Apollo. In addition to seeing Voyager as a source of post-Apollo work, the Langley management could not fail to appreciate the fact that a "real" NASA center might be assigned the Voyager management role instead of the "contractor" laboratory in Pasadena.13
 
AVCO delivered its final report on l March 1966, with the following proposed mission highlights:
 
Experiments
Entry capsule
Only technological problem area
 
Delivery of AVCO's results came just a week before the cancellation of the 1969 probe mission and the 1971 Voyager flight. The Langley team embarked on an in-house study of alternative approaches to Voyager landers and landings, giving special attention to out-of-orbit entry versus direct entry from a flyby.
 
0n 2 June 1966, JPL's Centaur-powered Surveyor 1 became the first American spacecraft to soft-land on the moon. While the landing demonstrated the feasibility of terminal retrorockets, there was some question about the application of other Surveyor mission elements to a Mars flight. Direct entry to the lunar surface was relatively easy, given the detailed knowledge of the moon's motion and the reasonably good views of landing areas from Earth. Mars was a much less well defined target. The absence of any lunar atmosphere also obviated the need for a heatshield and parachute. After the success of the soft-landing rocket system, the Langley team considered using a retropropulsion unit in conjunction with a heatshield and parachute for Mars landers. On 14 August, Lunar Orbiter 1 orbited the moon, the first American vehicle to do so. Besides mapping the lunar surface in detail for Apollo landing site selection, this Boeing-built, Langley-managed spacecraft demonstrated the center's ability to supervise a major project with a reasonably small staff. Langley also had fewer cost increases and schedule slips with the orbiter project than JPL had with the lander. That fall, successful tests of parachutes similar to those that would be needed for a landing on Mars also spoke for Langley's technical and managerial capabilities.
 
In August 1966, the results of an in-house study were presented to the Langley Planetary Missions Technology Steering Committee. Reflecting an increasingly complex series of planetary missions for the 1970s, the study made several recommendations regarding Mars landers; employment of a 5.8-meter conical heatshield, the maximum diameter compatible with the Saturn V launch shroud, to provide the fullest aerodynamic braking; development of a standard cone sized to the largest landers so that only one entry vehicle would have to be developed and flight-qualified; and use of the parachute for additional braking after the heatshield had been discarded and before the retrorockets had been fired. This study report, approved by the steering committee, was a rough outline of how Langley planned to land Voyager on Mars.15
 
[127] As a result of Langley's work, Edgar M. Cortright, deputy director of the NASA Headquarters Office of Space Science and Applications, called a meeting for 26 September to discuss that center's role in the Voyager mission.** Earlier that month, a JPL group had described a different approach to landing a spacecraft on Mars. Retrorockets would be actuated at about 6100 meters, continuing to fire through ports in the heatshield until the lander was separated from a protective aeroshell at about 610 meters. Final descent would be slowed by firing the lander engines from 24 to 3 meters. This approach had three major problems; it would be difficult to design ports that would not reduce the effectiveness of the heatshield; the lander and its experiments would have to be protected during separation from the effects of the retrorockets; and, given the unknown density of the Martian atmosphere, the engines would have to have a complicated electronic throttle and carry enough fuel to permit maximum thrust if the density of the atmosphere was at the lower end of the calculated range.
 
Leonard Roberts described for headquarters Langley's proposed landing techniques, stressing the role of the parachute. The Langley approach had been carefully thought out and analyzed. It was simpler than JPL's approach, more realistic, and practical. Langley's Mars team won their center a major role in the Voyager project-the development of the entry system, or capsule bus as it was called in space engineering jargon.16
 
Langley Research Center personnel took part in three kinds of Voyager activities during 1967. Twenty Flight Vehicle Systems Division engineers under Ed Kilgore worked on design aspects of the capsule bus. Nine engineers under David G. Stone, who had replaced Roberts as the focal figure for Voyager after Roberts had transferred to NASA's Ames Research Center, coordinated all project details. Another 60 research engineers were engaged in developing new technology. Both Stone and Kilgore sat on the NASA-wide Voyager Management Committee, but Stone's job brought him into more frequent contact with the other centers.
 
 
Jim Martin Joins the Mars Team
 
 
On 23 June 1967, Langley Director Floyd Thompson announced the appointment of James S. Martin, Jr., as manager of the capsule bus system, thereby forming a project management organization to control all Voyager-related activities at Langley.
 
Martin had joined the Langley staff in September 1964 after 22 years with the Republic Aviation Corporation. His experiences as assistant chief technical engineer, chief research engineer, and manager of space systems requirements at Republic, as well as his reputation for troubleshooting and no-nonsense management, had been the major reasons Langley Director [128]  Thompson had recruited him for the Lunar Orbiter assistant project manager job. During the nearly three years he had been on the Orbiter team, Martin had further demonstrated his ability to get contractors to meet the schedule and budgetary requirements of Langley's first major space project. By summer 1967, only one Lunar Orbiter*** flight remained, and Martin and his teammates could turn their attention to new projects. The Voyager capsule bus system was their high priority item.17
 
Martin and five engineers set up the Voyager Capsule Bus Manager's Office in June 1967. Plans called for the remaining Lunar Orbiter staff, about 25 more engineers, to join them in September after their last flight. Martin's approach to managing the capsule bus was structured around his people, who would handle project implementation. Ed Kilgore's team would act as consultants and advisers, tutoring Martin's managers. Stone's work on entry systems was controlled by Martin's use of the budget. Dollars would be allocated for only the activities that he thought were germane to the tasks at hand, and all requests for funds had to be justified to the Management Office.18
 
 
Cancellation
 
 
Martin had been at his new tasks for only two months when Voyager was denied further funding by Congress. In the wake of this blow, the Langley Planetary Missions Technology Steering Committee convened a "what-do-we-do-next" meeting on 6 September. Eugene C. Draley, assistant director for flight projects, and former supervisor of Lunar Orbiter in the director's office at Langley, told the nearly 50 persons at the meeting something of the background of Voyager's demise. The Office of Space Science and Applications in Washington had been informed by congressional staff members that NASA's budget cuts had been primarily the result of other higher priority programs, not simply disapproval of Voyager. As a result, headquarters requested JPL, Ames, Langley, and Lewis to help define a more modest planetary program. Draley told his audience that Langley's goal was to have a project concept ready for submission by l November 1967, and he asked the Planetary Missions Technology Steering Committee to investigate and recommend scientific objectives for such a new project.19
 
Eugene S. Love, chairman of the steering committee, presented a preliminary list of candidate missions. He believed that Mars should continue to be the focus of the agency's interest. "Venus is not nearly so interesting when we consider long term NASA objectives such as ultimately placing men on the surface. In looking at possible unmanned Mars exploration in the 1971-1973 time period at costs much lower than the Voyager concept, a number of approaches are possible." He listed seven of them at the early September meeting: [128] 
 
a) Direct entry probe, no fly-by spacecraft
b) Fly-by spacecraft only.
c) Fly-by spacecraft with entry probe.
d) Short period orbiter, no entry probe.
e) Short period orbiter with entry probe.
f) Long period orbiter, no entry probe.
g) Long period orbiter, with entry probe. 20
 
All of these alternatives had been considered at one time or another in the course of formulating Mariner and Voyager proposals. In Love's opinion, only the last choice deserved further investigation. "A long period orbiter (a goal covering one complete Martian year) capable of providing color photo mapping of most of the planet's surface over an entire seasonal cycle would provide information of immense and lasting value." The pictures taken during such an orbital mission could be used to compile an atlas that would be of "great value to astronauts in future missions." Scientists would find the images of "inestimable value in assessing past hypotheses and generating new knowledge of the planet." Whereas "color photo mapping of Mars over a seasonal cycle should in itself justify the mission, and should be the primary objective," correlation of the photographs with infrared and radar mapping would yield even greater insights into the nature of the planet.
 
But orbital photography and scientific measurements, according to Love, were only half the story. "Adequate information on the structure of the Martian atmosphere cannot be obtained from orbit." The addition of a simple entry probe, however, could provide the means for examining the atmosphere and obtaining data essential for refined engineering design of future Martian entry vehicles.
 
Getting the orbiter and its probe to Mars was still the major problem. Love recommended that the examination of candidate launch vehicles should be limited to those that are available or will be unquestionably flight proven considerably before the mission time period." He further suggested that the candidate boosters be few.
 
The initial study activity should progress as follows: (l) definition of the payload capability for a Mars mission for the candidate launch vehicles. (2) choice of the launch vehicle that gives the best overall capability provided costs are reasonably competitive, (3) definition of the fraction of the payload capability that must go into the orbiter, (4) definition of weight remaining that can be allotted to an entry probe. if any. 21
 
 
At the 6 September 1967 gathering of the steering committee, Chairman Love appointed a subcommittee to recommend a list of scientific [130] objectives for Mars and Venus missions. While the subcommittee deliberated and the committee adjourned for five days, Jim Martin traveled to Pasadena for the sixth meeting of the Voyager Management Committee. Donald P. Hearth told the attendees that the Voyager Interim Project Office would be closed out in early October. To make the best use of the information generated by Voyager, Hearth laid down an orderly plan for terminating existing work and preparing for a new project. 22
 
On 11 September, the Langley Planetary Missions Technology Steering Committee met again to discuss the science recommendations. In a fashion reminiscent of earlier JPL reports, the subcommittee emphasized orbiter and probe experiments rather than lander investigations (tables 18 and 19). There was considerable discussion as to the merits of orbiters, probes, and "minimum semihard-landers," and Clifford Nelson requested that a lander not be "locked out" for a 1973 mission. The other attendees agreed, although there was little enthusiasm for sending life-detection experiments to Mars that early. To carry out further study toward a November recommendation to headquarters, Nelson headed a Langley ad hoc study group of 80 engineers divided into 13 working groups. 23
 
 
Table 18
Sample Areas of Scientific interest
 
 
1. Orbits
 
2. Rotation
 
3. Size
Mean diameter
Shape
 
4. Mass
Mean density
Distribution
 
5. Fields and particles
Gravitational
Magnetic
Electric
Trapped radiation
Micrometeoroids
 
6. Ionosphere
Existence
Strength
Temporal changes
 
7. Atmosphere
Constituents
Scale height
Density
Meteorology
Clouds, winds, temperature
Temporal changes
 
8. Surface structure
Topography
Relief, morphology
Cartography
Temporal changes
 
9 . Surfact composition, properties
Constituents
Temperature
Texture
Radiation
Albedo and color
Temporal changes
 
10 Internal structure
Constituents
Volcanism
Seismicity
 
Table 19 [131] 
 
Specific Objectives of an Early Mars Orbiter Probe
 
- To obtain maximum coverage of the planet's topography with sufficient resolution to
identity major geological structures and features, including distinguishing characteristics, or different planetary areas during seasonal changes.
 
- To obtain topographical data over limited areas with sufficient resolution to provide morphological patterns, evidence of vegetation and volcanic activity, and terrain features of geological interest.
 
- To determine the structure, composition, and temporal changes in the atmosphere.
 
- To obtain information on the gravitational and magnetic fields and radiation and micro-meteoroid environments.
 
- To obtain information on the extent and nature of clouds.
 
- To observe diurnal and seasonal changes in surface temperature.
 
 
Alternatives for Planetary Investigation
 
 
That fall, NASA Headquarters, Langley, and JPL planetary project planners pursued possible alternatives to Voyager for Mars and Venus missions. In Washington, Cortright and Oran Nicks outlined four planetary options for Administrator James E. Webb, Deputy Administrator Robert C. Seamans, and Associate Administrator for Space Science and Applications Homer E. Newell in late September. Nicks later told Jim Martin that the lack of any comments from the managers at headquarters regarding the briefing indicated to him that Webb was still feeling the pressure of the White House's cost-cutting drive.
 
At a 9 October presentation for Administrator Webb, space science and applications representatives outlined five possible options they believed would help answer the general question; Should NASA plan any flight missions for planetary exploration in the 1970s? As they saw it, the alternatives included (l) providing no funds for fiscal 1968 and 1969; (2) providing the planetary program with a sufficient budget to "maintain technology and pools of scientific, technical and managerial talent to support" subsequent development of planetary missions after Mariner 1969; (3) establishing two 1972 Mariner flights to Venus and two 1973 Mariner flights to Mars; (4) planning for Voyager flight in 1975 if money was made available in fiscal 1970; or(5) initiating the Voyager program in fiscal 1968 or 1969 with a very small budget aimed at producing an orbital flight in 1973 and a lander mission in 1975 (table 20). 24 The space science staff at NASA Headquarters**** favored an extension of the Mariner flights (option 3). . . .
 
 
 

Table 20 [132-133]
Post-Voyager Proposals for Planetary Exploration Projects

Jet Propulsion Laboratory
(3 October 1967)

1970

Mariner-Venus Mercury 70, Atlas-Centaur, using Mariner Mars 69 equipment

1971

Mariner-Mars 71 orbiter (if funding permits).

1972

Mariner-Venus 72 fyby, 2 probes, Atlas-Centaur.

1973

Mariner-Mars 73, orbiter-probe, Titan III (2 flights).

1973

Mariner-Venus-Mercury 73 flyby (if funding permits).

1974

Mariner-Jupiter 74, flyby, Titan-Centaur.

1975

Voyager-Mars 75, orbiter-surface laboratory, 2 on 1 Saturn V.

 
Langley Research Center
(5 October 1967)

Plan 1

Plan 2

Plan 3

Plan 4

1971

Mars orbiter, Titan IIIC.

1973

 

Mars orbiter-probe, Titan IIIC (68-kg probe).

1972

Venus orbiter-probe, Titan IIIC (68-kg probe)

1971

Mars orbiter, Atlas-Centaur.

1972

Venus orbiter-probe, Titan IIIC (68-kg probe).

-

-

1973

Mars orbiter-probe, Titan IIIC (136-kg probe).

1973

Mars orbiter-probe, Titan IIIC (181-kg probe).

1973

Venus orbiter-probe, Titan IIIC (136-kg probe).

-

-

-

-

-

-

-

(Start in spring 1968 at cost of $893 million, exclusive of launch vehicle.)

-

(Start in spring 1969 at cost of $339 million, exclusive oi launch vehicle.)

-

(Start in summer 1968 at cost of $566 million, exclusive of launch vehicle.)

-

(Start in spring 1968 at cost of $378 million, exclusive of launch vehicle.

-

-

Plan "3-Extended"

-

-

-

1975-1977

Soft-landed missions to Mars with 1180-kg landing capsule , Titan IIIC-Centaur, 14-kg science package

-

-

(Start in CY 1971.)

 
NASA Headquarters
(3 &10 October 1967)

"Plan 5"

Mariner class spacecraft

1970

Venus-Mercury flyby, Atlas-Centaur, FY 1969 start.

1971

Mars orbiter, Atlas-Centaur, FY 1969 start; JPL using MM '69 equipment.

1972

Venus orbiter-probe, Titan III, FY 1969 start, Langley.

1973

Mars orbiter-probe, Titan III, FY 1970 start: JPL-developed spacecraft, Langley-developed probe.

Voyager class spacecraft

1975

Mars orbiter, lander, Titan III and Saturn V, FY 1971 start.

1975

Mars lander, Titan III, FY 1972 start.

1975

Mars orbiter-probe, Titan III or Saturn V. FY 1972 start.

 
Source: Donald P. Burcham, "Planetary Extension Program (PEP) -Historical Documents (incl. Only pertinent Voyager refs.), "27 Dec. 1967; and J.R. Hall and J.D. Church, "Schedule and Cost Analysis of Selected Planetary Programs, 5 Oct. 1967.
 
 
 
[134]....with plans for work on a mission like voyager (option 4) to begin in 1970. No budget, or a very small one for 1968 and 1969 (options l and 2), would seriously affect the continuation of JPL's work for the space agency. In fact, the first option would have reportedly required "the phase out of JPL after Mariner 69, the loss of the scientific support presently being provided to the planetary program, termination of all contractor efforts and the reassignment of all in-house personnel to other agency programs." Choice number 5 was equally unsatisfactory because the projected costs were too high. But a combination of options 3 and 4 might "provide for continuation of the planetary exploration (without a Voyager commitment) at a reduced level and more effectively use the scientists, engineers, and administrative personnel by focusing their activities at specific missions which incorporate the technologies required for future detailed exploration of the planets." 25
 
Combined options 3 and 4 became known as "Plan 5," or the Planetary Extension program. While there were no commitments to specific flights beyond Mariner 69, the managers did have a "wish list" ready if more money became available. Plan 5 was an attempt to keep the planetary team intact by focusing "new technologies (flyby, orbiter, probe and lander) activities toward classes of missions (Venus, Mars, Jupiter and Mercury) and various launch vehicles." This proposal would give the agency a flexibility in choosing future missions, provide a realistic environment for engineers carrying out mission studies, and build a planetary program data bank of mission concepts, technology, and scientific experimental techniques within the limits of current budgets. The agency would use its "supporting research and technology" (SR&T) monies to underwrite technical studies that would permit centers to undertake new projects at some later date without wasting time or talents. Use of SR&T funds would not constitute a new programmatic start, which Congress had banned. 26
 
By early November 1967, less than two weeks after Congress had canceled Voyager, Administrator Webb was ready to propose a revised planetary program. His opportunity came during congressional hearings on NASA's proposed operating plan for fiscal 1968. He responded to the inevitable question from Sen. Margaret Chase Smith regarding what the agency planned to do in the field of planetary investigation. The Office of Space Science and Applications was proposing five new Mariner missions (1971-1976), a Voyager-style flight to Mars with two orbiters and two small probes for 1973, and a more ambitious soft-lander expedition for 1975. The 1971 Mariner flight, launched by an Atlas-Centaur, would be a long-term orbiter to make extensive observations of Mars. It would replace the 1971 Mariner proposed earlier by NASA, a flyby craft with a small atmospheric probe. Without the expense of developing that probe, NASA planners expected that the new 1971 Mariner mission would be more economical; they also would use equipment left over from the 1969 Mariner project. The other Mariner flights Webb specifically mentioned to Congress were to Venus in 1972 and 1973 using the Air Force Titan IIIC launch vehicle. The [135] revised Voyager for 1973 had been scaled closet, so that it could be launched by Titan, as well. rather than by Saturn V, which would cost 10 times as much. However, the 1975 Voyager-style mission was still geared to Saturn.
 
Webb told the senators that "the conclusion of Mariner V, Lunar Orbiter, Surveyor and deferral of Voyager. . all occur at the same time - the end of this year." He noted that the decision on the 1969 budget would determine if "these teams, representing an estimated 20,000 to 30,000 man-years of experience, are to be disbanded. Together they have launched 16 spacecraft toward the moon and the planets. It cost over $700 million to do the work represented by their competence. "While NASA could use SR&T funds during 1968 "to hold a limited portion of this competence together," Webb stressed that "the President's decision on the 1969 budget and further consultations with this and other committees of Congress will guide our reprogramming action." 27
 
Webb's "bold" step toward maintaining NASA's planetary program was influenced by several factors. The principal sources for financing any new planetary efforts were funds that could not be spent on the Apollo Applications Program (AAP). Conceived as a means of exploiting Apollo-developed technology for various manned earth-orbital and extended lunar-based missions, the Apollo Applications Program had also been cut by Congress during the 1968 budget deliberations-from a request of $454.7 million to an appropriation of $315.5 million. Since the number of Apollo applications flights had been sharply reduced and no flights were scheduled before 1970, Webb could argue for more planetary missions without necessarily seeking an overall increase in NASA funds. This proposed alteration of planetary priorities would require overcoming resistance at the White House and the Bureau of the Budget and on Capitol Hill. But Webb believed that space science was a timely and worthwhile cause for which the agency should fight. 28
 
As Webb and his headquarters managers prepared for the fiscal 1969 budget process, the centers began to work on plans for executing new planetary missions should the money be made available. 29 JPL was assigned management responsibility for the two Mariner Mars 1971 orbiters, and Langley was directed to manage the Titan Voyager Orbiter 1973 project, which became known as Titan Mars 1973 Orbiter and Lander. On 29 January 1968, President Johnson assured these projects their survival when he said in his budget address to Congress, "We will not abandon the field of planetary exploration." He recommended the "development of a new spacecraft for launch in 1973 to orbit and land on Mars." The new Mars mission would cost "much less than half the Voyager Program included in last year's Budget." Johnson went on; "Although the scientific results of this new mission will be less than that of Voyager it will still provide extremely valuable data and serve as a building block for planetary exploration systems in the future. "Although Webb still viewed this new planetary activity as austere, he was glad to see it gain the support of the president. 30
 
[136] In a press conference on the budget, John E. Naugle, the new associate administrator for space science and applications, noted that this Mars exploration program would cost about $500 million, rather than the $2400 million for Voyager. Further, "This program of four orbiters and two landers . . . is a minimum program consistent with the need to maintain expenditures at a minimum. Nevertheless, when you compare it to the automated lunar exploration program we have just completed, we think it is an extremely good and sound program." When asked about experiments, Naugle indicated that this topic was still under study. Landed television pictures had a high priority, as did measuring atmospheric pressure and meteorological changes such as send velocity. Don Hearth predicted a 90-day orbital lifetime for the 1971 orbiters and 180 days for the 1973 craft. But he added, "Bear in mind that Mariner IV lasted for three years. So these numbers could be very pessimistic." Hard-landers weighing 360 kilograms were being contemplated for the later mission, which meant that about 10 kilograms of scientific instruments could be landed. This payload was about half the projected instrumented payload for Mariner B in 1961. 31 Though austere, Titan Mars 1973 might actually have the chance to fly (tables 21 and 22).
 
 
Titan Mars 1973
 
 
Getting a start on a new series of planetary flights was just a first step on a long road. To get Langley and JPL going, Naugle asked them on 9. . . .
 
 

Table 21
Estimated Costs for Mars Program
(January 1968, in millions)

FY 1968

FY 1969

FY 1970

Total All Years

Spacecraft:

Mariner Mars 69

$59.2

$30.0

$5.0

$125.0

Mariner Mars 71

-

18.0

40.0

86.0

Titan Mars 73

-

20.0

50.0

347.0

Launch Vehicle:

1969 (Atlas-Centaurs)

8.0

3.2

-

20.0

1971 (Atlas-Centaurs)

-

3.4

13.0

20.0

1973 (Titan IIIC)

-

-

-

38.4

Nonrecurring costs for Titan III-Centaur ~ $30.0

 
SOURCE: Donald P. Hearth, 30 Jan, 1968.
 
 

Table 22 [137]

Mars Program

(January 1968)

Year

Mission
Spacecraft
Weight (kg)

1964

Mariner 4

Flyby (1)
260

1969

Mariner Mars 69

Flyby (2)

385

1971

Mariner Mars 71

Orbiter (2) a

410 (useful b)

1973

Titan Mars 73

Orbiter (2) c

~ 455 (useful b)

(Science instruments
75)
2 launches, each with 1 orbiter and lander
Lander (2)
~ 365 (total)
(Science instruments on surface
14)

-

Voyager (for comparison )

Orbiter (2)

1800 (useful b)

(Science instruments
230)
1 Saturn V launch

Lander (2)

2700 (total)

(Science instruments on surface
75)

Weight Summary

1971

Mariner Mars 71

Useful orbiter

410

Propulsion

455

Total gross weight at Mars

865

Atlas-Centaur capability

910

1973

Titan Mars 73

Useful orbiter

455

Lander

365

Propulsion (orbit insertion)

725

Total gross weight
1545

Titan IIIC capability

c.1130

Titan-Centaur capability

c.4100

Titan IIIC-dual burn of spacecraft propulsion

c.2540

 
a 1971 orbiter a modification of 1969 flyby
b Spacecraft weight without propellant
c 1973 orbiter same as 1971 except as modified to support lander.
 
SOURCE: Donald P Hearth, notes, 30 Jan. 1968.
 
 
[138]....February 1968 for study of Titan III-class missions to Mars for 1973. "The objective of this study is to evaluate the baseline mission submitted to the Congress . . . together with all promising alternatives, to permit a mission definition for the 1973 opportunity." Langley's work in fiscal year 1968 was "intended to advance the state of the art of such potential missions and will not be directed at a specific flight project until such a project is authorized by the administrator." The baseline mission included:
 
l. Two launches in 1973.
2. Launch vehicle to be either a Titan III [D]/Centaur or a Titan III with multiburn spacecraft propulsion for interplanetary injection as well as orbit insertion.
3. Each launch vehicle to carry a Mariner 71 class orbiter and a rough-landing capsule. The capsule mayŠ enter the Mars atmosphere [either] directly or from orbit.
4. The 1973 mission is constrained to a total program cost of $395 M[illion], including launch vehicles. This is believed to be consistent with the use of a minimum-modified
Mariner 71 orbiter and an $00 pound [360- kilogram] class rough lander...
5. The science objectives should include the following:
A. Orbiter: Carry payload similar to Mariner 71.
B. Entry vehicle: Measure atmospheric temperature, pressure, composition, and 3-axis acceleration.
C. Lander: Transmit limited imagery and measure atmospheric temperature, pressure, wind, soil composition. and subsurface moisture.
 
The science objectives of a Mars lander mission would have to be tailored to fit physical and budgetary limitations. Naugle asked the people at Langley to consider two alternative missions:
 
l. Hard-landers. with or without orbiters. direct entry. or out-of-orbit entry.
2. Soft-landers. with or without orbiters. direct entry. or out-of-orbit entry.
 
Project management was assigned to the Langley Research Center. JPL would provide assistance in such areas as system management of the orbiter or the lander. 32
 
The 1973 Mars Mission Project Office under Jim Martin's direction prepared statements of work and awarded study contracts to industry. These studies concentrated on aspects of the "mission-mode" question. General Electric examined the hard-lander possibility; McDonnell Douglas investigated a soft-lander option; and Martin Marietta looked into the virtues of direct versus out-of-orbit entry for the landers. Martin's staff worked with JPL to ensure the laboratory's support of the orbiter portion of the Mars mission. 33
 
 
* James F. McNulty and Clarence T. Brown, Jr., were also in the team's early meetings
 
** Oran Nicks and Hearth represented OSSA; Mac C. Adams, OART; Kilgore and McNulty, Langley; and William H. Pickering and senior Voyager staff members, JPL.
 
*** The first four Lunar Orbiters had returned several hundred detailed photographs of the lunar surface, which would be used in Apollo landing site selection.
 
**** Effective 1 October 1967. Newell became associate administrator. In October. John . Naugle became head of the Office of Space Science and Applications and Cortright became deputy associate administrator for manned space flight. Nicks filled Cortright's old position as deputy associate administrator for space science and applications, and Health became director of lunar and planetary programs.