Lunar Mobility Studies At Marshall Space Flight Center

MSFC had been conducting lunar mobility studies since the early 1960s. The first of these was the Lunar Logistics System (LLS), followed by the Mobility Laboratory (MOLAB), then the Lunar Scientific Survey Module (LSSM) and the Mobility Test Article (MTA). They were based on the premise of a dual-launch scenario using two Saturn Vs, one to deliver the crew to lunar orbit and the lunar surface and the other to carry all the equipment to sustain and transport the crew while they were there. The LLS, begun in the fall of 1962, involved studies by the Grumman Aircraft Engineering Corp. and Northrop Space Laboratories Inc. Many of the large aerospace firms involved in the design and engineering of various segments of the Saturn V would also be involved in concepts and working prototypes for Lunar Rover studies. The LLS studies produced by Grumman and Northrop were among the first produced for MSFC and laid the groundwork for subsequent studies. These were pressurized cabin vehicle designs, using electrical power for each wheel.

Dr. Mieczyslaw G. Bekker was an authority on land locomotion during the late 1950s and the 1960s. Much of his pioneering work was conducted at the General Motors Defense Research Laboratories (GMDRL) in Santa Barbara, California. Bekker was head of the Mobility Research Laboratory there, and Samuel Romano was chief of Lunar and Planetary Programs. In May 1963, Dr. Bekker and Ferenc Pavlics released Staff Paper SP63-205, titled "Lunar Roving Vehicle Concept: A Case Study." This paper was prepared in conjunction with a GMDRL study contract for an unmanned roving vehicle for the JPL/NASA Surveyor Spacecraft program. The original wire frame wheel concept was developed for this rover with the cooperation of Goodyear Tire and Rubber Co. The paper described a six-wheeled articulated vehicle, with its wheels connected to each other by flexible rods. This gave the vehicle an elastic-like frame that permitted each of the three axles to move independently of each other. Each wheel was driven by a /{5 horsepower DC electric motor powered

Roving Vehicle Wheels
MSFC explored a number of different configurations of the MTAs during the 1960s. This MTA from 1965 was a single-seat design with an articulated chassis, built by Grumman. (NASA/MSFC)

by silver-cadmium batteries. The vehicle measured 366 cm long by 152 cm wide, with each wheel measuring 92 cm in diameter and 38 cm wide. The gross weight of the vehicle was kept to roughly 30 kg to simulate a 182 kg vehicle on the lunar surface. This was a robotic vehicle and was designed to test a number of concepts. It proved amazingly adept at scaling seemingly impossible obstacles.

Grumman and Northrop were not the only aerospace corporations involved with lunar vehicle studies. Bendix Corporation began such studies in 1960 as part of the company's long-term interests, and they would invest heavily in the design and development of lunar transportation systems. Boeing Aircraft Corporation also began such studies at this time. In February 1964, P.J. deFries, director of the Systems Concepts Planning Office at MSFC, reviewed the ongoing lunar vehicle design work by both companies to determine their capabilities for lunar vehicle hardware development. The following month, a Request for Proposals (RFP) was issued by MSFC as part of the forthcoming Apollo Logistics Support System (ALSS). Proposals from Bendix, Boeing, Chrysler, General Electric and Grumman for a preliminary design study were submitted to MSFC in April 1964.

Then in June, Boeing (with GMDRL as the vehicle technology subcontractor) and Bendix received contracts from MSFC with identical mission requirements, to initiate studies and build prototypes for the Mobility Laboratory (MOLAB) program. This was conceived to hold a crew of up to four men within a pressurized vehicle for longer traverses of several days to two weeks. The Bendix design was approximately 9 m in length and weighed 3,060 kg. It was a four-wheeled design and was capable of a range of 90 km. The Boeing-GMDRL design was 11.5 m in length, and consisted of a four-wheeled pressurized vehicle which towed a two-wheeled rear section for scientific tools and instruments, with a cargo area for lunar samples. It weighed approximately 3,600 kg and had a greater range than the Bendix design. Significant in the Boeing design was the use of woven wire wheels and electric motors to drive each individual wheel. These wheels were developed by GMDRL during the early Lunar Rover programs, and Ferenc Pavlics and his team would later receive a patent for them in 1969.

Several crucial design elements had already been chosen by 1964. Metal wheels were preferred to track-laying concepts because they consumed less power, were less complex, and were not as sensitive to temperature extremes, among other advantages. Electric motors were chosen as the means of propulsion, but significantly, each wheel would be driven by an individual motor. Initially, it was thought that hydrogen-oxygen fuel cells would be the means of providing electrical power to the motors, but these would ultimately give way to relatively conventional batteries. Vehicle steering would be achieved using two levers instead of a traditional steering wheel. This, too, would eventually be refined considerably. However, in November 1964, NASA Associate Administrator, Dr. Robert Seamans, announced general post-Apollo plans that effectively shelved the ALSS (including MOLAB) until after 1975, in favor of a less ambitious approach.

A follow-up contract was issued to both the Boeing team and Bendix after the MOLAB program, for the Lunar Scientific Surface Module (LSSM). Von Braun referred to this vehicle as a ''lunar jeep." It was an open vehicle designed to carry two

Apollo Applications Program The Molab
The Bendix Corporation MTA is shown nearing completion. The company took a unique approach to wheel design that would absorb shocks through the use of steel hoops within the outer body of the flat steel wheel, with square section steel tubing giving the wheel rigidity. (NASA/MSFC)

astronauts, or one astronaut with added cargo capability. The astronauts would drive this vehicle wearing their suits and Personal Life Support System (PLSS). It had a roll cage to protect them in the event of a rollover and it would be equipped with a dish-type communication antenna. The LSSM was designed to be mounted to the Lunar Module Shelter during its descent to the Moon - one concept being considered - and would then be lowered to the lunar surface by the astronauts after landing. A mockup of the LSSM was built and demonstration trials performed, powered by conventional batteries and using pneumatic tires.

As a precursor to the LSSM, Marshall Space Flight Center also looked into unmanned robotic rovers which could be controlled from Earth. Simulators were built and tested incorporating the actual time delay of several seconds between getting a visual image from the rover on the Moon to the Earth, and then sending the steering command back to the rover. Von Braun was a supporter of the unmanned robotic Lunar Rover and felt it could be a tremendous aid to properly establishing the actual geologic conditions for a considerable area around prospective landing sites. It was also studied as a vehicle for astronauts to use for exploring areas too dangerous for them to enter themselves.

Yet another vehicle concept was the Lunar Mission Development Vehicle (LMDV). This was designed and constructed by GM's AC Electronics-Defense Research Laboratories under the management of Sam Romano for a 1964-1965 NASA contract. Romano had joined General Motors in Detroit, Michigan in 1960 in charge of Special Vehicle Development in their Defense Systems Division. In 1961, GM moved the division to Santa Barbara, California as the Defense Research Laboratories and Romano became manager of Lunar and Planetary Programs. The LMDV was a fully-enclosed articulated vehicle incorporating a number of features described in Bekker's 1963 paper. It was designed for use by the Astrogeology Branch of the U.S. Geologic Survey in order to develop methods, exploration procedures and surface equipment for lunar exploration. It was identified on the side as the Mobile Geologic Laboratory. The LMDV measured 5.2 m long, featured 137 cm pneumatic tires, had a top speed of 40 kph and weighed 2,272 kg. It was powered by a horizontally opposed four cylinder gasoline engine.

As a later study, vehicles called Mobility Test Articles (MTA) were built to test propulsion concepts and wheel configurations. These were constructed under NASA contract between 1965 and 1966. The MTAs were open test vehicles with no body, only the chassis and wheels, with drivers out in the open.

Clearly, Marshall Space Flight Center was looking for the optimum vehicles to have for future lunar programs, but they were not confined to surface transportation. The Marshall Center also looked at flying vehicles. The primary contractor looking into these concepts was Bell Aerospace Systems. Bell built two flying prototypes; one was the one-man rocket belt design which was actually depicted in the James Bond movie Thunderball (1965). This design was fully capable in 1-G on Earth, and on the lunar surface its fuel consumption would be that on Earth. There was also a larger version, still employing one man to fly it, but with a frame that permitted the astronaut to sit during flight.

Von Braun wrote constantly on the various aspects of space flight and launch vehicles. In the early 1960s, he began to write a series of articles for Popular Science magazine on space exploration in general and on America's future efforts in particular. His article, "Dr. Wernher von Braun tells How We'll Travel on the Moon," appeared in the February 1964 issue. In it, von Braun revealed that studies had been underway at Marshall Space Flight Center in conjunction with Lockheed, Bendix, Boeing, General Motors, Brown Engineering, Grumman and Bell Aerospace systems. Von Braun wrote in particular: "For short distance travel, a non-pressurized 'moon jeep' may suffice. The astronauts would hop onto its open platform and depend for protection upon their pressurized space suits, while life support and communication would be provided by their backpacks.'' The subjects von Braun wrote of and had published in mass-circulation magazines were for public education, but were based not only on the studies conducted at MSFC but also on formal policies developed at scientific conferences held at the time. It was at these conferences that the scientific community outside of NASA could offer its input as to the goals, specific experiments and desired equipment that should go into missions

In this photo taken in June 1966, MSFC Director Dr. Wernher von Braun drives a Mobility Test Article (MTA) built by the Bendix Corporation. Data provided by the MTAs helped in the eventual design of the LRV. (NASA/MSFC)

The Lunar Exploration and Science Conferences of 1965 and 1967 9

being planned for Apollo. Geologic training of the astronauts was already underway (see Chapter 2), but hardware to be used on the lunar surface was still being established. The need for a Lunar Roving Vehicle to aid Apollo crews on the Moon formally came out of these conference discussions.

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