Lunar Surface Experiments

[Lovell training with barbell]

Commander Jim Lovell practices the "barbell carry," transporting a mockup of the lunar surface experiments package in a walkthrough of the first traverse planned for Apollo 13. The black object on the right with fins, is the radioisotope thermal generator (power unit).

During 1967 the Bendix Corporation and MSC ironed out the development problem of the Apollo lunar surface experiments package (ALSEP), and the project was on schedule for the first lunar landing mission. [see Chapter 6] But as the year wore on, doubts about the ability of the astronauts to set up the instruments in the time available,* expressed in July by a Headquarters official,5 [see Chapter 7] arose in other quarters as well. Planning for lunar surface operations called for one period of activity in which the astronauts would collect a contingency sample, inspect the lunar module, and familiarize themselves with the low-gravity environment. During this excursion - whose length was limited by the capacity of the portable life-support systems - they would scoop up 10 kilograms (22 pounds) of surface material and load it into the sample- return container. No one was sure how much time these activities would require. MSC tended to be very conservative in estimating how much work astronauts could do under lunar surface conditions, and since it was certain that setting up the experiments would take a good deal of time and effort, deployment was not scheduled during the first extravehicular period. "For planning purposes," preliminary plans called for a second moon walk during which the crew would unload, lay out, and connect the science instruments.6

As planning went on, however, and the limitations of time and life-support systems became clearer, the flight of the planned group of instruments on the first lunar landing mission became more doubtful. Simulations showed that a suited astronaut had serious difficulty in unloading the package from the lunar module. To complicate the situation further, weight was a growing problem with the lunar module and difficulties were developing with the radioisotope thermoelectric generator that provided power for the experiments. By mid-1968 planners were already discussing the need to develop a smaller, less complex package for that flight, so that some minimum scientific return would be realized.7

MSC's normal conservatism in matters of crew safety and mission success grew even stronger during the summer. The more engineers and mission planners looked at alternatives the more attractive a simplified plan for lunar surface operations became. The first lunar landing would, after all, be the most hazardous (potentially catastrophic) space mission yet, and it would be done with a spacecraft that had not been (and could not be) tested under conditions exactly duplicating the mission. Houston's concern had its effect in Washington. In June George Mueller asked Gilruth to schedule a simulation of instrument deployment so that he could make his own evaluation.8 After this was completed in mid-August 1968, Sam Phillips, Apollo program director at Headquarters, conferred with the chairman of the Science and Technology Advisory Committee** on proposed changes in plans for the first lunar landing. When they reached agreement, Phillips notified committee members of the new plans. Instead of a 26-hour stay on the moon and two-person excursions, he said, "it now seems prudent to limit the lunar surface staytime to about 20 hours and the EVA [extravehicular activity] to a single one-person excursion of 2 to 2 1/2 hours duration." This decision was based on experience in Gemini, where MSC had been unpleasantly surprised by the difficulty of working in null gravity. Whereas previous plans had called for the astronauts to set up a high-gain (strongly directional) antenna for television transmission, conduct preliminary geological exploration, collect samples, and emplace the lunar surface experiments package, mission planners now proposed to curtail the geological exploration, to depend on the 64-meter antenna at Goldstone, California, to pick up TV signals from a less directional antenna that did not have to be deployed by the astronauts, and to carry no scientific instruments at all. Phillips regretfully acknowledged that much scientific information would be lost but noted that subsequent missions would make up for it. Offsetting that loss would be operational advantages that looked extremely attractive: an increase in the safety margins for the lunar module's propulsion systems; maintenance of the lunar module in a state of readiness for quick departure in an emergency; and simplification of the training program, which was becoming undesirably complex.9

Phillips's action was welcomed by most of the MSC officials directly involved, but not by Wilmot Hess, director of science and applications. Hess, who had been fighting the battle for Apollo science on many fronts for the past two years, was dismayed by Phillips's proposals. In a vigorous remonstrance he deplored the severe loss to lunar science and the loss of credibility among the scientists that MSC would suffer if the proposed changes were adopted:

What can I answer to the critics of the manned program?. . . People in NASA and outside. . . have repeatedly told me that no useful science had been done on Gemini and that none would be done on Apollo. My answer has been that it . . . would start with the lunar landings. This is not the case now. A person who says now that the scientific program of Apollo could be carried out as well using the Surveyor Block III spacecraft has a very good story. I don't know how to answer him.

Hess strongly urged that the proposed single EVA be open-ended, lasting up to three hours if all should go well, and carrying all the scientific instruments:

. . . if there is a 50-50 chance of getting one experiment deployed . . . it would be better to carry ALSEP and take the chance of not deploying it rather than not carry [it] and . . . lose any chance to do this important experiment.
He closed with a strong recommendation to carry several small, easily deployed experiments on the first landing and to make a firm announcement that the second lunar landing would include a 35-hour stay, three EVAs, and the conduct of the entire science program: collection of samples, deployment of the full package of surface experiments, and carrying out the field geology program.10

In response to Hess's plea Phillips asked MSC to propose a contingency science program for the first landing; this was prepared and reviewed at MSC early in October. In discussions with Phillips and George Low, MSC Apollo spacecraft program manager, Hess, won back some important points for science. The new experiments package would contain three simple instruments: a laser retroreflector, requiring no electrical power, with which variations in the earth-moon distance could be measured with great accuracy; a passive seismometer powered by solar panels; and a solar-wind composition experiment, also passive and requiring very little astronaut attention to set up. The astronaut on the lunar surface would not spend time simply testing his mobility and agility, but would carry out some productive scientific tasks while acclimating himself, such as collecting and packaging samples and taking documentary photographs of samples as they were collected. Hess forwarded his proposals to Robert Gilruth and prepared a procurement plan for the new set of experiments.11

On November 5, Headquarters approved the new package and authorized MSC to modify Bendix's contract to build it. Manufacture could start before the final terms were negotiated, as time was critical. Some difficulty was expected in fabricating the laser reflector (an array of a hundred individual "corner reflectors," internal corners of cubes made of silica, polished to fine tolerances and precisely aligned) and MSC was authorized to pursue parallel approaches with the University of Maryland and the Air Force Cambridge Research Laboratory, both of which were working on similar projects.12 The new package would be called the "early Apollo scientific experiments package," or "EASEP."13 Total funding for the package was $5.3 million, and delivery was to be scheduled for May 15, 1969.14 Formal assignment of EASEP to the first landing mission was made by direction of the Apollo configuration control board on December 5.15

Hess's vigorous advocacy saved a minimal scientific return for the first lunar landing mission, and the original group of experiments - with some changes - would be flown on all subsequent missions. Whether the dire consequences he anticipated in the event of complete cancellation would have materialized is debatable. As early as May 1968 the Planetology Subcommittee of the Space Science and Applications Steering Committee had been warned of such a possibility and had not objected; it merely urged that a set of backup experiments be developed in parallel, to be ready in case the complete package could not be flown.16 The scientists who were to conduct the experiments agreed - after the fact - that the changes were acceptable under the circumstances, but expressed understandable vexation because they were not consulted before the decision.17 Still, the mood of many scientists outside NASA was such that removing the lunar surface experiments from the first mission might well have provoked a new storm of criticism of the Apollo program.

* An additional question, raised by MSC's Flight Operations Directorate, was whether any lunar module systems should be turned off during the lunar stay. FOD favored keeping critical systems running so that the astronauts could depart immediately in case an emergency developed; this would require additional consumables which would cut into LM weight margins. Minutes, Lunar Missions Planning Board, May 19, 1967.

** Principal external advisory group to the Office of Manned Space Flight, established by George Mueller in 1964.

5. Leonard Reiffel to Gen. S. C. Phillips, "Flight Schedule for ALSEP and Related Matters," June 10, 1967.

6. Donald K. Slayton to Dir., Science and Applications (MSC), "Apollo Lunar Surface Operations Planning," Feb. 28, 1968.

7. Verl R. Wilmarth, "Summary Minutes, Planetology Subcommittee of the Space Science and Applications Steering Committee (Meeting No. 3-FY68), May 15, 16, 17, 1968"; Edward M. Davin to Mgr., Apollo Surface Expts. Program, "Contingency Science Payloads," July 3, 1968; Richard J. Green to MSC, attn.: John W. Small, "Science Payload Options," July 3, 1968.

8. George E. Mueller to Robert R. Gilruth, June 5, 1968; Gilruth to Mueller, June 27, 1968.

9. Phillips to Dr. Charles H. Townes, Aug. 31, 1968, with encl., letter to members of OMSF Science and Technology Advisory Committee, same date.

10. George M. Low to G. W. S. Abbey, "Lunar Mission Planning," Sept. 3, 1968; Wilmot N. Hess to Mgr., Apollo Spacecraft Program (MSC), "Changes in Mission G Plans," Sept. 4, 1968.

11. Hess to Dir. (MSC), "Contingency Apollo Science Program," Sept. 30, 1968, with encl., "Contingency Apollo Science Program Implementation Plan" (preliminary), Sept. 27, 1968; idem, "Plans for Alternate Science Program on First Apollo Lunar Landing," Oct. 4, 1968.

12. Mueller, TWX to MSC attn.: Robert R. Gilruth, Nov. 5, 1968.

13. A. E. Morse, Jr., to Mgr., Apollo program, "KSC support for the LM-5 Early Apollo Scientific Experiment Payload (EASEP)," Nov. 12, 1968; Phillips to Gilruth, Nov. 15, 1968.

14. Phillips to Gilruth, Nov. 15, 1968.

15. Phillips, TWX to MSC attn.: G. M. Low, W. N. Hess, "Experiment Assignments to Lunar Missions," Dec. 5, 1968.

16. Wilmarth, "Summary Minutes."

17. Gilruth to Hqs., attn.: E. Taylor, TWX, "OSSA Activities-Weekly Report," Oct. 24, 1968.

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