Some NASA leaders flatly opposed the chimpanzee flight. Administrator Webb's office questioned MSC on the need for another unmanned Mercury mission in view of the successful orbital flights of Cosmonauts Gagarin and Titov. A Washington newsman suggested that the President's advisers feared another American animal flight would only invite Soviet ridicule. Paul P. Haney, a public-affairs spokesman at NASA Headquarters, finally cleared the air when he announced to the public, "The men in charge of Project Mercury have insisted on orbiting the chimpanzee as a necessary preliminary checkout of the entire Mercury program before risking a human astronaut."36
Other space-related events soon distracted public attention from the  impending primate voyage on MA-5. One was the perfect launching of the mammoth Saturn I on its maiden flight. On the morning of October 27, the 163-foot-tall vehicle, with its 1.3 million pounds of thrust, rocketed 215 miles into space. The flight immediately triggered public discussion of whether a super-Saturn might be selected for launching the lunar mission spacecraft.37 In Houston, the Manned Spacecraft Center, site for the direction of manned space projects of the future, captured the imagination of local citizens. A space-age tradition was born when H. T. Christman, a procurement officer, became the first member of the organization to buy a home in the Houston area, which was located in the Timber Cove residential development that was to become the neighborhood of several Mercury astronauts, near the site of the to-be-constructed Spacecraft Center.
Preparation for MA-5, initiated many months previously, continued without much fanfare. As early as January 1961, notes on the status of hardware for this mission had begun to appear in STG's quarterly progress reports to NASA Headquarters. Both booster and spacecraft then were being manufactured and tested. On February 24, spacecraft No. 9 had arrived at the Cape to begin a 40-week preflight preparation. This lengthy period, longest in the Mercury project, derived from the various flight program changes that required corresponding configuration changes. No. 9 had been configured initially for a ballistic instrumented flight, then for a ballistic primate flight, next for a three-orbit instrumented mission, and finally for a three-orbit chimpanzee flight.38
Another factor contributing to the long preparatory period was that the data obtained from the MA-4 mission demanded a number of modifications. For the environmental control system, a locking device was added to the oxygen emergency rate handle, while the inverters, one of which had failed during MA-4, were put through a severe vibration-test program. Since some unbonding had occurred on the heatshield of the MA-4 spacecraft, x-rays twice were made of the ablative layer to determine the soundness of the glue line. For the explosive side egress hatch, as yet untried on an orbital mission, thermocouples were added and a limit switch was installed to signal any premature hatch firing, an experience that cost the loss of a flight-tested spacecraft in MR-4. And the horizon scanner sensor system was modified to avoid the erroneous signals transmitted during the orbit of the "mechanical man."39
Thus the spacecraft mounted on Atlas No. 93-D for MA-5 differed considerably from that used on the September orbital flight. This was another reason Haney had said that "the men in charge of Project Mercury" wanted another qualifying round before a manned mission. Besides modifications already described, No. 9 had a landing bag installed and a large viewing window. Although the window had been used on MR 4 and had proved useful to Astronaut Grissom, it had not been subjected to the much greater reentry heat the MA-5 capsule would encounter. Aside from these new components, No. 9 had about the same equipment as carried in MA-4 - tape recorders for  gathering data and exercising the communications network, cameras, and radiation film packs. Of course, "Enos," the chimpanzee eventually selected from the colony in training, would need no simulator to do his breathing or perspiring. He had his own metal-plastic pressure couch, which was connected to the suit circuit of the environmental control system.40
The spacecraft operated in a fashion similar to the first orbital Mercury vehicle. Once again, as during MA-4, the hydrogen peroxide fuel supplies for the automatic and manual control systems were linked to provide a common reservoir. The automatic stabilization and control and rate stabilization control systems would be operated separately, so that the performance of each could be evaluated. The automatic system was programmed to exercise capsule attitude control until one minute after the .05-g light signal; then the rate system would take over for reentry, providing a constant-roll rate of about 7.5 degrees per second as well as damping motions in the yaw and pitch axes. The rate system would switch off at main parachute deployment.41
Recovery aids and operations, too, were about the same as for MA-4, including radar chaff, sofar bombs, a flashing light, and dye marker. The probable launch abort recovery areas were spaced and designated as before, although there were more contingency recovery areas because the mission was longer. For each of the three planned orbits about five contingency locations were selected. During the second orbit, for example, the emergency landing areas included the Atlantic Ocean near the west coast of Africa, the Indian Ocean near the east coast of Africa, the Indian Ocean near the west coast of Australia, and the Pacific Ocean either 440 miles southeast of Hawaii or 165 miles southwest of San Diego. The primary recovery zone shifted following the completion of each full orbit.42
Space Task Group officials expected delivery of the MA-5 launch vehicle, Atlas No. 93-D, about mid-August 1961, but it was decided by STG and the Air Force to delay shipment until the flight of MA-4. Then, when faulty transistors had delayed the MA-4 launch, intensive quality assurance inspections of the transistors had to be initiated. The electronic gear of the rocket was also modified, its 100-watt telemetry system was replaced by a 3-watt transistorized unit, and the autopilot circuitry was altered to alleviate the high vibrations experienced during the first orbital Mercury flight. These changes dragged the delivery date back to October 9, 1961. In Washington, George Low warned Seamans that the time needed to secure several components necessary for these modifications might affect the delivery date of Atlas No. 109-D, the booster scheduled to launch the first astronaut into orbit. No. 93-D was the third "thick skin" Atlas booster, employing a heavier gauge of metal in its forward tank.43
According to plans, which now were to approximate those for the manned orbital mission as nearly as possible, MA-5 would rise from complex 14 at Cape Canaveral on a heading 72.51 degrees east of north. Orbital insertion of the  spacecraft should occur about 480 miles from the Cape at an altitude of 100 miles and at a speed of about 25,695 feet per second. Retrofire to initiate entry into the atmosphere was planned for 4 hours, 32 minutes, and 26 seconds after launch. Twenty-one minutes and 49 seconds later the spacecraft should hit the water in the Atlantic. Estimated temperatures during reentry should be about 3,000 degrees F on the heatshield, 2,000 degrees on the antenna housing, 1,080 degrees on the cylindrical section, and 1,260 degrees on the conical section. The STG operation planners estimated that the spent Atlas sustainer engine would reenter the atmosphere after 9 1/3 orbits, a considerable change from their estimates for the descent of the MA4 rocket.44
35 Washington Post, Nov. 19, 1961; Houston Chronicle, Nov. 12, 1961. Even members of Congress began publicly speculating on the date of the manned flight. Rep. Olin E. Teague told an audience at Texas Agricultural and Mechanical College that he understood the tentative date was Dec. 6. Rep. Victor L. Anfuso predicted the flight would go on Dec. 20. Newport News Daily Press, Oct. 25, 1961; Washington Post, Dec. 3, 1961.
36 Purser, log for Gilruth, Sept. 13, 1961; Washington Evening Star, Nov. 19 and 28, 1961.
37 David S. Akens et al., History of the George C. Marshall Space Flight Center (Huntsville, Ala., 1960-1962), I, 25-26; Houston Post, Oct. 22, 1961.
38 "Status Report No. 9"; memo, Low to Assoc. Administrator, "MA-5 Launch Schedule," Oct. 18, 1961.
39 "Status Report No. 11 "; Low memo.
40 "Postlaunch Memorandum Report for Mercury-Atlas No. 5 (MA-5)," NASA/MSC, Dec. 6, 1961; "Project Mercury Mission Directive for Mercury-Atlas 5 (Capsule 9)," Project Mercury working paper No. 208, Oct. 20, 1961.
41 Ibid.; "Project Mercury, Mercury-Atlas No. 5 Recovery Requirements," NASA/STG, Oct. 5, 1961; "Detailed Test Objectives for NASA Mission MA-5," Aerospace Corp., Aug. 31, 1961. Objectives of MA-5 were (1) demonstrate spacecraft structural integrity, including that of ablation shield and afterbody shingles, (2) evaluate spacecraft systems performance during flight, (3) determine reentry motion, (4) determine vibration levels, (5) demonstrate launch vehicle and spacecraft compatibility, (6) demonstrate life-support capability in a three-orbit mission, (7) evaluate abort sensing and implementation system, (8) demonstrate capability of ground command control equipment, (9) evaluate network acquisition aids, and (10) evaluate telemetry performance. "Mission Directive for MA-5."
42 "Mercury-Atlas No. 5 Recovery Requirements."
43 "Status Report No. 11 "; Low memo; "Detailed Test Objectives for MA-5."
44 "Project Mercury Calculated Preflight Trajectory Data for Mercury-Atlas Mission 5 (MA-5) (Capsule 9 - Atlas 93-D)," Project Mercury working paper No. 207, Oct. 19, 1961. The Atlas rocket was tracked through five orbits. On the fourth the perigee was 93 miles and the apogee 118 miles. "Postlaunch Memorandum Report for Mercury-Atlas No. 5."