NASA negotiations with NAA on the Apollo spacecraft contract were held at Williamsburg, Va. Nine Technical Panels met on December 11 and 12 to review Part 3, Technical Approach, of the Statement of Work. These Panels reported their recommended changes and unresolved questions to the Technical Subcommittee for action. Later in the negotiations, NASA and NAA representatives agreed on changes intended to clarify the original Statement of Work. Among these was the addition of the boilerplate program. Two distinct types of boilerplates were to be fabricated: those of a simple cold-rolled steel construction for drop impact tests and the more complex models to be used with the Little Joe II and Saturn launch vehicles. The Little Joe II, originally conceived in June 1961, was a solid-fuel rocket booster which would be used to man-rate the launch escape system for the command module.
In addition, the Apollo Project Office, which had been part of the MSC Flight Systems Division, would now report directly to the MSC Director and would be responsible for planning and directing all activities associated with the completion of the Apollo spacecraft project. Primary functions to be performed by the Office would include:
Letter contract No. NAS 9-150, authorizing work on the Apollo development program to begin on January 1, 1962, was signed by NASA and NAA on December 21. Under this contract, NAA was assigned the design and development of the command and service modules, the spacecraft adapter, associated ground support equipment, and spacecraft integration. Formal signing of the contract followed on December 31.
A contract for the escape rocket of the Apollo spacecraft launch escape system was awarded to the Lockheed Propulsion Company by NAA. The initial requirements were for a 200,000-pound-thrust solid- propellant rocket motor with an active thrust-vector-control subsystem. After extensive study, Lockheed was directed to remove the control subsystem. A letter contract change was subsequently made with Lockheed to develop and manufacture a pitch-control motor to replace the thrust-vector-control subsystem. In conjunction with the use of the pitch-control motor, the escape-motor thrust was reduced to 155,000 pounds.
A meeting to review the lunar orbit rendezvous (LOR) technique as a possible mission mode for Project Apollo was held at NASA Headquarters. Representatives from various NASA offices attended: Joseph F. Shea, Eldon W. Hall, William A. Lee, Douglas R. Lord, James E. O'Neill, James Turnock, Richard J. Hayes, Richard C. Henry, and Melvyn Savage of NASA Headquarters; Friedrich O. Vonbun of Goddard Space Flight Center (GSFC); Harris M. Schurmeier of Jet Propulsion Laboratory; Arthur V. Zimmeman of Lewis Research Center; Jack Funk, Charles W. Mathews, Owen E. Maynard, and William F. Rector of MSC; Paul J. DeFries, Ernst D. Geissler, and Helmut J. Horn of Marshall Space Flight Center (MSFC); Clinton E. Brown, John C. Houbolt, and William H. Michael, Jr., of Langley Research Center; and Merrill H. Mead of Ames Research Center. Each phase of the LOR mission was discussed separately.
The launch vehicle required was a single Saturn C-5, consisting of the S-IC, S-II, and S-IVB stages. To provide a maximum launch window, a low earth parking orbit was recommended. For greater reliability, the two-stage-to-orbit technique was recommended rather than requiring reignition of the S-IVB to escape from parking orbit.
The current concepts of the Apollo command and service modules would not be altered. The lunar excursion vehicle (LEV), under intensive study in 1961, would be aft of the service module and in front of the S-IVB stage. For crew safety, an escape tower would be used during launch. Access to the LEV would be provided while the entire vehicle was on the launch pad.
Both Apollo and Saturn guidance and control systems would be operating during the launch phase. The Saturn guidance and control system in the S-IVB would be "primary" for injection into the earth parking orbit and from earth orbit to escape. Provisions for takeover of the Saturn guidance and control system should be provided in the command module. Ground tracking was necessary during launch and establishment of the parking orbit, MSFC and GSFC would study the altitude and type of low earth orbit.
The LEV would be moved in front of the command module "early" in the translunar trajectory. After the S-IVB was staged off the spacecraft following injection into the translunar trajectory, the service module would be used for midcourse corrections. Current plans were for five such corrections. If possible, a symmetric configuration along the vertical center line of the vehicle would be considered for the LEV. Ingress to the LEV from the command module should be possible during the translunar phase. The LEV would have a pressurized cabin capability during the translunar phase. A "hard dock" mechanism was considered, possibly using the support structure needed for the launch escape tower. The mechanism for relocation of the LEV to the top of the command module required further study. Two possibilities were discussed: mechanical linkage and rotating the command module by use of the attitude control system. The S-IVB could be used to stabilize the LEV during this maneuver.
The service module propulsion would be used to decelerate the spacecraft into a lunar orbit. Selection of the altitude and type of lunar orbit needed more study, although a 100-nautical-mile orbit seemed desirable for abort considerations.
The LEV would have a "point" landing (±½ mile) capability. The landing site, selected before liftoff, would previously have been examined by unmanned instrumented spacecraft. It was agreed that the LEV would have redundant guidance and control capability for each phase of the lunar maneuvers. Two types of LEV guidance and control systems were recommended for further analysis. These were an automatic system employing an inertial platform plus radio aids and a manually controlled system which could be used if the automatic system failed or as a primary system.
The service module would provide the prime propulsion for establishing the entire spacecraft in lunar orbit and for escape from the lunar orbit to earth trajectory. The LEV propulsion system was discussed and the general consensus was that this area would require further study. It was agreed that the propulsion system should have a hover capability near the lunar surface but that this requirement also needed more study.
It was recommended that two men be in the LEV, which would descend to the lunar surface, and that both men should be able to leave the LEV at the same time. It was agreed that the LEV should have a pressurized cabin which would have the capability for one week's operation, even though a normal LOR mission would be 24 hours. The question of lunar stay time was discussed and it was agreed that Langley should continue to analyze the situation. Requirements for sterilization procedures were discussed and referred for further study. The time for lunar landing was not resolved.
In the discussion of rendezvous requirements, it was agreed that two systems be studied, one automatic and one providing for a degree of manual capability. A line of sight between the LEV and the orbiting spacecraft should exist before lunar takeoff. A question about hard-docking or soft-docking technique brought up the possibility of keeping the LEV attached to the spacecraft during the transearth phase. This procedure would provide some command module subsystem redundancy.
Direct link communications from earth to the LEV and from earth to the spacecraft, except when it was in the shadow of the moon, was recommended. Voice communications should be provided from the earth to the lunar surface and the possibility of television coverage would be considered.
A number of problems associated with the proposed mission plan were outlined for NASA Center investigation. Work on most of the problems was already under way and the needed information was expected to be compiled in about one month.
[This meeting, like the one held February 13-15, was part of a continuing effort to select the lunar mission mode].
NAA was directed by the Apollo Spacecraft Project Office at the monthly design review meeting to design an earth landing system for a passive touchdown mode to include the command module cant angle limited to about five degrees and favoring offset center of gravity, no roll orientation control, no deployable heatshield, and depressurization of the reaction control system propellant prior to impact. At the same meeting, NAA was requested to use a single "kicker" rocket and a passive thrust-vector-control system for the spacecraft launch escape system.
The launch escape thrust-vector-control system was replaced by a passive system using a "kicker" rocket as directed by NASA at the June 10-11 design review meeting, The rocket would be mounted at the top of the launch escape system tower and fired tangentially to impart the necessary pitchover motion during the initial phase of abort. The main motor thrust was revised downward from 180, 000 to 155, 000 pounds and aligned 2.8 degrees off the center line. A downrange abort direction was selected; during abort the spacecraft and astronauts would rotate in a heels over head movement.
A new launch escape tower configuration with an internal structure that would clear the launch escape motor exhaust plume at 30,000 feet was designed and analyzed by NAA. Exhaust impingement was avoided by slanting the diagonal members in the upper bay toward the interior of the tower and attaching them to a ring.
Two aerodynamic strakes were added to the CM to eliminate the danger of a hypersonic apex-forward trim point on reentry. [During a high-altitude launch escape system (LES) abort, the crew would undergo excessive g forces if the CM were to trim apex forward. During a low-altitude abort, there was the potential problem of the apex cover not clearing the CM. The strakes, located in the yaw plane, had a maximum span of one foot and resulted in significant weight penalties. The size of the strakes had to be increased later because of changes in the CM which moved the center of gravity forward and because of the additional ablative material needed to combat the increased heating of the strakes during reentry. Removal of the strakes would cause a major redesign to permit the apex cover to be jettisoned in the low angle-of-attack (apex forward) region. In the summer of 1963, however, MSC and North American representatives agreed that the strakes should be removed and an apex-mounted flap be added. The flap could be jettisoned with the LES tower during normal missions and retained with the CM during a LES abort.
North American then suggested a "tower flap dual mode" approach. This concept incorporated fixed surfaces at the upper end of the LES tower which would be exposed to the air stream after jettison of the expended rocket casing, For aborts below 9,140 meters (30,000 feet), the jettison motor would pull away the expended motor casing, the LES tower, and apex cover. The contractor carried out extensive wind tunnel tests of this configuration and reported to MSC during October that a 0.5941-square-meter (920-square-inch) planer flap located in the upper bay of the LES, coupled with a more favorable CM center of gravity, would be required to solve the reentry problem.
An independent investigation of deployable aerodynamic surfaces, or canards, at the forward end of the LES rocket motor was also being conducted. These canards would act as lifting surfaces to destabilize the LES and cause it to reorient the spacecraft to a heatshield-forward position.
North American completed construction of Apollo boilerplate (BP) 9, consisting of launch escape tower and CSM. It was delivered to MSC on March 18, where dynamic testing on the vehicle began two days later. On April 8, BP-9 was sent to MSFC for compatibility tests with the Saturn I launch vehicle.
North American moved CM boilerplate (BP) 6 from the manufacturing facilities to the Apollo Test Preparation Interim Area at Downey, Calif. During the next several weeks, BP-6 was fitted with a pad adapter, an inert launch escape system, and a nose cone, interstage structure, and motor skirt.
On the basis of wind tunnel tests and analytical studies, North American recommended a change in the planned test of the launch escape system (LES) using boilerplate 22. In an LES abort, the contractor reported, 18,300 meters (60,000 feet) was the maximum altitude at which high dynamic pressure had to be considered. Therefore North American proposed an abort simulation at that altitude, where maximum dynamic pressures were reached, at a speed of Mach 2. 5.
The abort test would demonstrate two possibly critical areas:
Apollo Pad Abort Mission I (PA-1), the first off-the-pad abort test of the launch escape system (LES), was conducted at WSMR. PA-1 used CM boilerplate 6 and an LES for this test.
All sequencing was normal. The tower-jettison motor sent the escape tower into a proper ballistic trajectory. The drogue parachute deployed as programmed, followed by the pilot parachute and main parachutes. The test lasted 165.1 seconds. The postflight investigation disclosed only one significant problem: exhaust impingement that resulted in soot deposits on the CM.
MSC's Systems Engineering Division met with a number of astronauts to get their comments on the feasibility of the manual reorientation maneuver required by the canard abort system concept. The astronauts affirmed that they could accomplish the maneuver and that manual control during high-altitude aborts was an acceptable part of a launch escape system design. They pointed out the need to eliminate any possibility of sooting of the windows during normal and abort flight. Although the current design did not preclude such sooting, a contemplated boost protective cover might satisfy this requirement.
Engineers from ASPO and Engineering and Development Directorate (EDD) discussed the current status of the tower flap versus the canard launch escape vehicle (LEV) configurations. Their aim was to select one of the two LEV configurations for Block I spacecraft. ASPO and EDD concluded that the canard was aerodynamically superior; that arguments against the canard, based on sequencing, mechanical complexity, or schedule effect, were not sufficient to override this aerodynamic advantage; and that this configuration should be adopted for Block I spacecraft. However, further analysis was needed to choose the design for the Block II LEV.
At a NASA-North American technical management meeting, the tower flap versus canard configuration for the launch escape vehicle was settled. ASPO Manager Joseph F. Shea decided that canards should be the approach for Block I vehicles, with continued study on eliminating this device on Block II vehicles.
North American conducted the first operational deployment of the launch escape system canards. No problems were encountered with the wiring or the mechanism. Two more operational tests remained to complete the minimum airworthiness test program, a constraint on boilerplate 23.
Bellcomm, Inc., presented its evaluation of the requirement for a q-ball in the emergency detection system. [The device, enclosed in the nose cone atop the launch escape tower, measured dynamic pressures and thus monitored the vehicle's angle of attack, and was designed to warn the crew of an impending breakup of the vehicle.] Bellcomm's findings confirmed that the q-ball was absolutely essential and that the device was ideally suited to its task.
North American tested the canard thrusters for the launch escape system, using both single and dual cartridges. These tests were to determine whether the pressure of residual gases was sufficient to maintain the canards in a fully deployed position. Investigators found that residual pressures remained fairly constant; further, the firing of a single cartridge produced ample pressure to keep the canards deployed.
Boilerplate 23, Mission A-002, was successfully launched from WSMR by a Little Joe II launch vehicle. The test was to demonstrate satisfactory launch escape vehicle performance utilizing the canard subsystem and boost protective cover, and to verify the abort capability in the maximum dynamic pressure region with conditions approximating emergency detection subsystem limits.
North American and Lockheed summarized the qualification program for the launch escape and pitch control motors. While several performance deviations were reported, these were minor and, in general, the presentation was deemed satisfactory. North American followed up on the discrepancies and, on March 22, the motors were declared flight-qualified.
Because of the CM's recent weight growth, the launch escape system (LES) was incapable of lifting the spacecraft the "specification" distance away from the booster. The performance required of the LES was being studied further; investigators were especially concerned with the heat and blast effects of an exploding booster, and possible deleterious effects upon the parachutes.
Thiokol Chemical Company completed qualification testing on the tower jettison motor. An ignition delay on February 22 had necessitated a redesign of the igniter cartridge. Subsequently, Thiokol developed a modified pyrogen seal, which the firm tested during late August and early September.
NASA launched Apollo mission PA-2, a test of the launch escape system (LES) simulating a pad abort at WSMR. All test objectives were met. The escape rocket lifted the spacecraft (boilerplate 23A) more than 1,524 m (5,000 ft) above the pad. The earth landing system functioned normally, lowering the vehicle back to earth. This flight was similar to the first pad abort test on November 7, 1963, except for the addition of canards to the LES (to orient the spacecraft blunt end forward after engine burnout) and a boost protective cover on the CM. PA-2 was the fifth of six scheduled flights to prove out the LES.
ASPO Manager George Low wrote NASA Hq. - referring to a briefing of George Low at Downey on October 25, 1968 - that "MSC has reviewed the possibility of deleting the CSM boost protective cover. We have concluded that deletion . . . would require the following spacecraft modifications: a. A new thermal coating would have to be developed to withstand the boost environment. b. Protective covers would have to be developed for the windows, EVA handholds, vent lines, etc. . . . We have further concluded that a resulting overall weight reduction is questionable, and . . . have therefore decided that the cost of this change could not be justified and that the boost protective cover should be retained."