The Apollo Spacecraft - A Chronology.|
Part 3 (C)
Man Circles the Moon, the Eagle Lands, and Manned Lunar Exploration
January through March 1969
January 3Mission preparation for Apollo 9 continued on schedule. Rollout of the space vehicle from the Vehicle Assembly Building, KSC, began. Mission Control Center simulations checkout, which began at MSC on December 20, 1968, was proceeding on schedule. Also, a series of thermal vacuum tests was completed, with the Apollo 9 crew using extravehicular mobility unit (EMU) flight equipment. Wind up of these tests completed the required EMU testing for the Apollo 9 flight.
NASA OMSF, "Manned Space Flight Weekly Report - January 6, 1969."
January 14MSFC announced that Arthur Rudolph, special assistant to the MSFC Director, would retire January 31. Rudolph had served as the manager of the Saturn V rocket program from August 1963 to May 1968. He was one of the more than 100 rocket experts who came to the United States from Germany in 1945. The MSC ASPO Manager, in a congratulatory letter said, "I will always consider Saturn V to be one of the outstanding achievements that occurred during my lifetime. Its sheer size is simply fantastic. But even more astounding was its performance in its first flights." Rudolph's work in bringing the nation's most powerful launch vehicle to flight status was rewarded when the first Saturn V lifted off from KSC and performed flawlessly on November 9, 1967, Rudolph's birthday.
MSFC Release 69-10, Jan. 14, 1969; ltr., George M. Low, MSC, to Arthur Rudolph, MSFC, Jan. 16, 1969; NASA OMSF, "Manned Space Flight Weekly Report - January 27, 1969."
January 15The Apollo Program Director expressed concern to the Director of MSC over the lack of guidelines of sufficient scope and depth for the lunar missions that would be flown after the first lunar landing and before the proposed lunar exploration program tentatively scheduled to begin in 1973. He asked each of the manned space flight Centers to appoint a working group to define guidelines and to outline program objectives and content for the period of lunar exploration immediately following the first lunar landing. Areas requiring study were: scientific exploration, mission planning rationale, flight schedules and program impact, and vehicle product improvement.
Ltr., Samuel C. Phillips, NASA OMSF, to Robert R. Gilruth, MSC, Jan. 15, 1969.
January 15-17The final flight program for Apollo 9 was verified; the emergency egress test with the prime and backup crew was conducted; and the software integration test between the lunar module and Mission Control Center, MSC, was completed on January 15. On January 16 the Saturn V/Mission Control Center-Houston integration testing was conducted. Additionally, a critical design review of the Launch Complex 39 slide wire system was conducted on January 17. Launch preparations for Apollo 9 continued to proceed on schedule.
NASA OMSF, "Manned Space Flight Weekly Report - January 21, 1969."
January 16In response to a query, the ASPO Manager responded: "Insofar as the astronauts' 'call of nature' is handled, they urinate through a tube into a plastic bag. The bag is periodically emptied through an overboard dump nozzle. Although we have considered using an aircraft type relief tube that would dump overboard directly, we have not yet adopted this approach since an uncontrolled dump would most likely freeze the liquid in the tube or the dump nozzle. Defecation is handled through the use of a plastic bag, part of which fits over the hand like a glove. Although this method is primitive, it was found to work reasonably well, both in Gemini and in Apollo. A disinfectant pill is then placed in the bag and it is stowed in a special container in the spacecraft. The astronauts' diet, both before and during the flight, is such that the need to use this bag may only arise once or twice during the flight."
Ltr., George M. Low, MSC, to Larry Megow, Houston, Tex., Jan. 16. 1969.
January 16The Apollo Program Director requested that MSC present a Lunar Receiving Laboratory (LRL) review like that for design certification. The presentation would cover
Ltr., Samuel C. Phillips, NASA OMSF, to Robert R. Gilruth, Director, MSC, "Lunar Receiving Laboratory Readiness Review," Jan. 16, 1969.
January 17-20Checkout was on schedule for an Apollo 10 launch readiness date of May 17. On January 17 the backup crew participated in an altitude test run. The spacecraft docking test, using a simulated adapter, was completed January 20. All three fuel cells were being replaced because of suspected contamination in fuel cell No. 1 and the failure of fuel cell No. 2 to take any voltage load during the power-up for the manned altitude run.
NASA OMSF, "Manned Space Flight Weekly Report - January 27, 1969."
January 19-22The Apollo 9 flight readiness test began on January 19 and was successfully completed January 22, in preparation for a February launch (see March 3-13). A one-day delay in the testing was caused by a loss of air conditioning for the RCA-110A computer. The hatch and side windows of the spacecraft were being modified to overcome the fogging effect experienced during the Apollo 8 mission.
January 24The CSM Flight Readiness Review Board convened at MSC. Martin L. Raines presented the Reliability and Quality Assurance assessment and pointed out the improvement in discrepancy reports between spacecraft 101, 103, and 104 and concluded that 104 was better than 103 and ready to fly. George M. Low noted that the CSM Review had been outstanding.
Minutes of Meeting, CSM 104, Flight Readiness Review Board, approved by Robert R. Gilruth, Director, MSC, Feb. 7, 1969.
January 24In an exchange of letters, the feasibility and compatibility of experiments covering contrast perception, color perception, and distance estimation on the moon were discussed. Incorporation of the three experiments in the lunar landing mission's detailed test objective "Lunar Environment Visibility" for Apollo 11 was recommended.
Ltrs., Samuel C. Phillips, NASA OMSF, to George M. Low, MSC, "Lunar Surface Life Sciences Observation Experiments T033, Contrast Perception on Moon; T034, Color Perception on Moon; T035, Distance Estimation on Moon," Jan. 24, 1969; Low to Phillips, Feb. 25, 1969.
January 24-29The following tests were completed in preparation for the planned February Apollo 9 launch: all Mission Control Center data system integration tests, MSC preflight readiness test, KSC launch readiness test, and MSFC preflight test. In addition, recovery training exercises were conducted aboard the U.S.S. Guadalcanal, the prime recovery ship for Apollo 9.
NASA OMSF, "Manned Space Flight Weekly Report - February 3, 1969."
January 27MSC and North American Rockwell reached agreement on certification reviews for parachute packers in the Apollo program. The certification was effective for all parachute packers not previously certified, with upgrading of packers and recertification of present Apollo packers when required.
Ltrs., Dale D. Myers, North American Rockwell, to Kenneth S. Kleinknecht, MSC, Jan. 27, 1969; Kleinknecht to Myers, Nov. 8, 1968.
January 31About 30 small aluminum brackets and fittings were replaced or reinforced in Apollo lunar modules to rule out the possibility of cracking from stress corrosion. Stress corrosion monitoring began in December 1967 when small cracks were discovered in LM landing gear struts. Nine fittings were replaced in LM-3, scheduled for the Apollo 9 mission, and six fittings were repaired in LM-4, scheduled for the Apollo 10 flight. About 25 fittings were being replaced on LM-5 and LM-6 and 8 fittings on each of these vehicles were being reinforced.
NASA News Release 69-24, "LM Fittings Changed," Jan. 31, 1969.
January 31NASA Hq. asked Center directors for ideas for symbolic activities on the moon during the first landing to dramatize international agreements regarding exploration of the moon. Possible ideas were flying a U.N. flag with the U.S. flag on the moon; placing decal flags of the U.N. member nations on the LM descent stage; and leaving an appropriate information capsule at the landing site.
TWX, Samuel C. Phillips, NASA OMSF, to Robert R. Gilruth, MSC; Kurt H. Debus, KSC, and Wernher von Braun, MSFC, Jan. 31, 1969; ltr., Gilruth to Phillips, March 3, 1969.
January 31During integrated testing of the Apollo spacecraft, a well-qualified test pilot accidentally threw two guarded switches marked "CM/SM Separation" instead of the intended adjacent switches marked "CSM/LM Final Sep" to separate the lunar module from the command and service modules. Had the error occurred in a lunar flight, the CM would have separated from the SM, with a high probability of leaving the crew stranded in lunar orbit. Studies of methods to preclude such an accident in actual flight led later to provisions for visual differences in switch covers.
Memos, Robert R. Frazer, MSC, to Resident Manager Apollo Spacecraft Program, "CSM 108 Erroneous Switch Closure," Jan. 31, 1969; David B. Pendley, MSC, to Manager, Apollo Spacecraft Program, "CM/SM separation switches," Feb. 17, 1969.
Memo, Wilmot N. Hess, MSC, to ASPO Manager, "Temperature of lunar samples," Feb. 3, 1969; ltr., George M. Low, MSC, to Samuel C. Phillips, NASA OMSF, Feb. 7, 1969.
February 3NASA Hq. released a 12-month forecast of manned space flight missions, reflecting an assessment of launch schedules for planning purposes. Five flights were scheduled for the remainder of 1969:
February 5The MSF Management Council, meeting at KSC, agreed that MSC would take the following actions for augmenting the capability of the Apollo system to accomplish a successful lunar landing mission and for planning further lunar exploration:
February 8The permanently mounted spacecraft hoisting loop was inadequate for expected spacecraft loads and had failed on Apollo 8, ASPO Manager George M. Low informed Apollo Program Director Samuel C. Phillips. The auxiliary nylon loop installed by the recovery forces had adequate strength but its installation was not as well controlled as work on the spacecraft was generally. For these reasons, Low said, the astronauts would be required to leave the spacecraft before it was hoisted aboard the carrier. Low enclosed a memorandum from Don Arabian, "Hoisting spacecraft from sea," and minutes of a February 4 discussion at MSC on the subject.
Ltr., Low to Phillips, Feb. 8, 1969; memo, Donald D. Arabian to distr., "Hoisting spacecraft from sea," Feb. 6, 1969; Minutes of Discussion Concerning Hoisting Spacecraft from the Sea, W. F. Hoyler, Feb. 4, 1969.
February 11The possibility of an unmanned LM landing was discussed at NASA Hq. The consensus was that such a landing would be a risky venture. Proposals had been made which included an unmanned LM landing as a prerequisite to a manned landing on the moon. However, the capability to land the LM unmanned did not exist and development of the capability would seriously delay the program.
NASA Routing Slip, R. L. Wagner, Bellcomm, to Samuel C. Phillips, NASA OMSF, Feb. 11, 1969; draft memo, George E. Mueller, OMSF, to NASA Acting Administrator, "Unmanned LM Landing," undated, unsigned.
February 12Three members of the Interagency Committee on Back Contamination met at MSC to review Apollo operational plans and procedures. Some concern was expressed about the lack of a bacterial filter on the spacecraft postlanding system. However, the committee representatives indicated that the approach was reasonable in terms of the tradeoff on operational recovery problems. The full committee was scheduled to meet in March.
NASA OMSF, "Manned Space Flight Weekly Report - February 17, 1969."
February 12George M. Low, MSC, told Maxime A. Faget, MSC, that he had recently learned the Apollo Operations Handbook (AOH) was prepared for the Flight Crew Operations Directorate by prime contractors without any formalized review by engineering elements of MSC. On several occasions, when the Engineering and Development (E&D) subsystems managers looked at a section of the handbook in connection with problem areas they found the handbook in error. Low proposed that E&D should
February 14Flammability tests of the Sony tape/voice recorder were made to determine if the recorder met crew-cabin use requirements. Testing was by electrical overloads of nichrome wire ignitors in an atmosphere of 100 percent oxygen at 4.3 newtons per square centimeter (6.2 psia). Post-test evaluations indicated that flammability requirements had been met, since ignitions were self-extinguishing and only localized internal damage occurred.
Memo, Joseph N. Kotanchik, MSC, to Chief, Systems Engineering Div., MSC, "Flammability tests on Sony tape/voice recorder," Feb. 14, 1969.
February 17MSC was urged to reconstitute the Crew Safety Review Board to determine if the following questions could be affirmatively answered concerning the LM, extravehicular activity, portable life support system, and emergency procedures. Were all likely failure modes or anomalies that could jeopardize the crew from entrance to mission systematically analyzed? Were proper and timely cues coupled with a safe egress, abort, or contingency capability prepared for use in each of these? Was there a plan for the timely solution of the known crew safety-related problems?
Ltr., Samuel C. Phillips, NASA OMSF, to George M. Low, MSC, Feb. 17, 1969.
February 22The Apollo 9 countdown to launch began, with launch scheduled for liftoff February 28. The 10-day flight would mark the first manned earth orbital flight of the lunar module, the first Apollo spacewalk, and the first manned checkout, rendezvous, and docking operations of the complete Apollo spacecraft. The Apollo 9 mission would be open-ended, allowing the mission plan to progress from one step to the next on the basis of real-time success.
NASA OMSF, "Manned Space Flight Weekly Report - February 25, 1969."
February 27Maxime A. Faget, MSC Director of Engineering and Development, said he believed the Preliminary Lunar Landing Phase Photographic Operations Plan was seriously deficient in meeting its stated objectives. "From the standpoint of public information and historical documentation, I'm terribly disappointed to find that although 560 feet [170 meters] of movie film has been set aside for lunar surface use none will be exposed with the intent of providing first-class visual appreciation of the astronaut's activity on the moon during this singularly historical event. Everyone's impression of this occasion will be marred and distorted by the fact that the greatest frame rate is 12 frames per second. One can argue that 'suitable' (although jerky) motion rendition is produced by 'double-framing.' Nevertheless, it is almost unbelievable that the culmination of a 20 billion dollar program is to be recorded in such a stingy manner and the low-quality public information and historical material is in keeping with an otherwise high-quality program." Faget also noted he felt that, from a historical standpoint, both the lunar module pilot and the commander should be photographed with the Hasselblad camera while on the surface.
Memo, Faget, MSC, to Chief, Mission Operations Br., "Comments on 'Preliminary Lunar Landing Phase Photographic Operations Plan,'" Feb. 27, 1969.
Ltrs., Samuel C. Phillips to Manager, Apollo Spacecraft Program Office, "Initiation of a Program for the Measurement of Carbon Dioxide Production during Lunar Exploration," March 1, 1969; George M. Low to Phillips, May 5, 1969.
March 3-13Apollo 9 (AS-504), the first manned flight with the lunar module (LM-3), was launched from Pad A, Launch Complex 39, KSC, on a Saturn V launch vehicle at 11:00 a.m. EST March 3. Originally scheduled for a February 28 liftoff, the launch had been delayed to allow crew members James A. McDivitt, David R. Scott, and Russell L. Schweickart to recover from a mild virus respiratory illness. Following a normal launch phase, the S-IVB stage inserted the spacecraft into an orbit of 192.3 by 189.3 kilometers. After post-insertion checkout, CSM 104 separated from the S-IVB, was transposed, and docked with the LM. At 3:08 p.m. EST, the docked spacecraft were separated from the S-IVB, which was then placed on an earth-escape trajectory.
LM-3 is still attached to the S-IVB stage after launch on the Apollo 9 mission March 3, 1969.
Spider flies in lunar landing configuration, upside down to earth, with lunar surface probes extending from deployed foot pads. Apollo 9 commander James A. McDivitt flies with Schweickart in the LM, photographed by Scott from the CM Gumdrop.
On March 4 the crew tracked landmarks, conducted pitch and roll yaw maneuvers, and increased the apogee by service propulsion system burns.
On March 5 McDivitt and Schweickart entered the LM through the docking tunnel, evaluated the LM systems, transmitted the first of two series of telecasts, and fired the LM descent propulsion system. They then returned to the CM.
McDivitt and Schweickart reentered the LM on March 6. After transmitting a second telecast, Schweickart performed a 37-minute extravehicular activity (EVA), walking between the LM and CSM hatches, maneuvering on handrails, taking photographs, and describing rain squalls over KSC.
On March 7, with McDivitt and Schweickart once more in the LM, Scott separated the CSM from the LM and fired the reaction control system thrusters to obtain a distance of 5.5 kilometers between the two spacecraft. McDivitt and Schweickart then performed a lunar-module active rendezvous. The LM successfully docked with the CSM after being up to 183.5 kilometers away from it during the six-and-one-half-hour separation. After McDivitt and Schweickart returned to the CSM, the LM ascent stage was jettisoned.
During the remainder of the mission, the crew tracked Pegasus III, NASA's meteoroid detection satellite that had been launched July 30, 1965; took multispectral photos of the earth; exercised the spacecraft systems; and prepared for reentry.
The Apollo 9 CM splashed down in the Atlantic 290 kilometers east of the Bahamas at 12:01 p.m. EST. The crew was picked up by helicopter and flown to the recovery ship U.S.S. Guadalcanal within one hour after splashdown. Primary objectives of the flight were successfully accomplished. (Objectives of all Apollo flights are listed in Appendix 5.)
MSC, "Apollo 9 (AS-504) Flight Summary," undated; MSC, "Apollo 9 Mission Report" (MSC-PA-R-69-2), May 1969; NASA OMSF, "Manned Space Flight Weekly Report," March 4, 17, 1969.
March 5President Nixon, at a White House ceremony, announced the nomination of Acting Administrator Thomas O. Paine to be the NASA Administrator.
Office of the Federal Register, National Archives and Records Service, Weekly Compilation of Presidential Documents, March 10, 1969, pp. 369- 71.
March 6NASA Associate Administrator for Manned Space Flight George E. Mueller, wrote MSC Director Robert R. Gilruth of his concern about Apollo software. "Software as I mean it to be understood in this letter includes computer programs, mission profiles and procedures (training). As I recall, the Apollo project started with a legacy of warnings from other programs about the rigors and pitfalls of software development. . . . I believe we are giving far more management attention to hardware changes than to software changes of similar impact." He questioned "whether some of these changes make the system better or safer when the disruptive effects of change are also considered. . . . We are making too many discretionary software changes. These are costing money and effort which could better be used elsewhere. . . ."
Gilruth replied March 11: "I cannot agree with your contention that we are now controlling software with the same rigor and management attention that we are devoting to hardware changes. Our Apollo Spacecraft Program Office has organized a number of Configuration Control Boards at MSC. These include George Low's Apollo Spacecraft Configuration Control Board, Max Faget's Board for Government Furnished Equipment, Chris Kraft's Software Configuration Control Board, and Deke Slayton's Procedures Change Control Board. . . . Hardware changes . . . are directly under George Low's control. All computer program changes, both on board and on the ground, are controlled by Chris Kraft's Board. Changes to the Apollo Operations Handbook, flight crew procedures, crew checklists, trainers and simulators are controlled by Slayton. Changes in software or crew procedures that involve changes in schedule must additionally be approved by George Low's Board. The system I described is working well and, according to Sam Phillips, has resulted in a more disciplined change control than anywhere else in the Apollo Program. . . . We are not making discretionary software changes. We are only making those changes which our managers deem to be necessary in their effort to carry out the Apollo Program in the most effective manner."
Ltrs., Mueller to Gilruth, March 6, 1969; Gilruth to Mueller, March 11, 1969.
March 7In a report to the Administrator, the Associate Administrator for Manned Space Flight summed up the feeling of accomplishment as well as the problem of the space program: "The phenomenal precision and practically flawless performance of the Apollo 9 lunar module descent and ascent engines on March 7 were major milestones in the progress toward our first manned landing on the moon, and tributes to the intensive contractor and government effort that brought these two complex systems to the point of safe and reliable manned space flight. The inevitable developmental problems that plagued the LM propulsion system were recurring items in our management reporting, and the fact that essentially all major test objectives were met during last Friday's flight operations is an outstanding achievement. The earth orbital simulations of the lunar descent, ascent, rendezvous, and docking maneuvers, taking Astronauts McDivitt and Schweickart 114 miles [183.4 km] away from the CSM piloted by Dave Scott and safely back, were a measure of the skill of the Apollo 9 crew and the quality of the hardware they were flying."
NASA OMSF, "Manned Space Flight Weekly Report - March 10, 1969."
March 7A radiation survey of CSM 107 was planned to determine if the radiation produced by onboard sources would be of a sufficient level to impair the effectiveness of proposed experiments to measure the natural radiation emitted from the lunar surface. The survey would be conducted at KSC by personnel from the Goddard Space Flight Center.
Ltr., Kenneth S. Kleinknecht, MSC, to Rocco A. Petrone, KSC, "Background radiation survey of Apollo CSM," March 3, 1969.
March 10 and 31A Flight Readiness Review Board convened at MSC to determine the readiness of Lunar Landing Training Vehicle No. 2 and the Flight Crew Operation Directorate for resuming flight test operations. During the briefing and discussion the board agreed that the operation test team was operationally ready. However, a release for resuming flight test operations was withheld until certain open items were resolved. The board reconvened on March 31 and after examination of the open items, agreed that flight testing of LLTV No. 2 should be resumed as soon as possible.
Minutes, Lunar Landing Training Vehicle Number Two (LLTV No. 2) Flight Readiness Review Board (FRRB), April 1, 1969.
March 11Apollo 10 was transferred to Pad B, Launch Complex 39, at KSC - for first operational use of Pad B. Meanwhile, a revised work schedule providing for a Flight Readiness Test on April 9 and launch readiness on May 18 was being prepared for Apollo 10.
NASA OMSF, "Manned Space Flight Weekly Report - March 17, 1969."
March 11The additional direct cost to the Apollo research and development program from the January 27, 1967, Apollo 204 fire was estimated at $410 million, principally for spacecraft modifications, NASA Associate Administrator for Manned Space Flight George E. Mueller testified in congressional hearings. The accident delayed the first manned flight of the spacecraft by about 18 months. "During this period, however, there occurred a successful unmanned test of the Lunar Module and two unmanned tests of the Saturn V vehicle."
House Committee on Science and Astronautics, Subcommittee on Manned Space Flight. 1970 NASA Authorization: Hearings, 91st Cong., 1st sess., pt. 2, Feb. 28, March 6, 7, 8, 11, 12, 14, and 25, 1969, pp. 183-85.
March 12George M. Low discussed the status of a fire detection system for Apollo in a memorandum to Martin L. Raines, reminding him that such a system had been under consideration since the accident in January 1967. Low said: "Yesterday, Dr. [Maxime A.] Faget, you, and I participated in a meeting to review the current status of a flight fire detection system. It became quite clear that our state of knowledge about the physics and chemistry of fire in zero gravity is insufficient to permit the design and development of a flightworthy fire detection system at this time. For this reason, we agreed that we would not be able to incorporate a fire detection system in any of the Apollo spacecraft. We also agreed that it would be most worthwhile to continue the development of a detection system for future spacecraft." (See also entries of March 27 and September 28, 1967, and April 17, 1968.)
Memo, Low to Raines, "Fire detection system for Apollo," March 12, 1969.
March 13MSC requested that Apollo Program Directive No. 41 delivery dates for the LM be changed as follows: LM-6 from March 1 to March 26, LM-7 from April 16 to May 15, LM-8 from May 31 to July 15,and LMs 9 through 14 two months apart. The rescheduling was to permit incorporation of the redesigned ascent-stage fuel-tank torus ring, installation and testing of the liquid-cooled suit loop, replacement of the descent-stage tanks, and incorporation of structural fitting changes to prevent stress corrosion.
TWX, George M. Low to NASA Hq., Attn: S. C. Phillips, March 13, 1969.
March 14MSC Director Robert R. Gilruth forwarded plans for the MSC Lunar Gravity Simulation device to Apollo Program Director Samuel C. Phillips. He informed Phillips that "we have moved out on the design and fabrication of the inclined plane 1/6 g simulator and our schedule shows that it will be completed and ready for checkout by May 1, 1969 [see February 5]. The vertical system approach is somewhat more sophisticated and our scheduled completion is February 1, 1970." Phillips replied March 28 that he was pleased to read that the simulator program was progressing so rapidly and "I feel very strongly that this device will greatly contribute to our capability to create useful lunar exploration missions."
Ltrs., George E. Mueller to Gilruth, Feb. 14, 1969; Gilruth to Phillips, March 14, 1969; Phillips to Gilruth, March 28, 1969.
March 20ASPO 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."
Ltr., Low to S. C. Phillips, "Deletion of the boost protective cover," March 20, 1969.
March 24NASA announced that Apollo 10, scheduled for launch May 18, would be a lunar orbit mission during which two astronauts would descend to within 15,240 meters of the moon's surface. The decision followed reviews of technical and operational data from the Apollo 9 earth-orbit mission. The prime crew would be astronauts Thomas P. Stafford, spacecraft commander; John W. Young, command module pilot; and Eugene A. Cernan, lunar module pilot. Backup crew members were L. Gordon Cooper, Jr., Donn F. Eisele, and Edgar D. Mitchell. With the exception of the actual landing, the mission plan was the same as for the lunar landing mission. Stafford and Cernan were to enter the LM, separate from the CSM, descend twice to within 16 kilometers of one of the preselected landing sites, and then rendezvous and dock with the CSM. Because of propellant limitations in the ascent stage, landing and subsequent liftoff from the moon would be impossible.
NASA News Release No: 69-46, "Apollo 10 Mission Scheduled," March 24, 1969.
March 25The first flight-model ALSEP arrived at KSC, where it would undergo software integration tests and be prepared for installation in the LM.
NASA OMSF, "Manned Space Flight Weekly Report - April 1, 1969."
March 28Following a report by the Apollo 9 astronauts that they were thrown forward in their seats and had to grab their arm rests for support during the S-IC/S-II stage separation, an evaluation working group were studying the problem. Preliminary results indicated that the separation transients were a dynamic characteristic of the Saturn V vehicle; that the measured accelerations were within predicted range and below design limits; and that the separation sequences were normal. Conclusions were that similar separation dynamics could be anticipated on future Saturn V flights.
Memo, J. P . Lindberg, MSFC, to Addressees, "Special Bulletin on S-IC/S-II Stage Separation, AS-504," March 28, 1969.