second manned flight of the Saturn V launch vehicle, and the first manned flight of the lunar module.

This mission is expected to demonstrate crew/space vehicle mission support facilities performance with the CSM and LM in earth orbit; to demonstrate LM/crew performance; and to demonstrate performance of normal and selected backup lunar orbit rendezvous mission activities. These activities are to include transposition, docking, and LM withdrawal; intravehicular and extravehicular crew transfer; docked SPS and descent propulsion system (DPS) burns; and LM active rendezvous and docking.

This mission is to be open ended, lasting up to 11 days. The launch vehicle will place the manned spacecraft in a circular earth orbit. The CSM will separate from the launch vehicle, turn around, dock with the LM which will still be attached to the S-IVB. When docking is complete, the entire Apollo spacecraft will be spring-ejected from the S-IVB. Then the spacecraft will move away from the S-IVB so that the crew can observe two restarts of the S-IVB, the second boosting the stage into a solar orbit. The lunar module descent stage engine and the service module engine will each be burned while the spacecraft and lunar module are docked. While the CSM/LM is in orbit, the crew will transfer through the docking tunnel to power up the LM. Staging (separation of LM ascent and descent stages) will be performed with the LM manned and separated from the CSM by approximately 100 miles. LM active redezvous with the CSM will be performed with the ascent stage. CSM and LM orbits throughout the mission will not exceed 345 miles altitude.

Apollo 10 Mission Summary

Apollo 10 will use the SA-505 Saturn V launch vehicle, the CSM-106, and the LM-4. A test (non-operational) Lunar Surface Experiments Package (ALSEP) will be carried. The primary objectives of this mission will be to demonstrate crew, space vehicle, and mission support performance during a manned lunar mission with CSM and LM; and to evaluate LM performance in the cislunar and lunar environment.

Apollo 11 Mission Summary

The primary objective of the Apollo 11 mission will be a manned lunar landing and return. The flight will be configured with the SA-506 Saturn V launch vehicle, the 107 command and

service module, and lunar module 5. The Saturn V launch vehicle and the Apollo spacecraft will be the final spacecraft configuration. Two astronauts will descend to the lunar surface, collect a contingency lunar soil sample and shortly afterward a larger lunar soil sample. They will deploy three experiments-a solar powered seismometer to measure moonquakes, a glass mirror to reflect the light of ruby lasers in earth based telescopes and to measure the distance of the moon more accurately, and an aluminum foil which will absorb particles from the solar wind for analysis on earth. The time on the lunar surface is open-ended with the normal plan providing for an exploration period of up to three hours. The astronauts are to remain within 300 feet of the LM.

Development and Test

The flights of Apollo 7 and 8 proved the Apollo space vehicle and supporting systems, and the Apollo 7 flight completed the Apollo requirements for Saturn IB launch vehicles. Subsequently, NASA began phasing down the entire Saturn IB Project in support of Apollo. The IB program will be maintained at the minimum sustaining level that will allow reactivation when required for the Apollo Applications Program. During the last half of 1968, major ground test activities were aimed at certifying systems for manned flight, and at producing and verifying flight hard

ware.

Command and Service Modules.-The planned ground tests and flight activities of the CSM for the latter half of 1968 were carried out. The pogo oscillation experienced in the April launch of Apollo 6 resulted in higher than anticipated structural loads on the spacecraft and adapter. In June, NASA began a space vehicle static and dynamic structural test program, completing it in October. Analyses of the test results confirmed that the spacecraft and adapter could withstand the higher loads if the oscillation were to occur on vehicles with the pogo fix incorporated. To show that the Block II CSM could perform satisfactorily, NASA conducted additional unmanned and manned thermal/ vacuum tests (ground simulation of a space mission in the vacuum chamber), using a CSM test article. A special hatch test was conducted in July, and the final manned test was completed in September. Only minor anomalies occurred during the complete series of thermal/vacuum tests, and the CSM was approved for the Apollo 7 and 8 missions.

In spacecraft structural testing, the parachute loads test, forward tunnel and hatch test, end boost loads test, abort loads test, CSM/LM docked mode dynamic and structural loads tests, and numerous component tests were completed. The test of the probe and drogue for CSM/LM docking was nearing completion at the close of 1968.

The service propulsion system underwent an exhaustive series of tests to verify its performance during all mission phases. The Apollo 7 mission confirmed the reliability of the SPS, and on the Apollo 8 mission, it again performed flawlessly.

Increased weight of the command module made it necessary to redesign the main and drogue parachute and risers and to requalify the earth landing system. In a test program using a boilerplate drop test vehicle, the parachute qualification was completed in July, and the final qualification drop of the drogue/ riser in September. This drop removed the ELS constraint to the launch of Apollo 7.

In a test program to assure the safety of the astronauts in a land or water landing of the command module, over a dozen tests were conducted at KSC and the Manned Spacecraft Center (MSC) to simulate various land impact and water landing conditions that might be experienced. The tests were completed satisfactorily and the Block II command module structure and the redesigned crew couch struts were certified as acceptable for manned operations. The first CSM approved was flown on the Apollo 8 flight, and as the period closed, those for the Apollo 9 and 10 missions were being checked out at KSC.

Lunar Module.-The Lunar Module ground test program continued to move forward as most qualification tests were completed. There remain only a series of propulsion tests required to certify the LM ready for lunar missions, and applying only to the Apollo 10 and 11 lunar modules. The completed tests removed all constraints on the man rating of the LM for Apollo 9.

The ground tests to assess the flammability and propagation characteristics of the naw materials in the Apollo 9-LM-configured test articles cabin were completed in September. In the tests, numerous attempts were made to ignite materials in the LM cabin under various cabin pressures and oxygen content conditions. At the cabin conditions for flight operations, the only fires were caused by extreme ignition situations, and they were slow to build up and controllable, offering no limitation on safe manned operations.

The descent propulsion system tests conducted to select and to qualify an engine injector were satisfactorily concluded in September, lifting the restriction on the flight of the Apollo 9 LM. Ascent propulsion system tests on the Apollo 11 LM, the first potential lunar landing mission vehicle, are to be completed early in 1969.

The lunar module for Apollo 10, the second scheduled manned flight vehicle, was delivered in October and was in prelaunch checkout at KSC at the close of the period. (Fig. 1-10)

The LM flight test program was delayed when NASA decided to withdraw the designated LM from the Apollo 8 mission because a series of technical problems delayed checkout of the LM at KSC. The problems were resolved, and the LM completed all KSC individual and combined systems checkout operations. It was mated with the Apollo 9 CSM and launch vehicle, and the space vehicle was ready for transfer to the launch pad for a scheduled launch early in 1969.

ALSEP.-The first and second flight units of the Apollo Lunar Surface Experiments Package were accepted from the manufacturer. The astronauts successfully deployed the ALSEP during a mission simulation. (Fig. 1-11) After extensive review and evaluation, NASA decided to have the astronauts conduct only one excursion on the lunar surface during the first lunar landing. Since the full ALSEP would be deployed on a second excursion, both it and the field geology investigation will be deferred to the second lunar landing mission.

NASA decided on the delay because of the significant difference between orbital operations and the first lunar landing. The descent, landing, extravehicular activity (EVA), and ascent from the lunar surface are new operations in a new environment. Gemini EVA experience showed that a methodical increase in task complexity was necessary in order to understand and operate in the zero g space environment. The 1/6 g lunar surface environment will be a new experience, one that cannot be completely simulated on earth. For example, sufficient metabolic data is simply not available to predict, with high confidence, rates in a 1/6 g environment. Only educated assessments can be made of the difficulties the astronaut will have in maneuvering on the surface or the time it will take him to accomplish assigned tasks. As a consequence, a prime objective of the first mission EVA will be to assess the capabilities and limitations of the astronauts in the lunar environment.