https://ntrs.nasa.gov/search.jsp?R=19720013195 2020-03-23T11:26:57+00:00Z I1 NASA TECHNICAL NOTE -= bl- i;: Ww-3 LOAN COPY: RETURI+E=-c--3 AFWL (DOUL) - P KIRTLAMD AFB, N. f = z APOLLO EXPERIENCE REPORT - LUNAR MODULE ENVIRONMENTAL CONTROL SUBSYSTEM by Richard J. Gillen, Jumes C. Brady, - -,:-.,,i'.I : , ; .., ,,)-, , L! . , , :. .. and Frank Collier *;cL;L .. ... .,:-,* .,,a .I-., -.:.: '7 --.,I , '?. Munned Spacecrup Center : Lj. '^' , Houston, Texas 77058 NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON, D. C. MARCH 1972 TECH LIBRARY KAFB, "I I111111 11111 11111 11111 111ll1llll lllll1111 Ill1 -- - 0333453 1. Report No. 2. Government Accession No. 3. Reci?&nt's Catalog No, NASA TN D-6724 - 4. Title and Subtitle I 5. Repor1 Date APOLLOEXPERIENCEREPORT March 1972 LUNAR MODULE ENVIRONMENTAL CONTROL SUBSYSTEM 6. Performing Organization Code ~~ ~~ 7. Authods) 8. Performing Organization Report No. Richard J. Gillen, James C. Brady, and Frank Collier, MSC MSC $296 i ~ 10. Work Urit No. 9. Performing Organization Name and Address 9 14- 50- 80- 10- 72 --- - Manned Spacecraft Center 11. Contractor Grant No. Houston, Texas 77058 13. Type of Peport and Period Covered 2. Sponsoring Agency Name and Address Technilal Note National Aeronautics and Space Administration --L- 14. Sponsorib Agency Code Washington, D. C. 20546 i I 5 Supplementary Notes c The MSC Director waived the use of the International System dunits (SI) for this Apollo Experience Report, because, in his judgment, use of SI Units would impair the usefulness of the report or result in excessive cost. -~ 6 Abstract A functional description of the Apollo lunar module environmental control subiystem is presented. Development, test, checkout, and flight experiences of the subsystem are discussed; and the de- sign, fabrication, and operational difficulties associated with the various cohponents and subas- semblies are recorded. Detailed information is related concerning design &ages made to, and problems encountered with, the various elements of the subsystem, such as the thermal control water sublimator, the carbon dioxide sensing and control units, the water sfct,on, and so forth. The problems associated with water sterilization, water/glycol formulation1 and materials compatibility are discussed. The corrective actions taken are described wih tie expectation that this information may be of value for future subsystems. Although the main xpwiences described are problem oriented, the subsystem has generally performed satisfactorilTin flight. 7. Key Words. (Suggested by Authods) 1 18. Distribution Statement * Oxygen Control Systems Cabin Pressurization and Depressurization 'Water Management Systems Heat Transport Systems * Environmental Atmosphere Revitalization Control System 19. Security Classif. (of this report) 20. Security Classif. (of this page) of Pages 22. Price None None d -. ~ CONTENTS Section Page SUMMARY ..................................... 1 INTRODUCTION .................................. 1 DESCRIPTION OF THE LUNAR MODULE ENVIRONMENTAL CONTROL SUBSYSTEM .................................. Atmosphere Revitalization Section ....................... Oxygen Supply and Cabin Pressurization Section ............... Heat Transport Section ............................. Water Management Section ........................... TECHNICAL HISTORY ............................... General ..................................... 6 Heat Transport Section ............................. 11 Atmosphere Revitalization Section ....................... 17 Oxygen Supply and Cabin Pressurization Section ............... 24 Water Management Section ........................... 28 CERTIFICATION TESTING PROGRAM ...................... 34 General Scope ................................. 34 Feasibility Testing and Design Verification Testing ............. 35 Qualification Testing .............................. 36 Integrated Subsystems and Vehicle Testing .................. 38 VEHICLE AND ACCEPTANCE TESTING ..................... 41 FLIGHT EXPERIENCE .............................. 42 Lunar Module 1 (Apollo 5) ........................... 42 Lunar Module 3 (Apollo 9) ........................... 42 iii Section Page Lunar Module 4 (Apollo 10) .......................... 43 Lunar Module 5 (Apollo 11) .......................... 43 CONCLUDING REMARKS ............................. 44 iv TABLES Table Page I COMPONENT MAKEUP OF LM ECS ASSEMBLIES ........... 10 FIGURES Figure Page 1 Atmosphere revitalization section simplified schematic ........ 3 2 Oxygen supply and cabin pressurization section simplified schematic ............................... 4 3 Heat transport section simplified schematic .............. 5 4 Water management section simplified schematic ............ 6 5 Original design of interstage disconnect ................ 7 6 Final design of interstage disconnect .................. 7 7 Cutaway view of water sublimator .................... 13 8 Expanded section of water sublimator ................. 14 9 Coolant accumulator (item LSC-330-210) ................ 15 10 Simplified diagram of original design of redundant cooling loop/ water system .............................. 16 11 Schematic diagram of the LSC-330-192 package ............ 18 12 Centrifugal water separator (item LSC-330- 109) ............ 19 13 Primary LiOH cartridge (item LSC-330- 122) ............. 19 14 Suit-isolation valve (item LSC-330- 138) ................ 20 15 Simplified system diagram of a C02 sensor .............. 21 16 Lithium hydroxide cartridge performance curves ........... 22 17 Suit fan-motor assembly ........................ 23 18 Cutaway view of suit fan motor ..................... 23 V . Figure Page 19 Suit fan EM1 filter configuration ..................... 24 20 Cabin repressurization and emergency oxygen valve .......... 24 21 Seat and seal details .cabin repressurization and emergency oxygen valve (a) Configuration A ........................... 25 (b) Configuration B ........................... 25 (c) Configuration C ........................... 25 22 Cutaway view of oxygen demand regulator ............... 26 23 Elevation schematic of demand regulator/suit circuit ......... 27 24 Cabin dump and relief valve (item LSC-330-307) ............ 27 25 Burst-disk relief assembly (a) Normal sealed position ....................... 28 (b) Open position ............................ 28 26 Descent water tank (item LSC-330-404) ................. 29 27 Water pressure regulator .functional schematic ........... 31 28 Water bacteria filter locations ..................... 32 vi APOLLO EXPERIENCE REPORT LUNAR MODULE ENVI RONMENTAL CONTROL SUBSYSTEM By Richard J. Gillen, James C. Brady, and Frank Collier Manned Spacecraft Center SUMMARY The experiences at the subsystem level of the lunar module environmental control subsystem are summarized to assist the operational development of a future similar subsystem. The subsystem concepts used were generally well established; however, the specific hardware designs were new. As a generalization, most problems were caused by some relatively common procedure that had not been performed to the proper quality level or to a requirement that, at that time, could not be defined in sufficient detail. INTRODUCTION The development of the lunar module (LM) environmental control subsystem (ECS) required some improvements in the state of the art and was successfully accomplished. In the interest of preserving history and of perhaps benefiting designers of future sys- tems, some of the development problems are recounted. It should be noted that many of the problems are of a subtle type that appear only after the hardware is used re- peatedly in many different ways. In many cases, the problems were resolved by chang- ing a procedure of use rather than by redesigning the item. This approach was used when it was felt that the unit was very sound and that the benefit of experience with a less-than-perfect unit would be better than rebuilding to get a new, untried, "perfect" device with possibly new problems. The experience gained from use of the ECS is a very significant and positive asset. DESCRI PTlON OF THE LUNAR MODULE ENVIRONMENTAL CONTROL SUBSYSTEM This section describes the lunar module ECS from a functional standpoint. The ECS configurations of the LM-3, LM-4, and LM-5 were all substantially the same with the following exceptions. 1. The LM-3 vehicle was equipped with developmental flight instrumentation, and the ECS contained additional equipment-cooling provisions for this instrumentation. 2. The LM-5 (Apollo 11) lunar landing vehicle and later vehicles included suit- liquid- cooling provisions to enhance the crewman- cooling capability. These provisions were substituted for the cabin heat-exchanger assembly. The complete schematic diagram of the LM-5 ECS is shown on prime contractor drawing LDW 330-55000, which can be obtained from the NASA Manned Spacecraft Center (MSC), Houston, Texas. This drawing shows part numbers and detailed fluid and electrical schematics. In summary, the LM-5 ECS was divided into the following functional sections. 1. Atmosphere revitalization section (ARS) 2. Oxygen (02)supply and cabin pressurization section (OSCPS) 3. Heat transport section (HTS) 4. Water (H20) management section (WMS) Atmosphere Revita I izatio n Sect ion The ARS (fig. 1) removes heat, moisture, odors, and carbon dioxide (COz) from the suit circuit of the two astronauts and provides the required atmosphere circulation. One of the two suit fans circulates the warm, moist, suit-circuit gases through the backup