Contents PrefaceandAcknowledgments xi 1 HumanandMachineintheRacetotheMoon 1 2 ChauffeursandAirmenintheAgeofSystems 17 3 FlyingReentry:TheX-15 43 4 AirmeninSpace 65 5 ‘‘Braincaseonthetipofaﬁrecracker’’:ApolloGuidance 95 6 ReliabilityorRepair?TheApolloComputer 123 7 ProgramsandPeople 145 8 DesigningaLanding 181 9 ‘‘Pregnantwithalarm’’:Apollo11 217 10 FiveMoreHandsOn 235 11 Human,Machine,andtheFutureofSpaceﬂight 263 Notes 273 Glossary 305 Bibliography 307 Index 335 AbouttheCoverImage 361.
Preface and Acknowledgments OnJune14,1966,aroboticspacecrafthadjustlandedonthemoonandbeguntrans- mitting images to NASA. Project Gemini was drawing to a close, Apollo hardware was beginningtoemergefromfactories,andApollosoftwarewasexperiencingacrisis.And onthatdayIwasborn.
1 Human and Machine in the Race to the Moon AJulyDayontheMoon On a July day in 1969, after a silent trip around the far side of the moon, the two Apollospacecraftreappearedoutoftheshadowsandreestablishedcontactwithearth.
2 Chauffeurs and Airmen in the Age of Systems TestPilotsandSurvival TheSocietyofExperimentalTestPilots(SETP)helditsﬁrstannualawardsbanqueton October4,1957.Thesemensatatthetopofthepilotingprofession,crossingthebor- der between engineering and ﬂying skills. They had been rocketed to fame by Chuck Yeager’s epochal supersonic ﬂight nine years before. The atmosphere in the banquet hall was electric as the group celebrated its new society epitomizing professional ma- turity.Sixhundredandﬁftypeopleattended,manyofthemmakingthedrivefromthe dry desolation and professional focus of Edwards Air Force Base, a few hours north in theMojavedesert,downtothecosmopolitanfashionofthenewBeverlyHilton.This was Southern California at its 1950s best, as the serious, focused ﬂyers enjoyed an eveningintheheartofmid-centuryHollywoodglamour(ﬁgure2.1).
3 Flying Reentry: The X-15 There is no necessity to defend an aviator for trying to put things in a perspective from which they’vecreptandgetthingsbackintobalance.Thereisalsonochallengeonthepartofaviators toautomaticsystemsorelectronicsystemsorsophisticatedmechanicalsystems;it’sthechallenge ofputtingthemintotheperspectivesthatarenecessarysothattheyarethebestcomplementand augmentation and supplementary support you can give an aviator, an astronaut, or a pilot or whateveryouwanttocallhim.
4 Airmen in Space Thedevelopmentofmannedspaceﬂightisnotjustamatterofreplacingawarheadbyamanned cabin.Suddenly,aswitchisthrownbetweentwoparalleltracks,thoseofmissiletechnologyand thoseofaviationtechnology,andanattemptismadetomovetheprecioushumanpayloadfrom one track to the other. As in all last-minute switchings, one has to be careful to assure that no derailmenttakesplace.
5 ‘‘Braincase on the tip of a ﬁrecracker’’: Apollo Guidance It was a curious ship, a braincase on the tip of a ﬁrecracker.Without ﬁre it could not move; withoutelectricityitcouldnotthink.
6 Reliability or Repair? The Apollo Computer IfIwantedtowriteaphilosophicalnovelaboutApolloandsaywheredidthistechnologicalcapa- bilitycomefrom?Andwhatwasit?You’dhavetogobacktothesetwothings:youdevelopeda groupofmenandanapproach,asystemsapproachifyouwill,thatletyouundertakehigh-speed ﬂying,youdevelopedasystemsapproachthatletsyouundertakeriskymissionsandbeabletocall themethical.
7 Programs and People Questoculusnonvide,cornondelet Whattheeyedoesnotsee,theheartdoesnotregret ‘‘Alothappensthatwearenottellingyouabout.’’ —OpeninglinesofApollosoftwaresourcecode ProgrammingtheMoonFlights With the exception of integrated circuits and extremely high reliability, the hardware fortheApolloguidancecomputerrepresentedthestateoftheartwhenApollobegan.