How Apollo Flew to the Moon

W. David Woods, Praxis 2011, second edition ISBN 978-1-4419-7178-4, Central 629.454 w868h 2011

A useful reference, which I cannot afford to add to my groaning library. Borrowed January 2017

Notes:

• p118 ARIA: Apollo Range Instrumentation Aircraft, EC-135 (like Boeing 707) that relayed voice and recording telemetry.
• p127 PAD: pre-advisory data, spoken numbers uplinked to astronauts to a small form, used for navigation and manual operation in the event of automatic equipment failure
• p130 passing through van Allen belt at "10 km/s": minutes through the inner belt protons, 1.5 hours through the outer belt electrons. In lunar orbital plane, not through the densest equatorial portions of the belts.

• p133 EMS Entry Monitor System

• p134 TD&E Transposition, docking, and extraction of LM

• p136 SLA (spacecraft LM adapter) panel, 4 panels per mission, as many as 36 in heliocentric orbit. 6.6 meter diameter S-IVB (third) stage to 3.9 meter diameter service module. Estimated ( 6.6 x 4.3 to 2.8 ) meters.

• p138 COAS Crewman Optical Alignment Sight, aligned to target on LM

• p139 probe and drogue docking mechanism

• p149 "asteroid" J002E3 probably the S-IVB from Apollo 12

• p157 Unified S-Band, combination of all signals into one 2.1064 GHz (CSM) or 2.1018 GHz (LM) uplink carrier, used for distance and speed doppler. Transponder multiplied frequency by 240/221 for downlink.
• p160 Sextant telescope on opposite side of CM main hatch, 0.01 degree precision
• p161 SLOS = Star Line Of Sight.
• p163 Jim Lovell made P23 measurements and calculated state with P21 to within 500 meters of ground/doppler calculations

• p166 Apollo Guidance Computer at peak consumed half of the world's output of integrated circuits, 75 AGCs built between 1963 and 1969. NASA bought most chips for test. 80 KHz, 15 bits plus parity, Apollo 15 ran Colossus III software, 44 programs in 64 kilobytes of core rope.

  • ie. P51 to 54 guidance system alignment, P61 to P67 planetary descent.
  • Programs had verbs (instructions) and nouns (access to numeric values)

• p173 REFSMMAT Reference to a stable member matrix, numerical definition of an orientation in space to which the platform could be aligned.

• p220 TV bandwidth 2 MHz, 200/262.5 lines per field, 60 fields per second with RGB color wheel to make 20 color frames per second, reformatted at NASA with video recording tapes and drums
• p231 LOI = Lunar Orbit Insertion. SM used hypergolic fuels. 2 impulse to lunar orbit, first to capture and second two orbits later to a 110x20 km altitude orbit.
  • apolune/apocynthion

• p269 28 power sextant on LM, program 24 rate-aided optics tracking program

• p269 CM had DAC 16 mm Maurer data acquisition cameras monitoring LM departure. Cameras intended for engineering data, not history or publicity

• p270 normal movie speed is 24 frame/s, Apollo cameras were 1, 6, or 12 frames per second, wrong speed playback before recent advanced video processing
• p271 LM descent:
  • P63 at 1400 km and 22 minutes to landing.
  • PDI Powered Descent Initiation: perilune at 500 km and 11.5 minutes to landing
  • HIGH GATE begin approach, P64, 7 km downrange, 2.2 km altitide, 3 minutes prior to landing
  • LOW GATE terminal descent, P66, about 600 meters to landing

• p283 landing radar antenna, phased array?

• p300 fuel slosh interfered with attitude, RCS (reaction control system) firings oscillation, 2 second computer cycle time (baffles added later)
• p300 P1201 and P1202 program alarms, radar left on purposefully by "Dr. Rendezvous" Aldrin so it was warmed up for abort and rendezbous.

  • author claims not alarms radar, but phase mis-synchronization of 800Hz clocks in the computer and the ATCA attitude and translation control assembly, software counters continuously incremented or decremented, which used up too much computer time.

  • resilient software by MIT's Hal Laning, "Executive and Waitlist" system

• p316 Silver Spur photo by Dave Scott Apollo 15, layered, stratified ejecta. biological layers between lineaments?

• p375 Apollo 15 core sample, 2.5 meters, 58 layers
  • idea: in between the "big" layers of lunar impact ejecta may be microscopically thin layers of earth impact ejecta

• p386 Mass spectrometer package in SM SIM bay matched ALSEP experiments: natural Moon total atmosphere 10 tonnes, doubled by LM descent and ascent engine exhaust

• p392 Ultraviolet spectrometer ditto
• p398 plane change from 28 degree launch inclination LEO to lunar orbit inclination as costly as GEO to lunar transfer orbit perigee change
• p398 plane change by CM to match lunar rotation from LM descent to ascent, 10 to 20 seconds of SM engine fire, P30

• p400 to p463 not yet reviewed

• p466 ablative heat shield lighter than thermal tiles (carries off more heat), will be used on Orion. 300k honeycomb cells hand filled with epoxy resin, then shaped on large lathe
  • at shield 7 cm, center shield 2 to 4 cm (over most of the cone???), metal skin covered with kapton tape, most of which survived reeenty and was removed as souvenirs.
• p468 850 m/s at lunar/earth gravity strength crossover point. Two days to reach half of maximum entry speed, two hours to reach full speed
• p469 entry interface altitude at 400kft 121.92 km, 6.5° ± 1°, 0.05 gee event at 90.66 km altitude, computer flies and EMS (entry monitor system) monitors
• p470 entry pad example
• p472 orientation of entry REFSMMAT illustration, reminiscent of launch loop diagram on wikipedia
• p476 GDC gyro display couplers, backup orientation system
• p455 Diagram of the front panel of the EMS. The entry scroll shows through the velocity window in the center,

Notes: paraphrase: "real pilots needed, artists and poets could have described the trip better but would not have survived it"