154

The following is a speech written for President Nixon, in the event that the Apollo 11 mission did not succeed. Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace. These brave men, Neil Armstrong and Edwin Aldrin, know that there is no hope for their recovery. But they also know that there is hope ...


69

During the Apollo era, Deke Slayton, as chief of the astronaut office, was the primary decision maker when it came to choosing who was assigned to which crews. Slayton was chosen for the Mercury program but was grounded due to a heart issue. Since he had been through astronaut training, but wasn't in competition for a mission assignment himself, he was ...


64

Although the temperature at altitude can be several thousands of degrees, the atmosphere is so thin it does not transfer heat efficiently. Wikipedia explains it very well - The highly diluted gas in this layer can reach 2,500 °C (4,530 °F) during the day. Even though the temperature is so high, one would not feel warm in the thermosphere, because it is ...


60

Like everything else, the ascent and descent stages were built to be as light as possible. But because they knew they would operate only in a vacuum, many things really didn't need to be sturdy, nor did the shape of it matter. It would never have to deal with aerodynamic drag. In fact, the descent stage was designed to buckle in the right places upon landing,...


56

The Apollo lunar module was battery powered, so could only maintain a livable environment for a few days (this was a major concern for Apollo 13, since the crew was reliant on the LM after the accident which disabled the service module). Once out of power, it would be unable to circulate air or to maintain a comfortable temperature inside. Committing ...


54

The process was a great deal more sophisticated than pointing and thrusting, and the CSM was cooking along at over 1600 m/s, circling the moon every 2 hours. Mission control, however, had fairly precise tracking of the positions of both the CSM and the landing site, and they computed the correct time of launch to begin the rendezvous using powerful Earth-...


46

It's called, appropriately enough, the "sewn-on cuff checklist". Aldrin's tasks are in parentheses as shown by the (LMP) annotation at the top. It's a checklist of pretty much everything they were supposed to do on the surface, in NASA acronym-ese. Not just photography. Some examples: Set up the camera Preliminary checks Gather samples Inspect ...


41

These were the "1202" and "1201" program alarms, which were warning signals that the lunar module's computer was becoming overloaded. During Apollo 11's descent to the moon, the crew left the LM's rendezvous radar, which was used to find their way back to the command module, switched on in the "SLEW" mode, so it would be ready ...


38

They used the Mobile Service Structure (MSS), which for some reason is rarely shown in Apollo pre-launch photos. The large work platforms at upper right completely surrounded the spacecraft and the upper section of the S-IVB stage, which held the Lunar Module. From these platforms, technicians could make last-minute changes to the flight hardware. ...


36

A transcript exists in the Apollo 11 Lunar Surface Journal, Postlanding Activities, with extensive annotations. The exchange begins at Mission Elapsed Time 104:59:27. Owen Garriott has just taken over as CapCom: 104:59:27 Garriott: Columbia, Houston. Over. 104:59:34 Collins: Columbia. Go. 104:59:35 Garriott: Columbia, Houston. We noticed you are maneuvering ...


32

It's not the temperature that matters, it's the heat transfer. The density of the atmosphere up in the thermosphere is very very thin. There simply isn't nearly enough mass to transfer any significant amount of heat from the thermosphere to a spacecraft travelling through it. Spacecraft do need heat protection to survive re-entry, but that is because they'...


30

The set of landing sites considered for all the Apollo missions was driven by a desire to sample a wide variety of lunar geology, but the order for them was chosen to make the first landings easiest and safest from a technical standpoint. The scientific rationale for site selection is described in detail in an appendix to the NASA historical document Where ...


28

They did simulate the debugging alarms, such as the 1201 and 1202. From Apollo: The Race to the Moon*: On July 5, just eleven days before the launch, [...] the scenario included one of the computer alarms that [Jay] Honeycutt (one of the simulation supervisors) had discovered. When the alarm went off, the controllers didn't know what to do with it. The ...


25

Neil Armstrong thought they had a 90% chance of survival, but only a 50-50 chance of landing on the first attempt. I've seen one source that says Aldrin was less optimistic, estimating 2/3 chance of survival and 1/3 chance of success. At that time, Apollo spacecraft had flown several missions safely, including two lunar orbit missions, so presumably he was ...


24

Besides the recording equipment Earth-side, which picked up the "air-to-ground loop" (i.e. voice transmissions between the spacecraft and mission control), both the CM and the LM had multitrack tape recorders which were used to store and relay both telemetry and onboard voice data. The CM system was called DSE (Data Storage Equipment) and the LM system was ...


23

The "TLI burn" was filmed by the crew of Apollo 9 - an Earth-orbit test of the lunar module. As explained in Scott Manley's video on Youtube, How Did The Apollo 11 Documentary Get Film Of The Upper Stage Ignition?, a fully-fueled Saturn V was required to launch Apollo 9. Since the lunar module was extracted before a "TLI burn", the third stage still had lots ...


23

As DylanSp's answer notes, the 1201/1202 alarms were simulated, but the details of the computer overload that caused them on the Apollo 11 flight were complex, and were not specifically simulated prior to the mission. According to Mindell's Digital Apollo: The trouble was that the rendezvous radar and the rest of the guidance system had different electrical ...


22

That is not a shockwave. It looks like the edge of the second stage engine exhaust plume. If it were a shockwave, more shockwaves should be visible: one at each point where the diameter of the rocket changes, so escape tower, CM, both interstages. Shockwaves are rarely visible. In the lower atmosphere you can sometimes see condensation in the low-...


21

The distance is noted in Apollo by the Numbers. 22,500 feet, that is 6.858 km or 3.7 nautical miles or 4.26 statute miles. From the Apollo 11 Summary, link from called2voyage: The 756.39-second powered descent engine burn was initiated at 102:33:05.01. The time was as planned, but the position at which powered descent initiation occurred was about 4 ...


21

Eagle was already 3 miles downrange from the expected position at the start of descent, due to residual pressure in the docking tunnel pushing the spacecraft apart when they undocked. Final touchdown was about 4 miles downrange from the intended landing site: 104:15:13 Duke: Roger. Understand. Omni Charlie. Mike, be advised we have an update for you on ...


20

It's unlikely. They made no report of seeing it, although it was mentioned as a news item at several points during the mission. The sky is big, the moon's surface is big, rockets are fast, hypergolic propellant rocket plumes are very faint.


20

What happened: With just seven and a half minutes remaining before they were set to touch down on the moon, Armstrong and Aldrin reported a program alarm. "It's a 1202." The 1202 alarm indicated that the guidance computer was being overloaded with tasks. It was having trouble completing its work in the cycling time available. "We looked down at ...


19

The 18 rescue cases are detailed in the CMP Solo Book and they are all for the undocked phase of the mission after the LM undocks from the CSM in lunar orbit. In most cases the LM can not do or can't fully do the burns required to get back to the CSM in an emergency, so the CSM has to come and rescue it. Here is the page with the list of rescue cases: ...


18

I don't have a definitive answer to this question because I have never come across any discussion of NASA even considering the idea of giving the astronauts a script to read for part of the mission. As far as I know, that was just not something that NASA did or does now. The live TV broadcasts on the way to the moon were not scripted, just as the ISS tours ...


17

Liftoff in the video you link is at 12:00. 13:00 on the video is one minute after the launch, not 107 seconds. At 12:42 on the video, the "one bravo" call is heard, indicating a change in the abort mode to be used in an emergency. Abort mode IB takes effect at 42 seconds into flight, at about 3km altitude. At 12:55 on the video, the PAO says "altitude is ...


17

Supplementary answer (these answers cover it well, but there are a few other things of interest): For anyone interested in the details of this issue, the book Sunburst and Luminary by Don Eyles has, I think the definitive treatment. Eyles was the LEM descent guidance software programmer! Eyles explains that the problem was actually found on the ground ...


16

There was no chance to get them back alive - no ready to launch rocket, no ready to launch spaceship, no lunar module capable to take 3 persons (or land automatically) - just nothing.


16

On Earth, most of visibility of objects coming from space is created by interaction with the atmosphere. As Moon has no atmosphere, an approaching space object would appear in a similar way to how on Earth we perceive orbiting objects: light reflected from the Sun at best. That is, under conditions that the object is large, reflective and properly positioned ...


15

As @Rikki-Tikki-Tavi points out escape velocity is the velocity you would need at (or near) the surface of Earth to make out out of Earth orbit. Of course, just like anything thrown up into the air, the spacecraft decelerates as it moves away from the Earth. Having escape velocity means that your total energy (relative to the Earth in this case) is greater ...


15

The shoes of the A7L suit were white with partly-blue "lunar boots" worn over them, but soon were covered in grey-ish dust once on the moon. Have a look at this image on Wikipedia:


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