122

According to LMA790-3-LM Apollo Operations Handbook: Lunar Module LM 10 and Subsequent Volume I, section 2.3.6: The landing gear must be deployed before descent engine firing. If not deployed, the landing gear would be in the path of the descent engine plume and would be damaged. The manual also mentions that the landing gear is deployed with explosive ...


95

The film gets this mostly right. Merely taking the thrust, and, therefore, the acceleration of the rocket down to zero wouldn't throw the astronauts forward; there are a couple of other effects at work. The first is air resistance; 1st-stage cutoff happens at about 42 mi (68 km) altitude, where there's still some air; this will decelerate the vehicle but not ...


63

Noone talked about continuing the mission and having them die on the Moon, or abandoning the mission and letting them die in space. There had already been two successful moon landings at this point, and further landings planned and scheduled. There was no particular reason that this mission had to land, and the culture of NASA (at the time) was such that ...


59

Jack Swigert realized that he forgot to pay his taxes around the first hour of the second day. Here's the dialogue from the Apollo 13 transcript: Note, Jack Swigert is the CMP (Command Module Pilot), Jim Lovell is the CDR (Commander), and Joseph Peter Kerwin is the CC (CAPCOM, crew members just call him Joe). So I guess the answer to your question: He ...


51

Sort of, but not for the usual reasons. When you are low on batteries, parachutes are more important than radios. Remember that they were running off of batteries, everything non-essential was powered off, and those system which were needed were strictly powered on only as needed. There were several communication systems, which all would have been powered ...


45

It did, with the third rocket stage. Instead of just becoming another object in solar orbit like the previous Apollo third stages, this time the third stage was sent into the Moon for a crash landing whose impact would be recorded on the seismometer installed by Apollo 12. This test went off without a hitch and successfully returned data from the ...


41

From this NASA page about Apollo 13: There were four cartridges from the LM and four from the backpacks, counting backups. However, the LM was designed to support two men for two days and was being asked to care for three men for about four days. After a day and a half in the LM, a warning light showed that the carbon dioxide had built up to a dangerous ...


38

A means to transfer heat from the electronics to the cabin was simply not designed into the LM. It's worth noting that the LM had a very different approach to thermal management than the CSM. The electronics of the command module were inside the atmosphere of its cabin. This meant that a significant amount of heat from the electronics could conduct (or ...


37

You've hit on a really interesting question. To answer this, I'm going to look at JPL Horizons, using the center of the Earth and the center of the Moon as the distances provided. I'm going to look at each of the Apollo missions, with the time that they were orbiting the Moon, showing the max distance, with 10 minute increments included. All distances in kms,...


34

The authors of the paper are Harold A. Hamer, Katherine G. Johnson, and W. Thomas Blackshear. Of these, the name Katherine Johnson might ring a bell with people, as she was one of the protagonists in the 2016 movie Hidden Figures, honouring the women that were instrumental in the early days of the US space program. Katherine Johnson and her colleagues were ...


32

The same system was used on Shuttle - allow me to discuss that, the design philosophy applies to Apollo as well (Shuttle deleted the fans though, and had a special Avoid-Apollo-13-circuit in the O2 tanks). A supercritical fluid is any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist. ...


31

If I get you correctly, this should be the moment from the movie you're talking about:     And this is the corresponding part of the movie script: JACK SWIGERT - Now... Do we know for sure that we can power this thing back up?... It's going to get awfully cold in here. ANDY (CAPCOM - WHITE) - Copy that, Jack. We'll just have to deal with ...


31

The stack of the SM (service module), CM (command module) and LM (lunar module) was on a free return trajectory to Earth. To get into an orbit around the Moon, the main engine of the SM was needed. But the SM was damaged by the explosion of the oxygen tank and no electric power was available in the SM. Some of the parts (tanks, valves, tubes, electric cables)...


30

In addition to crashing the Saturn V's S-IVB into the moon to collect seismic data from sensors installed by the crews of Apollo 11 and 12, several life sciences experiments were performed on the crew before and after Apollo 13. While all of the inflight experiments were canceled, researchers still managed to collect data on the cardiovascular's response to ...


29

There was no "slush" in the Apollo cryo tanks. The O2 and H2 in the tanks were stored at conditions that made them supercritical fluids. The critical pressure for O2 is ~ 730 psi, the Apollo tanks were at ~ 900 psi. (H2 critical pressure is ~187 psi). from Apollo Operations Handbook Block II Spacecraft , emphasis mine These supercritical fluids tended to ...


27

Lets have a look into Apollo By The Numbers: There was a lot of unused fuel (Aerozin 50) and oxidizer (nitrogen tetroxide) remaining in the descent stage of the Apollo 13 LM, 55 %. No need to use the fuel in the ascent stage. The LM fuel was not used for a single burn, five burns were neccessary, the last about five hours before splash down. DPS– Descent ...


27

They weren't actually considering it. It's just one of those wishful thinking moments, or a joke to lighten things up. Furthermore, there isn't anything said along those lines in the official transcripts. The time it would have been said was around 3:05:00. Also, they really couldn't have done so. They had already used fuel from the descent stage. The ...


27

According to NASA's Space Educator's Handbook: As the men in Apollo 13 experienced what no men had undergone before, millions followed the developing drama by radio and television in public squares, private homes, schools, offices and factories. Pope Paul, at an audience in St. Peter's Basilica for 10,000 Romans and tourists, said "We cannot forget at ...


26

The clearances were calculated to be OK up to a 95th percentile wind. I assume there was a Launch Commit Criteria (LCC) for the ground wind, but I have not been able to find an Apollo LCC document. Bottom line, as long as the winds were below what the clearances were calculated for, there was not a problem. Source Saturn V Flight Manual SA-507 A word on ...


25

It appears that your speculation is correct. From the Lunar and Planetary Institute's Apollo 13 Mission Overview (emphasis mine): On the Apollo spacecraft, the Service Module (SM) was intended to provide most of the consumables such as oxygen, water, and power for the mission. It was also designed to serve as the primary propulsion and maneuvering ...


25

According to an article from the Lunar and Planetary Institute (archive.org link): As a result of the electrical disturbances experienced during the Apollo 12 launch, several experiments were performed prior to and during the launch of Apollo 13 to study certain aspects of launch-phase electrical phenomena. Measurements taken indicated a significant ...


25

Was the lunar module also used to perform a barbecue roll? Yes, although it took them a while to get there, according to the Apollo Flight Journal. Starting at about 7 and a half hours after the accident, the crew began rotating the spacecraft periodically 90 degrees at a time to approximate the effect of the passive thermal control roll: 063:24:52 Lousma: ...


22

From Apollo 13 by Jim Lovell, Jeffrey Kluger, the following is stated: In order to reenter Earth's atmosphere safely, Apollo 13 had to approach at an inclination no shallower than 5.3 degrees, and no steeper than 7.7 degrees. Come in at 5.2 degrees or below, and the blunt-ended command module would skip off the top of the atmosphere and boing ...


22

I believe the answer is yes, but just barely. The distance from the Earth to the moon varies significantly over time, from 356,400 to 406,700 km. I plugged the dates of orbital entry and departure for each of the lunar Apollo missions (8, 10-17) into pyephem to find the ranges of lunar distance. At Apollo 13's flyby, the moon was one day past apogee and ...


21

Alan Shepard is 1.80 John Glenn is 1.79 To quote Mercury Seven wikipedia page: Because of the small space inside the Mercury spacecraft, candidates could be no taller than 5 feet 11 inches (180 cm) and weigh no more than 180 pounds (82 kg). Now, to your question: when did that end? the answer is: it didn't. The requirements have been just ...


21

If so, what was stopping this ~750Ton vehicle (launch mass minus first stage fuel)? I can't speak to the severity of the "jolt" but there would certainly be one at MECO - not because the vehicle had "stopped" but because it had stopped accelerating upwards (for want of a better word). This graph is from Apollo 8 but should be close enough for our purposes: ...


20

The purpose of the Apollo missions wasn't to collect rocks. It was recover from the humiliation of being beaten to space by the Soviets. While there was some scientific value, it overwhelmingly was a publicity stunt, and saving the crew would serve that purpose, while letting them die would not (at least, not if it were known that a deliberate choice was ...


19

Regardless of consumables, the main concern with the descent module was the RTG. Each Apollo LM carried a small nuclear device containing nearly 4 Kg of plutonium that was to be left on the moon, a compact nuclear generator that would power the experiments left on the moon for years. See PAGE 67 of the original press release at NASA The reentry of Apollo ...


19

I think you are incorrect on your question. There were two main burns done using the Lunar Module descent engine. One was before reaching the moon, to position them into a free return trajectory, the other was about 2 hours after passing the moon, to allow them to land in the Atlantic Ocean instead of the Indian Ocean, a difference of about 19 hours. From ...


18

The serial numbers of the Apollo spacesuits are documented on this NASA webpage. Each astronaut was assigned three suits for a particular mission: a Flight Suit, worn only during the mission; a Back-Up Suit; and a Training Suit. Some suits did double duty, most usually when an astronaut moved from a Back-Up crew to Primary crew for a later mission. The ...


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