Apollo 11 notes
I was re-reading the Apollo 11 mission reports, as one does, and decided to take some notes along the way.
If you’re interested in these things, I also highly recommend curiousmarc’s series on the Apollo comms hardware.
Notes
First time I’ve seen the word “doff”. Can’t wait to use it in daily conversation.
The rocket equation is a beast. The LM descent stage had 8’210kg of
propellant. The ascent stage only 2’365kg.
– Volume 1, Page 50
In total 10’849kg out of 15’061 (72%) of the LM was
propellant. (excluding the astronauts themselves)
The LM flown on Apollo 10 did not have the landing program in its computer.
To prevent the temptation to land?
– Volume 1, Page 62
Armstrong’s parents were “Mr. and Mrs. Stephen Armstrong”. Michael Collins’ mother is mentioned, but her name is also lost to history, as she’s referred to as “Mrs. James L. Collins”. Only Buzz Aldrin’s mother is named (and what a name!), as Marion Moon Aldrin.
All three were born in 1930, making them turn 39 in 1969.
– Volume 1, Page 76-78
“High speed” data mode is 2400bps, divided into 240 bit blocks.
– Volume 1, Page 93
Aside from the ground stations, the communication network for Apollo
11 when near the earth also included 4 ships and 6-8 aircraft. The
aircraft are used during translunar injection and during reentry
– Volume 1, Page 94, 98, 99
The Nasa communication network has radio links way beyond the
horizon. Multi hop links, or HF?
– Volume 1, Page 97
Downlink telemetry apparently runs at “51.2 kilobits (12,800 binary
digits) per-second”. Huh? They mean 12.8kbps payload, FEC’d up 4x to
51.2kbps?
– Volume 1, Page 98
After re-docking, SM was overpressurised a bit, and LM leak a bit,
to maintain positive pressure and not get SM dirty.
– Volume 1, Page 178
Most burns were longer than I expected.
- TLI from the S-IVB was 347.3 seconds, with delta-V of 3182m/s.
- Lunar orbit insertion 362 seconds, 889.3m/s.
- Powered Descent Initiation 712.6s, 2065.3m/s
- TEI was 159.0 seconds and 999.4m/s.
– Volume 1, Page 226-227
Almost all consumables ended with more remaining than planned. The only real exception was (as you may expected watching the landing video), the descent stage, which had 2.5% (201kg) instead of the planned 5.1% (413kg). Also the LM finished light on RCS fuel.
Some others had twice as much left as planned.
A minor problem was that “the crew reported that the knob on the
ascent engine arm circuit breaker was broken”. Ok, only the ascent
engine, nothing important.
– Volume 1, Page 229
During ascent from the lunar surface, there was quite a bit of 5
degree oscillation, due to the center of mass changing as fuel is used.
– Volume 1, Page 237
Rougly half of the oxygen and water in the suits was left in the
end. They wanted a big margin, this being the first time.
– Volume 1, Page 239
The thing they were “least prepared to handle” was the post-mission tour.
– Volume 1, Page 240
Q: Based on your own experience in space, do you or any of you feel that
there will even be an opportunity for a woman to become an astronaut
in our space program?
Armstrong: Gosh, I hope so.
– Volume 1, Page 243
The display on the Abort Guidance System had one of the strokes
broken, so you couldn’t tell if it was showing 3 or 9. They used an 8
segment display where 9 has the bottom segment lit.
– Volume 2, Page 52. Volume 3, page 191 and 204
“Distances are deceiving. When we looked at this fairly large boulder
field off to the right, it didn’t look very far away at all before we
went out. […] Tendency is to think that things are good bit closer
than they actually are. This says they are probably a good bit larger
than what we might have initially estimated.”
– Volume 2, page 69
“I didn’t notice any temperature thermal difference in and out of the
shadow. There were significant light differences and visibility
changes but no thermal differences”
– Volume 2, page 75
I did some fairly high jumps and found that there was a tendency to
tip over backward on a high jump. One time I came close to falling and
decided that was enough of that.
– Volume 2, page 76
On earth you only worry about one or two steps ahead; on the moon, you
have to keep a good eye out four or five steps ahead.
– Volume 1, page 234. Volume 2, page 77
“The other problem we had with the camera was that it was falling over
all the time. I think this was the result of a little bit of
difficulty in figuring out the local vertical”
– Volume 2, Page 79
The flag’s telescoping top rod did not extend fully. Apollo 12 had
trouble with the latch mechanism. Funny how you can get all the way
there, but then have multiple problems with the flag deployment.
– Volume 2, page 82.
When re-entering, Armstrong held on to the handrails and jumped about
as high as he could. He ended up on the third step of the ladder,
which is about “5-6 feet” (1.5-1.8m) up.
– Volume 2, page 89.
“COLLINS: […] When the LM is on the surface, the command module should
act like a good child and be seen and not heard.”
– Volume 2, page 97
“ALDRIN: There is some discomfort when you swallow a fair amount of
gas, but the biggest thing, I guess, is the fact that you just pass
more gas. Of course, that’s a big odor problem in the spacecraft.
COLLINS: I beg your pardon.
ALDRIN: I beg yours.
ARMSTRONG: Let’s go on to water glycol system.”
– Volume 2, page 130.
Hatch opening for egrees to hatch closing for ingress was 2h31m40s.
– Volume 3, page 15
By creating a 66 by 54 mile orbit, with the estimate that
irregularities in the lunar gravitational field would circularize the
orbit at 60 miles. “However, the onboard estimate of the orbit during
the rendezvous was 63.2 by 56.8 miles, indicating the ellipticity
decay rate was less than expected”.
– Volume 3, page 27
The landed lunar module was perfectly able to track the orbiting
command module using radar.
– Volume 3, page 42, with a nice graph of page 63.
Volume 2, page 50 has an interesting graph of altitude to altitude rate.
Remaining engine fire time remaining at landing: 43 seconds. Expected
RCS usage for descent: 18kg (40 lb). Actual: about 43kg (95 lb).
– Volume 3, page 60
The DC bus was 28.8 volts, and max current during the mission was 81
Amps. That’s 2’333 watts.
– Volume 3, page 109
Oxygen leak rate was about 22 grams (0.05 pounds) per hour, compared
to the specced rate of 90 grams per hour.
– Volume 3, page 125
Average heart rates during the entire mission were 71, 60, and 67
beats/min for the Commander, Command Module Pilot, and the Lunar
Module Pilot, respectively. During the powered descent and ascent
phases, the only data planned to be available were the Commander’s
heart rates, which ranged from 100 to 150 beats/min during descent and
from 68 to 120 during ascent.
– Volume 3, page 169
The total dose for each crewman is estimated to have been less than
0.2 rad, which is well below the medically significant level.
– Volume 3, page 170
Armstrong’s heart rate was above 120bpm from approximately 600m above
the surface, peaking at about 150bpm at landing two minutes later, and
went back below 120 another four minutes.
– Volume 3, page 175