Launch from Cape Canaveral (
KSC) and
landing 1600 km southwest of Honolulu in the Pacific Ocean.
The
Command Module (CM) was a conical pressure vessel with a maximum
diameter of 3.9 m at its base and a height of 3.65 m. It was made of an
aluminum honeycomb sandwich bonded between sheet aluminum alloy. The base of
the CM consisted of a heat shield made of brazed stainless steel honeycomb
filled with a phenolic epoxy resin as an ablative material and varied in
thickness from 1.8 to 6.9 cm. At the tip of the cone was a hatch and docking
assembly designed to mate with the lunar module. The CM was divided into three
compartments. The forward compartment in the nose of the cone held the three
25.4 m diameter main parachutes, two 5 m drogue parachutes, and pilot mortar
chutes for Earth landing. The aft compartment was situated around the base of
the CM and contained propellant tanks, reaction control engines, wiring, and
plumbing. The crew compartment comprised most of the volume of the CM,
approximately 6.17 cubic meters of space. Three astronaut couches were lined up
facing forward in the center of the compartment. A large access hatch was
situated above the center couch. A short access tunnel led to the docking hatch
in the CM nose. The crew compartment held the controls, displays, navigation
equipment and other systems used by the astronauts. The CM had five windows:
one in the access hatch, one next to each astronaut in the two outer seats, and
two forward-facing rendezvous windows. Five silver/zinc-oxide batteries
provided power after the CM and SM detached, three for re-entry and after
landing and two for vehicle separation and parachute deployment. The CM had
twelve 420 N nitrogen tetroxide/hydrazine reaction control thrusters. The CM
provided the re-entry capability at the end of the mission after separation
from the Service Module.
The
Service Module (SM) was a cylinder 3.9
meters in diameter and 7.6 m long which was attached to the back of the CM. The
outer skin of the SM was formed of 2.5 cm thick aluminum honeycomb panels. The
interior was divided by milled aluminum radial beams into six sections around a
central cylinder. At the back of the SM mounted in the central cylinder was a
gimbal mounted re-startable hypergolic liquid propellant 91,000 N engine and
cone shaped engine nozzle. Attitude control was provided by four identical
banks of four 450 N reaction control thrusters each spaced 90 degrees apart
around the forward part of the SM. The six sections of the SM held three
31-cell hydrogen oxygen fuel cells which provided 28 volts, two cryogenic
oxygen and two cryogenic hydrogen tanks, four tanks for the main propulsion
engine, two for fuel and two for oxidizer, and the subsystems the main
propulsion unit. Two helium tanks were mounted in the central cylinder.
Electrical power system radiators were at the top of the cylinder and
environmental control radiator panels spaced around the bottom.
The
lunar module (LM) was a two-stage vehicle designed for space
operations near and on the Moon. The spacecraft mass of 15,065 kg was the mass
of the
LM including astronauts, propellants and expendables.
The dry mass of the ascent stage was 2180 kg and it held 2639 kg of propellant.
The descent stage dry mass was 2034 kg and 8212 kg of propellant were onboard
initially. The ascent and descent stages of the
LM operated as a unit until staging, when the ascent
stage functioned as a single spacecraft for rendezvous and docking with the
command and service module (
CSM). The descent stage comprised the lower part of
the spacecraft and was an octagonal prism 4.2 meters across and 1.7 m thick.
Four landing legs with round footpads were mounted on the sides of the descent
stage and held the bottom of the stage 1.5 m above the surface. The distance
between the ends of the footpads on opposite landing legs was 9.4 m. One of the
legs had a small astronaut egress platform and ladder. A one meter long conical
descent engine skirt protruded from the bottom of the stage. The descent stage
contained the landing rocket, two tanks of aerozine 50 fuel, two tanks of
nitrogen tetroxide oxidizer, water, oxygen and helium tanks and storage space
for the lunar equipment and experiments, and in the case of
Apollo 15,
16, and
17, the lunar rover. The descent
stage served as a platform for launching the ascent stage and was left behind
on the Moon.
The ascent stage was an irregularly shaped unit approximately
2.8 m high and 4.0 by 4.3 meters in width mounted on top of the descent stage.
The ascent stage housed the astronauts in a pressurized crew compartment with a
volume of 6.65 cubic meters which functioned as the base of operations for
lunar operations. There was an ingress-egress hatch in one side and a docking
hatch for connecting to the
CSM on top. Also mounted along the top were a
parabolic rendezvous radar antenna, a steerable parabolic S-band antenna, and 2
in-flight VHF antennas. Two triangular windows were above and to either side of
the egress hatch and four thrust chamber assemblies were mounted around the
sides. At the base of the assembly was the ascent engine. The stage also
contained an aerozine 50 fuel and an oxidizer tank, and helium, liquid oxygen,
gaseous oxygen, and reaction control fuel tanks. There were no seats in the
LM. A control console was mounted in the front of the
crew compartment above the ingress-egress hatch and between the windows and two
more control panels mounted on the side walls. The ascent stage was launched
from the Moon at the end of lunar surface operations and returned the
astronauts to the
CSM.
The descent engine was a deep-throttling
ablative rocket with a maximum thrust of about 45,000 N mounted on a gimbal
ring in the center of the descent stage. The ascent engine was a fixed,
constant-thrust rocket with a thrust of about 15,000 N. Maneuvering was
achieved via the reaction control system, which consisted of the four thrust
modules, each one composed of four 450 N thrust chambers and nozzles pointing
in different directions. Telemetry, TV, voice, and range communications with
Earth were all via the S-band antenna. VHF was used for communications between
the astronauts and the
LM, and the
LM and orbiting
CSM. There were redundant transceivers and equipment
for both S-band and VHF. An environmental control system recycled oxygen and
maintained temperature in the electronics and cabin. Power was provided by 6
silver-zinc batteries. Guidance and navigation control were provided by a radar
ranging system, an inertial measurement unit consisting of gyroscopes and
accelerometers, and the
Apollo guidance computer.
The
Early Apollo
Surface Experiments Package (EASEP) consisted of a set of scientific
instruments emplaced at the
Apollo 11 landing site by the astronauts. This package
was the forerunner of the
ALSEP experiment packages used on the later
Apollo missions. It consisted of two solar panels to
provide power (the
EASEP could only operate during lunar day), an antenna
and communications system to send data to Earth ground stations and receive
commands, a passive seismometer, designed to measure seismic activity and
physical properties of the lunar crust and interior, and a lunar dust detector,
to measure dust accumulation and radiation damage to solar cells. The
EASEP consisted of a square base on which was mounted
the seismometer and dust detector, along with an isotope heater and cylindrical
antenna mast with an antenna positioning mechanism. Two brackets protruded from
opposite sides of the base and held the canted rectangular solar panels,
positioned to face towards the east and west. The unit had a total mass of 48
kg. The
EASEP received uplink commands at 2119 MHz and
transmitted telemetry data back to Earth at 2276.5 MHz. The laser ranging
retroreflector (LRRR) was also considered part of the
EASEP although it was not attached to the unit and
required no power. It was deployed about 5 meters NNW of the
EASEP.
The
EASEP was deployed approximately 17 m south of the
LM, at 0.6735 N latitude, 23.4730 E longitude and was
turned on by ground command at 04:40:39
UTC on July 21, 1969 while the astronauts were still
on the surface. About 5 hours before local lunar sunset at 10:58:46
UTC on August 03, 1969 transmission was stopped by
ground command when the power began to drop as predicted. Despite operating
temperatures which exceeded the planned maximum by 30 C the
EASEP functioned normally. The instrument was turned
on again on the next lunar day but on August 27, 1969, near noon of this second
lunar day, the
EASEP no longer accepted commands from Earth stations
and the experiment was terminated.
This mission marked the
first
manned lunar landing on July 20, 1969 (Neil
Armstrong and Buzz
Aldrin). On July 20, 1969 the lunar module (
LM) Eagle separated from the command module Columbia.
Michael
Collins, alone aboard Columbia, inspected Eagle as it
pirouetted before him to ensure the craft was not damaged. As the descent
began, Neil
Armstrong and Buzz
Aldrin found that they were passing landmarks on the surface
4 seconds early and reported that they were "long": they would land miles west
of their target point. Five minutes into the descent burn, and 6,000 feet
(1,800 m) above the surface of the Moon, the
LM navigation and guidance computer distracted the
crew with the first of several unexpected "1202" and "1201" program alarms.
Inside Mission Control Center in Houston, Texas, computer engineer Jack Garman
told guidance officer Steve Bales it was safe to continue the descent and this
was relayed to the crew. The program alarms indicated "executive overflows",
meaning the guidance computer could not complete all of its tasks in real time
and had to postpone some of them. During the mission, the cause was diagnosed
as the rendezvous radar switch being in the wrong position, causing the
computer to process data from both the rendezvous and landing radars at the
same time. However, in 2005, software engineer Don Eyles concluded in a
Guidance and Control Conference paper, that the problem was actually due to a
hardware design bug that had been seen previously on testing of the first
unmanned
LM for
Apollo 5. Having the rendezvous radar on (so that it
was warmed up, in case of an emergency landing abort) should have been
irrelevant to the computer, but an electrical phasing mismatch between two
parts of the rendezvous radar system could cause the stationary antenna to
appear to the computer as dithering back and forth between two positions,
depending upon how the hardware randomly powered up. The extra spurious cycle
stealing, as the rendezvous radar updated an involuntary counter, caused the
computer alarms. When Neil
Armstrong again looked outside, he saw that the computer's
landing target was in a boulder-strewn area just north and east of a 300 meters
(980 ft) diameter crater (later determined to be "West crater", named for its
location in the western part of the originally planned landing ellipse). Neil
Armstrong took semi-automatic control and, with Buzz
Aldrin calling out altitude and velocity data, landed at
20:17
UTC on July 20, 1969 with about 25 seconds of fuel
left.
Apollo 11 landed with less fuel than other missions,
and the astronauts also encountered a premature low fuel warning. This was
later found to have been due to greater propellant 'slosh' than expected,
uncovering a fuel sensor. On subsequent missions, extra baffles were added to
the tanks to prevent this. Neil
Armstrong continued with the remainder of the post landing
checklist, "Engine arm is off" before responding to Charles
Duke
with the words, "Houston, Tranquility Base here. The Eagle has landed." Neil
Armstrong's abrupt change of call sign from "Eagle" to
"Tranquility Base" caused momentary confusion at Mission Control and Charles
Duke
remained silent for a couple of seconds before expressing the relief of Mission
Control: "Roger, Twan-Tranquility, we copy you on the ground. You got a bunch
of guys about to turn blue. We're breathing again. Thanks a lot." The landing
area was the Sea of Tranquility.
At 02:39
UTC on Monday July 21, 1969 (10:39pm EDT, Sunday July
20, 1969), Neil
Armstrong opened the hatch, and at 02:51
UTC began his descent to the lunar surface. The Remote
Control Unit controls on his chest kept him from seeing his feet. Climbing down
the nine-rung ladder, Neil
Armstrong pulled a D-ring to deploy the Modular Equipment
Stowage Assembly (MESA) folded against Eagle's side and activate the TV camera,
and
at 02:56:20
UTC (10:56:20pm EDT) he set his left foot on the
surface. The first landing used slow-scan television incompatible with
commercial TV, so it was displayed on a special monitor and a conventional TV
camera viewed this monitor, significantly reducing the quality of the picture.
After describing the surface dust as "very fine-grained" and "almost like a
powder", Neil
Armstrong stepped off Eagle's footpad and uttered his famous
line
"That's one small step for [a] man, one giant leap for mankind" six
and a half hours after landing. Buzz
Aldrin joined him, describing the view as "Magnificent
desolation." Neil
Armstrong and Buzz
Aldrin, who followed 13 minutes later, collected lunar rocks
and other material (21.55 kg). Also, a solar wind composition experiment was
deployed and later recovered and they build a scientific station (
EASEP), including a passive seismic experiment and a
laser ranging retro reflector. The crew had a telephone call with U.S.
President Richard Nixon during lunar surface staying and they erected the U.S.
flag.
The total lunar surface stay time was 21h 36m. At 17:54
UTC, they lifted off in Eagle's ascent stage, carrying
21.5 kilograms of lunar samples with them, to rejoin
CMP
Michael
Collins aboard Columbia in lunar orbit. During the launch
Buzz
Aldrin looked up in time to see the exhaust from the ascent
module's engine knock over the American flag they had planted. The two
spacecrafts performed a successful docking of
LM Eagle with
CSM Columbia (with Michael
Collins on board, who had little to do, while Neil
Armstrong and Buzz
Aldrin landed on the moon).
The recovery ship was
the
USS
Hornet. The astronauts were carried by helicopter to the Hornet where they
entered a mobile quarantine facility to begin a 17 day-period of observation
under strict quarantine conditions.