Apollo 11, The First Landing
Created | Updated May 17, 2018
Project Apollo: The Beginnings
| Mission Planning
| Landing Site Selection
| Earthbound Support Systems
Astronaut Selection and Training | The Saturn V | The Saturn 1B | The Apollo Spacecraft
Guidance and Navigation | Command and Service Modules | The Lunar Module
Assembling and Launching | Pathfinders | The Early Missions | Apollo 11, The First Landing
The Intermediate Missions | Apollo 15 Exploration | Apollo 16 Exploration | Apollo 17 Exploration
Skylab and Apollo-Soyuz | Conclusion
The crew chosen for Apollo 11 was Neil Alden Armstrong, as Mission Commander; Edwin 'Buzz' Eugene Aldrin Jr, Lunar Module Pilot; and Michael Collins, Command Module Pilot. All three were born in 1930.
Neil A Armstrong from Wapakoneta, Ohio, learned to fly at the age of 14, joined the US Navy and (as a pilot) flew 78 combat missions in the Korean war. He was shot down on one mission but parachuted to safety. After the war, in 1955, he became an aeronautical engineer and joined the Lewis Research Centre as a test pilot. In April 1962, he flew the X-15 rocket plane to 4,000 mph on the outer edges of the Earth's atmosphere. He was later selected as an astronaut in the second group to be chosen and commanded the Gemini 8 mission.
Edwin 'Buzz' Aldrin from Montclair, New Jersey graduated from West Point, the US military academy, in 1951 with a bachelor's degree with honours in science. He also flew in the Korean war completing 66 combat missions. He obtained a PhD degree in astronautics at Massachusetts Institute of Technology (MIT), where his thesis subject was on techniques of orbital rendezvous and docking. Selected as an astronaut in the third intake group in 1963 he flew the last Gemini mission.
Michael Collins was born in Rome, Italy, where his father was a military attaché. He also graduated with a science degree from West Point Academy in 1952. In the United States Air Force he held the rank of Lieutenant Colonel and amassed 4,000 hours flying experimental jets from Edward's Air Force base, California. He was accepted into the third astronaut intake with Aldrin and flew in Gemini 10. He was selected as command module pilot for Apollo 8, but an operation for a spinal bone spur problem forced him to relinquish his place to James Lovell.
It took a year to train an Apollo crew for its mission, each member usually having at least eighteen months of previous astronaut training experience. Their training included 'flying' simulators of both the command and lunar modules, rehearsing and testing their spacecraft's procedures for every stage of the flight, and setting procedures for any situation that could conceivably go wrong. They received briefings at the CM and LM manufacturer's factories during the construction of the modules they were to fly. Training for the moonwalks required repeated practice of the procedures that were to be used while on the lunar surface; they also underwent lectures on geology and field training in volcanic and cratered locations throughout the USA.
In addition to simulator experience, Armstrong and Aldrin also practised real life handling with the Lunar Landing Training Vehicle (LLTV). A flying bedstead contraption, built by Bell Aerosystems. This was powered by a 4,200 pound thrust jet engine, which lifted five sixths of the vehicle's weight, while two 500 pound variable thrust rocket motors lifted the remaining sixth, its proportional weight in lunar gravity. Attitude of the craft was controlled by jet thrusters in the same manner as the lunar module, to give the feel and handling of the LM in the last few minutes of a moon landing, as far as could be replicated inside the Earth's atmosphere. In practice, the machine proved difficult to handle, and on one occasion Armstrong had to eject from the machine as it went out of control.
Lift-Off, 16 July, 1969
At dawn on 16 July, 1969, the crew of Apollo 11 breakfasted on the now traditional low fibre, low waste meal of steak and eggs, donned their spacesuits, and took the transfer van to the waiting spacecraft, which was steadily progressing through the final countdown to Take-off (T). Two and a half hours before lift-off, assisted by the white room 'close down' team, the astronauts settled into their take-off positions. The technicians closed the access hatches and withdrew, while the crew carried on with their check out routine to prepare themselves and Apollo 11 for launch.
T minus 43 minutes - The crew's access arm on the launch tower is retracted and swings away from Apollo to a ready position clear of the spacecraft but able to be redeployed if an emergency occurred. If sufficient time is available, the crew's escape route at this point in the countdown would be down a high speed access lift in the launch tower and into a chute that would take them to a concrete bunker under the launch pad. If time is limited, the escape would be in a cage and down a zip line to an armoured fire tender waiting at the edge of the pad.
T minus 6 minutes - The monotone voice of Launch Control, Public Affairs Announcer Jack King, broadcasts to television audiences around the world:
This is Apollo Saturn launch control. We've passed the six-minute mark in our countdown for Apollo 11, now five minutes, 52 seconds and counting. We're on time at the present time for our planned lift-off at 32 minutes past the hour. Spacecraft test conductor Skip Chauvin now has completed the status check of his personnel in the control room, all report they are go for the mission, and this has been reported to the test supervisor Bill Schick. The test supervisor is now going through some status checks... Launch operations manager Paul Donnelly reports go for launch. Launch director Rocco Petrone now gives the go, We're five minutes 20 seconds and counting...
T minus 5 minutes - The access arm is fully retracted and the Launch Escape Tower (LET) armed. At this point, in the event of an emergency evacuation of the spacecraft, the crew's only choice of escape route is with a twist of the abort handle, situated by Armstrong's left knee, which will fire the solid fuel rocket of the LET, mounted on a tower above the command module. This will lift the CM clear of the moon ship and launch pad to a height that will enable the CM's re-entry parachutes to be deployed and return the crew to the ground.
T minus 3 minutes 10 seconds - The automatic launch sequencer in the Launch Control Centre's (LCC) firing room takes over the countdown and begins a controlled sequence of several hundred events leading up to lift-off at T minus 0:00. The launch team continue to monitor the 'red line values', that is the temperatures and pressures in the Saturn's fuel systems, as pressure builds up in the tanks and the fuel load is topped off.
T minus one minute 54 seconds and counting... Our status board indicates that the oxidiser tanks of the second and third stages now have pressurised. We continue to build up pressure in all three stages here at the last minutes to prepare for lift-off... T minus one minute35 seconds on the Apollo mission, the flight to land the first men on the moon. All indications coming into the control centre at this time indicate we are go... One minute 25 seconds and counting... Our status board indicates the third stage completely pressurised... 80-second mark has now been passed....
T minus 50 seconds: - The Saturn V switches to its own internal power source; four of the nine service arms disconnect from the rocket and swing back to the launch tower.
Neil Armstrong just reported back it's been a real smooth countdown... we've passed the fifty second mark. Power transfer is complete, we're on internal power with the launch vehicle at this time... 40 seconds away from the Apollo 11 lift-off... all the second stage tanks now pressurised... 35 seconds and counting. We are still go with Apollo 11... 30 seconds and counting...'
T minus 17 seconds - The final alignment of the Saturn's on-board guidance computer in the instrument unit is completed by the master computer at launch control. The Saturn's guidance computer is transferred to its own internal power supply.
T minus 15 seconds... guidance is internal, twelve... eleven... ten...
T minus 10 seconds - A deluge system begins to pump water into a flame trench under the launch pad apron to cool the trench and damp out some of the noise and vibration from the exhaust of the Saturn's five engines.
T minus 8.9 seconds - Ignition of the five F1 engines begins, as the launch sequencer fires pyrotechnics inside each of the engines, igniting the pressurised fuel being pumped into their combustion chambers. Exhaust flames roar into the trench vaporizing the water deluge.
Ignition sequence starts, six... five... four... three...
T minus 2 seconds - Internal turbines in each of the five engines, driven by the exhaust gases, have built the supply of kerosene and liquid oxygen up to full flow, bringing the engine's thrust up to launch power. All five engines are running at 90 per cent of full power and are consuming fuel at the rate of 10,000 pounds per second. The water from the deluge system has increased to 50,000 gallons per minute, which is vaporised in the flame trench by the exhaust gases that are travelling at up to four times the speed of sound. The steam adds to the huge billowing cloud jetting out to each side of the launch pad. The on-board computer checks the systems in the Saturn twice per second for faults; if it finds one, it will shut the engines down.
T minus 0 seconds. GET 00:00:00 (Hr:Mn:Sec) - 32 minutes past nine EDT, the 'launch commit' signal from launch control's computer releases the hold down clamps on the launch pad, allowing the 3,000 ton rocket, which had now consumed some 80,000 pounds of fuel, to rise. As the Saturn V lifts off the launch pad, the first two centimetres of vertical travel trips the catch plates of the remaining service arms, which disconnect and swing clear. At the base of the S-IC twelve bolts, which anchor the rocket to the pad, pull through dies to slow the initial acceleration. At the moment of lift-off the launch countdown ends and the Ground Elapsed Time (GET) clock starts, which will time the mission to the final splashdown.
... zero, all engines running. Lift-off, we have a lift-off, 32 minutes past the hour, lift-off on Apollo 11.
GET 00:00:02 - The four outer F1 engines tilt slightly on their gimbals to induce a yaw manoeuvre, tilting the Saturn off vertical and moving the whole rocket stack sideways, away from the tower. Ice, which has formed on the Saturn's outer skin next to the liquid oxygen tanks begins to shed in large flakes. Three miles away in the viewing stand near launch control the air and ground vibrates from a wall of sound that can be felt beating against the spectators' chests. The shouts and cheers of 'Go!... Go!...Go!...' from among almost a million spectators in the surrounding countryside viewpoints are drowned out by the crackling roar of the Saturn's engines. In eight seconds it has cleared the launch tower, trailing a 300 foot sheet of flame.
Launch Control reports 'Tower clear'. On board the spacecraft, Armstrong reports, 'We have a roll program'. As Apollo 11 clears the launch tower, launch control's job is done; responsibility for the flight is assumed by the flight controllers at Mission Control Centre (MCC) in Houston, Texas, who also take over the commentary.
GET 00:00:15 - The Saturn begins a roll and pitch manoeuvre to point it out over the Atlantic ocean and into a trajectory that will curve it over and into the planned orbital insertion flight path. Apollo 11 accelerates into a near cloudless sky, building up a pressure wave in front of the craft. It passes through the speed of sound at over 600 mph vertically.
GET 00:01.00 - The three crewmembers are being pressed into their couches, as they experience acceleration forces in excess of 3g. From the ground the spacecraft disappears into the heavens, leaving a trail of exhaust gases and the sound of rolling thunder, as a cloud of white smoke drifts away from the now empty launch pad.
Downrange 1 mile, altitude 3, 4 miles now... velocity 2,195 feet per second.
GET 00:01:21 - The moment of maximum dynamic pressure (Max-Q) occurs, as the Saturn accelerates to 1,800 mph through 43,000 feet altitude, pushing the craft through the lower atmosphere and towards the thinner layers above. The ride is smooth; the crew lie back in their couches and monitor their instrument readings.
Eight miles downrange, twelve miles high, velocity 4,000 feet per second.
GET 00:02:00 - The fuel in the S-IC is running down. Armstrong gets the 'Go for staging' clearance from mission control.
GET 00:02:15 - The centre F1 engine shuts down at 145,000 ft altitude, the rocket is now 28 miles down range from the launch site, and at a speed of 4,400 mph.
GET 00:02:40 - The remaining four outboard engines shut down. They have consumed over 2,000 tons of fuel and reduced the rocket's weight by two thirds. Altitude is now 217,000 ft, downrange 57 miles and its speed is 6,100 mph. The crew slam forward in their harnesses. One second after shutdown, clamps holding the first stage release; eight solid-fuel retro-rockets fire to slow down the expended S-IC and separate it from the S-II second stage. The S-IC's work is done. The empty first stage drops away under the influence of gravity to fall back into the Atlantic Ocean. As the first stage separates, four 21,000 pound thrust ullage rockets in the S-IC/S-II interstage ring fire to push the fuel in the S-II to the bottom of its tanks. One second later the five J-2 engines of the second stage ignite and build up to full power. Acceleration continues and the crew are once more pressed back into their couches, as they continue to build up the lightened craft's speed and height.
GET 00:03:11 - At 301,000 feet altitude, downrange 100 miles, and speed 6,400 mph, the interstage is jettisoned; six seconds later the Launch Escape Tower's (LET) solid fuel rocket ignites and pulls the Boost Protective Cover (BPC) free. In the event of an emergency, the astronauts will now have to complete a short hop into space before they can re-enter.
GET 00:07:40 - Five minutes after ignition, the J-2 engines have built the craft's speed up to 12,800 mph. It is 690 miles downrange and at 588,000 feet. The centre engine shuts down and mission control reports that 'Apollo 11 is go for staging'.
GET 00:09:11 - Altitude 610,000 ft, Downrange 1,018 miles, Speed 15,500 mph. The four remaining engines shut down and the S-II separates. The single engine of the S-IVB third stage starts up. Two minutes into the S-II burn, mission control reports that 'Apollo 11 is go for orbit'. The J-2 engine continues to burn, accelerating Apollo 11 to an orbital velocity of over 17,000 mph.
GET 00:11:40 - Altitude 617,000 feet, downrange 1,639 miles, Speed 17,380 mph. The J-2 engine shuts down as Apollo 11 attains an orbital height of 101 nautical miles. The total weight of the spacecraft is now 300,000 pounds, four per cent of its original lift-off weight. The crew and mission control check out the craft during the next one and a half orbits and get the 'go' signal for the Translunar Injection (TLI) burn.
GET 02:44 (Hr:Min) - The J-2 engine is started for a second time, to burn for 5 minutes 20 seconds, which increases Apollo 11's speed to 24,182 mph, easing it out of the Earth parking orbit and on towards the moon.
GET 03:15 - The crew separate the CSM from the S-IVB; the four panels covering the lunar module are jettisoned; they carry out the Transposition and Docking Manoeuvre (TDM) to remove the LM from the top of the S-IVB. Apollo 11 and the S-IVB are now flying on parallel paths. The crew restart the S-IVB's engine remotely for the last time to send it on a course that will take it in a slingshot manoeuvre around the back of the moon and out into a permanent orbit around the sun.
During the translunar journey the astronauts settled into a routine and carried out a number of tasks, including putting Apollo into Passive Thermal Control (PTC) or 'barbecue mode'. They fired the attitude thrusters to induce a 0.3 degree per second roll around its central axis, preventing localised overheating due to the same side of the craft being constantly exposed to the sun while the opposing side freezes in constant shadow. Rotating the craft in this way evened out the overall thermal exposure.
Meals prepared from dehydrated, freeze-dried packs were reconstituted by adding water from either a hot or cold spigot that measured out one ounce quantities of water to the packs; after kneading, the contents were ready to be eaten. Typically, a meal in space for the Apollo 11 crew consisted of chicken and rice with salad, followed by sugar cookies and a pineapple drink. After the meal germicide pills were placed in the empty food packs to prevent fermentation and gas production while stowed in the waste compartment.
Toilet facilities were basic. Solid waste was collected in plastic defecation bags, containing germicides to prevent bacterial action, and stored in a compartment for post-flight analysis. Urine, also collected in bags, was ejected into space through a valve in the CM's cabin wall. Earlier Gemini astronauts had found that, if the ejection was timed so that the craft's valve opening rotated into the sunlight during the spacecraft's 'sunrise', a miniature fireworks display could be produced.
In a weightless environment water tends to separate into globules; to prevent the risk of droplets getting into electrical systems, washing was accomplished by means of wet towels and tissues. Shaving with the aid of an aerosol foam was found to be the most effective answer to the problem of a multitude of weightless bristles circulating in the capsule. Thousands of dollars had already been spent on the development of an electric razor with an attached vacuum cleaner and collection bag before shaving foam proved to be just as effective. In reality, the astronauts had an even more effective answer to the shaving question, as they rarely shaved at all throughout the flights. To clean their teeth the crew used chewing gum and edible toothpaste.
At this time in the Apollo program a recognised part of any space flight was television coverage, which attracted huge audiences throughout the world. On Apollo 11, the crew gave several transmissions of the craft's interior, demonstrated weightlessness with various objects floating in front of the camera, and showed the Earth from space through the CM's observation windows. Pictures of the western coast of North America, Mexico, and down through the Yucatan peninsula to Venezuela were all relayed back to Earth audiences.
GET 22:30 - The crew wakes after a rest period and prepares for a midcourse correction. Four burns of the Service Propulsion System's (SPS) engine in the Service Module are scheduled during the outbound flight. An earlier course correction burn had not proved to be necessary and had been cancelled. For the second, in order to get the correct parameters for engine's alignment and the duration of the burn, Collins has to take a star sighting to establish their position and attitude relative to a theoretical flight path, which has been stored in the on-board computer. He sights on two of a number of known stars through a sextant in the craft's navigation bay and, by pressing a key on the navigation computer, the alignment is transferred for comparison with the stored memory of star positions. With information supplied by MCC of the craft's range and speed , the computer is able to calculate the necessary alignment of the engine and duration of the burn to return it to the correct path.
GET 26:46 - At a distance of 109,000 miles from Earth Collins carries out a midcourse correction burn of the main Service Propulsion System (SPS) engine of three seconds duration to successfully correct the flight path. The trajectory of the spacecraft is now accurate enough to cancel the two subsequent planned correction burns. With the midcourse correction completed the crew settle down to rest, as, under the influence of the Earth's gravity, Apollo's speed slows to 3,400 mph. As it passes the point where the Earth's and the moon's gravity balance one another Apollo comes under the influence of the moon's pull, and begins to accelerate again.
GET 57:00 - The crew pressurise the lunar module; Armstrong and Aldrin enter it for the first time through the docking tunnel to check out its systems. Another television broadcast is given by Armstrong to show a world audience around its interior.
GET 75:32 - Apollo 11, accelerating under the gravitational pull of the moon, swings around its far side and approaches the critical Lunar Orbit Insertion (LOI) burn, where it will have to fire the SPS engine (retrograde to its line of flight) to reduce its speed, placing it in lunar orbit.
Apollo eleven, this is Houston. All systems are looking good going around the corner. We'll see you on the other side.
GET 75:41 - Mission control loses the signal (LOS) from Apollo 11 as it passes out of sight of the Earth. This will happen each time the spacecraft's orbit takes it around to the far side of the moon.
We have loss of signal as Apollo eleven goes behind the moon... We're seven minutes and forty five seconds away from LOI. With a good burn the Madrid station should acquire Apollo eleven at 76 hours 15 minutes and 29 seconds.
GET 76:15 - Acquisition of Signal (AOS). 'Apollo eleven, ... Apollo eleven, this is Houston, can you read me?'
Armstrong: 'Read you loud and clear...'
Apollo 11 had achieved an elliptical orbit of 170 by 60 miles with the LOI burn; after another two orbits, the SPS engine was fired from behind the moon for a further 16 seconds to establish a circular orbit of 60 miles above the lunar surface, from where the crew could observe the approach to the landing site, as they overflew the Sea of Tranquillity every two hours.
The First Lunar Landing
After ten orbits Armstrong and Aldrin entered the lunar module, Eagle, to prepare for separation from the command and service module, Columbia. Eagle was named after the bald eagle, the American national bird; Columbia was named in honour of the famous explorer and national figure, and with a nod in the direction of the fictional giant cannon, the Columbiad in Jules Verne's book From the Earth to the Moon. Co-incidentally, in the book, the Columbiad was situated near Tampa in Florida, only a hundred miles or so from Kennedy Space Center. It had been thought prudent to use less flippant call signs than those chosen by previous crews, which would be regarded as more appropriate for historical purposes if the landing was successful.
The mission patch on crew uniforms had been designed by Michael Collins, and originally depicted a bald eagle over a moonscape with wings spread, talons extended, and an olive branch in its beak. The outstretched claws were thought by the approval committee to be too menacing; the design was modified to show the olive branch in its talons. Collins observed dryly that he '...hoped it dropped the olive branch before landing'.
Inside Eagle, Aldrin began to test the Primary Guidance Navigation and Control System, PGNCS or 'pings', as it was generally referred to. The task of pings was to fly Eagle down a predetermined flight path to the landing site. Armstrong could take over control if necessary with the aid of the Abort Guidance System (AGS or 'aggs') and fly the craft manually. Aggs, a second on-board computer, would run a similar program consecutively with pings and comparison between the two checked out and backed up the primary system.
Aldrin checked the alignment of the LM's Internal Measurement Unit (IMU), which supplied orientation data to the 'aggs and pings' systems. The IMU sensed changes in the lander's orientation in relation to a theoretical flight path programmed into the computer. Gyroscopes and inertia sensors in the IMU registered Eagle's movements in the three planes of pitch, roll, and yaw, and fed the information to the computers for comparison. Once below 30,000 feet the computer would also have data from the landing radar; pings could make corrections to the actual flight path by gimballing the descent engine and firing the attitude thrusters to keep the craft on course.
Once their pressure suits were connected into the LM's environmental system, Aldrin aligned the S-band antennae with the Earth tracking station, while Armstrong checked out the VHF radio communication with Collins in the CSM. They completed their checks on all the LM's subsystems and, by the thirteenth orbit, were strapped into the restraining harness and ready for undocking.
GET 99:22 - Columbia and Eagle are about to pass around to the rear of the moon, where the craft undock; Collins will visually check out Eagle to see that its landing legs are fully extended. The Capcom for the landing is astronaut Charlie Duke.
MCC: 'Apollo eleven, Houston. We're go for undocking, over.'
Armstrong: 'Roger, understand.'
Apollo 11 passed out of sight and communication with Earth. Mission control transmitted their exchanges with Apollo 11 to an estimated one third of the world's population:
This is Apollo control at 100 hours and 14 minutes. We are now less than two minutes from re-acquiring the spacecraft on the 13th revolution... We're presently 25 minutes from the separation burn that will be performed by Mike Collins in the command module to give the lem and the CSM a separation of about two miles... We'll stand by now to re-acquire the spacecraft...
Columbia and Eagle undocked; Armstrong pirouetted Eagle to allow Collins to check that the landing gear was down and locked. Collins observed, 'You've got a fine looking flying machine there, Eagle, despite the fact you're upside down.' Undocked and with their individual call signs, the two craft re-appear from behind the moon keeping station with one another separated by about 1,000 feet.
MCC: 'Hello Eagle, Houston. We're standing by...'
Armstrong: 'Roger Houston... The Eagle has wings.'
GET 101:27 - Eagle and Columbia pass behind the moon again; the LM's descent engine is started for a 30 second burn for the Descent Orbit Insertion (DOI) manoeuvre. This is to create a new elliptical orbit for Eagle with a low point ten miles above the lunar surface east of Apollo Landing Site 2, from where they can initiate the final phase of the landing. The second burn is the Powered Descent Initiation (PDI) burn, which will slow Eagle sufficiently to drop out of orbit and descend to the landing site.
GET 102:27 - Communication is breaking up between Eagle and Houston. The computer program controlling the High Gain aerial alignment is having difficulty tracking Earth, as it is on the limit of its adjustment. Transmission between them has to be relayed to Eagle by Collins in Columbia. Houston recommends a ten degree yaw manoeuvre to align Eagle's aerial with Earth. They are only five and a half minutes from beginning the powered descent. 'Eagle, Houston, if you read you're go for powered descent.' Collins relays the message on.
GET 102:33 - Eagle reaches the lowest point of its new elliptical orbit, 300 miles up range of the landing site, 50,000 feet over the western edge of the Mare Fecunditatis (Sea of Fertility). Flying face down and landing legs first, Armstrong now has to decide whether to commit to the landing. He starts the computer's programmed flight plan and the engine restarts at 10 per cent power to initiate the PDI burn, then builds to its full thrust of 9,800 pounds, slowing Eagle's orbital speed so that its rate of descent increases and the craft begins its long drop towards the lunar surface.
Armstrong and Aldrin checked off landmarks on 'US 1', the unofficial name given to the landing site approach path. As they overflew the edge of the Sea of Tranquillity and the crater Maskelyne, Armstrong realised that, although their altitude and rate of descent are correct, they were arriving over their check positions about three seconds early. This meant that they were going to overshoot their target by about a mile for every second.
Eagle passed Maskelyne and three minutes into the burn Armstrong rolled the lander 180 degrees into a face up attitude to find themselves looking at the lunar sky with the Earth framed in their windows. Eagle's ground ranging radar locked on and began feeding altitude readings back to the computer and the crews display panel.
GET 102:38 - Descending through 34,000 feet, an amber coloured alarm light comes on for the first time.
Armstrong: 'Program alarm... It's a 1202.'
The alarm warned that the onboard computer was showing a '1202 executive overload.' Neither of the crew could immediately recognise the coded alarm but programmer-engineer Steven Bales in MCC, acting as flight controller monitoring computer activity, recognised the signal and was able to advise them that there was no serious cause for concern. Mission control informed the crew, 'Roger, we got you, we're go on that alarm.'
The computer was trying to advise the crew that it was overloading and was diverting excess information from the ground ranging radar. Aldrin cancelled the alarm, but it continued to re-occur as they descended at a rate of 132 feet per second. On their return to Earth, Steve Bales stood beside Armstrong and Aldrin in the White House Rose Garden and received the 'Medal of Freedom' in recognition of his decision to continue the mission.
GET 102:39 - At 25,000 feet pings cuts the engines to 60 per cent power and begins to pitch Eagle up so that the crew can begin to see the moonscape in the direction of the landing site through their observation windows. The alarm starts to flash again. Mission control reported:
Seven minutes 30 seconds into the burn... Altitude 16,300 feet.
Eagle, ten miles up range from the landing site was being taken by pings to a point in the descent flight plan 7,500 feet high and five miles up range, where it would fire Eagle's thrusters in a 'pitchover manoeuvre' to bring the spacecraft from its near horizontal attitude to 45 degrees off the vertical, allowing the crew to see the approaching landing site.
We are now in the approach phase...everything looking good. Altitude 5,200 feet.
Eagle continued to kill off its vertical descent rate, but still had forward speed. Armstrong took control of the attitude thrusters as Aldrin read off rate of descent and horizontal ground speed figures from the computer display. Armstrong called for the Landing Point Designator (LPD) readings, which he could align with two scales scribed on the LM's window to give him a line of sight to the precise point on the ground to which pings predicted the landing point would be. By blipping the hand controller Armstrong could command the computer to move the projected landing spot, which would alter the spacecraft's attitude, flying the craft to the re-designated site.
Altitude 42 hundred feet.
At 3,000 feet the alarm went off again. Aldrin reported: 'Program alarm... 1201.' Mission control gave the go-ahead to continue the descent.
Eagle approached its landing site with minimal forward and descent speeds, but it had already overshot the original target site by nearly four miles. As it descended through 600 feet towards the surface, Armstrong could see that they were heading towards the edge of a crater, West crater, which was surrounded by large boulders. He switched the guidance system to aggs, allowing him to take full manual control and fly Eagle directly through the hand controller in the manner of a helicopter.
...400 feet (altitude), down at 9... 8 forward... (feet per second)... You're pegged on horizontal velocity...
Controlling the engine thrust with his left hand and the attitude thrusters with his right Armstrong increased the forward speed, overflying the crater and the boulder field while searching for a suitable place to set down. Mission control read out the estimated remaining fuel reserve as Aldrin continued to call out the instrument readings:
300 feet down at three and a half... 47 forward, slow it up... That's it's (LM's) shadow out there...
Armstrong and Aldrin could now see the shadow of the LM on the surface in front of them.
Altitude velocity light, three and a half down, 220 feet.. Coming down nicely, 200 feet, four and a half down... 100 feet three and a half down, nine forward.. 5 per cent [fuel remaining]... quantity light.. Okay 75 feet, things looking good...
Mission control reported that there was only 60 seconds worth of fuel remaining.
Lights on... sixty feet... down two and half... forward... forward... that's good... forty feet, down two and a half... picking up some dust...
As they approached the surface the crew's sight of the ground was being obscured by surface dust blown across it from the engine's efflux.
30 feet, two and a half down.. faint shadow.. four forward, four forward...drifting to the right a little...
Armstrong tried to correct Eagle's sideways drift and keep the craft's forward movement, so that touchdown would occur on ground he has just passed over, reducing the risk of putting a landing pad in an unseen crater. Mission control reported 30 seconds of fuel left.
One of the three, five foot long probes extended under the landing gear pads touched the lunar surface and triggered a blue warning light on the dash display. Armstrong punched the engine stop button and Eagle settled onto the moons surface.
In a flurry of activity Aldrin disarmed the power circuits to the engine and called up the computer program 413 that stored the spacecraft's orientation at landing. This would serve as a base navigational reference which would have to be used by the abort guidance computer if they needed to make an immediate take-off.
Neil Armstrong reported:
Houston, Tranquillity base here. The Eagle has landed.
Mission supervisors and technicians in the control centre erupted in a spontaneous burst of applause and cheering as Armstrong's words came through.
Roger Tranq... Tranquillity, we copy you on the ground. You've got a bunch of guys about to turn blue, we're breathing again, thanks a lot.
GET 102:45:43 - Touchdown on the Sea of Tranquillity at 0.71 degrees North, 23.63 degrees East was at 3.17pm Houston time, 8.17pm GMT 20 July, 1969, with less than 30 seconds of fuel remaining.
The First Lunar EVA
One minute after touchdown, there was another decision for Armstrong to make: T1, stay/no stay. Was it safe to remain, or should they abort the mission and take-off if the craft was in a precarious position? They began a countdown to prepare for an immediate take-off, as they assessed their situation. The T1 extension would last only 4 minutes, the time during which they could take off, catch, and rendezvous with Collins in Columbia, who had passed overhead during the final minutes of Eagle's descent. Four minutes later with the landing established, mission control advised them that they were OK to stay until T2. This extended the stay time to at least two hours, the duration of Columbia's next orbit when it would have circled the moon and returned to a point where Eagle could launch to meet up. Meanwhile, mission control had also been busy,
This is Apollo control at 103 hours 44 minutes. We have some updated information on the landing point. It appears that the spacecraft Eagle touched down just about on the lunar equator at 23.46 degrees longitude, which would put it about four miles from the targeted landing point down range. At this point all LM systems seem to look very good.
T2 passed and Eagle was committed to stay. Armstrong and Aldrin abandoned the countdown and began to power down the lander. They described the view from the observation windows while configuring the lander to stay. Aldrin commented on their surroundings,
Ah, we'll get to the details of what's around here, but it looks like a collection of just about every variety of shape, angularity, granularity, about every variety of rock you could find. The colours are, well pretty much depending on how you're looking relative to the zero phase point. There doesn't appear to be too much of a general colour at all, however it looks as though some of the rocks and boulders, of which there are quite a few in the near area, it looks as though they're going to have some interesting colours to them over.
[The view from] the window is a relatively level plain cratered with a fairly large number of craters of the five to fifty foot variety and some ridges, small twenty, thirty feet high, I would guess, and literally thousands of little one and two foot craters around the area, we see some angular blocks out several hundred feet in front of us that are probably two feet in size and have angular edges. There is a hill in view, just about on the ground track ahead of us, difficult to estimate but might be half a mile, or a mile.
GET 105:00 - The crew take a meal and are scheduled to start a four hour rest period, prior to commencing the first Extra Vehicular Activity (EVA).
The mission planners' expectation that the crew would be able to sleep immediately after completing the first moon landing, during which Armstrong had registered a heart rate of 156 and Aldrin 125, was somewhat optimistic. They were about to step out onto another world and mission control concurred with the crew's plan to bring the moonwalk forward in the schedule. They began their preparations to go outside by donning their EVA Personal Life Support equipment.
The EVA suit, known as the Integrated Thermal Meteoroid Garment (ITMG), worn throughout the landing consisted of a multilayered garment costing over $100,000. Manufactured by the International Latex Corporation of Delaware, the outer layers were made from Mylar, an aluminiumised material which was designed to reflect direct sunlight and ward off possible hits from micro meteorites.
The innermost layer worn next to the skin, was a cotton, long john like, comfort garment called the Liquid Cooled Garment (LCG), which was equipped with a network of plastic tubes, through which cooling water was circulated next to the astronauts' skin to remove excess body heat within the suit. The next layer was a one-piece pressure bladder, made of thin neoprene rubber, to retain the inner oxygen pressure. To prevent this bladder ballooning when inflated, a restraint layer of stiff fabric, articulated joints and wire cables retained the suit's shape while allowing flexibility. Separate integrated gloves locked onto the pressure suit's metal cuff rings; supplementary over-boots and gloves for use during the EVA went over them.
The suit was articulated at the ankles, knees, hips, elbows and shoulders to facilitate movement. Umbilical tubes connected the suit to the spacecraft's environmental system during the landing, but were connected to a Personal Life Support System (PLSS) backpack for the EVA. The inner pressure helmet consisted of a 0.25 inch thick 'Lexan' plastic globe that locked onto a neck ring on the pressure suit, and an outer plastic helmet incorporating two visors: one with a polarising finish and the second coated with a reflective metallic oxide to guard against direct sunlight.
The PLSS backpack unit was essentially a portable environmental unit which provided the oxygen, temperature regulation, and communication services to the suit. Manufactured by Hamilton Standard, the PLSS fed oxygen to the suit at a pressure of 3.8 pounds per square inch, circulating it by a fan through the suit and a lithium hydroxide filter to remove exhaled carbon dioxide. The cooling water from the inner LCG garment was circulated by a pump in the PLSS through the backpack and the suit in a closed loop. A secondary, expendable water supply from a header tank in the PLSS, removed the heat in the primary circuit through a heat exchanger coil. The secondary water circuit sublimated the heated water to the vacuum of space thereby removing the excess heat from the suit.
The PLSS also contained batteries and radio for communications on the lunar surface with the other astronaut and back to Earth via a relay through the LM. Carried on top of the PLSS was an Oxygen Purge System (OPS) for use in an emergency, if either the PLSS or the suit failed. Operation of a toggle on the suits control panel could maintain suit oxygen pressure from a reserve oxygen bottle for up to an hour in the event of failure of either the suit or the PLSS, giving the astronaut time to return to the LM and plug into its environmental system. In all, the complete suite and PLSS backpack combination, referred to as Extra vehicular Mobility Unit (EMU), weighed more than the astronaut, but its use in weightless or one-sixth lunar gravity made it manageable.
GET 109:04 - The crew decompressed the LM, venting its oxygen into space and, with a little difficulty, pried the hatch open. Assisted by Aldrin, Armstrong backed through the hatch and out onto a porch at the top of the lander's ladder. By pulling a lanyard at the top of the access ladder he deployed the Modularised Equipment Stowage Assembly (MESA), which included a monochrome TV camera focussed on the ladder. As the camera came into operation, the first stark, grainy television pictures from the surface of the moon were transmitted back to Earth; an Earth-wide audience was able to see the figure of Armstrong descending the ladder to the lunar surface. He paused on the footpad of the lander.
I'm at the foot of the ladder. The lem footpads are only depressed in the surface about one or two inches, although the surface appears to be very, very fine grained, as you get close to it, it's almost like a powder. Now and then it's very fine... I'm going to step off the lem now...
From the landing pad Armstrong moved his left foot out and placed it on the surface of the moon.
That's one small step for man... one giant leap for mankind.
GET 109:24:26 - Armstrong stepped with his left foot onto the moon at 9.56pm Houston time, 20 July 1969. In London, England, it was 2.56am GMT 21 July, 1969; in Canberra Australia the time was 12.56pm AEST 21 July, 1969.
On the surface Armstrong described the lunar surface surrounding the craft and his footprint in the dust. He clipped a Hasselblad camera to the front of his suit and photographed the area under the lander and the footpads. He stepped back from Eagle's shadow into the sunlight to take more photographs of the LM and a panoramic view of the surrounding moonscape. Mission control meanwhile was becoming concerned that he should collect a 'contingency sample', one of the prime objectives of the mission, a sample of moon rock. In the event of having to abort the EVA at this early stage they wanted to be sure that they had a sample to return to Earth.
Using a scoop with an extendible handle he scraped a sample from the surface and tried to put it into a pocket in his suits legging. Hampered by the suit it required Aldrin's guidance from the LM to get the pocket flap open and the sample into the pocket. Back on Earth scientists breathed a sigh of relief as their object of the mission was secured.
Armstrong guided Aldrin out of the LM's hatch and down the ladder taking a photograph of him as he descended. Aldrin later remembered 'making sure not to lock it on the way out'. He stepped out onto the surface some 18 minutes 12 seconds behind Armstrong and described his surroundings as 'Magnificent desolation'. Aldrin had set a 16mm camera in the LM's window running exposures at one frame per second to record their movements around the spacecraft. They adjusted the TV camera lens to show themselves as they uncovered a plaque on the lander. It showed the two hemispheres of the Earth with a message below:
Here Men from the Planet Earth First set Foot Upon the Moon.
JULY 1969, AD.
We Came in Peace for All Mankind.
Below the inscription it bore the signatures of the three crewmen and President of the United States, Richard Nixon.
Moving around on the surface did not prove difficult, but the astronauts were still hampered by the space suits, despite the low gravity. Various means of locomotion were tried and the one easiest to maintain was a bouncing walk dubbed the 'kangaroo hop', although their ability to stop or change direction required care due to their high centre of mass. Armstrong then relocated the TV camera to a point north of the LM showing the lander and its surrounding moonscape. They continued with a number of scheduled tasks and setting up experiments to be left behind on the surface.
The priority of the Apollo 11 mission was to establish a landing and, due to weight and time constraints, it carried only a limited scientific package. The Early Apollo Surface Experiment Package (EASEP) contained only two experiments to be left behind on the surface, a solar powered Passive Seismic Experiment (PSE) and a Laser Ranging Retro Reflector (LRRR). Aldrin deployed the PSE, a passive seismometer, the purpose of which was to measure seismic activity or 'moon quakes'. The instrument contained a weight which remained immobile while the remainder of the casing responded to tremors from the lunar landscape; the relative motion between the weight and casing, converted to an electrical signal, was beamed back to Earth. Power for the instrument came from two attached solar panels, converting sunlight to electricity. Accompanying the seismometer, the LRRR received a laser beam fired from Earth and reflected it back, so that the exact distance from the Earth to the moon could be measured from the returned beam.
Aldrin erected the Stars and Stripes flag, but he had difficulty getting the frame on which it was mounted to fully unfold; he also had problems getting the support pole far enough into the surface to stay upright. He then set out a Solar Wind Experiment (SWE). The SWE was a panel of thin sheet aluminium on a frame set to face the sun to record the passage of any free particles such as helium, neon, krypton, or xenon through the foil.
Armstrong meanwhile, carried on collecting for the bulk sample and using the Hasselblad camera. He also carried a second 'Gold' camera, named after radio-astronomer Thomas Gold. It was used for close-up stereoscopic surface photography to investigate Gold's theories on lunar surface composition. Gold had postulated that the lunar surface would be covered in a deep layer of loose dust, into which the spacecraft could sink without trace.
Aldrin only used the Hasselblad for a short period during the EVA, taking panoramic photographs around the lander and of the lander itself during his inspection of the craft. Consequently few photographs taken with the Hasselblad are of Armstrong on the lunar surface. Post flight analysis of the photos revealed difficulties in identifying individual astronauts and led to the introduction of 'commanders stripes', on later crew's suits and helmets to make individual identification in photographs easier.
Aldrin then carried out a number of mobility experiments, evaluating the ease with which they were able to move around in the one sixth gravity. With movement curtailed in the stiff suit he experimented with running, changes of direction, and stopping. Their perambulations were interrupted by mission control to bring them into the TV camera's field of view together to be addressed by the United States President, Richard Nixon from the White House's Oval Office.
Hello Neil and Buzz, I am talking to you by telephone from the Oval Room at the White House and this certainly has to be the most historic telephone call ever made. I just can't tell you how proud we all are of what you... For every American, this has to be the proudest day of our lives, and for people all over the world, I am sure they too join with America in recognizing what an immense feat this is. Because of what you have done, the heavens have become a part of man's world, and as you talk to us from the Sea of Tranquillity it inspires us to redouble our efforts to bring peace and tranquillity to Earth. For one priceless moment, in the whole history of man, all the people on this Earth are truly one. One in their pride in what you have done, and one in our prayers that you will return safely to Earth.
Aldrin later recalled that among all the talk of peace and tranquillity he was concerned that the flag would not fall over in front of the television cameras. The proceedings were relayed to Collins circling above who was 'probably the only person around without television coverage'. In fact only four nations on Earth, China, Albania, North Korea and North Vietnam did not inform their populations of the landing, while the USSR made the announcement on a television broadcast some six hours after the event.
Armstrong continued to take the main bulk of rock samples, while Aldrin took core samples from the surface. He experienced extreme difficulty in driving the sampler tube into the surface more than a few inches; with time running out, despite an extension of the EVA by 15 minutes, he was unable to complete all the scheduled sampling tasks.
At this point in the EVA, Armstrong had decided to carry out a small, unscheduled excursion of his own. During the landing he had overflown the large 'West Crater', into which pings had been directing the craft, and then a 30 yard wide 'Little West crater', some 50 yards from the landing point, which is the closest feature to Tranquillity Base on the otherwise flat mare. Unannounced, and out of sight of the television camera, Armstrong ran out to Little West Crater to take a panoramic photo of the crater, but didn't have time to take a sample from its interior. His trip used the last few minutes available to him before the astronauts began to close up the EVA.
Buzz, this is Houston. You have approximately three minutes until you must commence EVA termination activities, over. Neil, this is Houston. Anything else you can throw into the box would be acceptable.
Aldrin returned to the LM; Armstrong hoisted the sample boxes, camera, and solar wind experiment using the Lunar Equipment Conveyor (LEC), which essentially was an endless looped lanyard and pulley, to transfer the samples up to the Aldrin on the LM's porch. Armstrong recorded his highest heart rate of 160 while using the LEC, which he had dubbed the 'Brooklyn Clothesline'. Aldrin's highest rate during the EVA had reached 125. With both astronauts inside the LM they depressurised the cabin and removed the PLSS packs, outer boots, and gloves. Connected back up to the LM's systems by umbilical they later depressurised the cabin again and jettisoned the backpacks and now redundant overgarments to compensate for the weight of rock samples.
The EVA had lasted for 2 hours 31 minutes, during which they collected a total of 44 pounds of lunar rock and dust. After answering a number of questions on various aspects of the EVA they finally settled down to a rest period of eight hours fitful sleep, during which Aldrin slept on the LM's floor while Armstrong laid across the engine cover with the aid of a jury-rigged strap hammock for his legs. Neither of the crew slept well in the cramped conditions, both were cold and the environmental system pumps were noisy, preventing either of them resting. They were awake when the following morning's wake-up call from mission control came through to begin breakfast and the countdown to launch from the lunar surface.
Return to Orbit
GET 124:03 - With twenty minutes to go before lift-off Armstrong and Aldrin begin the final checklist to clear the spacecraft for take-off. Capcom Ron Evans reminds them of a revised procedure to leave the radar circuit breakers open to prevent another computer overload. Evans clears them for take-off. Aldrin quips, 'Roger, Understand, We're number one on the runway.'
GET 124:05 - Armstrong test fires the attitude control thrusters to confirm that they are functioning correctly. Aldrin fires two squibs, small explosive charges that open valves in the craft's helium tanks to pressurise the engine's propellant tanks. The helium tank's pressure gauge does not show the expected drop that it should if it has opened correctly. They try again, repeating the process, but the pressure remains constant. They continue with the countdown checks, as the propellant tank gauges are showing that the tanks are fully pressurised. Aldrin arms the circuits to the explosive bolts that will sever the ascent and descent stages just before the ascent engine's ignition. A communication check with Collins in Columbia brings them to the last two minutes of the countdown.
GET 124:20:58 - Aldrin arms the ascent engine and begins the final countdown.
GET 124:22:00 - The explosive bolts blow, separating the ascent stage; at the same instant, the ascent engine fires. Eagle lifts off from the moon's surface for its final flight. The four foot high, 3,500 pound thrust ascent engine accelerates Eagle out of the Sea of Tranquillity while the 'aggs and pings' guidance system fires the attitude thrusters to pitch the flight path west over the nearby craters Sabine and Ritter, to intercept the approaching Columbia's orbital path.
Eagle continued to gain height, wallowing slightly; after seven minutes, having obtained an orbital height of over 60,000 feet, the engine shut down. The flight path took them into a 9.5 by 47 mile high elliptical orbit over the lunar equator to the far side of the moon, where they begin a number of manoeuvres, using the attitude thrusters to create a circular orbit about 15 miles below and 67 miles behind Columbia, closing at about 130 feet per second.
GET 127:55 - As Eagle and Columbia re-appear from behind the moon for the second time they are lined up and closing to docking distance. Collins docks smoothly with Eagle but, as he throws the switch for the hard dock, in his own words, '...all hell breaks loose'. The alignment of the two craft is slightly off; as the docking mechanism pulls the two craft together into a hard dock, the computers in both craft sense the yawing movement and try to compensate by firing their thrusters in competition with one another. It requires both Collins and Armstrong to isolate the LM's computer and correct the pitching craft's movement with their thrusters.
Under control once more the docking tunnel hatch was opened; after vacuuming themselves and the 'million dollar' sample boxes thoroughly, Armstrong and Aldrin transferred back into Columbia. Eagle was closed off and jettisoned to be left in orbit around the moon. It was abandoned in orbit with all its systems still running, but with the cooling water supply to its electronic systems cut off to allow flight engineers to monitor its demise. It was another eight hours before its signals faded and contact was lost. Eagle eventually crashed back on the lunar surface, as its orbit decayed; but the information obtained would later prove critical to the Apollo 13 mission. Eagle's final point of impact remains unknown.
GET 135:25 - Once more above the far side of the moon the service module's engine is fired for a two and a half minute burn to build up speed to an escape velocity of 5,300 mph, pushing Columbia out of lunar orbit and into a return path to Earth.
GET 150:04 - The crew carry out a midcourse correction in an otherwise largely uneventful return trip.
In one midcourse correction, the SM's thrusters were fired retrograde to slow the craft by 4.8 feet per second to align the flight path with the re-entry corridor, bringing it over the Pacific Ocean where the recovery fleet were awaiting its return. No further course adjustments proved necessary. Back on Earth scientists were beginning to receive data from the moon bound seismometer; but they were having difficulty in locating the laser reflector, as they had not yet pinpointed Apollo 11's exact landing spot.
GET 177:31 - The crew send back their last television transmission to Earth audiences. They give their impressions of the mission. They thank the scientists and technicians who had built the craft and developed the technology, and salute the will of the American people that had made the mission possible. Around the world a force of nine ships and 54 aircraft are taking up station, while 19 tracking stations are preparing for their return. The recovery ship, the aircraft carrier USS Hornet steams around the predicted splashdown point, some 1,000 miles south-west of Honolulu in the Pacific Ocean. The use of the carrier, the USS John F Kennedy had been vetoed by the Nixon administration.
Re-entry and Splashdown
GET 194:50 - Collins 'deadfaces' the circuits between the command and service modules, then arms and fires the pyrotechnics to separate the two parts of the craft. An explosive charge operates a guillotine that cuts through the connecting wiring and links between the two craft; a ring of explosive bolts severs the final connection, allowing the service module to separate. The SM is jettisoned, leaving the CM weighing 12,250 pounds, one fifth of a percent of the original craft that lifted off the launch pad eight days previously, and the only part of Apollo 11 to return under controlled flight to Earth. The CM manoeuvres to place its two inch thick heat shield forward, ready to protect the craft from the heat produced by friction with the atmosphere as it plunges in at 24,000 mph.
GET 195:03 - Heat begins to build up as Apollo re-enters the outer fringe of the Earth's atmosphere. The heat shield, composed of carbon fibre plugs in a honeycomb matrix, protects the crew from a 5,000 degree external temperature, which ionises the surrounding air, cutting off radio waves and causing a total communication blackout with the craft during the re-entry flight, lasting about four minutes. The outer layers of the ablation material burn away taking heat from the craft, while blue and violet flames curl around the edge of the heat shield. The flames can be seen by the crew through their observation window, as they travel across the dawn sky, leaving a glowing ionised trail from 1,700 miles up range of the splashdown target area. The friction also begins to slow Apollo's velocity through the atmosphere.
As the craft plunged through the upper layers of the atmosphere, the computer began to manoeuvre the capsule through a parabolic, switchback-like curve designed to relieve the g-forces being experienced by the crew. It also slowed the capsule's rate of descent, allowing it to cool for a few moments, before continuing its downward flight into the denser atmosphere at a reduced velocity.
GET 195:12 - Apollo has slowed sufficiently to deploy drogue parachutes at 23,000 feet to stabilise the craft and slow its rate of descent still further. One of the tracking aircraft operating west of the target area gets a visual contact with Apollo. The drogues continue to slow the descent, until at 175 mph the three main recovery parachutes are deployed at 10,000 feet. Apollo descends through an eighteen knot wind speed and into a sea running a seven foot swell.
GET 195:18:35 - Splashdown in the Pacific at Latitude 13 degrees 19 min North, Longitude 169 degrees 9 min West. The end of Apollo 11's flight to the moon finally realises President John F Kennedy's challenge.
Recovery and Isolation
Four Navy Sea King helicopters from the recovery ship Hornet were already airborne and on their way to the spacecraft, which had been dragged upside down by the collapsing parachutes in the sea swell, into a 'Stable 2' position. Inflation of buoyancy bags brought the craft upright to a 'Stable 1' position. Divers from one of the Sea Kings jumped into the water and attached a flotation collar around the capsule and then withdrew to a dingy upwind of the spacecraft. Mindful of the possibility of 'Back Contamination', the crew were to be kept in isolation for 18 days to insure against the possible spread of any harmful bacteria brought back from the moon. One diver clad in a biological isolation suit remained with the spacecraft as the hatch was opened. He passed three more isolation suits to the Apollo crew to wear during their transfer to USS Hornet. The suits, which included respirators, permitted the crew to breath fresh air, but their exhalations were filtered to prevent the escape of bacteria.
As the Apollo crew left the capsule they were scrubbed down with a decontaminating iodine solution by the diver who, in return, was brushed down by the astronauts. The outside of Apollo's hatch was also cleaned and sealed. The crew were picked up by the helicopter and transferred to Hornet, which on landing, was immediately lowered to one of the hanger decks and placed alongside an isolation cabin. The cabin, which displayed a notice, 'Hornet plus 3', above its observation window, was to be the astronauts' home until they were transferred to the Lunar Receiving Laboratory (LRL) quarantine quarters at Houston, Texas. The astronauts transferred between the helicopter and the isolation cabin; a final cleaning of the helicopter and the deck where they had walked completed the transfer. They were later greeted by President Nixon, who had flown out to Hornet for the homecoming.
The Apollo crew in the isolation cabin were initially transferred to Honolulu, along with the Apollo spacecraft, and then on to more permanent quarters at the Lunar Receiving Laboratory at Houston, where they were debriefed on all aspects of the flight and recuperated, before being returned to the outside world two and a half weeks later. During one of the debriefings Collins was asked if he had any further comments, his reply: 'I want out!'
The samples returned by Apollo 11 provided the first tangible evidence of the moon's make up. The 44 pounds of moon rock and dust also provided some surprises. On opening the sample bags in the LRL, in view of full television coverage, the first sight of the rocks covered with dust looked like 'Dirty coal'. When cleaned and analysed, half of the rock samples proved to be igneous basalt, which had originated from the lava flows that had created the maria, proving that the moon had at one time been hot and active. Dating the samples showed them to be around 3.65 billion years old. The lava samples proved to have a high titanium content, indicating a low viscosity when molten and explaining their apparent dark colouring. A new titanium bearing mineral was also found and given the name Armalcolite, derived from the first letters of the crew's surnames, ARMstrong ALdrin and COLlins.
Other rocks were regolith breccias, rocks created by the fusing together of components of the regolith soil by the forces generated in high speed meteoric impact. Many of the rocks also exhibited minute 'zap pits', where they had been exposed to the rain of micro meteorites over aeons. The soil samples, which mainly consisted of pulverised basalt, also provided a surprise in the form of a proportion of minute glass spherules, thought to have originated from the fusion of the rocks by the heat of high-speed impact. What the samples did not show was any sign of life. No evidence was found of any water, sedimentation or organic compounds, from which it was concluded that the moon had always been dry and lifeless.
The image of Columbia's descent and splashdown was picked up on a television camera on one of the waiting recovery helicopters, and relayed to audiences throughout the world. The pictures were also displayed on one of the large screens on mission control's status board. Alongside, another screen bore the words:
I believe that this nation should commit itself to achieving the goal, before the decade is out, of landing a man on the moon and returning him safely to Earth.
- John F Kennedy , 25 May, 1961
A second screen showed the words:
Task accomplished, 24 July, 1969.