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Apollo 11 Zusammenfassung
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Gestartet: 16. Juli 1969
Gelandet auf dem Mond: 20. Juli 1969
Landestelle: Das Meer der Ruhe
Rückkehr zur Erde: 24. Juli 1969
Kommandomodul: Columbia
Mond-Landemodul: Eagle
Mannschaft
Neil A. Armstrong, Kommandant
Edwin
E. Aldrin, Jr., Pilot des Landemoduls
Michael Collins, Pilot des
Kommandomoduls
Ersatzmannschaft
James Lovell, Ersatzkommandant
Fred Haise, Ersatzpilot des
Landemoduls
William A. Anders, Ersatzpilot des Kommandomoduls
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Apollo 11 Animationen |
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Das Kommandomodul über Kratern, vor dem Verlassen der Umlaufbahn des Landemoduls zur Landung.
Start des Sinkflugs, die Stimme sagt: „You're go for landing“.
Ansicht der Oberfläche: Jede Art Felsen, die man sich vorstellen kann.
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In seinem Kommentar zum Apollo 17 Protokoll sagt Gene Cernan, daß, nach seiner Erfahrung, die Landung eines Jets auf einem Flugzeugträger bei Nacht schwieriger ist als die Landung des LM. Sicherlich, im LM erhielt er jede Hilfe von der Erde, die Sicht war gut, und es gab keine Winde oder Wellen, die das Ziel bewegen. Trotzdem, das LM war ein experimentelles Fluggerät, und das, welches Neil Armstrong und Buzz Aldrin gelandet hatte, war erst das vierte, das jemals gefolgen worden war. Und, natürlich, keine Flugzeugträgerlandung hatte jemals die historische Bedeutung der Apollo 11; und keine Trägerlandung wurde jemals vor einem derart umfangreichen Publikum ausgeführt. Buchstäblich Milliarden Menschen hörten zu, als es passierte.
Bis zu einer Höhe von 50.000 Fuß (etwa 15.000 Meter) unterschied sich Apollo 11 kaum von Apollo 10. Armstrong, Aldrin und der Pilot des Kommandomoduls Mike Collins hatten einen makellosen Start von der Erde, einen langen, ereignislosen Flug zum Mond und einen nominellen Maschinenstart, um sich selbst auf eine Umlaufbahn um den Mond zu bringen. Als sie zum ersten Mal das Meer der Ruhe überquerten bemerkte Armstrong, daß „die Bilder und Karten, die Apollo 8 und 10 gebracht hatten, eine sehr gute Vorschau auf das gegeben hatten, worauf man hier sieht. Es sieht genauso aus wie auf den Bildern; aber, wie beim Unterschied zwischen dem Ansehen eines Fußballspiels im Stadion und dem im Fernsehen: es gibt keinen Ersatz dafür, tatsächlich hier zu sein.“ Während diesem ersten Umlauf war die geplante Landestelle selbst noch von der Dunkelheit vor Sonnenaufgang umhüllt, und es dauerte bis zum vierten Umlauf, bis Aldrin - während des Checks des LMs - davon berichtete, sie durch das Fenster des LMs sehen zu können.
In seinem exzellenten Buch „To a Rocky Moon“ („Zu einem felsigen Mond“) diskutiert der Geologe Don Wilhelm das Prozedere, nach dem die Landestellen der Apolloprogramme ausgesucht wurden. Nach Apollo 12 erhielten wissenschaftliche Überlegungen ein denkbares Gewicht, aber für die ersten Landungen wurden die Stellen vollkommen nach durchführbaren Gesichtspunkten ausgewählt. Während der Lunar Orbiter Missionen wurden die hochauflösenden Kameras auf die vielversprechenden Stellen entlang eines 10 Grad breiten Bandes um den Mondäquator gerichtet. Die Gebiete um den Äquator waren deshalb von Interesse, weil sie mit einem Minimum an Treibstoffverbrauch zu erreichen waren. Die Stellen befinden sich mindestens 45 Grad westlich des östlichen Horizonts des Mondes - der rechten Kante von der Nordhalbkugel der Erde aus gesehen - weil die Landefahrzeuge von Ost nach West flogen und Houston mehrere Minuten zum Datensammeln benötigte, bevor die Daten der Landungscomputer vor dem Absinken angepaßt werden konnten. Jack Schmitt bemerkte das Folgende, als er diese Einführung revidierte: Der angepeilte Punkt für Apollo 8 wurde als der östlichste ausgesucht, von dem die Flight Control Division (Flugkontrolle) dachte, sie könne ihn noch handhaben, die östlichste gesicherte (akzeptabel glatt) Stelle, von der man dachte, es würde die Zeit nach AOS (Acquisition of Signal, Wiederempfang des Sendesignals) ausreichen, um das Lunar Module zu erkennen, seinen Bewegungsvektor zu aktualisieren und eine erfolgreiche Landung hinzulegen. So wurde Apollo 8 auf dieses Ziel (bezeichnet als Apollo Landestelle 1) eingerichtet und, als die Zeit für Apollo 10 gekommen war, fand die Stelle wieder Verwendung, weil ein grobes Datenpaket bereits bekannt war (das heißt, Daten über Orbits und das Timing der Ereignisse während der Mission), die noch auf Grundlage der relativen Positionen von Erde und Mond zur geplanten Startzeit verfeinert werden konnten (die Startzeiten wurden so ausgesucht, daß im Zeitpunkt der Landung die Sonne dort zwischen 5 und 13 Grad über dem Horizont stehen würde, tief genug, um durch den Schattenwurf Aufschluß über die Gegend zu erhalten, und hoch genug, um das Überdecken und damit mögliche Übersehen wegen langgeworfenen Schatten zu vermeiden. Die Lichtverhältnisse am Cape und an den Abbruchlandestellen waren ebenfalls von Kalkül).
Als ich hörte, daß man beabsichtigte, Apollo 10 zur gleichen Landestelle zu schicken wie Apollo 8, ging ich zu Tom Stafford und sagte, „Tom, Sie wissen, das ist wahrlich nicht der geeignetste Weg, um Apollo 11 vorzubereiten. Erstens kennen wir die Apollo-8-Stelle, zugegebenermaßen aus einer hohen Umlaufbahn (60 Meilen Höhe), und wir kamen mit gewisser Überzeugung davon ab, daß sie akzeptabel sei. Zweitens, lassen wir Apollo 10 zur nächsten gesicherten Landestelle westlich davon fliegen (die gesicherten Landestellen wurden etwa 12 Grad von einander entfernt ausgesucht - das ist ungefähr die Entfernung, die die Tageslinie in 24 Stunden wandert - für den Fall, daß es eine Startverzögerung gab und man deshalb nicht einen ganzen Monat warten wollte), und eingedenk der Tatsache, daß Apollo 10 einen zusätzlichen Tag im Orbit bleiben sollte, wird die Sonne, wenn wir soweit sind zu starten, an einer dritten Stelle aufgegangen sein. So werden wir nach Apollo 10 über drei Optionen für Apollo 11 verfügen.“ Dies war mein grundlegendes Argument. Und Tom mochte die Idee.
So arbeitete ich weitere Details aus und begann damit, die Idee die Kommadokette entlang nach oben weiter zu reichen. Eine der angesprochenen Personen war Jerry Hammack, der Chef der Wiederbeschaffung, der mit der Bergung auf der Erde befaßt war. Wir waren in unserer Diskussion etwas hängengeblieben, um seine Aufmerksamkeit zu erregen, den hätten wir das gleiche Ziel für Apollo 10 wie für Apollo 8 angepeilt, wäre es zu einer vormorgentlichen, sozusagen nächtlichen Wasserung gekommen. Und deshalb war er nervös. Wir hatten keine Ahnung, wie nervös er war, aber es erschien uns als keine sehr gute Idee, und durch die Auswahl der nächsten Landezone würde im Pazifik eine Wasserung nach Sonnenaufgang daraus folgen. Und als wir Chris Kraft ansprachen, ging die Diskussion hin und her, und Jerry sagte, als ich einen Moment einhielt: 'All das und eine Landung bei Tageslicht'. Das hatte Chris beeindruckt, und ich denke, deshalb schlug er sich auf unsere Seite.
Danach gingen wir, spät abends, eine Ebene höher zu George Low und Sam Phillips, die zur Zeit in der Stadt (Houston) waren, und boten ihnen eine ganze Präsentation. Als wir den Raum wieder verließen deutete George an, er hielte es für keine sehr gute Idee. Sam hatte gar nichts angedeutet, aber er sgate, wir wären gerade noch unterhalb der Grenze, ab der wir das Datenpaket ändern könnten. So waren wir ausgesprochen entmutigt, als Tom und ich gingen. Aber am nächsten Morgen rief mich Tom an und sagte, George habe seine Meinung geändert. Ich antwortete, „ich denke, Sam Phillips hat seine Meinung geändert.“ Aber, aus welchem Grund auch immer, sie sagten, wir sollen weitermachen und die nächste Landestelle ins Visier nehmen. Und die lag dann im Meer der Ruhe. Als wir Apollo 11 in Angriff nahmen, gab es keine Fragen. Wir wußten, daß wir genügend Zeit zur Verfügung haben würden, nachdem der Horizont überschritten war, die Erfassung wäre abgeschlossen (auf Apollo 10), und wir hätten Nahansicht (zwischen 9 bis unter 60 Meilen). Und sogar ich konnte nicht dafür streiten, daß wir weiter westlich landen sollten.“
Sechsundachtzig Stunden und fünfeinhalb Umläufe nach Start der Mission machte sich die Mannschaft der Apollo 11 auf die letzte Ruhephase vor der Landung bereit. Wie Jack Schmitt in seinem Kommentar zu Apollo 17 ausführt können sechs Stunden eingeschobenen Schlafs im Orbit so erholsam sein wie sechs Stunden ununterbrochenen Schlafs auf der Erde, zumal die Mannschaft der Apollo 11, während der Entfernung von der Erde, während jeder der Ruhephasen zwischen neun und zehn Stunden Schlaf hatte. Die letzte Ruhe vor der Landung war notwendigerweise kurz, aber alle drei genossen sechs Stunden tiefen Schlafs. Als der Weckruf - beantwortet von einem sehr verschlafenen Mike Collins - nach 93 Stunden Missionsverlauf ankam, waren sie ausgeruht für den historischen Tag, der vor ihnen lag.
In den nächsten acht Stunden machten sich Armstrong, Aldrin und Collins bereit für den Abstieg. Als sie zum vierzehnten Male hinter dem Mond verschwanden, waren sie umgezogen und bereit, und gerade noch wenige Minuten entfernt von der 30-sekündigen Zündung entfernt, die das LM auf die absteigende Flugbahn der Apollo 10 bis zu einer Höhe von 50.000 Fuß bringen sollte. Collins würde auf der kreisförmigen Bahn 60 nautische Meilen oberhalb des Mondes bleiben, und wegen dieser höheren Flugbahn hatte er zuerst wieder Funkkontakt zur Erde. Alles hatte funktioniert. Das LM würde gleich um die Ecke kommen und völlig pünktlich sein.
Es gab keine Sitze im LM. Armstrong und Aldrin standen, festgehalten von Gummibändern, die am Boden angebracht waren. Sechzehn Minuten lang sahen sie durch das Fenster und maßen die Zeit, die die Bodenmerkmale für ihr Vorbeiziehen benötigten (gesehen durch eine markierte Skala auf Armstrongs Fenster), um die Daten zu bestätigen, die Houston empfing. Mit Hilfe aus Houston überprüften sie auch den ordnungsgemäßen Zustand des LM.
Als die zwölfeinhalbminütige Landezündung erfolgte, hatten sie ihr Fahrzeug so gedreht, daß sie mit ihren Füßen und dem Antrieb voraus flogen. Sie flogen auch mit den Fenstern zum Mond, so daß sie eine Kontroll-Zeitnahme anhand der Bodenmerkmale machen konnten; aber dann, wie geplant, drehte Armstrong das Fahrzeug mit der Vorderseite nach oben. Nun mußten er und Aldrin mit dem Rücken zum Mond fliegen, so daß Armstrong, wenn sie der Landestelle näherkommen und sich das LM wieder richtig herum drehen, den Grund voraus sehen kann und einen guten, klaren Blick auf die Landestelle erhaschen kann. Während sie flogen überwachten sie die Funktion des LM und die Ausgaben des Steuerungscomputers. Alle Daten wiesen darauf hin, daß sie sich sehr nahe an der geplanten Flugbahn befanden.
Falls, wie Cernan meint, eine Landung auf dem Mond leichter ist als eine auf einem Flugzeugträger bei Nacht, war eines der vielen Abenteuer, daß das LM mit einem - für die damalige Zeit - hochentwickelten Onboard-Computer ausgestattet war, der einen Großteil der Routinearbeiten beim Fliegen des Raumfahrzeugs übernahm. Die ganze Zeit über mit Ausnahme der letzten Momente der Annäherung war die richtige Flugbahn zu halten eine Angelegenheit des ständigen Analysierens der Navigationsdaten aus den Trägheits- und Radarsystemen und dann feiner Abstimmungen des Schubs und der Richtung des Antriebs des LM. Es war eine arbeitsintensive Aufgabe und bei einem Computer in den besten Händen. Bis zu einem Ereignis namens Pitchover (wörtlich etwa Umkippen) - bei dem sich das Fahrzeug von einem Winkel von 60 zu einem von 20 Grad zur Vertikalen rollt - hatten die Rollen der Astronauten nicht mehr bedeutet als zu überwachen.
Mehrmals während des Sinkflugs hatten die omputer Alarm gegeben. Die Flugbahn sah gut aus, aber eine „1202“-Warnung - wie eine spätere „1201“ - waren der Mannschaft unbekannt, und so gab es einige angespannte Sekunden, bis Houston ein „Wir sind auf GO mit diesem Alarm“. Wie sich herausstelte waren Teile der Speicher der Computer mit fremden Daten aus dem Rendezvous-Radar überlastet, doch glücklicherweise wurden die Computer nicht nur so programmiert, daß sie die wichtigen Aufgaben weiter verfolgen konnten, außerdem benötigte die Person, die die Maschine am besten kannte, - der Ingenieur Steven Bales - nur wenige Sekunden, um das Problem zu erkennen und zu erklären, daß die Landung fortgesetzt werden kann. Bales stand später neben der Mannschaft bei einer Feier im Weißen Haus und wurde für seinen einzigartigen Beitrag zum Erfolg der Mission ausgezeichnet.
The on-board computer handled a variety of tasks during the descent and, in addition to the unanticipated flood of data from the radar, there were also annoying, computer-related losses in communications with Earth. The LM was equipped with a pair of broad-beam, "omni-directional" antennas, but a high rate of data transmission could be achieved only through use of a narrow-beam, steerable antenna. It was the computer's job to maintain proper spacecraft orientation so that the high-gain antenna could maintain a lock on Earth. The computer had been instructed to avoid certain spacecraft orientations which would force the antenna to look through the LM and, thereby, lose enough signal strength that the "lock" on Earth would be lost. However, the computer had been given an inaccurate "map" of the LM and loss of signal was a recurring problem throughout the descent. Because the precise landing spot was not critical on this first mission, all that Houston needed was enough information to be sure that the spacecraft was operating properly and, through the combined use of the omni antennas and voice relays through Collins in the Command Module, adequate communications was maintained.
The program alarms and the communications dropouts were annoying but in all other respects, the LM computer and the navigation system performed beautifully. Eight minutes and thirty seconds into the burn, the computer pitched the LM nearly upright and Armstrong got his first close-up view of the place to which the computer was taking them. He was about 5000 feet above and about 20,000 feet east of it. As planned, he had fuel enough for five more minutes of flight. Each of the astronauts had a small, double-paned, triangular window in front of him. On the inner surface of each pane in Armstrong's window, there was a long vertical scale marked in degrees and, at right angles to it, a similar but shorter horizontal scale. At pitchover, Armstrong positioned himself so that the vertical scales were aligned; and Aldrin read a computer output to him that indicated just where he should look on the scale to see find the computer's intended landing point. In principle, if he didn't like the spot, he could pulse the pistol-grip hand controller forward or back or to either side and, thereby tell the computer to move the target a small amount in the indicated direction. According to plan, Aldrin was to give Armstrong an "angle" every few seconds until, at an altitude of about five hundred feet, the window targeting lost its usefulness and Armstrong took over complete manual control for the final descent.
However, once Aldrin had given him an initial target angle, Armstrong realized that, although the site selection team had picked a smooth patch of ground, the state of the guidance art at the time of Apollo 11 wasn't nearly as refined as it would be for the later missions, and fate and the computer were taking the LM into a field of boulders on the northeast shoulder of a crater the size of a football field. Nowhere on the Moon are craters of that size more than a few kilometers apart and, for this first landing, the NASA flight engineers were not yet ready to fine-tune the approach trajectory to much better than about eight kilometers east or west of the target point and about two kilometers north or south. The Apollo 11 "landing ellipse" contains dozens of craters a hundred meters across or more, and the important point is that the LM had plenty of range so that Armstrong could avoid even the largest of them.
There was no doubt in Armstrong's mind about landing in the boulder field. It wasn't essential that he land the LM perfectly upright. A tilt of up to fifteen degrees would cause no particular problem with a launch. However, if he hit the engine bell or one of the landing struts on a large rock, there would be a real chance of sustaining structural damage. Two minutes after pitchover and about two minutes prior to the landing, Armstrong took action. He decided to follow an old maxim: "When in doubt, land long." To do that, he would have to overfly the crater and land well to the west of it; and there was clearly no point - nor really much time - to give the computer enough of an update via the hand controller. The Landing Point Designator (LPD) was designed for fine tuning and what Armstrong needed was a big change. So he switched to manual control, pitched the LM forward, and began to fly it like a helicopter. Within seconds, he had slowed his rate of descent from about twenty feet per second down to about three and flew the LM about 1100 feet west beyond the craters and the boulders
Even with the computers to help, landing a LM was a tricky operation, one that required countless hours of training in indoor simulators and in an ungainly "flying bedstead" called - more formally - the Lunar Landing Training Vehicle. According to Cernan, the LLTV was actually harder to fly than the LM. It was equipped with a big jet engine which provided enough thrust to counteract 5/6th of the pull of Earth's gravity and that big engine - firing more or less straight down - made the trainer more unstable than the LM. Indeed, during training, Armstrong had to eject from one of the LLTV's. His was the second of three trainers that went unstable and crashed and, as Cernan relates, the trainer he flew in preparation for Apollo 17 was the only survivor of an original fleet of four. The long hours of training paid off, of course.
While Armstrong flew the LM toward a good landing spot, his attention was totally focused on the job at hand. Aldrin did virtually all the talking; and he, too, was all business. He read the computer output to Armstrong, giving him their altitude, their rate of descent and their forward speed. Back in Houston, Flight Director Gene Kranz and other members of the support team in the Mission Control Room were watching telemetry from the LM. They did not know about the crater yet - Armstrong wouldn't discuss it until well after the landing - but it was obvious that the landing was taking longer than planned. Indeed, with each passing second there was mounting concern about how much fuel remained. Because of uncertainties in both the gauges in the tanks and the estimates that could be made from telemetry data on the engine firing, the amount of time remaining until the fuel ran out was uncertain by about 20 seconds. If they got too low, Kranz would have to order an abort.
Drama was the last thing that any one had wanted for the first landing. The event itself was exciting enough. Finally, Armstrong found a place that he liked and he began to kill his forward velocity and let the LM ease down toward the surface. As they came down through 75 feet, Duke radioed that they had sixty seconds of fuel left and, in the cabin, Aldrin had already seen a warning light that was telling him the same thing. But they were close now and it was just a matter of easing themselves down. Armstrong had killed almost all of their forward velocity and now, as they began to kick up dust with the engine exhaust, he asked Aldrin to confirm that they were still moving forward a little. He wanted to land on the surface he could see in front of them, rather than on ground he couldn't see behind them. Aldrin gave him the confirmation that he wanted and, eight seconds later, they saw the contact light. The ten-foot-long probes that dangled from the landing gear had touched the Moon. A second or two later they were down and had the engine shut off. Forty seconds had passed since the sixty-second warning, but they were down.
(Post-mission analysis indicated that they actually had about 45 seconds of fuel left, rather than 20. Nonetheless, it the smallest margin of all the Apollo landings. Note, also, that, in the interest of reducing uncertainty, the fuel gauging system was improved for Apollo 12.)
Despite the drama of the moment and the enormous feelings elation and relief that they both felt, Armstrong and Aldrin had little time for anything but getting the LM ready for an immediate departure. No one expected that they would have to launch right away but, just in case a problem did develop - say a leak of the high pressure helium that they would use to pressurize the propellant tanks in the Ascent Stage, they wanted to be ready. However, despite being very busy with things in the spacecraft for nearly two hours after they landed, from time to time they stole glances out the window and described the scene for the radio audience back on Earth.
In all directions, the land was West Texas flat. The circular horizon was broken here and there by the subtle rims of distant craters. In the middle distance, Armstrong and Aldrin could see boulders and ridges, some of the latter perhaps 20 or 30 feet high. Close at hand, a hodgepodge of craters pockmarked the surface; and there were small rocks and pebbles scattered everywhere. It was a flat, level site but, as with Australia's Nullarbor (Latin for "Treeless") Plain, small variations gave the surroundings a subtle beauty of its own. And, of course, because this was the very first landing on the Moon, everything was of enormous interest. However, before Armstrong and Aldrin could pay much attention to the view or think about going outside themselves, they had to be sure that they had a healthy spacecraft and that the navigation computer was properly loaded with the information needed to get them back to orbit for a rendezvous with Collins. Finally, two hours after the landing, they and the NASA engineers were satisfied that the LM was ready to come home and, therefore, that it was safe to stay for a while.
According to the flight plan, Armstrong and Aldrin were scheduled to take a five-hour rest break before getting ready to go outside. However, it came as no surprise when they suggested to Houston that, after a scheduled hour-long meal, they prepare for what was called, in the NASA jargon, an EVA - a period of Extravehicular Activity. Normally, the EVA preps were supposed to take about two hours but, because this was to be the shortest of the Apollo EVA's no one -except, perhaps, the waiting, worldwide TV audience - was bothered when the EVA preps actually took three and a half hours.
Finally, about six and a half hours after the landing, they had the hatch open and Armstrong crawled out onto the porch - feet first and on his hands and knees. Moments later he was on the top rung of the ladder and pulled a lanyard to release a work bench / stowage area that was attached to the side of the LM. The Modular Equipment Storage Assembly or MESA was pivoted at the bottom so that, when Armstrong pulled the lanyard, the MESA swung down into a horizontal position. The most important piece of gear on it was undoubtedly the black-and-white TV camera. It was mounted in such a way that, when the MESA swung down, the camera was pointed directly at the foot of the ladder. For the astronauts, the landing had been the big moment of the mission. But, for the waiting world, the big moment was still to come - the first footstep.
From the bottom rung of the ladder, Armstrong had to make a three-foot jump down to the footpad - a contingency against a less than gentle landing that might have compressed and shortened the landing strut. From the footpad, he had only a couple of inches to step down to the surface itself. He stood on the pad for a moment or two, testing the soil with the tip of his boot before he made the epochal "small step".
The soil was very fine grained and had a powdery appearance and, once he stepped down, his boot sank perhaps a couple of inches, making a sharply defined print. Because of the Moon's relatively weak gravity field (one-sixth as strong as Earth's), Armstrong's total weight - half astronaut, half suit and backpack - was only about sixty pounds. Movement wasn't particularly tiring but because of the dramatic upward-shift in his center of mass caused by the backpack, he had to lean forward to keep his balance and it took a few minutes before he could walk comfortably. Just in case he had to end the EVA suddenly, Armstrong used a long-handed tool called the Contingency Sampler to scoop up a bit of rock and soil into a Teflon bag. He then removed the bag from the Sampler, folded it, and stored it in a shin pocket.
Aldrin joined Armstrong out on the surface about fifteen minutes later and then, for the next hour and forty minutes, the two of them examined the LM, moved the TV camera out about 50 feet, deployed a pair of scientific instruments, and collected more samples. One important set of questions to be addressed, of course, concerned the crew's ability to get the work done. If all went well, following crews could stay longer on the Moon, venture farther from the LM, and undertake more ambitious sets of tasks. For the first half hour or so, neither Armstrong nor Aldrin did more than a shuffling walk as they went about their work and it was planned, after this initial period of familiarization, for Aldrin to try to take advantage of the 1/6th gravity and try to run. Starting from near the LM, he first ran toward the TV camera, rolling from foot to foot in a loping or, as Jack Schmitt calls it, a cross-country skiing stride. Then as he turned and ran back toward the LM, he used the same gait again but twice changed direction by sticking a foot out to the side and pushing off of it, rather like an American football running back. Coming back toward the camera for a second time, he tried a kangaroo hop but decided that it didn't give him as much fore/aft stability as he got with the loping gait. It looked as though a crew that ventured a few hundred meters away from their LM would be able to run back in just a few minutes if the need arose.
In general, the crew of Apollo 11 went about their work with appropriate caution. However, as with later crews, as time passed, their confidence grew. Generally, they walked without bounding and, compared with later crews, their movements seem fairly stiff and restricted. However, toward the end of the EVA, the TV audience got a glimpse of Armstrong running back from a brief visit to a crater 60 meters east of the spacecraft. There was even one moment - a bit earlier in the EVA when Aldrin was lifting the scientific instruments down from its storage compartment - when Armstrong appeared to bob down on one knee, a difficult maneuver in the stiff spacesuit. Clearly, it was possible to get work done and to move with relative ease. Later crews would have more time to adapt and, building on the Apollo 11 experience, would do their work with greater and greater confidence.
With only a short time at their disposal, Armstrong and Aldrin had only a few things they could get done before they had to have the hatch closed. They raised an American Flag, deployed a solar wind collector, gathered forty-seven pounds of samples, and carried a laser reflector and the passive seismometer about twenty meters south of the LM for deployment. They hammered two, short core tubes into the soil, took about one hundred color photographs, and, finally, got themselves and the samples back into the spacecraft. Because of the restrictions imposed by the pressurized suits, by the shifted center of mass, by the weak gravitational field, and especially by the clumsy, pressurized gloves, the work was generally harder to do than it would have been in a shirtsleeve environment.
Compared with later missions, the suite of scientific gear that Armstrong and Aldrin deployed was quite modest and, as Jack Schmitt told the story during our review of this Apollo 11 summary, at least part of the reason was a concern over fuel margins.
"Probably it was spring of '68. The PSAC - the President's Scientific Advisory Committee which was chaired by Charlie Townes - asked NASA for a set of briefings that would detail how the first lunar landing mission would be conducted. And NASA had never done that because they were concentrating so hard on getting the spacecraft ready to fly. And it was a very good request; PSAC was right on the money. Asking questions like that is the way a science advisory committee can really contribute to the process, and the PSAC forced NASA to think things through. So what NASA did was assign two astronauts to each of three phases of the mission: launch to Lunar Orbit Insertion (LOI), LOI to TEI (TransEarth Insertion), and then the trip home. And Buzz Aldrin and I were assigned the middle part of that. He was to do spacecraft stuff in orbit and I was to put together what we were going to do once we were on the surface. At that time the only thing NASA really had ever done in any detail was the so-called design reference mission. In fact, NASA didn't do it; Grumman did it. And that was a mission with four 4-hour EVA's. And the only thing that had happened since then was NASA backed off and said 'Well, with the ALSEP (Apollo Lunar Science Experiment Package) on board and the geology experiment, we'll have two EVA's.'
"There was lots of discussion about it. I mean, at that same time, some people were saying 'Well, maybe we ought to just have one guy go out on an umbilical; it's too dangerous.' Slayton wanted a buddy system -two guys going out with backpacks - and I was supporting him on that and I got into a lot of arguments. God, the kinds of things we went through to finally get there. And, at the same time, Buzz Aldrin was trying to get to be the first guy to go out. (Laughing) He had me working on some scheme to figure out how in the world we could justify having him and Armstrong switch places in the LM after landing. God! Anyway, in putting together the Lunar Surface EVA Operations Planning Book for the PSAC - which was the first time anybody tried to do a detailed timeline for two EVA's - it became increasingly obvious - when you put it in light of the problems the LM was having in terms of weight and everything - that the chances of 300 plus pounds of ALSEP flying were pretty small. So, in my draft charts before the final briefing, I included some issues that had to be addressed. And one of them was: do we need a contingency ALSEP? What were the two experiments that you'd like to have on the Moon if you never got another chance? And, very quickly, it was obvious what those were. One was the seismometer and one was the corner reflector. And so I had this on my draft charts.
"We did a dry run with the JSC management before giving it to PSAC. And, when that chart came up Bill (Wilmot) Hess just went ballistic! He wouldn't hear of not flying the ALSEP. I mean, the guy just lost it. And everybody was just sort of staring at him. He was Science Director and he just couldn't control himself. I don't think he's ever forgiven me for doing that. But the judgment of Bob Gilruth and George Low was 'It makes sense, so let's go to work.' Basically, we had six months - I think it was - to get it ready. It would be solar powered and lightweight. I don't remember how much it weighed. And Bill Hess was absolutely convinced - and was right - that, as soon as the contingency package existed, they'd take the ALSEP off of Apollo 11. Well, my position was that they were going to do that anyway and, if you didn't have something, you weren't going to get anything. God, we went around and around on that. But that's why Apollo 11 didn't have ALSEP but did have some science experiments."
Weight limitations were certainly one reason why Apollo 11 flew with only a few pieces of scientific gear. Another was the simple fact that, on this first landing, it was unlikely that NASA management would have approved an EVA long enough to allow the astronauts to deploy a complete ALSEP. On the Apollos 12 and 14, the ALSEP deployment typically took most of the first four-hour EVA and, as the first crew to do a lunar EVA, it seems unlikely that Armstrong and Aldrin would have been allow to stay out that long.
As Cernan suggests in his Apollo 17 commentary, there is always a best way to get a job done under lunar conditions; and, although Armstrong and Aldrin didn't have time to discover many of the tricks and didn't have the experiences of prior crews to guide them, the EVA went smoothly. That success can be ascribed readily to forethought, to careful training, and to a measure of justified caution on this first lunar visit. The only significant problem that they encountered came when Aldrin tried to drive the core tubes into the soil. Despite hammering hard enough to actually dent an extension handle attached to the top of the tubes, on both attempts Aldrin only managed to drive the tubes about 8 to 9 inches into the ground. In hindsight, the cause of Buzz's troubles was the fact that, more than a few inches below the surface, lunar soil is almost perfectly compacted, a circumstance that had not been anticipated. The core tubes were of a fairly standard design which included an internal bevel to provide some compaction of the entering soil so that it wouldn't promptly fall out. Because the lunar soil was already very compact, it simply couldn't be forced into a standard tube and it was impossible for Buzz to drive one more than a few inches deep.
What was probably the least efficient work that either Armstrong or Aldrin did came during the final minutes when Armstrong used a piece of equipment called the Lunar Equipment Conveyor or LEC to get the rock box up to Aldrin in the cabin. Essentially, it was a clothesline. After Aldrin hooked the LEC to a pulley in the cabin, Armstrong hooked the rock box to the LEC, backed away from the LM to make the line taut, and then pulled hand-over-hand as the box bounced its way up to Aldrin. It was hard work. At the start of the EVA, Armstrong's heart rate had been about 120 beats per minute and it had declined more or less steadily toward a low of about 80 as he took pictures at the rim of the crater east of the spacecraft. With time running short, he began a hurried collection of rocks and soil and his heart rate climbed to the 120-140 beat range. And then, while he was using the LEC, his heart rate shot up to 160 beats per minute and Houston had to call for a short rest. Other Apollo Commanders didn't have to work quite so hard when they were using the LEC. The excitement of the moment and the rush of collecting the bulk sample surely were contributing factors in Armstrong's case. But the LEC was an inefficient tool and, beginning with Apollo 14, the astronauts started carrying at least some of their gear up to the cabin by hand. The 16 and 17 crews did away with the clothesline LEC entirely - having decided that it was more trouble than it was worth - and hand carried everything except a bag containing their camera. That bag they raised and lowered with a hook and lanyard, a humble rope that somehow managed to inherit the LEC's name.
Two hours and thirty one minutes after they first opened the hatch, Armstrong and Aldrin reported it closed again. There were still five hours to go before Houston said "Good Night" and there was still plenty to do. There were samples to stow, gear to be jettisoned, and a long list of housekeeping tasks to be taken care of before they could have a scheduled rest period.
They slept in their suits - or tried to - with Aldrin curled up on the floor and Armstrong propped up on the ascent engine cover in the rear of the cabin. The rest period was, they said, "almost a complete loss." They were bothered by spacecraft noises and by sunlight leaking around the edges of the window shades and in through the sextant. They were cold and damp in the suits and, of course, they were really too excited to sleep. Not until Apollo 15 did anyone really get any sleep on the Moon. From Apollo 12 onward, the crews had a heater to help with the cabin temperature and hammocks they could lie in. However, it wasn't until Apollo 15 that the lunar stays were long enough - and the astronauts and mission planners had confidence enough - that the crews got out of their suits during the rest periods and, with the help of earplugs to cut down on the noise, really got some sleep. Aldrin may have gotten two hours of fitful sleep. Armstrong got none at all.
For seven hours Houston left them alone with their thoughts. Then it was time to wake up, have a quick breakfast, and get ready for the launch, the rendezvous with Collins, and the heroes' welcome awaiting them at home. If, from a practical point of view, Apollo 11 was a demonstration flight, a point of departure for the more sophisticated missions that would follow, it was still the one for the history books. The other crews would work in relative obscurity, stepping briefly into the spotlight but without leaving so lasting a public impression. There would never be anything quite like making that first footprint on another world but then, too, there was still a long way to go before humanity could claim to be more than temporary visitors to the Moon.
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