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They had a crew round the Moon before going for landing, but they didn't test any of the new landing and ascent operations uncrewed on the lunar surface. Why? Couldn't it be done by remote control? Were they for some reason very confident that the risk with landing and ascent was comparatively low? Was it perceived as too costly? Were uncrewed launches politically difficult to motivate?

Ideas about crewed space missions today often include the preplacemen of a return vehicle and other payloads before the crew arrives. For example the Mars Direct and derivatives, and I think also the orbiting realtime telerobotic Herro mission ideas to Mars and Venus.

Could the Apollo program have preplaced an uncrewed lander, or other equipment, on a site within range of where later a crewed landing took place? Or didn't they have that precision in landing area (they did land near a Surveyor)?

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    $\begingroup$ There was an unmanned test of the LM during Apollo 5. The descent stage was tested, the in flight separation of the ascent stage from the descent stage with a "fire in the hole" maneuver as test of a landing abort and the ascent stage alone. Of course there was no real landing test possible in an Earth orbit. $\endgroup$ – Uwe Dec 12 '18 at 23:26
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As Loren Pechtel mentions, time pressure was a big part of it; also, Apollo 10 did actually test a large part of the descent, ascent and rendezvous operations even through they didn't slow all the way to 0 and touch down.

It was by no means certain that Apollo 11 would successfully make a landing. A variety of abort options were available at every stage of the operation, so if something had gone unrecoverably wrong it's still likely that the crew would have survived, and lessons could have been learned to allow a successful landing on Apollo 12.

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    $\begingroup$ It would also very likely have required some serious retrofitting of the LM to allow such remote-controlled operations. Again, time for which wasn't available. $\endgroup$ – a CVn Jun 8 '14 at 21:03
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    $\begingroup$ @pericynthion Good point. Apollo 11 was heading for a rock garden. I don't think they could have landed it from Earth, it would have to have been controlled from lunar orbit. $\endgroup$ – Loren Pechtel Jun 8 '14 at 21:35
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    $\begingroup$ @dotancohen The specific design of the Apollo LM, yes, but that was a design limitation, not a technological one of the time. The Russian Luna programme soft-landed several remote-controlled craft on the Moon between 1966 and 1976, including ones that deployed rovers and ones that returned surface samples to Earth. The remote versus piloted design goal was a major philosophical and engineering difference between the American and Russian space programs that persists today. $\endgroup$ – SevenSidedDie Jun 9 '14 at 17:07
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    $\begingroup$ The US has not attempted unmanned sample return from the Moon. $\endgroup$ – pericynthion Jun 9 '14 at 20:38
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    $\begingroup$ @dotancohen Does Apollo 12 and Surveyor 3 count? It was an unmanned landing, but manned return. Of course in that case one could argue that all Apollo missions that landed on the Moon did sample return of material that had landed unmanned on the Moon... $\endgroup$ – a CVn Dec 18 '16 at 13:58
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Time.

They were coming down to the wire on Kennedy's challenge. There might also have been technical reasons look how close to the end of the timeline Apollo 12 was. It easily could have slipped.

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  • $\begingroup$ Time pressures were evident as early as Apollo 8. It was supposed to involve the LEM in Earth orbit but was changed to fly around the Moon without a LEM because the LEM wasn't ready. $\endgroup$ – Anthony X Jun 8 '14 at 20:06
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    $\begingroup$ The US was fearful that the USSR might upstage it with a manned lunar orbital mission, so Apollo 8 was repurposed to be more of a publicity stunt than a useful mission. NASA wasn't happy that they were being pressured to do it that early, but it turned out OK (and that Earthrise picture really jump started the environmental movement). $\endgroup$ – Phil Perry Jun 9 '14 at 13:09
  • $\begingroup$ Technically, they had about two years left, given that Kennedy made that statement in 1961 and the decade starting at that moment wouldn't expire until that time 1971... $\endgroup$ – Sean Nov 22 '18 at 5:22
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Remember the state of computers at the time. It is very unclear that an automated landing could have been executed -- indeed, the first moon landing was under manual control, and came uncomfortably close to running out of descent fuel before landing,

Remote control from Earth would not be practical due to speed-of-light issues. The moon is about 1.28 light-seconds from Earth. By the time you could see what's happening, react to it, and send a parameter change to the lander, over 2.6 seconds have passed. It is VERY hard to operate something remotely with that much lag; it's probably effectively impossible to fly with that delay.

Remote control from the orbiter might have been possible... I don't remember how long the orbiter was in communications range of the lander on each pass.

But in the end, the answer is that the space race was seen as just that, a race, and called for making judgements about the degree of risk (as best it could be calculated) versus the time that would be required to reduce that risk. The astronauts knew that what they were doing wasn't "safe", but they too estimated the risks and judged them worth taking. The fact that they were generally military test pilots (and that, despite being a "civilian" agency, NASA was also functioning as a military research program) also meant the level of risk considered acceptable was higher than it would be for civilians. The landing was made at the earliest date when they thought it stood acceptable odds of succeeding; a test landing, even if it could have been conducted, might not have told them much about how a human in direct control of the vehicle would affect those odds.

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  • $\begingroup$ Today, computers are advanced enough to allow a fair amount of autonomy -- we might be able to land safely even though initially, Apollo 11 was heading towards a boulder field. A TV linkup might have allowed enough time to evade such problems, if Mission Control were limited to selecting the general area to touch down on, and the computers would do the rest. Still, it probably would have been a close call, even today. $\endgroup$ – Phil Perry Jun 9 '14 at 13:12
  • $\begingroup$ @PhilPerry given the successful Mars landings, I think it's safe to say we can build a "LEM-II" w/ automated soft-moon landing capability :-) $\endgroup$ – Carl Witthoft Jun 9 '14 at 13:41
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    $\begingroup$ This wasn't a technical limitation of the computers of the time or of communications delays, as the Russian moon program's several remote-controlled soft-landers and rovers shows. $\endgroup$ – SevenSidedDie Jun 9 '14 at 17:12
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    $\begingroup$ @SevenSidedDie: There is a significant difference between landing a relatively lightweight probe softly enough to operate and a relatively heavy man-rated vehicle softly enough to not injure humans and to take off again. It might have been possible... but if it had failed what we'd mostly have learned was that the automation wasn't good enough. A manned descent, with the ascent stage as an "escape pod" option if needed, was more informative and had the potential of actually achieving the end goal -- as it did. $\endgroup$ – keshlam Jun 9 '14 at 17:33
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    $\begingroup$ @SevenSidedDie - The Soviet Luna program had a large number of failures, none publicized. Only successes were publicized. The failures -- they never occurred. It was only after the collapse of the Soviet Union that the large number of failures became public. $\endgroup$ – David Hammen Jun 9 '14 at 21:33
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Without Neil Armstrong taking over manual control, Apollo 11 would have crashed into a rock filled crater. Possibly something like this happened to the unmanned Mars probe Beagle2? A failure of that would have halted the programme completely preventing the first manned mission from starting. You think even back then NASA was taking risks? Later the risks t hey took proved fatal but back then they pulled it off. Perhaps the astronauts were expendible? Behind the scenes maybe the experts considered that it was just so risky that they might as well send the men and take the chance to get to the moon before the Kennedy deadline. As far as I know, most things hade backups except the heat shield and the ascent engine of the LM, so it was maybe a change worth taking.

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  • $\begingroup$ Manned landing seems less risky to me, since the pilot can make intelligent decisions about the terrain conditions which machines would find very difficult. I $\endgroup$ – Innovine Jun 29 '17 at 10:59
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According to The Apollo Spacecraft: A Chronology, there was a meeting at NASA headquarters exactly about such a matter. It was decided that the spacecraft did not have the capability at that time:

  • 1969 February 11

    The possibility of an unmanned LM landing was discussed at NASA Hq. The consensus was that such a landing would be a risky venture. Proposals had been made which included an unmanned LM landing as a prerequisite to a manned landing on the moon. However, the capability to land the LM unmanned did not exist and development of the capability would seriously delay the program.

Also consider that there were too many unknowns of the lunar surface, such as the amount of dust, roughness, and stability. These conditions could have caused sensors to malfunction. A human could adapt to such conditions; a computer could not.

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During Apollo 5 an unmanned LM flight in Earth orbit was tested, with a inflight separation of descent and ascent stage. This "fire in the hole" maneuver was necessary for a lunar landing abort.

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While Apollo 10 flew all the way to the Moon and could theoretically have executed a landing, its ascent stage was deliberately short-fueled to discourage the flight crew from making any such attempt (doing so would have left them stranded). According to this Wikipedia article: http://en.wikipedia.org/wiki/Apollo_10 an important objective was to perform system calibrations necessary for the actual landing mission, presumably requiring a human operator present in the vehicle.

Apart from time pressure, (and perhaps that there was no functionally adequate substitute for a human operator to perform the required tasks) this was also very much about cold war geopolitics; Americans in space, preparing to land on the Moon, sending back live video in the process, had immeasurable PR value in the context of the cold war. Flying the system unmanned, especially after other manned missions, would not have had the same impact. After all, the whole exercise was about sending humans to the Moon.

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  • $\begingroup$ "the whole exercise was about sending humans to the Moon." In terms of publicity, perhaps. In terms of international politics, I think sending a teddy bear on the same journey would have had similar effect (Kennedy's explicitly stated goal notwithstanding). :) $\endgroup$ – a CVn Aug 1 '14 at 18:30
  • $\begingroup$ Teddy bears don't need food, water or air. The point is about both making and demonstrating incremental progress toward the ultimate goal of the manned landing. A vehicle that is keeping its crew alive and safe as it makes its soft-landing rehearsal makes the statement that "we're ready to do this on the next flight". An uncrewed flightmakes it seem like there's much more yet to do. $\endgroup$ – Anthony X Aug 1 '14 at 23:54
  • $\begingroup$ On the other hand, an ICBM also doesn't need food, water or air. For "we can do this with people", I absolutely agree with your point. To show ability to deliver a payload within the Earth-Moon system, a teddy bear (of appropriate weight) probably would have sufficed. Hence also my reservations in the original comment above. $\endgroup$ – a CVn Aug 2 '14 at 9:57

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