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Author
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Topic: Landing the Lunar Module without a LM pilot?
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Obviousman
Member Posts: 438
From: NSW, Australia
Registered: May 2005
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posted 04-24-2011 06:43 AM
   
We were discussing, on another board, about how the title Lunar Module Pilot (LMP) was a bit of a misnomer, with the LMP never actually flying the LM (stand fast Al Bean and Ed Mitchell). It got me wondering if it was possible for the commander (CDR) to land the LM without the LMP, even in P65.Thinking about the data monitoring required, I would think that effective loss of a crewman during descent would have been a mandatory abort, and even if circumstances dictated a landing by the remaining crewman, it would have been very hazardous. Thoughts from others would be welcome. |
Tykeanaut
Member Posts: 2216
From: Worcestershire, England, UK.
Registered: Apr 2008
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posted 04-24-2011 12:25 PM
Am I correct in thinking that only one astronaut to the lunar surface was once considered? |
Obviousman
Member Posts: 438
From: NSW, Australia
Registered: May 2005
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posted 04-24-2011 02:25 PM
To the best of my knowledge, a two-crew Apollo LM was only ever considered. The Lunar Gemini concept had one crewmember landing on the surface, if I recall correctly. |
SpaceAholic
Member Posts: 4494
From: Sierra Vista, Arizona
Registered: Nov 1999
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posted 04-24-2011 09:33 PM
How did those pilots that landed the Surveyors hitch a ride back? |
Obviousman
Member Posts: 438
From: NSW, Australia
Registered: May 2005
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posted 04-25-2011 12:52 AM
Ho ho ho - Viktor, you very funny man! |
SpaceAholic
Member Posts: 4494
From: Sierra Vista, Arizona
Registered: Nov 1999
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posted 04-25-2011 07:16 AM
My weak attempt at humor was alluding to the point that autonomous landing was demonstrated on the lunar surface well before the first LM touched down. Had it been a heavy interest item, the scope of the Surveyor (and LM) program could have been expanded to include maturation of that capability for man rated operations with follow-on integration into the LM. |
stsmithva
Member Posts: 1940
From: Fairfax, VA, USA
Registered: Feb 2007
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posted 04-25-2011 07:28 AM
Perhaps not tremendously relevant to this thread, but I have one of the von Braun "working papers" (daily updates on aspects of the space program) from 1962 which mentions consideration of an unmanned "logistics" LM that would be sent ahead of the manned one. No other details are provided, but I assume it would have carried additional supplies and experiments. |
MadSci
Member Posts: 230
From: Maryland, USA
Registered: Oct 2008
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posted 04-25-2011 06:29 PM
I think the "Supply LM" was part of a program concept for extended duration missions.The idea was to ship the supplies first, then make a pin point landing and utilize them for a long duration stay. If you missed them, you could still stay for a standard duration mission. At least it was an improvement over the plan to send an Astronaut to the moon with no return capability, and keep re-supplying him by automated landers until some means of bringing him back was devised! |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 04-26-2011 01:42 AM
Getting back to the original question - As an example, doesn't it all depend on how relevant was the input of Aldrin's comments of "4 feet down, three forward, drifting to the right a little..." to Armstrong's landing? As I understand it, the landing was automatic until it became apparent that the target was a boulder field. |
Obviousman
Member Posts: 438
From: NSW, Australia
Registered: May 2005
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posted 04-26-2011 05:32 AM
Well, not quite automatic but rather the semi-automatic mode; Armstrong had the ability to change the landing point in P66 and could alter the vertical and horizontal velocities. To determine where the computer was intending to land the LM, they required a Landing Point Designator number. The number (e.g. 42) would be used by the pilot, looking through the LPD on the window corresponding to the number given. This would tell the pilot the current landing location. To get the LPD, the LMP had to enter some keystrokes into the LM computer. If the CDR had to do that, they would have had to divert their attention from flying the LM (looking outside) and bring their attention to inside the LM, manipulate the keypad, then look at the DSKY display for the LPD and then return their attention back outside the LM. Similarly with the altitude, h-dot, v-dot and fuel state. All of that would have required the flying crewmember to break focus with outside the LM and refocus inside the LM. My understanding of all the landings was that they all required extreme attention. I just don't think it could have been done solo unless driven by the most extreme of conditions (e.g. failed abort).
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garymilgrom
Member Posts: 1966
From: Atlanta, GA
Registered: Feb 2007
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posted 04-26-2011 07:49 AM
Looking at the original question reminds me of the book Digital Apollo. Orbital mechanics are not intuitive like flying in the atmosphere, and astronauts had to learn to trust computed solutions instead of "seat of the pants" answers. The LMP was actually an early systems engineer and the LM was designed to be flown by a pilot and an engineer. To me this means the system could not have been flown easily by one person but it might have been possible in an emergency situation; and that an automated landing had a higher chance of success than a single crewman landing.This is a long way of saying I agree with original poster's thoughts. |
Lou Chinal
Member Posts: 1332
From: Staten Island, NY
Registered: Jun 2007
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posted 04-26-2011 02:03 PM
quote:
Originally posted by Tykeanaut:
Am I correct in thinking that only one astronaut to the lunar surface was once considered?
By this do you mean one astronaut flying the LM or do you mean an EVA on the lunar surface?The answer is - no, yes. In that order. quote:
Originally posted by stsmithva:
...mentions consideration of an unmanned "logistics" LM that would be sent ahead of the manned one.
Steve, Conrad talked about an 'unmanned LM'. The idea was dropped when NASA realized how hard it was to do (but then of course he did it). quote:
Originally posted by moorouge:
...how relevant was the input of Aldrin's comments of "4ft down, three forward, drifting to the right a little..." to Armstrong's landing?
Gene Cernan said "I don't need the numbers anymore", during the Apollo 17 landing. The commander must have had the glide slop locked in his eyeball at this point, regardless of what any computer or window grid told him.Aldrin said during an interview not long ago, "Neil seemed to intuitively know where he was going". |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 04-26-2011 03:35 PM
To summarize then - the answer appears to be 'possible' but not recommended. |
MCroft04
Member Posts: 1647
From: Smithfield, Me, USA
Registered: Mar 2005
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posted 04-26-2011 09:14 PM
quote:
Originally posted by Lou Chinal:
Gene Cernan said "I don't need the numbers anymore", during the Apollo 17 landing. The commander must have had the glide slop locked in his eyeball at this point, regardless of what any computer or window grid told him.
Yeah but the geologist continued to do what he was trained to do. |
Explorer1
Member Posts: 180
From: Los Angeles, CA, USA
Registered: Apr 2019
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posted 01-02-2020 12:41 PM
I have heard that the Apollo Lunar Module was capable of making a fully automated lunar landing from the time of separation from the Command Module. And I assume this would have been an automated landing from the onboard computer and not a remote-controlled landing from Mission Control. Is any of this correct? Editor's note: Threads merged. |
Jim Behling
Member Posts: 1488
From: Cape Canaveral, FL
Registered: Mar 2010
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posted 01-03-2020 08:52 AM
quote:
Originally posted by Explorer1:
I have heard that the Apollo Lunar Module was capable of making a fully automated lunar landing...
No, it couldn't. |
Blackarrow
Member Posts: 3160
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 01-03-2020 11:53 AM
Would that not depend on how many pieces you want it in after "contact" with the lunar surface? |
taneal1
Member Posts: 237
From: Orlando, FL
Registered: Feb 2004
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posted 01-14-2020 05:21 PM
quote:
Originally posted by Explorer1:
I have heard that the Apollo Lunar Module was capable of making a fully automated lunar landing from the time of separation from the Command Module.
Presumably, you are referring to a "hands-off" landing with the crew present? The answer is "no," because... A crew input is required at every important decision point. e.g. The engine will not fire to begin the powered descent until the crew pushes the "PRO" (proceed) button on the computer DSKY. The crew must manually tell the computer to accept the Landing Radar data; give permission for the computer to switch from Major Mode P63 to P64 at High Gate altitude, etc. Early versions of the landing program automatically switched to P65 at about 150 feet altitude, then nulled forward and lateral velocities while reducing descent rate to a constant 3 feet per second. The blue "Contact" light would illuminate at landing probe touchdown, and with no CDR to press the engine "Stop" button, the DPS would continue to maintain a 3 fps descent until physical contact with the lunar surface. The computer would then reduce the throttle to it's 10% (minimum) setting in an attempt to maintain a 3 fps descent. Would it bounce first, or just sit there for several minutes at 10% thrust until it ran out of propellant and shut down? The unmanned LM-1's systems were monitored and controlled from Houston. If the required "PRO" commands were eliminated from the computer, and the touchdown sensor wired to send an engine stop command then an automatic landing would be possible. A supply LM's landing program could even include a MCC performed landing site update for touchdown accuracy. A supply LM wouldn't require any new technology. A month-long stay on the Moon and moonwalks in Earthlight — sign me up! |
oly
Member Posts: 971
From: Perth, Western Australia
Registered: Apr 2015
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posted 01-14-2020 08:49 PM
quote:
Originally posted by taneal1:
Would it bounce first, or just sit there for several minutes at 10% thrust until it ran out of propellant and shut down?
I suspect that allowing the engine to run out of propellant would be a high risk. Combustion instability caused by differing fuel mix ratios or sporadic feed may result in a catastrophic engine failure, and allowing the engine to operate with the exhaust nozzle close to the lunar surface was considered a risk and one reason why the lunar surface probes were introduced. There may be a risk that a damaged engine nozzle or back pressure would result in engine failure. |
taneal1
Member Posts: 237
From: Orlando, FL
Registered: Feb 2004
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posted 01-15-2020 12:17 AM
You don't think I was proposing that they actually do that, do you? I was merely explaining what would happen without a crew aboard. You'll note that I mentioned connecting the lunar contact probe to the engine stop relay for a LM Supply vehicle.Back pressure from the surface, especially with the extended DPS nozzle, was expected to cause an internal 'explosion' or something similar, long before mixture ratios or whatever would cause a significant problem. This is why the procedure was to press the engine "STOP" button upon illumination of the blue lunar CONTACT light despite being several feet above the surface. Also, the thrust "tailoff" time must be considered following the engine STOP command. Neil Armstrong stated that he forgot about this procedure and touched down with the DPS still operating... |
Blackarrow
Member Posts: 3160
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 01-15-2020 10:29 AM
If the thrust (no pun intended) of the original question was whether the LMP was actually necessary on a lunar landing, then the answer has to be yes for a number of reasons. Lunar surface operations were designed for two astronauts working together (and separately). Contingency plans allowed for a limited one-man EVA, but so much less would have been achieved.However, if the commander had died on the surface (say from a torn suit) then the LMP had to be able to come home alone, so he had to be capable of pressing the right buttons to launch the ascent stage. I don't know what impact the reduction in launch-weight would have had but if the ascent stage ended up in a "non-nominal" orbit, that's where the CMP's training came in. Final point: whether the LMP was seen as "just a systems engineer" or as a crucial part of the landing-team, each Apollo crew had three members and each one of them had a crucial role to play. |
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