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Author
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Topic: Apollo: Why the lack of spacewalks in lunar orbit
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ASCAN1984
Member Posts: 1049
From: County Down, Nothern Ireland
Registered: Feb 2002
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posted 04-19-2013 06:47 PM
   
Why did they never do an EVA in lunar orbit? Even Gemini had stand up EVAs to photograph the earth. |
randy
Member Posts: 2231
From: West Jordan, Utah USA
Registered: Dec 1999
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posted 04-19-2013 08:16 PM
There were plans for lunar orbit EVA in case the docking probe/drogue failed. There was a hand rail on the lunar module and hand holds on the command module to get the LM crew back to the CM. |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 04-20-2013 03:23 AM
Whilst I agree that an EVA would have taken place in the event of an emergency situation, surely the real reason is that why take additional risks on what was an already hazardous occasion. |
Max Q
Member Posts: 399
From: Whyalla South Australia
Registered: Mar 2007
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posted 04-20-2013 05:51 AM
I would imagine there would have been no shortage of volunteers had there been EVAs on offer. |
Headshot
Member Posts: 891
From: Vancouver, WA, USA
Registered: Feb 2012
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posted 04-20-2013 06:38 AM
For me, I always believed that the Deep-Space EVAs of Apollos 15, 16, and 17 were dramatic enough.It is too bad that the crews were unable to take pictures during those EVAs that would have reproduced Pierre Mion's painting of Al Worden's view during his EVA. It is shown on page 261 of the February 1972 issue of National Geographic. |
space1
Member Posts: 861
From: Danville, Ohio
Registered: Dec 2002
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posted 04-20-2013 06:46 AM
I don't think any of the Gemini stand-up EVAs were done for the purpose of earth photography, but rather for astronomy.In Apollo the worst platform for photography would have been an astronaut on EVA. Lunar surface photography through the windows was very successful. The Scientific Instrument Module cameras of Apollo 15-17 were perfect for the task of lunar surface photography. And the Far Ultraviolet Camera carried to the surface on Apollo 16 was a well-placed platform for star photography. As fun as it might have been, a lunar orbit EVA would simply have had no benefit. |
Obviousman
Member Posts: 438
From: NSW, Australia
Registered: May 2005
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posted 04-20-2013 07:18 AM
I think the concern for a cabin re-press had a part to play; unless there was a valid reason for taking the risk then why do it? |
Max Q
Member Posts: 399
From: Whyalla South Australia
Registered: Mar 2007
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posted 04-20-2013 11:51 AM
From what I can see NASA seems to have a much more cavalier attitude towards EVA these days than they used to or is it just that the technology is better. |
Blackarrow
Member Posts: 3160
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 04-20-2013 12:39 PM
quote:
Originally posted by Obviousman:
I think the concern for a cabin re-press had a part to play; unless there was a valid reason for taking the risk then why do it?
There was, of course, a very valid reason: the retrieval of the SIM bay film cassettes. This could have been done in lunar orbit, but without checking I can, off the top of my head, think of three reasons to choose deep space in preference to lunar orbit: - Any delay or problem during a lunar orbit EVA might have left the astronaut in darkness during lunar night;
- Time spent retrieving the film cassettes in orbit would have been wasted SIM bay observation time;
- The most important task in lunar orbit after the LM ascent stage was jettisoned was the crucial TEI burn. Anything which distracted attention from preparing for a safe TEI burn would have been unwelcome.
None of the above need necessarily have prevented a lunar orbit film retrieval, but none of the above applied on the post-TEI return journey, making the deep-space option the logical choice. Have I missed anything? |
Skylon
Member Posts: 277
From:
Registered: Sep 2010
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posted 04-20-2013 03:57 PM
quote:
Originally posted by Max Q:
From what I can see NASA seems to have a much more cavalier attitude towards EVA these days than they used to or is it just that the technology is better.
Gene Kranz observed that the "veterans" of the Gemini EVA's remained very leery about spacewalks. The successful repair of Skylab must have been a huge boost for NASA's confidence in EVA's, but the early Shuttle mission EVA's seemed to succeed more due to improvisation than what was planned (STS 41-C, STS 51-A). I don't think NASA got really confident in its ability to train and prepare for EVA's until the success of STS-61.
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ilbasso
Member Posts: 1522
From: Greensboro, NC USA
Registered: Feb 2006
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posted 04-20-2013 10:23 PM
Regarding MaxQ's comment about NASA's attitude being "cavalier" about EVA's nowadays, I don't think that's an appropriate word. NASA has gotten more experienced about what to expect in EVA, true. However, anytime that someone is sent outside into vacuum, they are VERY thoroughly prepared and rehearsed. Say instead that NASA knows better nowadays how to conduct EVAs. Even recent EVAs have run into their share of trouble, as with one US EVA in recent months on ISS.EVAs in Gemini and on Apollo 9 were conducted to test procedures and hardware. Trans-Earth EVAs on Apollos 15, 16, and 17 were done to retrieve the SIM data because there was no other way to get the cassettes into the Command Module. Skylab EVAs were done as repairs and also to replace film cassettes, operations that could not be done from inside the ship. In my mind, EVA is only done when the risks can be appropriately mitigated and the need for the EVA is sound. |
BBlatcher
Member Posts: 57
From: Savannah, GA, USA
Registered: Aug 2011
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posted 04-21-2013 11:12 AM
quote:
Originally posted by ASCAN1984:
Why did they never do an EVA in lunar orbit?
There's no concrete reason for further risking astronaut lives by doing an EVA in lunar orbit.On Apollo 17, Ronald E. Evans was enjoying his EVA to retrieve the film canisters, noticed paint peeling from the thruster blasts and wanted to investigate further. Houston's response was essentially "No, grab the canisters and get your ass back inside." Spaceflight is risky. The Apollo lunar missions were incredibly risky. EVA was risky and NASA was well aware that there was plenty they didn't know about doing an EVA in deep space. Hell, Apollo 1 killed astronauts on the ground because NASA missed a few aspects of design and training. That had to have haunted the planners and astronauts and reminded them to be careful in taking risks. A lunar EVA would have been spectacular of course, but that isn't a good reason to do. The goal was bring everyone back alive and unharmed, so minimizing risk was the way to go in all aspects of the Apollo missions. |
robsouth
Member Posts: 769
From: West Midlands, UK
Registered: Jun 2005
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posted 04-21-2013 07:37 PM
The crew would not have communications with Houston when passing behind the moon. During the TEC this wasn't an issue. |
Norman.King
Member Posts: 378
From: Herne Bay, Kent, UK
Registered: Feb 2010
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posted 04-22-2013 11:42 AM
Had the Soviets managed to get the N-1 working I guess a lunar orbit EVA would have been another first for them (there being no other way to transfer between the LOK and LK lander). |
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