During their lunar exploration in 1971, Apollo 14 moonwalkers Alan B. Shepard Jr. and Edgar D. Mitchell had some unexpected problems navigating on the rugged surface.
Fifty years later, this conversation from their technical debriefing still has value for Artemis astronauts.
SHEPHARD
Until we really get a feel for navigation on the surface, there should be some strong check points to follow.
First of all, it gives you a feeling of security to know where you are. You know where you are distance-wise and what you have left to cover.
Second, there's no question in my mind that it's easy to misjudge distances, not only high above the surface -- that we discussed before -- but also distances along the surface.
It's so crystal clear up there -- there is no closeness that you try to associate with it in Earth terms -- it just looks a lot closer than it is.
Fifty years later, this conversation from their technical debriefing still has value for Artemis astronauts.
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| Alan Shepard assembles a double core tube as he stands beside the portable workbench or modular equipment transporter (MET) unique to this mission during the second moon walk on Feb. 6, 1971. Credits: NASA/Edgar Mitchell |
Until we really get a feel for navigation on the surface, there should be some strong check points to follow.
First of all, it gives you a feeling of security to know where you are. You know where you are distance-wise and what you have left to cover.
Second, there's no question in my mind that it's easy to misjudge distances, not only high above the surface -- that we discussed before -- but also distances along the surface.
It's so crystal clear up there -- there is no closeness that you try to associate with it in Earth terms -- it just looks a lot closer than it is.
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| Edgar Mitchell moves across the lunar surface as he looks over a traverse map during exploration of Fra Mauro. Lunar dust can be seen clinging to the boots and legs of the space suit. Credits: NASA/Alan Shepard |
MITCHELL
I certainly agree with that. I think there are two problems that affect your distance measurements.
One, as Al described, and the second is there has to be a little bit of distortion in the bubble. I don't know how much that contributed to it, but I think it contributed some.
I believe that our primary problem in navigation was the surprise brought about by the roughness and the undulation of the terrain.
We couldn't see -- one set of landmarks, the prominent landmarks -- our next set of landmarks from our present position.
Large craters which we expected to be able to see standing out on a reasonably flat plane were not on a flat plane. They were hidden behind other craters, ridges, and old worn-down mounds.
You'd say , "Well, this next big crater ought to be a couple of hundred meters away, or 100 or 150 meters." It just wasn't anywhere in sight.
So you'd press on to another ridge and you still didn't see it. All you would see would be another ridge. Finally, you'd get over to it and there it was. You could not get enough perspective from any one spot to pin down precisely where you were.
...but that was kind of the feeling I had. I never knew what to expect when I went over the ridge of the sand dune or what I was going to see on the other side of it.
SHEPHARD
I think that complicated our problem. I don't know what to suggest on that.
I think that we have talked about navigation problems before. We always felt that you know you'd see these craters out here. Men have planned for them and they're very well defined and we ought to be able to locate them easily, but that just isn't the case.
There has to be more thought given to some better way of positioning oneself on the chart.
Source: "Apollo 14 Technical Crew Debriefing"; February 17, 1971; https://www.hq.nasa.gov/alsj/a14/a14-techdebrief.pdf
