Author Topic: Apollo 14 MET cart?  (Read 6732 times)

Offline mako88sb

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Apollo 14 MET cart?
« on: March 05, 2016, 10:41:09 PM »
While searching for some other Apollo related info, I stumbled across this familiarization pdf about the MET that I must admit, I never really thought much about. Interesting to see it used pneumatic tires. For some reason, I thought those wouldn't be practical on the moon but obviously I was wrong. I got curious enough about the deployment and assembly of it that I imagine there must be some training videos with Shepard and Mitchell that would be interesting to see but no luck on youtube. Just curious if the Apollo 14 Mission Report cd has anything about it?

Offline ka9q

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Re: Apollo 14 MET cart?
« Reply #1 on: March 06, 2016, 04:04:43 AM »
Why wouldn't pneumatic tires work? I don't know the pressure, but lots of tires have pressures in the 2-3 bar range, so you just launch them about 1 bar low and they'll be fine when you get to the moon.

Offline Zakalwe

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Re: Apollo 14 MET cart?
« Reply #2 on: March 06, 2016, 04:43:05 AM »
Here's the operator's manual:
https://www.hq.nasa.gov/alsj/a14/a14METManual.pdf

Tyres? 1.5 PSIA. That sort of pressure is no problem for a pneumatic tyre.
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Offline bknight

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Re: Apollo 14 MET cart?
« Reply #3 on: March 06, 2016, 09:09:43 AM »
IIRC, the crew reported difficulties using the MET and with the upcoming LRV missions the MET was cancelled for future missions.  I don't remember which component of the MET was the problem, perhaps the assembly or the use.  Anybody have a post mission evolution of it, other than my generalizations?
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Glom

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Re: Apollo 14 MET cart?
« Reply #4 on: March 07, 2016, 11:16:52 AM »
Why wouldn't pneumatic tires work? I don't know the pressure, but lots of tires have pressures in the 2-3 bar range, so you just launch them about 1 bar low and they'll be fine when you get to the moon.
My bike operates at 4 bar.

Offline BazBear

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Re: Apollo 14 MET cart?
« Reply #5 on: March 07, 2016, 12:31:14 PM »
Why wouldn't pneumatic tires work? I don't know the pressure, but lots of tires have pressures in the 2-3 bar range, so you just launch them about 1 bar low and they'll be fine when you get to the moon.
My bike operates at 4 bar.
The Schwinn touring bike I had a few decades ago used 6.2 bar (90 psig) tires (or tyres for those of you in Blighty, Oz, Kiwi-land etc. ;) ).
"It's true you know. In space, no one can hear you scream like a little girl." - Mark Watney, protagonist of The Martian by Andy Weir

Offline mako88sb

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Re: Apollo 14 MET cart?
« Reply #6 on: March 07, 2016, 02:26:17 PM »
Why wouldn't pneumatic tires work? I don't know the pressure, but lots of tires have pressures in the 2-3 bar range, so you just launch them about 1 bar low and they'll be fine when you get to the moon.

I think I got a touch of the hoax-heads mentality with this one. I assumed the main reason they went with the stainless steel wire-mesh for the LR was that the rubber tired ones wouldn't work with the temp extremes. Sound familiar. Looking into it, the main reason for the non-rubber wheels was the big weight saving and as I'm sure you all know, the +/- temperatures were not an issue.

I'm still curious if there's any training videos with the MET? Pretty mundane topic I admit but I can't locate my Apollo 14 Mission Report book to see what's on it. I'm pretty sure it's buried in one box in the garage attic but it would take some time to get to it. If there's nothing about this on the CD, it would be good to know.

Offline BazBear

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Re: Apollo 14 MET cart?
« Reply #7 on: March 07, 2016, 10:09:00 PM »
The Space Shuttle orbiter's tires were exposed to vacuum as well as a pretty wide range of temperatures, so engineering a tire for  a lunar dolly cart thingy seems to this layman likely to be relatively trivial.
"It's true you know. In space, no one can hear you scream like a little girl." - Mark Watney, protagonist of The Martian by Andy Weir

Offline BazBear

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Re: Apollo 14 MET cart?
« Reply #8 on: March 07, 2016, 10:31:35 PM »
« Last Edit: March 07, 2016, 10:47:29 PM by BazBear »
"It's true you know. In space, no one can hear you scream like a little girl." - Mark Watney, protagonist of The Martian by Andy Weir

Offline Dalhousie

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Re: Apollo 14 MET cart?
« Reply #9 on: March 07, 2016, 11:15:25 PM »
IIRC, the crew reported difficulties using the MET and with the upcoming LRV missions the MET was cancelled for future missions.  I don't remember which component of the MET was the problem, perhaps the assembly or the use.  Anybody have a post mission evolution of it, other than my generalizations?

Apparently it all worked very well, I guess the superior capabilities of the LRV meant that it was superfluous on all subsequent missions.  See https://www.hq.nasa.gov/alsj/a14/A14_MissionReport.pdf 

Offline Kiwi

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Re: Apollo 14 MET cart?
« Reply #10 on: March 08, 2016, 05:56:36 AM »
While searching for some other Apollo related info, I stumbled across this familiarization pdf about the MET that I must admit, I never really thought much about. Interesting to see it used pneumatic tires. For some reason, I thought those wouldn't be practical on the moon but obviously I was wrong. I got curious enough about the deployment and assembly of it that I imagine there must be some training videos with Shepard and Mitchell that would be interesting to see but no luck on youtube. Just curious if the Apollo 14 Mission Report cd has anything about it?

IIRC, the crew reported difficulties using the MET and with the upcoming LRV missions the MET was cancelled for future missions.  I don't remember which component of the MET was the problem, perhaps the assembly or the use.  Anybody have a post mission evolution of it, other than my generalizations?

Have you read the Apollo 14 Technical Debrief at the Apollo Lunar Surface Journal? The MET is mentioned by Shepard and Mitchell on pages:-
10-21
10-23 to 10-26
10-45 to 10-49

Unfortunately the PDF I have of the Tech Debrief on the DVD-Rs of the ALSJ is pretty useless for a computer as it doesn't have electronic text that can be searched, so I have to search it the old-fashioned way, with eyes. :) So it could be mentioned on pages other than those above.

http://www.hq.NASA.gov/office/pao/History/alsj/a14/a14-techdebrief.pdf

« Last Edit: March 08, 2016, 06:00:22 AM by Kiwi »
Don't criticize what you can't understand. — Bob Dylan, “The Times They Are A-Changin'” (1963)
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Offline bknight

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Re: Apollo 14 MET cart?
« Reply #11 on: March 08, 2016, 10:48:38 AM »
Mitchell reported on pages 10-25,26
Quote
I found that I could not b en d down t o the MET level . I could
not j us t bring my body forward like I could in the t raining
suit and get down to the MET . I had to bend my knees or get
down on a knee to reach things low on the MET such as the
weigh bags down on the side , or the camera retaining clips
on the MET . It was more difficult for me to bend down for
them.
So I would say that yes the crew reported difficulties.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Dalhousie

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Re: Apollo 14 MET cart?
« Reply #12 on: March 09, 2016, 12:41:02 AM »
Mitchell reported on pages 10-25,26
Quote
I found that I could not b en d down t o the MET level . I could
not j us t bring my body forward like I could in the t raining
suit and get down to the MET . I had to bend my knees or get
down on a knee to reach things low on the MET such as the
weigh bags down on the side , or the camera retaining clips
on the MET . It was more difficult for me to bend down for
them.
So I would say that yes the crew reported difficulties.

Those difficulties don't seem to have made it into the mission report https://www.hq.nasa.gov/alsj/a14/A14_MissionReport.pdf (which is searchable)

Page 3-16

"The modular equipment transporter ( described in appendix A, section
A.2.l and shown in fig. 3- 7) was deployed at the beginning of the
first extravehicular activity. Deployment was impeded by the thermal
blanket which restrained the modular equipment transporter from rotating
down from the bottom of the modular equipment stowage assembly. The crew
released the transporter by pulling the upper pip-pins and allowing the
transporter and thermal blanket to fall freely to the lunar surface. The
thermal blanket was easily discarded and erection of the transporter went
as planned. The tires had inflated as expected. Equipment was loaded on
the transporter without difficulty. Two of the three pieces of Velcro
which held the lunar maps on the transporter handles came off at the beginning
of the first extravehicular activity. These pieces had been
glued on a surface having a different finish than the one to which the
Velcro adhered.

The modular equipment transporter stability was adequate during both
traverses. Rotation in roll was felt by the crewman through the handle
but was easily restrained by using a tighter grip if the rotation sensed
was excessive. The jointed legs in the front of the transporter operated
as expected in that they flexed when hit and would spring back to the
vertical position readily. The smooth rubber tires threw no noticeable
dust. No dust was noted on the wheel fenders or on top of the metal
frame of the transporter.

The modular equipment transporter was carried by both crewmen
at one point in the second extravehicular activity to reduce the effort
required for one crewman to pull the vehicle. This was done for a short
period of time because it was believed to be more effective when traveling
over certain types of terrain."

9-11

"The little dust that accumulated on the modular equipment transporter could easily
be removed by brushing . "

9-13-14

"Modular equipment transporter - The modular equipment transporter
deployed satisfactorily from the lunar module except as previously noted.
The spring tension on the retaining clips was sufficient to hold all the
equipment on the modular equipment transporter during lunar surface activities.
However, with the transporter unloaded, the retaining springs
have sufficient tension to lift it clear of the lunar s urface when placing
equipment in stowage locations. This was not noticed after the
transporter was fully loaded.

The wheels did not kick up or stir up as much dust as expected before
the flight. Very little dust accumulated on the modular equipment
transporter.

The modular equipment transporter was stable, easily pulled, and
proved to be a very handy device for both extravehicular activities .
Only at maximum speeds did the transport er evidence any instability
and, then , only because of rough terrain. This instability was easy to
control by hand motion on the triangular-shaped tongue .

Hand tool carrier. - The hand tool carrier mated to the modular
equipment transporter well, and was adequately retained by the hand tool
carrier retaining clip . All stowage areas except the deep pocket were
acceptable. This pocket was very difficult to reach when standing adjacent
to the modular equipment transporter. It is too deep for one to
easily retrieve small items. With this exception, the hand tool carrier
performed satisfactorily."

Offline Glom

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Re: Apollo 14 MET cart?
« Reply #13 on: March 09, 2016, 07:55:07 AM »
Why wouldn't pneumatic tires work? I don't know the pressure, but lots of tires have pressures in the 2-3 bar range, so you just launch them about 1 bar low and they'll be fine when you get to the moon.
My bike operates at 4 bar.
The Schwinn touring bike I had a few decades ago used 6.2 bar (90 psig) tires (or tyres for those of you in Blighty, Oz, Kiwi-land etc. ;) ).
And aren't these all gauge pressures anyway?

Offline Kiwi

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Re: Apollo 14 MET cart?
« Reply #14 on: March 09, 2016, 08:37:04 AM »
Mitchell reported on pages 10-25,26
Quote
I found that I could not bend down to the MET level. I could not just bring my body forward like I could in the training suit and get down to the MET. I had to bend my knees or get down on a knee to reach things low on the MET such as the weigh bags down on the side, or the camera retaining clips on the MET. It was more difficult for me to bend down for them.
So I would say that yes the crew reported difficulties.

From the earlier part of the same quote, I took that to be only a criticism of the reality spacesuit versus the well-broken-in training suit, and not at all a criticism of the MET.

First part:
Quote
I have the comment that although my suit did exceptionally well, far better than the training suit ever did, it was still stiffer and took more effort to just hustle it around than the training suit did, which was well broken in. I encountered a little bit of a problem with bending over, which I had not encountered in one-g, and I think this is in proportion to the forces between the one-sixth g and the stiffness of the suit as compared with the well-worked-in suit in one-g.

Second part:
Quote
I found that I could not bend down to the MET level. I could not just bring my body forward like I could in the training suit and get down to the MET. I had to bend my knees or get down on a knee to reach things low on the MET such as the weigh bags down on the side, or the camera retaining clips on the MET. It was more difficult for me to bend down for them.

And Shepard immediately adds, with no mention of the MET:
Quote
I don't know whether it was unique to Ed's suit or not, because I didn't have that problem.

« Last Edit: March 09, 2016, 09:07:01 AM by Kiwi »
Don't criticize what you can't understand. — Bob Dylan, “The Times They Are A-Changin'” (1963)
Some people think they are thinking when they are really rearranging their prejudices and superstitions. — Edward R. Murrow (1908–65)