Author Topic: Quiz!  (Read 56714 times)

Offline ka9q

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Re: Quiz!
« Reply #90 on: June 25, 2012, 07:03:08 PM »
Note that the 4 motors on the actual Apollo LRV were each rated at 1/4 HP. A full HP is 746 W and the Leaf has only 935 W of rolling resistance at 65 mph, so given the LRV's lower mass it quite likely could have made it to 65 mph on a level paved road on the moon. Extra power or lower speed would be needed to climb hills.

Offline ka9q

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Re: Quiz!
« Reply #91 on: June 25, 2012, 08:41:16 PM »
The Apollo LRV had a "curb weight" (mass) of 210 kg and could carry a payload of 490 kg. The batteries were rated at 121 amp-hour at 36V; that's 4.356 kWh. I can't find the rolling resistance coefficient for the tires.

I wonder if it would be possible to show that attaining the demonstrated lunar performance of the LRV on the earth would have exceeded the known battery technology, thus providing additional evidence that the lunar missions were real. Of course, those who deny them wouldn't accept such an esoteric argument anyway.

Offline Echnaton

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Re: Quiz!
« Reply #92 on: June 25, 2012, 09:21:54 PM »
ON the moon your Leaf be even more like the LRV than I thought because the LRV also had a passive heat radiator.  Brushing the dirt off at every stop would get very tiring, so I am volunteering to do it for you.  When do we leave?
The sun shone, having no alternative, on the nothing new. —Samuel Beckett

Offline ka9q

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Re: Quiz!
« Reply #93 on: June 25, 2012, 09:30:00 PM »
As I recall, the thermal problems with the LRV were primarily (or entirely) with the batteries. They got warm during driving, and the covers that kept dust off them got dirty themselves and either absorbed more sunlight or would not radiate heat as efficiently as expected. They had to be opened when the LRV was parked to let the batteries cool off directly to space.

A lot of the thermal problems on the lunar surface involved overheating due to dust accumulation. It seems to be a real problem.

Offline ka9q

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Re: Quiz!
« Reply #94 on: June 25, 2012, 09:43:24 PM »
Let's see. A perfect thermal radiator, i.e, one with an alpha (visible/near IR absorptivity) of 0 and an epsilon (emissivity in far IR) of 1 would radiate 617 W/m^2 at 50C into a dark sky at 0 K. 50C is a reasonable temperature for electronics and electrical equipment, though probably not for batteries. If the temperature had to be only 20C, then it could radiate 418 W/m^2. That's not too bad for a lunar rover, especially as drag would not be an issue. But it does show why a radiator would be impractical on a PLSS that has to produce chilled water at below body temperature.

The sun wouldn't be a problem for our radiator because it's so small that its far-IR flux is negligible compared to its visible/near IR flux that our radiator would perfectly reflect. The warm lunar surface would be a problem, so the radiator should face straight up.

Offline Inanimate Carbon Rod

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Re: Quiz!
« Reply #95 on: June 26, 2012, 07:01:15 AM »
How many $ per pound of weight saved did NASA pay Grumman in order to reduce the mass of the LM? And what were the weight loss programs called?

The weight loss program was called "Operation scrape" and I think they offered either $1000 or $10000 per lb saved.
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Offline Inanimate Carbon Rod

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Re: Quiz!
« Reply #96 on: June 26, 2012, 11:00:12 AM »
What do Jim McDivvit, Neil Armstrong and Frank Borman have in common?
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Offline Bob B.

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Re: Quiz!
« Reply #97 on: June 26, 2012, 11:25:57 AM »
What do Jim McDivvit, Neil Armstrong and Frank Borman have in common?

They were the only three of the new nine to be in command of their first mission.

Offline Zakalwe

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Re: Quiz!
« Reply #98 on: June 26, 2012, 02:14:33 PM »

The weight loss program was called "Operation scrape"
Correct. But there also was a major study to review the design and to challenge the subcontractors to reduce the weight further. What was that called?

and I think they offered either $1000 or $10000 per lb saved.

Nope. ;)
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Offline ka9q

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Re: Quiz!
« Reply #99 on: June 26, 2012, 11:18:32 PM »
Saving weight was obviously very important in the LM. But there's an obvious threat to safety or at least reliability if you go too far. E.g,. you could save a lot of weight by removing redundant hardware.

In these programs, who ruled on the safety of each proposed weight-saving measure?


Offline VincentMcConnell

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Re: Quiz!
« Reply #100 on: June 28, 2012, 03:09:38 AM »
What did John Young dub the group that consisted of 19 astronauts?
"It looks better now, Al. What change did you make?"
"I just hit it on the top with my hammer."

-Mission Control and Alan Bean on Apollo 12 after the TV camera failed.

Offline Inanimate Carbon Rod

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Re: Quiz!
« Reply #101 on: June 28, 2012, 08:04:13 AM »
What did John Young dub the group that consisted of 19 astronauts?

The original 19.
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Offline VincentMcConnell

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Re: Quiz!
« Reply #102 on: July 04, 2012, 02:55:14 AM »
What did John Young dub the group that consisted of 19 astronauts?
The original 19.

LOL. When I first read that in Carrying the Fire I was laughing aloud in class.
"It looks better now, Al. What change did you make?"
"I just hit it on the top with my hammer."

-Mission Control and Alan Bean on Apollo 12 after the TV camera failed.

Offline Inanimate Carbon Rod

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Re: Quiz!
« Reply #103 on: July 04, 2012, 03:20:20 PM »
LOL. When I first read that in Carrying the Fire I was laughing aloud in class.

But did you believe any of it?
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Offline VincentMcConnell

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Re: Quiz!
« Reply #104 on: July 06, 2012, 03:52:55 AM »
But did you believe any of it?

Of course I did. Michael Collins is a personal role model to me.
In short, that guy is a boss. I believe he did everything he said he did. I believe his Gemini 10 spacewalk and entire mission happened the way he said it did. I believe he flew to the moon and ran several orbits at ~100 kilometers. If I am disappointed in Collins for one thing it's that he didn't stay in the program long enough for a landing mission. He deserved a moon walk for all the work he put into Apollo 11.

(Edited to add a tiny bit about Collins)
"It looks better now, Al. What change did you make?"
"I just hit it on the top with my hammer."

-Mission Control and Alan Bean on Apollo 12 after the TV camera failed.