The Apollo Lunar Lander (And How We Screwed It Up)

You called it, and we are grateful! Hank analyzes what went wrong with our intro, which gave us the perfect opportunity to talk about the awesomeness that is the Apollo Lunar Lander!

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Happy Birthday my love Mads m Hansen. From karikari

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SOURCES:

[CodyShell]

My Grandpa worked for Grumman aerospace for almost 40 years, he made parts for the apollo landers. im very proud! 

[HenryZhaosTextbook]

The first frame of this video is gorgeous.

[Shipwright]

The LEM was perhaps the one true spacecraft that humanity has ever made, i.e. it was designed solely to operate in the vacuum of space, and given the fact the onboard computer has less processing power and memory than your average digital watch or calculator of today, what it managed to do is all the more amazing.

Because weight was such a big issue in terms of landing on the moon, the hull of the crew compartment is so thin that you could easily put a hole in it with your foot, so the astronauts had to be really careful when they were working inside it, and the first aid kit only had four or five band-aids in it (they were being miserly to the point of ounces when it came to weight).

I'd really like to see humanity return to the moon, and it'd be neat to a see an episode about the pros, cons, and what it might take to do it sometime in the future.

Cheers Lads,
Brendan O.

[DanaStAmand]

I love that you guys just admit mistakes

[unomad]

Thank you for this... it's been driving me nuts ever since I started watching your channel. :)

[TheEntroseth]

I would not be terribly surprised if, knowing Hank's favorite topics, he noticed it but never mentioned anything wrong with the graphic just so that he could have an excuse to nerd out over space a little be more on his show. I'd do it. Nerding out is fun.

[Allan_aka_RocKITEman]

At about 2:16 ▶ You mentioned "the *command module* was damaged". Actually, the *service module* was damaged, as you mentioned a couple of sentences earlier. The damage to the service module made the command module "uninhabitable".

[pauldart]

gotta love when the views match the time of the video

[CromemcoZ]

Great video, Hank. I do think you were a touch melodramatic about the "no backup" bit. NASA considered a backup, but failure analysis showed there just wasn't much that could go wrong with the ascent stage before launch.

The fuels were hypergolic, so no ignition system to fail. Instead of pumps the fuel tanks were pressurized with helium using a manual valve, and so on. The astronauts themselves were the backup for systems like radar and the guidance computer. If one of those failed while they were on the moon, they'd still have used the LEM.

There weren't many hypothetical cases where a backup ascent system would be of any use.

[robbbyk]

i thought you were going to explain how to build a better lunar module .. i .. got really excited about that

[GickelsGaming]

Hank, this is not my real name of course, but your videos are awesome, highly educational and inspiring.
thanks for making my boring nights more boring in a very good way. im sure you can understand what i mean by deciphering that. thanks scishow, and hank.

[dlobom]

Just realized, episode 1 of Futurama is WRONG! My life is a lie!

[danheidel]

Heh, I was wondering when you'd fix that.  Aren't you a charter member of the Mars Society Hank?  I think that entitles us to keep poking fun at you for that mixup for at least another year. ;)

[rseguizabal]

Yeah always noticed this, also noticed theres no decoupleing of the landing legs

[MrAjfish]

One more interesting point is that the ascent engine on each craft was never tested. Test models were built and tested but the engine used hypergolic fuels to make it as simple as possible. There were no pumps or moving parts. The only down side to this is that the fuel was so corrosive that firing the engine also ruined it. The first time each engine was fired was on the moon, if there were any mistakes made in putting the engine together no one would know until it was too late.

[AllanFolm]

14.700 kg was the mass before Descent Orbit Initiation. When it was landed on the moon, the 8 tonnes of descent stage fuel was almost depleted, and the mass was therefore only about 7 tonnes. The ascent stage had a mass of around 4700 kg. 2000 kg of that was the ascent fuel.

[radfordra]

Hank if you feel bad about that little mix up. I wouldn't if I where you. Think about it for a second. How long was it in there before someone (or a few hundred caught it)? What does it say about our ability to notice insignificant details. Like a fun little lunar lander lifting off with it's base still attached.

[TechLaboratories]

Caught that the first time I watched through the credits and it's bugged me every time since.  Though, I just always imagined it as the decent stage animation running backwards...

[snoballuk]

Also please remember: there's no visible flame from a rocket using hypergolic propellant in a vacuum.

[xorthan]

How does the camera at 1:11 pan up to follow the lander? I imagine they did not leave a guy behind to record the ascent...