Chemistry of Lunar Lift-Off - Periodic Table of Videos
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- Опубліковано 27 вер 2024
- We re-create the chemical reaction that allowed astronauts to blast free from the Moon's gravity... and show why it has a surprising connection with The Periodic Table of Videos.
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Neil spoke!!!
You should have named the video "An explosion in Nottingham sends two men to the moon."
Neil does not need a rocket to go to the Moon, he just jumps up there!
When you light a candle, for example, the products of combustion hang around for a while at the reaction site, glowing as a flame, before they're transported away by atmospheric convection and cool down. When you burn something in a vacuum, the combustion products are carried away so quickly that you never have chance see anything. Also, the engine and the fuel/oxidizer mix are designed very carefully to give almost complete combustion, unlike the Nottingham demo unit.
The 'sparks' flying away from the base of the LEM are likely bits of the golden-colored insulation and other fragments blasted away by the power of the rocket motor. The reason they appear multi-colored is most likely an artifact from the type of color television camera which was used on the rover. (The rover was parked a small distance away and its camera was used to capture the departure of the LEM.) I believe this camera used a color-wheel which spun at several tens of revolutions per second... The wheel used a series of red, green and blue filters... and each 3 exposures would be combined into a single full-color frame. With 'normal' slower-motion events the RGB strobe effect is invisible - but these particles flying off the LEM are moving at such tremendous speed that part of their motion is captured with only a single filter, and then the next, and then the next as the color wheel spins- producing this multi-colored effect. In this type of camera, the color wheel would have to be spinning INSANELY fast in order to eliminate the RGB strobe from particles moving as such velocities. This was a very simple and reliable mechanical camera (with only a single image sensor, or 'tube') designed to produce color video from the moon... cameras today wouldn't have this problem as most of them use an individual sensor (or CCD) for each red, blue and green color.
Ed Fendell at mission control in Houston controlled the camera on the rover via radio. Just as he and others controlled the camera when it followed the astronauts when they moved around on the surface. He hit the "tilt up button" at about "minus one second" during the count down, to allow for th delay in the signal. The camera tilted up at a steady rate, so the rover was parked at a distance where the LM would be in the frame the whole time.
Every detail is described in books and other places.
I remember reading somewhere that it was a stationary camera mounted on some sort of a tripod. It was operated remotely from Houston. Since the radio signal needs approximateley one second to travel to the Moon, the camera operator had to pan the camera upwards one second before the take off. Allegedly, he won an award for doing so.
The camera was left there and the camera motion was remotely controlled by a guy in Houston, who had to time his commands very carefully to compensate for the 1.3-second delay in transmission! Presumably, he was quite nervous...
The ascent engine wasn't gimballed. Only the descent engine was. At ascent, the module was controlled by the 16 small directioal thrusters. Therefore it "swayed".
The exhaust from the main engine was invisible because of the lack of an oxygen atmosphere. The same kind of invisible exhausts can be seen on several videos, filmed from rockets when they reach a high altitude.
To my knowledge the LM does NOT defy physics.
Who recorded the apollo lander lift off?
It's on the lunar rover. They had to time it quite intricately, as there is just over a second delay to the Moon, and they wanted the camera to swivel up when the lander lifts off.
I don't remember the details, but it was quite a tricky shot to pull off in those days by remote control.
Cont....The ascent module weighed 10,024 lb (4,547 kg) (including fuel), and had a Ascent Propulsion of 3500 lbf... Even on the moon the module should have moved left to right from gimbal guidance, and weight of the craft. Instead it swayed like it was being pulled with a massive cable. I'm not saying we did not go, but this clip was of a craft being pulled, not pushed. There was no weight to thrust hesitation, nor a speed increase once the propulsion weight ratio became equal.
You guys make the most entertaining and educational videos I've EVER come across on UA-cam. I have even gotten my son (14 yrs old) looking forward to them now!! You have peaked his curiosity about Chemistry. Thank you so very much!!!!
Rocykel is correct it was controlled remotely by Ed Fendell at Mission Control. No timer was used.
The most fun thing for me as a chemistry student was being able to play around with liquid nitrogen. I coined the phrase "cryomaniac" to describe myself. When poured out onto the floor it boils spectacularly and makes cold vapour clouds.
It is also fun to scare people with. Some legal students used to use one of our upstairs lecture theatres, so we'd go up and down the stairs "accidentally" spilling drops of it. They had no idea what it was, they must have thought it was a powerful acid...
no, i don't need to be asking that question at all. i'm questioning the accuracy and precision of moving that "simple" robotic camera from such great distance. i'm not doubting it, i'm just mind-boggled over it.
Pretty smooth camera work for someone holding a camera...maybe it was a sacrificial automated TV unit, beaming its signal to the Command module? Easy to do and make even in 1969. Ya think? ;-)
The Camera on the Lunar Rover was remotely operated by Mission Control.
The camera is on the lunar rover. There is film of LM ascents in previous missions, but it wasn't until Apollo 17 that they managed to synchronise the camera movement with the launch.
They just showed the most dangerous chemical they have ever used in a demonstration here...UDMH.
Yes, and as shown on the last episode of From the Earth to the Moon, the same attempts to capture AP-15 & AP-16's lift offs with the LRV weren't as successful clearly showing just how easily it was to mess it up. I only found out recently that they were attempting to capture the AP-17 LM impact with the moon using the LRV camera but again, it was one attempt only type of event that the time delay probably made it too difficult to pull off.
The last 3 Apollo missions had lunar rover vehicles with remoteley controlled cameras upon them.
I think that take-off footage was from the Apollo 17 rover.
It is clever that it follows the ship up into the sky -considering the time delay between earth and the moon.
The Isp of UDMH+N2O4 is usually cited as around 310 sec, lower than my 388 sec because no real engine is 100% efficient at turning heat into kinetic energy of the exhaust. Also, real engines usually burn rich mixtures to protect them from corrosion by free oxidizer and to reduce the average molecular weight of the exhaust.
why are the sparks at the lift off blue red and green!? :36
@sirnlawson No, all of the Apollo spacecraft thrusters were bipropellant. All used N2O4 as shown here as oxidizer. All rockets on the LM and the big rocket on the CSM used a 50-50 mix of hydrazine (N2H4) and UDMH (shown here) as fuel, the CSM maneuvering thrusters used MMH, monomethyl hydrazine.
This demo just mixed UDMH and N2O4 without pressurizing them or carefully controlling the ratio so it didn't look like the plume from a real rocket engine.
Why is there no flame on the moon?
When dealing with these types of oxidizers an and fuels, technicians normally use SCAPE suits due to the high toxicity of these chemicals. Were the oxidizer and fuel used watered-down, or were they is such small quantities to not pose a significant harm?
@DFTBA10000 Well, he was talking specifically about the lunar module lifting off the moon. At that point it contained only Armstrong and Aldrin; Collins was waiting for them in the CSM.
Perhaps he should have spoken about the service propulsion system engine on the CSM needed to send all three back to earth. It was even more important than the LM ascent engine as Collins' life also depended on it. It too used hypergolic propellants.
Im no camera expert, but on the whole "swaying thing", if I am correct, that is the pilot pitching over to begin his burn to get up to orbital velocity. Also, about the flame not being visible, it might be because of a few factors, one, the camera has terrible quality, and two, the flames might be directed into a different direction. If you want to see some of the flames, go to 5:31 and watch there, if you look in the center you can see a tiny yellow flame.
good point, and how did the camera follow the space craft as it left the surface of the moon? And how did they recover that video?
Most impressive video for some time!
I'd love to see this repeated with the capsule unbolted from the background so it shoots off into the sky!
Mike Collins remark about the TV picture coming thru to mission control during the Apollo 11 moonwalk of Neil and Buzz..
"Does the lighting look halfway decent"?
LOL
Because it was attached to the table and mounting. It isn't a separate rocket, it is a rocket-shaped prop to demonstrate the reaction.
Simply put (the only way I know): Nitrogen gets stable on a diatomic configuration, since it have 5 electrons in it's outermost orbit, plus the 3 shared in the bond, and it gets the octet, becoming stable.
Carbon is not particularly stable with a triple bond, since it have so much energy, since it's tendency is to have a lower energy state, it seeks for more simple bonds to stabilize it's orbit. With the appropriate activation energy, all this excess from the triple bond is released.
hypergolic, storable, not overly toxic or corrosive... truly a great discovery
The Space Shuttle's positioning thrusters use the same fuel and the flame is clearly visible.
Ah, okay, thank you for clarifying that. Also thank you for the civil internet conversation, one unlike most.
I would like to ask this common trivia, if the most strongest bound between two atoms is really the N2 gas, or the N2 gas is the most strongest bound between the same kind of atoms.
@thelleht Small or medium rockets burning these propellants have them driven by gas pressure (usually helium at 10-20 bar) into an injector that thoroughly mixes them in a precise ratio. Here it looks like they were just mixed at low pressure and with no attempt to balance the reaction.
If you want to see how they react in an actual rocket engine, watch a Titan II or Ariane 1, 2, 3 or 4 (not 5) launch. The flame is a very faint blue in air, invisible in vacuum.
a physicist once calculated that taking off from the moon to lunar orbit would take over 70 tons of fuel.
They did it with 0.3 tons of fuel ? !!!
damn....
Dear scientists, could you please have a go at explaining why the huge flames of even your smale scale experiment, isn't visible in the moon footage. I don't understand it. There is no visible light or flame in the footage?
Ironically, the futuristic high tech required to wire up a giant continuously tenanted building with demolition explosives, without any of the tenants noticing this, and without any trace of explosive residue showing up in tests of the wreckage, and making the building implode in a way which superficially looks a bit like a controlled detonation to the untrained eye but not to anyone who has actually seen many demolitions, was developed by our Reptoid colleagues as part of the Apollo program. :P
It's been 6 days and the only comment I've had is someone who agrees that the lack of CTs and other assorted oddballs is strange....
That in itself is strange! Maybe they just don't want to post anything stupid in front of the Periodic Videos crew because they know that as soon as they did, The University of Nottingham's Physics department (youtube /sixtysymbols) would turn around and rip them a new spacetime...
I love these videos ^_^
OK, thanks! I must say I have missed that information. That they actually tried to film the impact. I only knew they registered the impacts with the seismometers.
At the point of liftoff the ship is guided by gimbaled thrust vectoring, which the pilot has no control of the craft. Only until the ship is at pitch, and roll distance does the pilot have control of vector thrust to pitch, yaw or roll the craft. At liftoff the nozzle acts like a finger keeping a broomstick balance, it stays under the center of gravity of the craft using gyroscopes for guidance. The pitch move is a rotation, not a sway. The pilots purposely rotates the shuttle for course.
It's telling how moon landing deniers don't troll these kind of videos! They know they would receive a mental bitch slap!
now I did.. the propellant was Aerozine 50 (which is 50% N2H4 and 50% C2H8N2) as fuel, and N2O4 as oxidizer. So not much carbon involved after all ;)
N2H4.. "Hydrazine"
C2H8N2.. "UDMH"
N2O4.."nitrogen tetroxide"
This isn't as likely as the movies would have you believe. Aircraft are extremely strong, made of composites that are good at absorbing forces and don't crack readily, and can fly even after suffering damage.
And this stuff here isn't a proper high explosive anyway. It's spectacular, but not up there with purpose made high explosives in terms of blast pressure etc.
The limiting factor is not bomb-maker know-how, "they" have plenty of chemistry graduates too.
(2 of 2).....impact speed of 6000 km/hr, it's doubtful that they would of caught the actual descent but it would of made for quite an impact explosion. I always find it fascinating how they tried to wring as much scientific info as possible from each mission such as what they did with the LM's and the S-lVB's so they could determine the moons inner composition. I also found out that the LRO has captured the LM's impact craters and that they look elongated which matches their descent profile.
@recoveringcultmember For the LM descent engine I see Isp figures in the range of 305-311 seconds. That means one pound (mass) of propellants could produce one pound (force) of thrust for that many seconds. The ascent stage carried 2358 kg of propellants, about half of its liftoff mass.
The camera was controlled by mission control at Lyndon B. Johnson Space Center, in Houston..
What is the simplest way to determine the length of chemical bonds? I.E. when the Professor mentions "long bonds?"
Very interesting....I did not know that.
Correction. I took a better look through the AP-17 vol 1 mission report and found a short statement that the impact site was supposed to be 5 NM from the LRV. They had a nice map in AP-12's report so I was looking for that. I also found out that they were zooming in and out plus panning around with the LRV camera so it would of been quite a bit of good luck to have caught the impact.
@recoveringcultmember OK, I worked it out. For pure UDMH+N2O4 (remember the Lunar Module used Aerozine 50), the balanced equation is (CH3)2N2H2 + 2N2O4 -> 2CO2 + 4H2O + 3N2. (UDMH is 60.1g/mol, N2O4 is 92.01 g/mol). Then I worked out the total change in enthalpy (liquid propellants, gaseous products) as 1765.63 kJ per 1 mol UDMH and 2 mol N2O4. That's 7232.63 kJ/kg of propellants. At 100% efficiency, that's an exhaust velocity of 3.8 km/s or an Isp of 388 sec.
You can also take a canister of liquid nitrogen and toss it on the floor towards a door to allow the vapors to spill from under the door and into a nearby hallway. Sure doesn't sound impressive but when you add a large lecture class that just got out and impressionable people into the mix then it just because funny. :)
@recoveringcultmember We should probably redo it for the actual LM fuel, Aerozine 50, a 50-50 mix by weight of UDMH and N2H4. The mixture is more stable and freezes at a lower temp than pure N2H4, but is denser than pure UDMH.
everyone is entitled to an opinion, you don't have to slam anyone ...there's no trolling involved in that ! Take Care
Could you do more rocket related chemistry videos :D
please also explain why there is no visible flame coming out of the Lunar Ascent Stage.. I'm not a chemist, but I suspect some carbon gets oxidized..
The N2O4 came from a lecture bottle and the UDMH was in an ordinary glass bottle, so what is the large tank of gas to the left of the demo apparatus? Did it provide a pressurant of some sort?
Ever consider how amazing it is that this species went from the wright brothers to landing on the moon in seventy years?
like the small pop right at the end
So many reasons to study at Nottingham. Love the rocket ;)
*whistfull sigh* ... memories of my undergrad...
Of course there was the time I poured out LN on the floor and the dewar wasn't actually fixed into the stand/handle thing it was in, so it slipped out and smashed on the floor with a spectacular pop, scaring the crap out of everyone within earshot. Oops.
I think the question you need to ask is "if they landed on the moon, is a robotic camera THAT hard to build"?
It was filmed with a remote controlled camera, operated by NASA on earth. The pictures were beamed straight back to earth.
The N=N bond is really the strongest bond between two atoms that there is?? Sounds a bit odd. I've never heard this. (Between two atoms of the same element, perhaps?)
the same way they kept the cabin cool, only better.
@ApolloWasReal And should you really want this in archaic English units, 7232.63 kJ/kg is 3109.47 BTU/lb. Note the "kg" and "lb" refer to the sum total weight of the UDMH and N2O4, burned at a stoichiometric ratio of 1 mole UDMH + 2 moles N2O4, or a oxidizer:fuel mass ratio of 3.06:1 or an ox:fuel volume ratio of 1.68:1 (N2O4 is nearly twice as dense as UDMH).
Remember the Apollo LM actually burned AZ50 (50-50 UDMH+hydrazine) and NO was added to the N2O4 to reduce its corrosiveness.
@recoveringcultmember That's just my point, 428 kJ/kg is too low to account for the known exhaust velocity (specific impulse) of the UDMH+N2O4 propellant combination. The energy density must be considerably greater. Only some of the chemical energy is turned into kinetic energy of the reaction products, still more appears as exhaust heat, infrared radiation, etc.
The camera was remotely controlled from earth and as it lifted off they followed the LEM upper stage..simple as that. The spirit of the old NASA, sheer guts..!
So their workshop technician "many years ago" made this rather lovely model, and they burn the crap out of it. :D
It's a great video, but I can't say I'm not sad about what happened to the model. It seems it was made of plastic, at least at the exhaust hole.
This is very cool, great video.
The launch you guys did sounded kind of like a burp.
He speaks once in the halloween pumpkin vid too!!
Because the reactants are only volatile when they come into contact with oneanother. Heat doesn't effect it.
@recoveringcultmember From the equation for kinetic energy, E = 1/2 mv^2. Solve for v and plug in E/m.
They probably used slightly different fuels which were contained inside the spacecraft
Relatively expensive, but they're not the type of things any member of the public could ordinarily buy without being able to demonstrate a serious need for it, especially in these days of bus bombs.
In that video of the Apollo lifting from the moon who was holding and operating the camera!?
who filmed the moon take off?
@soberek You know, this has GOT to be the most animated I'd ever seen him. I mean applauding! He didn't get that animated when they blew up that umpty-gram sample of Cesium!
Oh, and for the only other example of him being heard on UA-cam, check out their hydrogen video -- the first time Dr. Pete....well, I won't spoil the surprise.
lol, attributing the 'first' bane to Mr Armstrong is pure internet genius.
America, putting the first men on the moon, Brits getting the first men off the moon, poetic?... Maybe not :-P
Got your message "Oh dear! Don't let this video get out or your entire house of cards will fall."
You care to explain how this video is so devastating to the hoax theory?
It's a tape about a bunch of guys explaining out hypergolic engines work. Wow.
Bill Kaysing explained the same in his book and in various interviews.
To catch the LM impact on Moon, they would have had to crash it very near, where the LRV was parked. That couldn't have been easy.
4:36
Sell that soundbite to a dubstep artist.
Excellent video, as usual! =)
@ApolloWasReal This is really a small scale experiment in a ventilated laboratory. They weren't in a real danger.
Camera was actually on a timer ;)
@endimion17 Oh sure, I can think of gases that are definitely worse, although I'd be very surprised to see them in many labs (Sarin, VX, etc). Occasionally there are accidents, such as during the landing of the ASTP Apollo mission when the crew accidentally opened the cabin vent valves while dumping excess propellants. They got lungfuls of N2O4 and spent some time in hospital but seemed to recover OK.
He gets a warm feeling?
That's hysterical.
I guess he lacks the necessary distancing from emotions that allows one to clearly see through the wool NASA pulled over his eyes.
Hysterical.
Dear skribzy1157: they left a tv camera along the experiment stuff to record and transmit lunar liftoff
Rocket fuel? Isn't it just Neil's morning cup of coffee?
Lots of people are bad at keeping secrets, it's a fact that everyone knows. Do you really think that (about) 400,000 people could keep such a big and prolific secret.
that was awesome
It may not be a conspiracy, and we probably did go to the moon, but why in the experiment above do you see the highly volatile liquid emit a yellow flame, using the same gas that the lunar module used, but yet at 0:37 there is no flame below the module? And where is the big blast, besides the little flakes of aluminum flying everywhere. And why in mid flight does the lunar module sway, as if it's being pulled up, not pushed up?
Cool, I'll subscribe to that. How come you've never pimped that channel here before?
@ApolloWasReal
Fair enough - I stand corrected ^_^
I was just guessing, so I'm not surprised I got it wrong - it was an educated guess but a guess nonetheless.
aww he didn't get to use the hydrazine model :( 2:12