Apollo Lunar Module

Coaxial injectors surround a central stream of one propellant with an annular flow of the other, often with the outer flow swirling to promote mixing, an approach favoured for hydrogen engines and used extensively in Russian designs.

Pintel injectors, where a single central postmeters both flows, offer wide throttling range and were used in the Apollo Lunar Module descent engine, which had to hover and choose a landing site, and in the Merlin engines that land Falcon 9 boosters today.

The injector is also where one of the most feared problems in rocketry begins.

Combustion instability occurs when small pressure fluctuations inside the chamber, coupled with the acoustic resonances of the chamber volume and with the way propellant is being injected, Under the wrong conditions, those fluctuations reinforce each other and grow, and they can grow with astonishing speed.

There is no drag to slow a descent and no air for a parachute to grip, so every metre per second of arrival velocity must be removed by rocket thrust, and the descent from lunar orbit to the surface costs somewhere around 1.9 kilometres per second of delta-v.

On the other hand, lunar gravity is only about one-sixth of Earth's, and with no atmosphere, there is no need for aerodynamic shaping, no heat shield, and no fairing.

Landers can be built as open frameworks of tanks, engines, and legs, which is exactly why the Apollo Lunar Module looked the way it did.

Modern designs range from small robotic delivery vehicles carrying instruments to large crewed landers derived from orbital launch vehicles, and several are being developed to be reusable, refuelled in lunar orbit rather than discarded after a single descent.

Yeah.

My housekeeper doesn't do as good a job cleaning my kitchen as the Apollo Lander was.

When they landed on the moon and they had a rocket that moon dust is everywhere.

The lunar lander, when they're driving around, what's happening with the tires? Oh, dust is going everywhere.

Now you have something tangible to work with.

For those of you who have watched the film Apollo 13, there's a fantastic scene where the character, Ken Mattingly, who is a real person or was a real person, is in the Lunar Module Flight Simulator.

And they are trying to find a startup procedure that would not draw more than 20 amps.

This meant that they had to find out what they could turn on and what they could not.

[laughs]

And there's the, there's the lander right there, the Apollo lander.

I can put like a little-

Wait, what is-

...

David Bowie right here next to it.

Why is there an, why is there an Apollo lander? What's going on, Frive? This was the, the moon shot referred to earlier or-

Oh, this is what you were working on.

But there have been a few more weird and unexplained observations that occurred during the later Apollo missions.

The astronauts of Apollo 12, meaning Commander Charles P. Conrad, Command Module Pilot Dick Gordon, and Lunar Module Pilot Alan Bean, reported seeing powerful flashes of light, the same as Buzz Aldrin.

These occurred in the dark while the men were trying to sleep, and were powerful enough to be visible even with their eyes closed.

Plenty of other subsequent astronauts would report seeing these flashes, sometimes varying in brightness and even color.

And according to some, NASA is not only aware of this fact, but is actively concealing it from the general public.

That would be the case if you would ask Edgar Mitchell.

As the lunar module pilot for Apollo 14, he was the sixth man to walk on the Moon, and in his mind, there was no doubt that aliens were not only out there, but down here as well, visiting us all the time.

He was probably the biggest true believer in UFOs that actually went into outer space.

Okay

... and Lunar Module Pilot James Irwin.

Mm, mm-hmm.

And then Command Module Pilot Alfred Worden.

You're providing a blow-by-blow explanation to them that can be relayed to a studio with a commentator standing by.

There was the thrill of the takeoff, the thrill of the moon landing, and now the thrill of this activity that's about to unfold.

Mission Commander Dave Scott and Lunar Module Pilot James Irwin have just completed their third and final moonwalk.

They float and bob back to the lunar module.

But as it turns out, after he helped NASA all this time, I noticed, and I started college when I was in 1980, and he was one of my professors, and I learned a story around that time.

He had a picture of the LAM, the Lunar Excursion Module of Apollo 11 on the moon, and it was yellowing a little bit.

NASA was so grateful to him for tracking.

Oh, and he was also a ham radio operator, just like you.

The Apollo 11 mission launched from Cape Kennedy, Florida, now known as Cape Canaveral, on July 16, 1969.

The lunar module landed safely on the moon on July 20, 1969.

Mission Commander Armstrong was joined by Command Module Pilot Michael Collins and Lunar Module Pilot Edwin Buzz Aldrin, Jr., The Eagle has landed, Armstrong famously declared, after the lunar module touched down successfully on a surface that had never been before visited by human beings.

Those gathered in Mission Control celebrated the achievement with cheers and applause.

Although the live television images transmitted to Earth were grainy and in black and white, millions of viewers witnessed one of the most momentous events in American history.