Hello and welcome back.
If you follow the channel, you know that we have been restoring all kinds of Apollo electronics
hardware over the last few years.
I you also know that I was in Seattle recently, and visited the Connections Museum, near the
former Boeing airfield.
And you might even know that at the other end of that historic Boeing field, there is
another museum, the Museum of Flight.
So today we’re taking a lazy day off, not reverse engineering nor restoring any complicated
Apollo electronics, but instead going to see some big Apollo hardware in the museum.
I mean, really big.
This museum is an amazing place, with a superb collection of major aircrafts and aerospace
items.
One of the stars of the show is the sole remaining M-21, a version of the Archangel A-12 aircraft,
the early version of the SR-71 Blackbird.
The M-21 had the unique ability to launch a supersonic drone that sat on a pylon at
the back.
You can also climb inside an SR-71 cockpit, and I was happy to oblige.
And outside there is a whole bunch of stunning aircrafts, including a supersonic Concorde
that you can climb into.
But I quickly whizzed past the main aircraft collection and spent the day in the lesser
known section of the museum, dedicated to the space race, of which local Boeing was
a large participant.
But boy, it sure deserves to be more well-known, as it is one of the best presentations I have
ever seen of Apollo hardware.
I started the visit admiring a display case at the entrance of the exhibit.
It had all the US rockets from the first manned space flight to the Apollo moon rocket, all
at the same scale.
From the Redstone and Atlas rockets of the Mercury program, to the Titan for the Gemini
flights, to the Saturn IB for the low earth orbit Apollo flights, to the Saturn V moon
rocket which didn’t even fit in the frame.
Then it dawned on me that this entire evolution took place from 1961 to 1968, a mere 7 years.
Compare that with the 17 years it has taken to fly the first SLS, and by no means on a
small budget.
Clearly NASA isn’t quite what it used to be, but still, the Apollo program is an engineering
achievement of outlandish proportions.
That’s one tough engineering act to follow, and that display immediately put things into
perspective.
That was going to be a good visit.
I was then immediately drawn to the Apollo command module.
This is CM-007A.
It started life as CM-007, the very first production Block I command module delivered
to NASA.
After the being upgraded for the Block II configuration, it became known as CM-007A.
It was used for further recovery testing and training, including a 48 hour survival test
where astronauts Jim Lovell, Stu Roosa and Charlie Duke spent 48 hours bobbing around
in the open ocean in rough swells.
It is beautifully restored, and very well presented and lit.
And since it never flew, it is nice and shiny.
The hatch has been removed, which is great, because it gives us a great opportunity to
take a nice peak in there.
As we walk around it, we can see the small side windows.
There are also the forward facing ones.
These are the rendez-vous windows, used for centering the spacecrafts visually in the
docking maneuvers.
There is a large window in the hatch, which we’ll see in a minute.
Let’s go in for a quick look.
On the top of the panel, you have all the alarm lights.
The center dials are for environmental control and cooling.
I am trying to make it to the bottom right portion of the panel, which is the communications
section.
In this still, at the bottom left, you can recognize the two large knobs for manual control
the high-gain S-band antenna position.
One for pitch, and one for yaw.
Above them are three meters, the middle one is the S-band received signal strength, the
one we wired up in our restored transponder.
On either side of it are the S-band antenna pitch and yaw position indicators.
Above them, the three vertical meters are the cabin and suit pressure and temperature
indicators, and the CO2 partial pressure meter.
Here is a better view of our high-gain antenna control and meters.
The comms section is obscured by a strut, and I end up a bit too far right looking at
the fuel cell and electrical control.
It says Main bus A and main bus B on the voltmeter knob, of Apollo 13 fame.
I’m trying my luck from a better angle to see the communications section that Eric is
trying to reproduce right now.
Unfortunately, the angle is a bit steep.
I can see the squelch A and B thumbwheels, but I can’t discern much else.
We end up in the number 5 side panel, with the fuel cell pumps that they’d turn off
for Apollo 13, and the cabin lighting controls.
There are panels all over the place, including in the lower bay.
Here is an overall view of that right section, with the lower bay panels.
I have not researched what they do, but these would not be accessible while the astronauts
are strapped in their couches.
Coming in from the other side, we have the propulsion controls, the prominent FDAIs commonly
referred as 8-balls, and our favorite computer interface, the DSKY, which is clearly a Block
II.
Drifting to the alarm lights.
The mission timer numbers are fake, it would be an electro-lumiscent display like the DSKY.
Drifting back towards the RCS maneuvering controls.
It looks like the protective cap switches for the staging pyrotechnics have been torn
off, and were hastily epoxied back together.
Now coming straight in, we go on a trip to the lower bay, with the prominent sextant
and telescope optics.
There is a little cheat sheet for the guidance computer verb and nouns.
The computer sits right underneath this section.
There is another DSKY to the right, that’s the navigation DSKY.
This entire area is used to align the inertial navigation platform using star sightings,
a process that is tightly orchestrated by the Apollo guidance computer.
The Block II unified crew hatch is displayed nearby, superbly presented and lit.
It’s unified, because the heatshield part of the hatch, and the crew cabin part of the
hatch, have been unified in one single outward opening hatch, after the Apollo 1 accident.
It is a marvel of mechanical engineering.
There are 15 latches operated by a long linkage around the periphery.
The locking and unlocking is via the long handle on the left.
It actuates a ratcheting gearbox located towards its base, in a pumping-like action.
It takes about 5 pumps to lock or unlock.
The golden selector on the gearbox selects whether the pumping action is set for locking
or unlocking.
There is also a golden safety pin on the side that will lock the gearbox, and that you have
to pull before actuating the handle.
However, it was design to shear in the event of an emergency, if you really cranked hard
on the handle.
The round thingy at the right of the window with the little handle is the venting valve,
to manually depressurize the cabin.
You’ll notice that the center window has markings on its rim.
They are used to monitor roll on re-entry.
During re-entry, the AGC rolls the entire cabin around to orient the lift, up, down
or sideways as it actively targets the landing zone.
The astronaut in the center couch can monitor the roll by looking at how the earth horizon
lines up with the marks.
At initial re-entry, the horizon should be lined up with the zero roll mark.
There are other markings for 55 degree and 90 degree roll, left or right.
You can see some pretty good rolling action from this Apollo 15 re-entry footage, probably
taken from the rendez-vous window, not the hatch one with the markings.
Now we turn around to see the mother of all engines, the Rocketdyne F-1.
These are of course the 5 ginormous engines that lifted the Saturn V rocket off the ground.
I had never seen one up close.
That engine is just, huge.
It stands at 19 foot tall.
For you, metric-centric rest of the world, just know that this is so high, that there
is no equivalent metric dimension for it.
The diameter of the bell is 11 ft 7 inches.
Same thing, too large to convert to metric, I’m told it wouldn’t fit.
As I was craning my neck for the better part of an hour, trying to understand the plumbing
upstairs, a friendly docent finally came to me and asked if he could bring me a ladder.
He was joking apparently.
However, if you are a little bit familiar with rocket engines, because you have watched
enough Scott Manley or Everyday Astronauts videos, you’ll be able to identify the main
parts of this engine.
The large pipe around the nozzle is for the gas generator exhaust.
It injects a curtain of gas to cool the nozzle extension below it.
It’s still quite hot, but much less than the main rocket exhaust, so the curtain appears
black when it exits the nozzle.
Same as the black spots on the sun, that aren’t really black nor cold - they are just less
hot than the other parts of the sun.
The thrust chamber, which is part combustion chamber and part nozzle, starts right above
the big wrap-around pipe.
It is entirely lined with cooling tubes.
The F-1 engine is cooled by its own fuel, 70% of which passes in the tubes lining the
chamber, before being injected back at the top.
Looking up at to the top section, you can spot the bottom round part of the gas generator,
which powers the turbo pump.
The turbo pump itself is not easily visible, sandwiched in-between the inlet pan way up
top, and the gas generator exhaust funnel underneath.
However, you can easily see the output pipes carrying the high pressure liquid oxygen and
RP-1 fuel from the turbo pump to the combustion chamber.
They are the two large horizontal pipes with NO STEP written on them.
The oxygen one is at the very top, and the fuel one is underneath.
Here, I am zooming in on one of the attachment point for the hydraulic gimbal actuators.
Only the 4 outer engines were gimbaled, while the fifth center one was fixed.
And if you are wishing to see more of the internals of the engines, you are in luck.
For this, you have to thank another local, Mr. Jeff Bezos.
He funded an expedition to look for the remnants of the spent Saturn 1C first stages, at the
bottom of the Atlantic.
And finding them he did, at an incredible 4.3 km below the surface of the Atlantic ocean.
Which is much too large to be converted in British imperial units.
Three miles below where I'm standing right now is a wonderland that is testament to the
Apollo program.
It looks like a magic sculpture garden.
All of these pieces from different missions, that are in some cases perfectly preserved,
and in other cases twisted into these beautiful shapes.
And here they are.
So this is part of the thrust chamber of one of the Apollo 16 engines.
Starting from the left, the liquid oxygen inlet dome, a reproduction plexiglas injector
plate, the fuel inlet annulus, the combustion chamber and the first top part of the thrust
chamber expansion nozzle.
You can see all the cooling tubes I was just talking about.
Up there is the bottom part of the turbo pump.
That’s the gas exhaust, which first passes through a heat exchanger to heat up the liquid
oxygen and create gas to pressurize the LOX tanks during flight.
The disc is part of the gas turbine providing 55,000 horse power to the pump.
And here is the real injector plate, with the famous baffles that they had to add, in
order to prevent the engine from destroying itself in spectacular fashion, because of
combustion instability.
Here is a cross section showing how the injector plates distributes the LOX and the fuel from
the intakes we just saw.
And next to it, is turbopump turbine stage 1, removed from the exhibit we just saw.
You can see it in this cutaway of the turbopump, one of the bladed discs at the bottom.
That’s how it is supposed to look.
Thank you very much for fishing this out Mr Bezos, very impressive.
But enough of engines already.
Let’s make our way to the lunar rover.
This is, of course, a donation of another local company.
Boeing is the contractor that developed the rover.
I am of course immediately attracted to its color camera and the S-band communication
antenna, as we just got that bit working in our recent restoration of the Apollo communication
system.
Take note Elon, this is how a proper electric vehicle control panel is done.
None of this flat screen button-less rubbish.
This must be a film camera.
The super light, foldable wire wheels were a point of pride in the design.
And I was surprised how small the foldable S-band antenna was.
They must have made some improvements on the transmitter to get enough signal to noise
for color TV through an antenna this small.
The camera is the later RCA color camera, mounted on its robotic mount, which could
be controlled from Houston.
And there was so much more to see.
There is a LM ascent stage, which is quite a big piece of hardware.
They also had an Apollo inertial measurement unit, or IMU, which had the gyros and accelerometers
used by the Apollo guidance computer.
And in a corner, the spare Mars Viking lander.
But the museum was closing, and you get the gist of it: if you ever are in the area, and
a space nerd like me, pay a visit to the Museum of Flight.