It is not exactly in Paris, 1.5-2h south east by car, and 1.5h by train and bus. I took the train from Gare de Lyon to Melun and then a bus that took about as long as the train to go to Safran, for employees that work there. Uber would have been close to $200....

I did want to stress that the museum is at the plant and in the middle of nowhere ;)

After 1h45, I got there, finally. I was not able to enter the company grounds for good reason, but the museum is on the side and free to enter on wednesdays during limited hours 09:00 to 12:00 and 14:00 to 17:00. There is an anoying 2h gap at noon where you can't enter and I was stressed that I would have to leave at noon, not have time to finish and have to wait outside for 2h in the sun to come back in at 14:00. In the end, I got lucky as one of the volunteer guides (most are retired employees who enjoy doing this for fun), ended his tour at 13:00, so I got closer to 4H and got to see it all. I believe if you are on your own, no one kicks you out and you can continue to look at things by yourself without anyone kicking you out, which is nice.

There were multiple guides roaming around, I joined a few separate tours as they roamed around multiple exhibits with different explanations. After all these years, I finally learned the difference between multiple jet engines and realized that airliners use turbofan engines that are effectively custom turboprops that use fan blades to make thrust instead of propellers but otherwise they are reasonably similar. The exhibits also made it very clear that military jet engines are pretty huge and often the entire plane is built around the engine and happens to be as long as the engine is. I also didn't know how much space the postcombustion chambers for afterburners, took:

multiple versions of the same engine

those are the engines that SNECMA/Safran is known for

SNECMA is also known for the Concorde engine, a marvel of its time:

still very impressive engines to this day

And those are the turbofans that power airliners. Safran and GE make many of the engines used by Airbus and Boeing:

they even designed more efficient variable pitch fans

For comparison, here is a turboprop:

And a bad ass huge radial engine with reduction gears:

The cool part is they had a shop in the back where they were rebuilding old engines with retired employees that were probably bored at home and happy to see their friends at work and help build/restore engines they used to work out:

Then we had a small break as a vintage Mirage 2000 was scheduled to do a low pass, and land:

After the quick break, I restarted the museum from the beginning with another guide:

Great so see museums that show that the first heavier than air aircraft was indeed french (Avion 3) and predated the wright brothers by 10 years, even if it was a very poor aircraft, it did fly in ground effect for a short distance. It's hard to call it an airplane by any standards, but it was still the first heavier than air aircraft to take flight on its own (not using wind, or a hill and gliding):

The company started as Ghome Omega which made the most efficient and durable radial engine in 1909:

50 horsepower and over 3H of runtime by then, which was a small miracle

french world record of fight endurance thanks to the best engine made

the propeller was were made in glued slices to guarantee the wood quality

The competition made V engines:

Safran then converted to jet engines by using knowledge brought by the germans during WWII:

and they soon became leaders

post combustion chambers took extra room

And Safran makes other things

including landing gears, who knew?

Various other displays:

Interstingly when during the war, they were not able to work on plane engines, they also made motorcycles to keep the factory oworking, and they made a lot:

And last, was the space section as they work with satellites as well as Ariane

I had no idea Ariane did consider making a space vehicle

Missiles:

Propulsion for satellites:

And more random things, still:

And that as it for the visit. It can be done thoroughly in 3h flat if you are fast, but 4H is a bit more comfortable, so I'm super thankful for the volunteer I was with who stayed through his lunch hour to finish the tour at 13:00

the mathematicians that did the job

part of the machine that helped decode the sequence in the day's encryption key

and the full machine that was used for the daily decryption

later enigma was improved with a 5th rotor and an even bigger machine had to build in the UK by Betchley park to crack that

the next machines that did the work during WWII

New room showing in details the differences between the 2 bombs and how they were made:

Other fission powered vehicles:

nuclear planes were tried, but it never happened

same thing for nuclear cars

And then the big bonus for me was the fallout exhibit. I had no idea it was a series of video games first:

Then went to see the rest of the regular museum I had already seen:

It's a fantastic museum, so glad I went back.

And the most famous part of course, the full scroll:

And actually even better, the airport has the even bigger version on display: