Cryogenic just means “really cold!” Maybe with a few additional “really”s in front.

Liquid oxygen boils and condenses at -273F, at atmospheric pressure and it freezes at -361F, where absolute zero is -459.67F. So they are trying to get more oxygen into the tanks by cooling it closer to the freezing temperature. It looks like it has been quite a feat and problem.

There is another form of oxygen, ozone, but they are not using that, just extra-cooled regular LOX.

BTW: thank you for telling me about JPL’s von Karman lecture series. I am now spending (too much) time watching the archives.

Do you know what the difference is between regular LOX & the “deeply cryogenic” stuff?

Spent a good long time at the SpaceX website yesterday– fascinating stuff.

My father asked that same question, and I wrote to him:
“I think that most of the 33% performance improvement is in other modifications, but that they are trying to eek out a little bit more so that they have just enough to land on a barge after doing a GTO (geostationary transfer orbit) launch.”

Right now, if they cannot recover after a GTO launch, then the first stages for these launches will still be expendable and expensive. I suspect that the customer, SES, is willing to wait a little bit in order for future launches to be far less expensive than they are now. SES is a major satellite operator, and they would greatly benefit from lower launch costs.

Eagerly watching SpaceX launch at T -3 minutes and counting, and hoping that the long hold did not warm the LOX too much for a successful barge (drone-ship) landing.

Now we know that the colder temperature (denser oxygen) helps with performance of the engine. I suspect that they have enough performance to get the payload to its proper orbit, but they are looking for optimum performance in order to have enough fuel left over to recover the first stage. They are likely learning the techniques and procedures needed to do this on a regular basis.

I was wondering why they would have to drain the rocket and start again. It seemed like a bizarre thing for that one engineer to say, but now it makes sense.

I agree, though, that at some point they need to stop making this an experiment and get their customer’s payload to orbit. The competition has the advantage of timeliness in their launch schedules, and SpaceX needs to keep that in mind as they improve their system.

My father has long been concerned that rockets sometimes failed due to problems with incremental improvements, wondering if the small improvements were worth the loss. Not only do we have to worry about the loss of the spacecraft, with these changes in the rocket, but the customer’s revenue stream is also an important consideration.

I once worked on a satellite whose owner had started training people to install the TV receivers on people’s houses, when we had a major setback with faulty equipment on the satellite. While we sent the equipment back to the supplier for repair, the customer had to fire all those people in training, because they could not afford to keep them on the payroll for the extended repair time. Although it did not affect my team directly, we learned an important lesson in the importance of schedule, and the effect on the lives of people who have no influence on the problem.

Maybe instead of just loading the tank and hoping they could cycle the tank during filling operations.
Fill the tank once with coldO2 then start to drain that as they load in the super cold O2. letting it drain slowly as they keep filling it with thesupercoldO2 just before launch.
Obviously recovering the draining O2 during the whole thing.

That and add more insulation to the tank.