Boosters don't really "explode". When ruptured they burn really fast, but (assuming engine shutdown and non-malfunctioning capsule separation) at such high altitude there is not that much danger from simple conflagration.

Sure, in _very_ rare case engines might not shut down or something else might get broken, but "If the booster had exploded, the crew would have been in extreme danger." seems too over the top. Launch escape tower is jettisoned for a reason ...

Was jettisoning the escape tower at that moment planned, or was that a failure?

Normal the tower is used for launch pad abort and for a very short window afterwards.

The Soyuz launch abort system is actually quite robust probably the best launch abort system that has been implemented for manned flight so far with the Orion and Crew Dragon only marginally improving on it and even that is still not clear given those haven’t been flown yet alone actually used in practice yet.

It hasn't flown any missions, but Crew Dragon has had its launch pad abort tested: https://www.youtube.com/watch?v=wcHD9AmkxA0

Yes, but there is a difference between being tested and being used. On paper the Crew Dragon launch abort system is slightly better since it doesn't rely on an escape tower for launch pad abort but in reality it's not clear how much better and safer for the crew the whole thing would be.

I'm not sure if having eight high-pressure hydrazine engines (which must work in perfect sync) inches apart from the crew is safer than a classic launch escape tower with a single solid booster on top.

Do other types of rocket engines not need to be in perfect sync?

A classic launch escape system doesn't. It has several exhausts, but it's a single booster.

The original plan for Crew Dragon was to have it land with rockets like a rocket should, instead of with parachutes. They also wanted to have a design that could also land on Mars. Safety first NASA didn't allow that plan. Not sure if rockets are still powerful enough to do a powered landing coming from orbit. I hope so and that tourists will have the option of returning that way even if NASA astronauts don't.

They will not develop powered landing. SuperDraco or not, one of the main obstacles was the difficulty and risk of putting legs through the heatshield.

Smaller Dracos are used for in-orbit maneuvering. SuperDracos are now solely for launch abort. They could conceivably be used for an orbital maneuver requiring more delta-v than the fine-tuning the Dracos do, but at this point the only likely destination for Dragon is the ISS.

One advantage is that you avoid having to jettison the escape tower which would add some complexity and risk.

Also, the engines are designed for use in space during a normal mission and to be recovered. So in that configuration the crew would still need to be located close to a hydrazine thruster as a part of a normal flight.

> eight high-pressure hydrazine engines (which must work in perfect sync)

There's eight for redundancy, it's a fault-tolerant system.

There are 8 independent engines, IIRC, mounted two by two. I think they are controlled in pairs, one on each side of the craft so as to avoid an engine on one side not knowing its counterpart on the other side failed and forcing the capsule to spin instead of fly away from the faulty booster.

Orion has also done a pad abort test, for what it's worth.

https://www.youtube.com/watch?v=j68mszdhTmY

Why does Lockheed's official video look like it was filmed by my uncle on his VHS camcorder?

Looks like someone is recording a video feed broadcast via a projector onto a dark wall with a cellphone or camera. Probably a cellphone from 8yrs ago.

Off-topic, but, a cellphone from 8 years ago is the iPhone 4. Isn't that crazy to think about?

We're way off topic at this point. I think the iPhone 4's video quality would be better.

Regardless it's a video recording of a video being projected onto a wall. The cellphone quality is the least important part of my comment and has improved dramatically in quality on the average smart over 8yrs (iPhone tends to be leading edge and that phone was brand new at the time which not everyone has).

Planned (nominal). See here:

https://www.youtube.com/watch?v=bIxkVAXPYPc&t=134

It's so bizarre that in NASA-speak the word nominal means not the value that a parameter should have ("in name") but the fact that the parameter is within a specified tolerance of that value. It's like a contraction of "<value> is what it should be, according to its formal definition". https://english.stackexchange.com/questions/184876/how-did-n...

SNAFU, so to speak.