Since a number of cool things are happening in space exploration these days, we'll widen the scope of this thread a smidge. Conversation about all things space exploration are welcome, whether it be from NASA, SpaceX, ULA, Blue Origin, or anyone else. Chances are most of the discussion will still be about SpaceX since they love to make things public and fun, but nothing's off limits. I'll eventually get around to modifying the OP to include resources for other companies too, but in the meantime, feel free to post any cool stuff you run across.
Tim Dodd (Everyday Astronaut) - A "random dude" who got really into space (particularly SpaceX). He's a great resource for simple explanations of this stuff, as well as live hosting launches.
USLaunchReport - Lost of videos of the more mundane stuff (e.g., booster recovery operations). Not a ton of commentary.
NASASpaceFlight - Live hosting of most launches including a ton of video of Starlink operations.
Glossary
Spoiler!
Space discussions tend to get a little bogged down in jargon, so here's a list of terms you might encounter. (Others, please let me know of others that should be added.)
ASDS - Autonomous Spaceport Droneship - The "barges" that they sometimes land rockets on.
Dragon - The cone-shaped capsule that sits at the top of the rocket for ISS-bound launches that holds the cargo (or, in the future, humans).
F9 - Falcon 9, the name of the rocket itself.
FH - Falcon Heavy, the three-booster version.
GTO - Geosynchronous Transfer Orbit, a type of orbit that will eventually result in the satellite orbiting the earth as it turns so that it seems to be in the same spot from the ground (such as DirecTV or Dish satellites). These types of launches are particularly challenging because they require a lot of power to get them into the right orbit, leaving very little fuel left for landing.
HIF - Horizontal Integration Facility - the building near the launch pad where they put all of the pieces of the rocket together before rolling it out to the pad.
ISS - The International Space Station
JRTI - Just Read The Instructions, the name of the "barge" that they land on for west-coast launches.
LEO - Low Earth Orbit, a fairly low orbit shared by many satellites and ISS. These launches usually require less power to achieve the proper orbit, so the first stage can often be landed back on land rather than on a drone ship.
LZ1 - Landing Zone 1, basically a big open slab of concrete at Cape Canaveral where the first stage will attempt to land (for some launches).
NET - No Earlier Than, basically the date they're hoping to launch, but rocket launches have a tendency of getting delayed.
OCISLY - Of Course I Still Love You, the name of the "barge" that they land on for east-coast launches.
RTLS - Return to Landing Site, a mission where the first stage comes back and lands at LZ1.
Starship - SpaceX's next-generation rocket (and spacecraft) that will hopefully one day take us to Mars. Starship is the "second stage" that will carry cargo or people, but also refers to the whole system. (It's confusing, but think of it like the Space Shuttle, which was both the shuttle itself and the entire launch system.)
Super Heavy - The giant booster that will carry Starship to space.
Yeah, I'll be curious if they say anything about it. They said that the tower was good earlier, so presumably some sort of sensor on the booster said no.
Turned out Mechazilla was the culprit, after all.
Ok, so #SpaceX have officially stated now that "automated health checks of critical hardware on the launch and catch tower triggered an abort of the catch attempt".