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Comment by usermac | Hacker News Reader

I wonder what emergency procedure is in place in case the landing is off-course. Does it blow itself up?

As far as I understand, the Flight Termination System is safed before the landing burn. It's more dangerous to have it potentially still active after landing. So at this point it can't blow itself up anymore.

Until the last moment it also doesn't target the barge itself, but slightly to the side. Only very shortly before landing does it correct the target to the actual landing position. So in most cases it would simply hit the water instead of anything else when there is a major issue.

If you watch the livestream for yesterday's falcon heavy launch on youtube the second camera angle is a rendering showing trajectory, and you can actually see the center core adjusting closer and closer to the droneship with each step as it gets more confident that it's able to land safely.

The booster's trajectory targets offshore or away from droneship in case landing burn fails. The landing burn brings the booster onto the landing pad. See CRS-16 where the booster landed in the water when the booster lost roll control when the grid fins failed.

They've had a few "on purposes misses" over the years. The Falcon Heavy demo launch had the center core purposely miss the droneship as it was coming in way too fast since 2 of the engines didn't light.

IIRC it purposely missed the droneship by only a few hundred meters, but it was going something like 300 miles per hour!

CRS-16 landed in the water offshore when it lost control.

https://www.youtube.com/watch?v=5p1SDaXRaWY

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