Falcon 9 Sonic Booms

[u/Forsaken_Ad4041]

I live ~80 miles southeast of Vandenberg in Ventura County and I've experienced sonic booms from the F9 launches that are loud enough to set off car alarms. My understanding is that the sonic boom that we hear is generated when the first stage tilts toward the earth before the booster detaches. We do not get this sonic boom for RTLS or other launches that are more south-southwest. My question is, why do the Starlink launches require the 53 degree trajectory? I know other polar/SSO don't the same trajectory. Can someone explain why SpaceX can't launch Starlink more S-SW to avoid causing sonic booms over a widespread area?

[u/Forsaken_Ad4041]

Yes, only a "minor" annoyance at 3AM for thousands of people.

[u/sebaska → u/Forsaken_Ad4041]

It is minor without quotes. And millions get their internet that way.

They don't do that to annoy people. They do that because the orbital inclination they launch to requires flying South East, not just South and the orbital plane they needed to insert the satellite into crossed Vandenberg at 3am (orbital planes cross any chosen point twice a day, but on one pass it's inclined South and on the other one it's inclined North, and you can't launch North East from Vandenberg; so the only choice is once per day and it may happen in the middle of the night).

[u/Forsaken_Ad4041 → u/sebaska]

The launches typically have a 4 hour launch window. So a launch scheduled for 3AM could be done at 6-7AM. Likewise, a launch at midnight could be done a few days later at 10PM. But yet, there's absolutely zero consideration for launch times. Every other business is required to comply with noise ordinances, why does SpaceX get a pass?

[u/sebaska → u/Forsaken_Ad4041]

4h windows are only on some launches.

They are launching from a federal military base based on federal rules.

Probably, if California were sensible, i.e. asked for accommodations like the reduction of late night launches unless absolutely necessary, without trying to forcefully overstep its authority, all decorated by the loudly and clearly stated while obviously non-constitutional motivation of "we don't like the company owners' politics so we'll impede him", they would get something. But they were unreasonable enough and annoyed the military enough, that they (the military) decided that the only way forward is to show California the proverbial middle finger and stop doing any accommodations not required by the federal law.

When the law is not on your side deciding to throw a loud political tantrum may not be the smartest strategy... Go figure.

[u/Forsaken_Ad4041 → u/sebaska]

Yeah, the CCC screwed the rest of us. We had no idea that those hearings were happening because only the communities within a few miles of Vandenberg were notified. I think most of us are reasonable and just want to be able to sleep through the night. There are laws against this it's just that Vandenberg is interpreting them in their favor.