SpaceX - Uppskjutningar med mera

A 170 degree cone is just impractical for two main reasons -- scan loss, and element density. These two conspire so that it's just not going to happen.

Typical scan loss (cosine losses) for a +85 degree scan is just off the charts. Take a paper plate, and put it in front of a fan facing it, so that it's catching maximum wind. Then then it to +85 degrees, so there's only a sliver of it in the wind. There's over an order of magnitude reduciton in wind force. That's just physics. The exact same thing happens with antennas, with the incident RF wave receive strength as an analog for wind force on the plate.

See here for a simple graph of what this looks like (blue dashed line): https://www.mwrf.com/technologies/co...cations-part-2.

In RF, when scanning your beam also widens, gets ugly, you let in more interference, etc. You can also see that in the above paper, where it goes form being a nice pencil beam to a mis-shapen blob. That blob means extra receive noise, and that you're illuminating a bunch of extra open space with your transmit power, which isn't good either.

Then there's element density. To steer to +85 degrees, your element spacing has to be quite dense. This poses RF problems (mutual coupling, layout spacing and issues, etc) that spikes cost, and makes the design very, very tough. This is just a no-kidding spot where shit's hard. A typical design might do 0.55 lambda spacing, which gives you a 120 degree cone, and is typically considered about what the sweet spot is -- the elements now aren't so tightly packed as to make the RF problem very very hard to solve, you have fewer elements, saving cost, and so on.

If things go according to plan (if!), #SpaceX is actually on the Eastern Range's schedule for two launches in the coming days: Crew Dragon in-flight abort on 1/18 and another Starlink mission on 1/20. This of course depends on IFA, static test fire, weather, etc.