[Pearls Before Swine]

It’s a tight focusing problem. How few MOA (moments of arc) is a spacecraft at altitude?

Would the beam have to be coherent?

[SpinnerWebb]

Would the beam have to be coherent?

Not really. As long as it's just slurring a little, it's cool.

[Another Post-American]

That’s a very good question. I like to brainstorm about launch methods like this, and the general principle of “Leave the power source on the ground” is a great one... if we can make it work!

[InterceptPoint]

Would the beam have to be coherent?
++++
The phased array that they refer to would have to be huge resulting in an extremely narrow beam. It would, by its very nature, be coherent.

Multiple independent arrays would not have to be coherent with each other but a single array would be more efficient overall.