I thought this would be about flying in formation for consumer planes. Couldn't some fuel economies realized that way? More impressive yet than the article ar

I thought this would be about flying in formation for consumer planes. Couldn't some fuel economies realized that way? More impressive yet than the article are proposals for space telescopes made of millions of accurately positioned mirrors. With a spherical constellation, you can cover the whole sky at once. I wonder if such a constellation would require a star shade, or if you could just orient some mirrors not to reflect their light?