This sounded like a weird comparison to me. I got curious so did some math. Brazil area = 3300000 sq mi = 9.2e13 sqft. A film 1mm thick of this area would be 9

This sounded like a weird comparison to me. I got curious so did some math. Brazil area = 3300000 sq mi = 9.2e13 sqft. A film 1mm thick of this area would be 9.2e13 sqft x 0.003 ft = 2.76e11 cuft. Great wall of China, average of 33 ft tall and 20 feet wide, with a length of 13,170 mi (69,537,600 ft) is a volume of 4.6e10 cuft. According to this a 1mm film the size of brazil would be an order of magnitude more volume than the great wall of china. Using silicon’s density of 2.32 g/cm3, at a volume of 2.76e11 cuft (7.82e15 cm3) gives us 1.8e16 g, or 1.98e10 tons. The falcon heavy launch capacity to geostationary transfer orbit is 26.7 tons. However, L1 is much further altitude (1.5 million km) than GTO (42,164 km @ apogee). (But we’ll just use GTO capacity since the only other listed capacity for the falcon heavy is for mars transfer orbit and I couldn’t find an altitude for that from earth.) 1.98e10 tons would require almost three quarters of a billion falcon heavy launches. If we did 100 launches per day, this would take 20,000 years. Maybe there’s some solid silicon asteroid out there, but even if that were the case, we’d have to lift up the machinery and fuel to move it in space. Vesta, one of the largest known asteroids with a mean diameter of 326 mi, if a sphere would have a volume of 1.8e7 cumi = 2.65e18 cuft. So by volume we could flatten that out with enough to spare, but you’re dealing with maybe a lot of undesirable content. I’m bored now so Ill let someone else calculate how much fuel it would require to move Vesta the required distance, or guess at how much of it is useful and what it would take to convert it to the necessary structure. But my guess is that in any case, “huge undertaking” is underselling it. Sounds like pure fantasy to me. Actually sounds remarkably similar to the scale of the problem humanity is faced with in The Three Body Problem trilogy. (I’m half way through The Dark Forest now, guess I should go back to that!)