I believe the parent is right, you couldn't hide it. Even if you succeed in building them completely stealthy, it's just a matter of time until the enemy finds

I believe the parent is right, you couldn't hide it. Even if you succeed in building them completely stealthy, it's just a matter of time until the enemy finds out the locations using espionage or signals intelligence, and after that they will place the site unde non-stop satellite surveillance. They are massive and can't be moved, so they are sitting ducks. As for launching, you are guaranteed to produce a thermal signature in the first few seconds of flight, since you hit the high density atmosphere at a 3-5 Km/s speed. You will leave a distinct, large and highly detectable infrared signature and the enemy will be alerted: https://youtu.be/JAczd3mt3X0?t=274 https://youtu.be/JAczd3mt3X0?t=274