No we don’t.
1) It was an interesting concept but, like all things space, very expensive.
2) If you know anything about orbit mechanics you would know you can’t be everywhere all the time and orbit revisits could be many hours to a half day.
3) gravity alone doesn’t get you Mach 10, in fact the speed slows down to a few hundred mph due to atmospheric drag
4) with hypersonics we can get there faster with sub orbital systems than waiting for proper orbit geometry and that (hypersonics) is the next tech
5) having systems based on the ground keeps cost down, let’s you upgrade much easier and cheaper, lets you test easier.
You can believe some old copy of popular mechanics if you like, but we dont have them. We may have prototyped the idea during the Cold War under Reagan, but certainly never operationalized.
I’ve explained this in the past. If you could drop anything from orbit and hit the earth at Mach 10, then we would all be dust from the meteor strikes that bombard the earth routinely. The atmosphere slows and oblates all those rocks. But you would have to understand some real atmospheric physics to know this.
“The atmosphere slows and oblates all those rocks (meteors).”
That friction from air resistance is what will establish an objects terminal velocity, depending on the objects cross section and “slipperiness” of its surface. Otherwise, gravity would continue to accelerate a falling object.
I wonder what the theoretical maximum speed would be for an object with the optimum needle shape, with the best possible coating? If its incremental drag were less than its incremental gravitational acceleration, it might continue to speed up.