Those didn’t come back from deep space they simply made a U-turn in low orbit and returned to the surface. In theory two gliders taking off at the same time at

Those didn’t come back from deep space they simply made a U-turn in low orbit and returned to the surface. In theory two gliders taking off at the same time at the right distance on a long enough axis could collide in deep space and create something new, which would then return to the planet surface like some kind of invasion, but I doubt it.