Just before dusk I was viewing satellites using my 15×70 binoculars in my back yard when into my field of view from the east was an object lower then the orbiting satellites. Refocused binoculars for the suborbital object (maybe at somewhere around 100K feet) straight overhead. This was a pure black triangle, at each of the 3 points a red light would appear to flash (all 3 together) then the object would accelerate rapidity. This happened about 4 times before the object was approaching the western horizon and out of my view. Without the binoculars none of the craft or red lights flashes were visible. One might even say that it was possibly igniting fuel during each red burst, but the acceleration jump must of been so great that I suspect the inertia was dampened or possibly a unmanned craft.