Anomolous entity crosses the night's sky @speed

In March of 1985, I was a 20 year-old active-duty medic in the army. I volunteered for duty- doing  temporary duty (TDY) in Central America assigned to the 8th Hospital. This was in Honduras’ Palmerola Air Base, near the town of Comayaqua.
The only night I would ever do guard duty during the six months there, both Pfc. (blank) and myself observed an anomalous entity cross the night’s sky.  The “guard station” itself was a wooden structure with sandbag-reinforced walls and ceiling.  We were allowed to lay up on the roof of that bunker and stargaze for the evening-no contact was expected with others…very isolated part of the base:  “Just report back if you see or hear anything “out of the ordinary.”  So, both Pfc. (blank) & I laid up atop that makeshift bunker admiring how clear that moonless night’s sky was.  With minimal light pollution, and almost a total field of view from horizon-to-horizon, as we were in the middle of the huge Comayagua Valley. (Years later I would become a commercial sailor, so that night’s conditions were almost like being on the open ocean-optimum conditions.) Also, no clouds or water vaper or suspended ice crystals in the upper atmosphere were observed.
At approx. 01:30am it appeared, rising up, above the mountain range to our West. It was a bright point of light (generic white light) several magnitudes brighter than any other celestial object observed that night. Out of the west, it arced up swiftly, reaching its apogee, almost overhead of us in less than 15 seconds. It came to an immediate stand still, resting for about 4-5 seconds, then, with no apparent “gradual”/ gradient/ exponential increase in speed, it arced downward by approx.  10-15 degrees, stopped for around 3-4 seconds, arced over to one side, stopped, performed one more arcing maneuver, stopping one last time for around 5-8 seconds. Then it shot off…arcing away, down towards the other side of the valley to our East.
It appeared to have only two speeds…dead-stop…or full tilt throttle open fast.  My point is that no acceleration could be noticed from my observation…one could only guess as to the actual speed of that object.
Years later I would see the International Space Station (ISS) traveling across the sky, either right before sun rise or right after sunset.  It takes more than 6 minutes for the ISS to cross the nights sky if its apogee is close to overhead…at 17,500 mph. So, what would take the ISS 3 minutes to be above us, that thing did in 15 seconds!  That’s roughly 12 times faster than the ISS, so doing the math you get a speed of approx. 210,000mph!  Depending on orbital height…  Well, that’s my story…  I always wondered if (blank) thought about that night in the years since…if he saw value or, at least, a little wonder &awe in the experience…for me the experience was like having an open-ended question bouncing around in your head…with no one to satisfy the itch it leaves behind…I find solace in the fact that just writing about the experience gives me a kind of closure…  Thanks for reading