Bright, long-delayed flashing light/strobe (?)

[MNNightwing]

I apologize if this is the incorrect place to post this query, but I am new to the lounge and very curious as to what I have been seeing.

From my perspective on my back deck: 46.8634745, -95.9774050, I have watched/witnessed a very bright, long-delayed flashing light in the night sky on four separate occasions - 3 times traveling from SSE to the NNW in a nearly straight South to North line along the longitudinal, and once traveling NNW to SSE in a nearly straight North to South line (in other words not very east to west at all), usually to the east of my location and at a very high altitude and angle (nearly 90 degrees above...say about 85 degrees from the eastern horizon). The flash catches my eye, and I can count to about 30-one-thousand before it flashes again, so roughly thirty seconds between flashes. The flash is very bright and very long compared to any of the limited air traffic I generally see in this remote locale. (Most air traffic is small craft out of Detroit Lakes airport, 7 miles to the east, or Fargo International, about 60 miles to the WNW. ALL of which I am accustomed to seeing and readily identifying...even those few jet liners that have their landing lights on flying toward me from Fargo.)

I have searched and researched online to find out what type of aircraft (or high atmosphere, lower outer space objects; i.e., satellites) might have a strobe that flashes so infrequently as thirty seconds between flashes, but have found no information whatsoever.

The flash is approximately one-half-second long (if counting one-one-thousand, two-one-thousand, etc., it flashed for about "one-one" in the count). It appears to be white or possibly a light amber and resembles the reflection of the sun off of a satellite at dusk (which I have seen often in the western portion of the sky at dusk; i.e., tracing a dimly lit satellite travelling SSE to NNW not long after sunset when trying to see the first stars as they appear, and then, there is a bright flash as the satellite reflects the sun which set some 30 to 40 minutes prior, and then, going back to the dimly lit pin-prick of light that a satellite normally is until it fades from view to the NNW). However, even though I can "guess" or estimate where the flash will occur again in thirty seconds (roughly a straight line), I do not or cannot see the pin-prick dot of light that one normally sees when viewing a passing satellite in the interim between flashes.

The most recent sighting occurred on about February 20 (sorry that I did not note the exact date), and I was out at about 3 a.m., watching "The Summer Triangle" rising in the northeastern sky. While surprised that Deneb, Vega, and a bit of Altair were already visible in February, the flash caught my eye not far from Vega...just NW or toward Polaris from Vega's position. It was very cold out (-25 to -30 F or so), and the night sky was very clear. I watched without blinking so that I could see if the next flash would occur along the path it had the past three times I had seen it; i.e., to the NNW of its last flash, but this time whatever the object was had traveled to the SSE. I was able to infer its trajectory and where it would next flash two more times along its trajectory before it was obscured by nearby trees and rooftops.

I don't know if my description helps anyone to help me with an answer to the quandary, but if not, I will try to have more exact specifics the next time I see it. Oh! By the way, the four sightings have all been within the last year or 18 months out of the 40 to 45 years I have star gazed. I have not seen this peculiar flashing light before 2019.

Thanks in advance for any possible sources for this phenomenon.

[MNNightwing]

NOTE: I forgot to mention how bright the flash is. It was about as bright as Vega or Arcturus in the night sky, as a comparison. MUCH brighter than most transponder lights or strobes on private, commercial, or civil aircraft regardless of how close those aircraft might be...much brighter.

[Sunshine]

Funny, I just wrote a possible answer regarding satellites rotating and panels catching sunlight which would appear like flashes then deleted it. When I took a closer look at your location and realized you're a few hours drive from me and, I now remember being perplexed a few nights ago by a set of delayed flashes to the north east of me which were unlike any satellite I've seen in my 20 years looking up at the sky.  It suddenly hit me, it was fairly low on the horizon, like a bright light which was being faded in and out.  Each time it took about two seconds on then a few seconds off then again.  I am well aware of satellites reflecting light but, this appeared totally different and rather strange. 

Who knows what it was, not blowing the UFO alarm but, it's fun to speculate!

Edited March 3, 2021 by Sunshine