At appx 1:12am today, I watched the Minuteman launched out of Vandenberg.
I was sitting on the back porch, enjoying a positively nipple-crinkling 87-degree breeze. I was hoping to see it (launch window was set from 12:01 am to 6:01 am) but not expecting to be so lucky.
So around 1:12 I saw an orange dot clear the mountains west of my location, about 150 miles away from the launch site. From me it is on an azimuth of 259. Quite unlike the Falcon 9s I’ve seen launched from there, this one went straight up from my vantage. That means I was sitting pretty much in the trajectory plane.
It was rather less bright than I expected — no brighter than a Falcon 9 first stage.
I had my 15x binos in my lap, so I watched the whole sequence except the first 20ish seconds which were below my horizon. I saw 1:2 staging (T plus 60 seconds), then interstate jettison 16 seconds later. The spent first stage tumbled about 1/sec, visible as an orange blinker as the hot end swept through my line of sight. I tracked it for about 20 seconds before the hit end went dark. (Tumble had slowed to about 1/2sec.)
2:3 staging and 2:3 interstate jettison (T plus 120 and ~135) was also pretty clear. Third stage winked out 3 minutes in (kinda cool that each stage had 60 seconds burn time. I’m sure the missile’s name has nothing to do with that.) at an elevation of about 20 degrees.
I saw it go up on a constant bearing (straight up). The usual target is Kwajalein in the Marshall Islands at a latitude of 9N, while Vandenberg is at 35N.
I found this map, which suggests that I was within a degree of the ballistic trajectory plane (great circle).