Long exposure of Minuteman III launch
Sunday morning I got an email from the launch-alert mailing list about an upcoming Minuteman III ICBM test out of Vandenberg AFB on Tuesday morning. I had just gotten back from photographing the Iridium 7 launch a few days prior, but being a cold war nerd I definitely did not want to miss seeing an ICBM going up. So, I headed south once again, bringing along gear to camp out on the central coast.
The Air Force occasionally pulls a random active missile out of a silo in Montana, South Dakota, or Wyoming, removes the nuclear warhead, and ships it down to Vandenberg AFB to test launching it. They make sure the thing still flies and hits the expected target way out in the South Pacific, usually near Kwajalein or sometimes near Guam.
VAFB – Kwaj path
I didn’t know much about Minuteman launches so I scrambled to find out more. I knew roughly whereabouts on base they were launched from, and the path they’d take, but didn’t know how high it’d get, how visible it’d be, nor the best vantage for photographing it. Most importantly I didn’t know exactly when it would launch, for this launch there was a 6 hour window between 12:01 AM and 6:01 AM, which is a lot of uncertainty. Without a way to know exact timing I’d have to watch the horizon constantly for launch to avoid having super long exposure photos. From what I gathered it would lift off a lot faster than a Falcon 9, have a considerably higher apogee, and because it was a solid fuel booster the exhaust plume should be much brighter.
Some people had compiled information about Minuteman launches, but most had ran out of steam and interest in the late 2000s. Not many people have photographed a launch recently either it seems. Fortunately the 30th Space Wing posts a ton of launch video on Youtube, and cross referencing against news articles, I was able to get a rough idea of the launch windows and when the launch actually takes place. Apparently I had just missed MMIII launches in April and May. They seem to launch at the beginning of the window, but there were still many that launched much later.
Trivia: the “GT” in launch titles, e.g. GT-226GM, apparently stands for “Glory Trip”, an Air Force designation stretching back into the 70s. Interestingly they also occasionally test launches by sending commands from an airborne launch command in case silos become isolated from ground launch command centers.
==== 2018 ==== GT-226GM 2018-04-25 05:26:00 AM LF-10 Window 03:26 AM-09:36 AM GT-225GM never flown? GT-224GM 2018-05-14 01:23:00 AM LF-04 Window 01:21 AM-07:21 AM ==== 2017 ==== GT-223GM 2017-08-02 00:02:10 AM LF-10 Window 12:01 AM-06:01 AM GT-222GM 2017-05-03 00:01:59 AM LF-04 Window 12:01 AM-06:01 AM GT-221GM 2017-02-08 11:38:59 PM LF-04 Window 11:30 PM-05:39 AM GT-220GM 2017-04-26 00:03:06 AM LF-09 Window 12:01 AM-06:01 AM ==== 2016 ==== GT-219GM 2016-09-05 02:10:00 AM LF-04 Window 12:01 AM-06:00 AM GT-218GM 2016-02-25 11:00:59 PM LF-10 Window 11:00 PM-05:00 AM GT-217GM 2016-02-20 11:34:02 PM LF-09 Window 11:00 PM-05:00 AM
I settled in on a site in the Los Padres National Forest north of Santa Ynez. From there in the distance I could see the red lights of the antenna tower at Vandenberg just off Ocean Ave, right next to the unofficial viewing area for SpaceX launches from SLC-4E. I knew the Minuteman launches happened just north of this, but didn’t know how far, so I aimed my camera in this direction and hoped for the best. I was relieved when I turned on my radio and heard the launch net chatter discussing the launch checklist, because then I would know for sure when it would launch and click off the camera right before.
Recycle, recycle
At first everything was going fine for a 12:01 AM launch, when I heard “not clear to proceed” about T-15 minutes. The held the countdown, then started recycling after mention of some sort of launch anomaly. After a while they restarted the countdown for 1:20 AM, then another hold until 1:40 AM. At the last minute they held and recycled again due to an anomaly. Then they tried for 2:55 AM and again held at the last minute of the countdown. The moon had risen around 11 PM and was conveniently staying out of the way. By now it was starting to add glare to my photos.
(Times are approximate from bits of video+audio I recorded and photo EXIF, I didn’t know I’d be making a timeline later)
Finally after a long time they tried again around 4:40 AM and it finally launched. The sky to the west was still fairly dark and the missile made this bright, rich, orange dot as it rose up in the air. About a minute or two into the flight I thought I saw the first stage separate and glimmering as it fell back to earth. After this, there was just a very faint spec continuing westward. I kind of expected see a brighter exhaust plume for longer, but wrote it off as flying so far away from me. The arc is barely noticeable on the photo I took, but it’s there. Like the Falcon 9 launch from afar, after a few minutes a very very faint rumbling sound comes in and goes away.
Looking at the photo the glimmering is following the upward trajectory, so I’m not sure what I was looking at. The shitty iPhone video I made clearly shows something falling away around 4:41 AM and something else continuing to burn upward. Lesson for next time, get a heck of a lot closer and further south.
Surprise ending
I later found out from the news they actually terminated the flight of this missile due to an anomaly (I’m finally learning how to spell “anomaly”). The article says they terminated at 4:42 AM, in theory I was still exposing the photo. It makes me wonder if the pulsating brightness was the missile being destroyed, a sign of the problem, or that’s just what it normally does. It probably explains why I could barely see anything after it arced over. I never saw a giant explosion or flash, nor heard a big boom to indicate it went out in a blaze of glory.
At the time during all the launch holds I was thinking to myself “gee I thought these were supposed to launch at a minute’s notice”. Then it entered my mind that because this is a test flight, they could be intentionally running down to the last minute to test recycling the missile and exercising their checklists so people get practice. I guess this one really did have problems.
