I was fortunate to see another spectacular launch from Vandenberg Space Force Base on Christmas Eve morning. I typically check the launch listing sites every few days to keep track of when the next launch will be. These are listed weeks or even months ahead of the launch date–although the dates can and do change. There are exceptions to this advance posting: certain top-secret satellites are often announced with only 24 hours notice. The SARah 2 & 3 satellites had this abbreviated announcement.
Fortunately, I happened to check the updated schedule about 12 hours before launch so I was able to make preparations for viewing it.
The launch was scheduled for 0611 MST (0511 PST) on the morning of December 24. I went north of Flagstaff to the San Francisco Volcanic Field.
The launch was on time at 0611 MST and about a minute later I was able to see the rocket as it rose above the horizon. I wasalso able to photograph the first stage separation. A few minutes later the high-level clouds appeared once the rocket had ascended high enough to be illuminated by the Sun–which was still well below the horizon at my location.
Here are a few photographs of the launch plus a time-lapse video that shows the dramatic expansion of the high-altitude cloud from the rocket exhaust.
SpaceX/Falcon 9 launch of the SARah 2 & 3 satellites.
The next launch is in a week but may be too late in the evening to catch the last light of twilight.
Another SpaceX Falcon 9 was launched from Vandenberg SFB during the evening twilight hours (07 August 2023). And this one might have been even more spectacular than the previous launch (19 July 2023).
The rocket exhaust is beautifully illuminated by the light of the Sun–which is well below the horizon. Next, the rocket moves through the ionosphere and a red glow develops. From the SpaceWeather.com site:
“This is a well studied phenomenon when rockets are burning their engines 200 to 300 km above Earth’s surface,” says space physicist Jeff Baumgardner of Boston University. Some rocket engines spray water (H2O) and carbon dioxide (CO2) into the ionosphere, quenching local ionization by as much as 70%. The F-layer of the ionosphere is particulary effected. Oxygen ions (O+) in the F-layer are hungry for electrons, which they readily steal from the rocket’s exhaust. Captured electrons cascade down the oxygen atom’s energy levels, emitting red photons at a wavelength of 6300 Å–the same color as red auroras.
The exhaust and red glow were bright enough to be reflected in the waters of Lake Mary.
Time lapse of the launch of the SpaceX Falcon 9.
The next launch of a Falcon 9 is scheduled for much later at night and will not be as well lit as this launch.
Over the years there have been some rocket launches from Vandenberg Space Force Base (SFB) that have been spectacular even when viewed from here in northern Arizona. This requires that the launch occur during twilight. During the day the bright sky overwhelms the faint light of the launch; at night there is no light other than the glow from the rocket engines.
At twilight the sky is dark but as the rocket rises higher it is lit by the Sun and the exhaust gases from the rocket engines are illuminated. Twilight launches do not occur often so being able to see one is an infrequent event. Also, clouds can obscure the view reducing the number of times that one can see these events.
Last night–after a one-day reschedule owing to an abort at T-5 seconds–SpaceX launched a Falcon 9 rocket into the sky from Vandenberg SFB at 2109 MST. The end of astronomical twilight was at 2120 MST in Flagstaff (and 2154 at Vandenberg) so there was reason to expect a good show as the rocket rose out of darkness and into the twilight-illuminated sky.
It was a good show. It took a few minutes for the rocket to rise above the western horizon and into the light but once that occurred it was easy to see. The rocket was visible until 2115 and then was blocked by distant clouds. After it was gone, the glowing exhaust gases remained visible for a few more minutes then faded quickly.