Rocket Launch from Vandenberg SFB–II

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).

Launch of SpaceX Falcon 9 with a brightly illuminated and expanding exhaust plume.
Launch of SpaceX Falcon 9 with a brightly illuminated and expanding exhaust plume.
As the exhaust fades the red glow in the ionosphere can be easily seen.
As the exhaust fades the red glow in the ionosphere can be easily seen.

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.

Rocket Launch from Vandenberg SFB

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.

A SpaceX Falcon 9 rocket climbs into the night sky after a launch from Vandenberg SFB.
A SpaceX Falcon 9 rocket climbs into the night sky after a launch from Vandenberg SFB.
Composite of two images taken 13 seconds apart.
Composite of two images taken 13 seconds apart.

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.

Rocket exhaust gases illuminated in the twilight sky (21:17:03 MST 19 July 2023).
Rocket exhaust gases illuminated in the twilight sky (21:17:03 MST 19 July 2023).
Rocket exhaust gases illuminated in the twilight sky (21:18:26 MST 19 July 2023).
Rocket exhaust gases illuminated in the twilight sky (21:18:26 MST 19 July 2023).
Rocket exhaust gases illuminated in the twilight sky (21:20:35 MST 19 July 2023).
Rocket exhaust gases illuminated in the twilight sky (21:20:35 MST 19 July 2023).
Rocket exhaust gases illuminated in the twilight sky (21:22:12 MST 19 July 2023).
Rocket exhaust gases illuminated in the twilight sky (21:22:12 MST 19 July 2023).

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.

Beautiful!

An explanation for the red glow can be found at SpaceWeather.com.

Edit: Added more photos and a link to SpaceWeather.com