ionosphere – Flagstaff Altitudes

Wide-angle photograph of the Firefly Alpha launch. The exhaust plume from the 1st stage can be seen low near the horizon while the rapidly expanding rocket exhaust from the 2nd stage develops an arch shape. Also visible is the red glow in the ionosphere.

The 5th flight of a Firefly Alpha rocket was launched from Vandenberg Space Flight Base last week (03 July 2024). This was the first time I had observed a Firefly launch and was not certain what to expect. I started photographing the launch using a telephoto (80mm) but a few minutes into the flight I realized I needed a wide-angle lens (12mm) to fully capture the rapidly expanding rocket exhaust.

Firefly Alpha rises above the trees as seen from Upper Lake Mary near Flagstaff, Arizona. (80mm telephoto)

I manually tracked the flight and captured a few more images in which the 1st stage and fairings can be seen.

Firefly Alpha 2nd stage rocket with 1st stage following a short distance behind.

Firefly Alpha launch with 2nd stage. The 1st stage is executing a spiral as it begins its descent.

The 1st stage continues to produce a spiral rocket exhaust cloud.

Using the wide angle lens I was able to capture a sequence of images suitable for time lapse, presented below.

Time lapse video of the Firefly Alpha rocket launch from Vandenberg SFB on 03 July 2024.

As noted above, I switched from a telephoto lens to wide angle lens a few minutes into the flight–thus the time lapse starts well after launch. Nonetheless, the rapidly expanding rocket exhaust shows up well. Also, there is a hole punched in the ionosphere causing it to glow red. This video was featured on Spaceweather.com and a description of the red glow was provided:

The lingering red glow is “the hole.” Earth’s ionosphere is a layer of electrically-conducting gas enveloping our planet more than 100 km high. It plays a key role in shortwave radio communications and GPS positioning. When Alpha burned through the ionosphere, water and carbon dioxide in therocket’s exhaust quenched local ionization by as much as 70%. Red light is the afterglow of this process.

It was spectacular to watch and photograph. As always, I look forward to additional launches from Vandenberg SFB.

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.

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.

Flagstaff Altitudes

Tag: ionosphere

Launch of Firefly Alpha FLT005

Rocket Launch from Vandenberg SFB–II