Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
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Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
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Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#2Can someone ELI5 how this would cause GPS errors?
Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#3Can someone ELI5 how this would cause GPS errors?
Ionosphere's charge density introduces change in speed of the radio waves passing through it. This messes up with the GPS' calculations which assumes that ionosphere's density doesn't changes rapidly.
Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#4Can someone ELI5 how this would cause GPS errors?
GPS works by computing your distance from satellites by measuring how long it takes radio signals from those satellite to reach you. As an electromagnetic wave, radio moves at a different speed through plasma (which is full of charged particles) than through holes in that plasma, so this will change how long those radio signals take to reach you, which will change how far away from the satellite you think you are.
Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#5Can this cause any other issues other than GPS errors? Lines like
It is followed by ionospheric hole (plasma depletions) due to rapid chemical reactions of rocket exhaust plumes and ionospheric plasma.
sound concerning but that's most likely because I only understand half the words, and have even less of an understanding when they're strung together in that manner!
Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#6I wonder why a SpaceX Falcon-9 was singled out. Wouldn't any sufficiently large rocket have the same effect? And if so, wouldn't the Falcon heavy cause an even more dramatic effect?
Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#7I'm taking the liberty of reworking their "plain language summary." I aimed for maintaining accuracy with relaxed precision, but please correct me if I've lost too much of either in the process.
I corrected a specific bit of imprecision in language in the source's plaintext summary not clearly distinguishing between vertical/y v. vertical/z, something the technical abstract clarified by stating "vertical altitude."
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In plainest language, the rocket was lobbed up, not hurled forward, and this resulted in a shock wave that was followed some interesting reactions in the ionosphere between the rocket exhaust plume and the plasma in the ionosphere, all of which need further study because of potential risks to things like how accurate your GPS might be in the area around the "hole" caused by these reactions.
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Plain(er) Language Summary
On 24 August 2017, a SpaceX Falcon 9 rocket took off from Vandenberg Air Force Base in California, carrying Taiwan's FORMOSAT‐5 Earth observation satellite into orbit. The lightly weighted solo payload lets the rocket fly a path higher than the bare minimum to insert the payload directly where it needs to operate (the mission altitude), at 720 km. This unique nearly vertical path away from the ground is different from the usual satellite launches where rockets fly over horizontal paths more closely to the ground and insert satellites at 200 km above Earth and rely on orbit maneuvers to reach mission altitudes. Because of this lofty (more vertical) launch path, the rocket launch generated a gigantic circular shock wave in the ionosphere covering a wide area four times greater than California. It is followed by an ionospheric hole (plasma depletions) due to rapid chemical reactions of rocket exhaust plumes and ionospheric plasma. Large spatial gradients caused by these reactions and the resulting hole could lead to ~1 m range errors into GPS navigation and positioning system. Understanding how the rocket launches affect our upper atmosphere and space environment is important as these human-caused space weather events are expected to increase at an enormous rate in the near future.
Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#8I wonder why a SpaceX Falcon-9 was singled out. Wouldn't any sufficiently large rocket have the same effect? And if so, wouldn't the Falcon heavy cause an even more dramatic effect?
A sufficiently large rocket with a similar payload being launched to reach a similar orbit.
Apparently that combination is not very common.
Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#9Even plainer language:
Rocket exhaust can have impact with atmosphere, we need to study it more on short and long term effects.
Re: Circular Shock Acoustic Waves in Ionosphere Triggered by Launch of Formosat‐5
#10Even plainer language: Rocket exhaust can have impact with atmosphere, we need to study it more on short and long term effects.
This is ELI5 territory, which is cool because we probably need one of these as well.