10 ms·
Seems like this isn't considered to be a big issue, beyond that it is a very visible thing that instinctively 'feels' like a bad idea. > Rocket engines spray w
by esquivalience 3y ago
Seems like this isn't considered to be a big issue, beyond that it is a very visible thing that instinctively 'feels' like a bad idea.
> Rocket engines spray water (H2O) and carbon dioxide (CO2) into the ionosphere, quenching local ionization by as much as 70%. A complicated series of charge exchange reactions between oxygen ions (O+) and molecules from the rocket exhaust produce photons at a wavelength of 6300 Å–the same color as red auroras.
> Once rare, ionospheric “punch holes” are increasingly common with record numbers of rocket launches led by SpaceX sending Starlink satellites to low-Earth orbit. Ham radio operators may notice them... These effects may be troublesome, but they are shortlived; re-ionization occurs as soon as the sun comes up again.
- KRAKRISMOTT 3y agoWill excess radiation leak through to Earth during re-ionization?
- Jeff_Brown 3y agoIf the holes are quickly healed by sunlight, and only local to where a satellite is launched, the answer would seem to be no.
- arbuge 3y ago> One famous example occured on August 25, 2017, when a Falcon 9 rocket carrying Taiwan’s FORMOSAT-5 satellite created a hole four times bigger than the state of California. Doesn't sound too local to me.
- Jeff_Brown 3y agoGood point. Deserves some numbers. California's area is about 500 thousand km^2, and the Earth's is about 500 million, which means the side facing the Sun is about 250 million, so we're talking about 0.2% of the area facing the sun. Suppose the hole takes six hours to heal (the article makes it sound like it takes much less), and suppose there's a launch every month (since launches have in the past carried 600 satellites at once, that seems plausible, no?), and suppose the hole lets in twice as much of whatever radiation we would like the ionosphere to keep out. Then that's an increase of 0.2 * (1/4) * (1/30) %, which is less than 0.002% -- that is, an increase by a factor of less than 1.00002. Not negligible, but if the satellites provide a substantial public good, then it seems worth the cost. I feel like due to StarLink's use in Russia-Ukraine war alone, it more than qualifies.
- coldtea 3y ago>so we're talking about 0.2% of the area facing the sun Doesn't sound small at all.
- saagarjha 3y agoRight, but presumably the effects are greater for the people in California?
- onethought 3y agoBecause the hole was similar sized to their state? I guess so, they will have to deal with increased fame and awareness of the size of their state. People in Oregon on the other hand will continue to be snubbed.
- dylan604 3y agoWe'll start seeing placards attached that says it's known to cause
- cdot2 3y agoYeah they get to see red lights and have trouble with HF HAM radio. If youre aware of other effects please share.
- TaylorAlexander 3y agoAnother way of putting it is that it could potentially affect 40 million people.
- eru 3y agoThere are areas of the globe that are more densely populated than California. But on the other hand, you typically don't launch rockets there.
- TaylorAlexander 3y agoOh I was assuming the launch was actually from Vandeburg in California and that’s why people said the hole was the size of California. But it could have been from Florida.
- deleted 3y ago[deleted]
- dfox 3y agoOnly insignificantly. Most of the radiation is filtered/diverted by the magnetosphere. The only really practical effect of the disturbance is making the already hard to predict sky-wave propagation of HF even more harder to predict and characterize. Which is today realistically of an interest to HAMs and mostly as an fallback for intelligence agencies and diplomatic services. Edit: It also somewhat changes the scatter/delay characteristics of GNSS, which may or may not cause a somewhat significant error of the GNSS fix (it probably should not, but it can).
- op00to 3y agoWhat about high frequency trading shops?
- dfox 3y agoThat is completely different definition of HF. And if they use radio (lower latency than fiber, in theory and in right circumstances ), it is somewhere between SHF and EHF (C through V in the IEEE nomenclature), ie. what sane person would informally call “microwave”, not HF.
- jrockway 3y agoThere was a thread on here the other day about HF traders using HF radio.
- tomjakubowski 3y agoYes that's right, also known as shortwave radio. https://spectrum.ieee.org/amp/wall-street-tries-shortwave-radio-to-make-highfrequency-trades-across-the-atlantic-2650277134 https://spectrum.ieee.org/amp/wall-street-tries-shortwave-ra...
- dfox 3y agoWell, the article itself does a pretty good job of describing why it is not an exactly good idea. What it does not say (and what probably nobody suggesting that ever though about) is that the sky-wave propagation mode is either about reflection off the ionosphere or refraction effects of the ionosphere, both of which means that the propagation path is significantly longer and in the refraction case over “slower” medium. The resulting latencies are almost certainly large enough that the whole thing does not make sense even before thinking about the bandwidth and frame sizes.
- perihelions 3y agoDon't believe the ionosphere has any role in any sort of radiation absorption, outside of RF?
- angiosperm 3y agoThe Ozone Layer is considerably lower than the Ionosphere proper, and protects all surface life from ionizing solar UV radiation. It most likely is as damaged by rocket exhaust as the ionosphere, and much more slowly healed. That undoubtedly deserves its own article, which will unavoidably be confused with this one and be considered old news.
- reaperman 3y agoWhy would O3 be damaged by H2O? SpaceX rockets are powered by hydrogen and oxygen and produce water as exhaust.
- HPsquared 3y agoKerosene and oxygen.. Anyway it's probably that the exhaust plume will contain reactive species like nitrogen oxides, maybe the water vapour could have a role. It's not a big effect. Hydrazine powered rockets have a much bigger effect (all those nitrogen oxides) and are still not a very big deal.
- pseg134 3y agoIt may not seem like a big issue but it speaks to the attitude of billionaires. I am no longer free to vent personal amounts of coolant from a refrigerator but Elon Musk can punch all of the holes he wants with his expensive rockets.
- katbyte 3y agoVenting refrigerant does actual measurable damage that takes decades to repair, this does not (that we k ow of) and is undone in a single day I get what and agree with what your trying to say but a better comparison is needed
- ddq 3y agoThey stole the commons from us and hold it ransom.
- simonh 3y agoWhere by ‘stole’, you mean granted licensed access to the commons by elected representatives, under strict regulation and monitoring, in order to provide services to the public at competitively bid prices.
- dylan604 3y ago[flagged]
- cj 3y agoI wonder what the total carbon footprint is of the Musk Empire. (Tesla + SpaceX + X + Boring Company + …)
- machdiamonds 3y agoAnd I wonder how many times over Tesla makes up for it.
- W0lfEagle 3y agoZero?
- samstave 3y agoTotally stupid Q: Can we harvest any of this energy>?
- tekla 3y agoSolar Panels
- jakeinspace 3y agoWho measures light wavelengths in angstroms rather than nm?
- thrdbndndn 3y agoI was curious too so I checked Wikipedia [1]. Apparently, angstrom was invented exactly for measuring light wavelength. Its (arguably more common today?) usage for atoms and other microscopic structures actually came after that. [1] https://en.wikipedia.org/wiki/Angstrom https://en.wikipedia.org/wiki/Angstrom
- jakeinspace 3y agoHuh, learned something new.
- tigershark 3y agoEveryone? It’s the preferred unit for electromagnetic wavelengths.
- ly3xqhl8g9 3y ago[flagged]