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SpaceX punched a hole in the ionosphere

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Re: SpaceX punched a hole in the ionosphere

#121

Post by jack_pp »

ericd wrote: post #118
lacrimacida wrote: post #108

Earlier quoted context omitted.

The space industrial complex would pollute a whole lot more than today, and let’s hope space tourism it’s not something too feasible, aside from stroking egos it wouldn’t do much, space is very human unfriendly after all. I for one hope we move slower not faster.

It’s not just stroking egos; if you read any accounts by astronauts, there’s a profound effect on people that get a chance to look back at earth, and see how it’s actually not infinite. I hope every powerful person gets the chance to do that, I think it’d go a long way in reducing the petty bullshit we engage in.

You could do that with a VR headset

Re: SpaceX punched a hole in the ionosphere

#122

Post by dermesser »

eqvinox wrote: post #79

"molecules from the rocket exhaust produce photons at a wavelength of 6300 Å – the same color as red auroras." Anyone else have this use of Ångström trigger an exception in their brain? The unit of default for wavelength is nm, not Å… (1nm=10Å)

If you look in another field, the default wavelength (wave number) unit is 1/cm. Meaning, there's not really a default wavelength unit.

Re: SpaceX punched a hole in the ionosphere

#123

Post by ly3xqhl8g9 »

esquivalience wrote: post #5

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…

[flagged]

Re: SpaceX punched a hole in the ionosphere

#125

Post by dguest »

eqvinox wrote: post #79

"molecules from the rocket exhaust produce photons at a wavelength of 6300 Å – the same color as red auroras." Anyone else have this use of Ångström trigger an exception in their brain? The unit of default for wavelength is nm, not Å… (1nm=10Å)

I don't know if there's a "default" unit, but most people I interact with would use SI units (i.e. km, m, cm, mm, micron, nm, pm). Maybe more to your point, 630 nm is the same number of characters and a slightly more familiar unit. Writing a wavelength as 6300 angstroms is a bit like saying a marathon is 421,950 cm.

Anecdotally I've only really heard angstroms used in material science / condensed matter physics, where most small structures are small integer numbers of angstroms across.

Re: SpaceX punched a hole in the ionosphere

#127

Post by ricardobeat »

ajhurliman wrote: post #114
rTX5CMRXIfFG wrote: post #90

Earlier quoted context omitted.

Not being able to tell the difference between a news article and a blog post is par for the course of modern society.

It’s honestly astounding you consider them to be distinct

Different eras. Journalism used to be bound by much stricter ethics.

Re: SpaceX punched a hole in the ionosphere

#128

Post by nologic01 »

Commercial space is a tragedy of the commons in the making. What is its "carrying capacity", who calculated it, who enforces it? What are the long term effects, when do they kick in? What are potential secondary effects or tipping points?

Astronomy is already a casualty as the sky stops being "dark". I guess who cares about fundamental knowledge when there is profit to be had.

Re: SpaceX punched a hole in the ionosphere

#129

Post by alden5 »

nbltanx wrote: post #7

Starlink plans to deploy 12,000 - 42,000 satellites. What if two competitors want to do the same? Can the low earth orbit handle 150,000 satellites that turn into space debris at some point?

Starlink satellites only last about 5 years before they run out of gas and are decommissioned with an end of life maneuver which sets them on course to burn up in the earth's atmosphere. I doubt many others besides maybe amazon will want to launch satellites at the same height as spacex's, especially considering how insanely expensive and complicated launching something like the starlink network is. Another point to consider is how small they are compared to the area they occupy, they have plenty of room to spread out and they're constantly monitored to calculate the probability that they might collide.

Re: SpaceX punched a hole in the ionosphere

#130

Post by aledalgrande »

InspiredIdiot wrote: post #75
rdlw wrote: post #61

Earlier quoted context omitted.

What do you mean? If they're both circular orbits, they'll have the same period, so they'll never collide—they'll always be on opposite sides of the Earth. In fact, this goes for any two orbits with identical periods.

Once anything collides with anything in orbit it has a slightly different trajectory. Any movement up or down will make its orbit more ellipsoidal than the original orbit. Also the atmosphere moves up and down in response to solar wind and therefore varies in both time and space. Atmospheric drag is apparently still a factor up to 600km https://www.swpc.noaa.gov/impacts/satellite-drag Debris in a crowded orbit will e…

From the article you linked:

> Debris between 1 cm and 10 cm (approximately 500,000), referred to as the “lethal” population, are the most concerning as they cannot be tracked or cataloged and can cause catastrophic damage when colliding with a satellite. Objects smaller than 1 cm (approximately 135 million measuring from 1mm to 1cm, and many more smaller than 1 mm) that could disable a satellite upon impact are termed the “risk” population

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