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Loss of key US satellite data could send hurricane forecasting back 'decades'

theguardian.com

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Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#131

Post by declan_roberts »

mh- wrote: post #70
lupusreal wrote: post #34

Earlier quoted context omitted.

Good grief. American KH-11 electro-optical spy satellites have 2.4 meter primary mirrors and orbit at ~300km or less. Ease yourself off the anti-Musk subreddits or wherever you're getting this incoherent nonsense.

Additional context for those unfamiliar: KH-11s are thought to weigh 30-40 thousand pounds (~20k kg). The mirror itself would dwarf anything launched for Starlink, multiple times over.

Starlink is 65x closer to earth. If a geostationary satellite was 1 km away, Starlink would be ~15 meters.

Dramatically different scale.

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#132

Post by XorNot »

mschuster91 wrote: post #113
XorNot wrote: post #106

Earlier quoted context omitted.

Except they won't. There's no reason to expensively launch your own forecasting system when you can instead just wait for someone else to do it and then use their insurance rates to do your own forecasting. Which is why the government running satellites it would need to run anyway is much more efficient.

> There's no reason to expensively launch your own forecasting system when you can instead just wait for someone else to do it and then use their insurance rates to do your own forecasting. Indeed but who's going to do that? The US government will, more likely than not, have lost the ability entirely, and Europe... good luck waiting on us. > Which is why the government running satellites it would need to run anyway i…

Well exactly - it's a classic tragedy of the commons situation. The first one to solve the problem bears all the expense, and worse so long as no one solves the problem you can also just raise rates to cover the broader risk pool. Meanwhile the tax payer has still paid for the actual instrument to be built and operated - they just get no benefit from it.

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#133

Post by mh- »

declan_roberts wrote: post #131
mh- wrote: post #70

Earlier quoted context omitted.

Additional context for those unfamiliar: KH-11s are thought to weigh 30-40 thousand pounds (~20k kg). The mirror itself would dwarf anything launched for Starlink, multiple times over.

Starlink is 65x closer to earth. If a geostationary satellite was 1 km away, Starlink would be ~15 meters. Dramatically different scale.

Thanks for the extra context, that's helpful.

How big would the optics on a satellite in Starlink's orbit need to be to achieve similar clarity, then?

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#134

Post by ethan_smith »

Rebelgecko wrote: post #15

So IIRC for the last 50 years the DMSP satellites broadcast all their data in the clear. If the program is only shutting down the ground stations and data distribution, it seems like an opportunity for some researchers to buy some SDRs and start collecting their own data. I'm actually surprised that the successors to DMSP don't meet the same needs. Or is the problem that they do and the government just doesn't share…

DMSP satellites broadcast on 2.2-2.3 GHz S-band with relatively simple modulation, making reception possible with a 1.5m dish and ~$300 in SDR equipment.

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#135

Post by 827a »

trehalose wrote: post #129
827a wrote: post #122

Earlier quoted context omitted.

What I find interesting is how clear your media biases shine through even while attempting to make a statement about how this is something that's happening to the other side. I haven't seen evidence that the Austin robotaxi launch was unreasonably bad. There were a couple viral incidents of undesirable behavior, though no collisions as far as I've heard, which is significantly better performance than one expects from…

You expect a group of less than twenty human drivers to have at least one collision per week?

Between 0 and 1 collisions per week, the actual number significantly more than FSD as a whole system experiences.

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#136

Post by defrost »

declan_roberts wrote: post #131
mh- wrote: post #70

Earlier quoted context omitted.

Additional context for those unfamiliar: KH-11s are thought to weigh 30-40 thousand pounds (~20k kg). The mirror itself would dwarf anything launched for Starlink, multiple times over.

Starlink is 65x closer to earth. If a geostationary satellite was 1 km away, Starlink would be ~15 meters. Dramatically different scale.

The communication relay sats are in a geosync orbit at 35,786 km constant.

The imaging satellites with the mirrors and telescopes are more dynamic and in eccentric LEO orbits at a similar height to the starlink sats.

see: https://en.wikipedia.org/wiki/KH-11_KENNEN (and the heading Resolution and ground sample distance indicating the close approach height being closer to earth's surface than typical starlink sat).

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#137

Post by CamperBob2 »

Taniwha wrote: post #130
Animats wrote: post #5

It's part of the Administration's war on ... Florida?

When you have a president who can predict the paths of hurricanes with a sharpie you don't really need all those expensive satellites.

And threaten to nuke them if they don't go where he says.

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#138

Post by aurizon »

Someone in the USA should litigate to forestall any irreversible shut down/sunsetting of these satellites. Under automatic systems they might last until the midterms when a 'night of the long knives' might reap a huge harvest - perhaps a dual supermajority to allow for some reforms?

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#139

Post by e3bc54b2 »

softwaredoug wrote: post #57

The problem of important projects surviving political change is a tough one. A lot of these important projects have a single point of failure - who is the president every four years. I wonder how we build institutions and resources resilient to that? I realize privatization is an ugly word, but could some of this stuff be provided by the private sector? Can we make it possible to fund initiatives in a multinational m…

> who is the president every four years...could some of this stuff be provided by the private sector?

A president cares about election every four years. Private sector cares about it every quarter. I doubt privatization is improvement if you want to focus on long term.

Re: Loss of key US satellite data could send hurricane forecasting back 'decades'

#140

Post by defrost »

mh- wrote: post #133
declan_roberts wrote: post #131

Earlier quoted context omitted.

Starlink is 65x closer to earth. If a geostationary satellite was 1 km away, Starlink would be ~15 meters. Dramatically different scale.

Thanks for the extra context, that's helpful. How big would the optics on a satellite in Starlink's orbit need to be to achieve similar clarity, then?

A little bit bigger, the starlink sats have a uniform height, the optical spy sats with the big mirrors have a similar mean orbital height but are in elliptic orbits that come in closer, then further away. The best photos are taken closer to the earth than a typical starlink sat is.

The above comment about geostationary orbits is confused .. the spy sats with mirrors relay their data out to geostationary relay sats and then back to earth ground stations.

If you're curious you can read more in the wikipedia link (and other references) I linked in a peer comment.

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