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Starlink lost 40 satellites to a geomagnetic storm

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Re: Starlink lost 40 satellites to a geomagnetic storm

#151

Post by Shank »

wilg wrote: post #147
Shank wrote: post #102

So…we have the Space Weather Prediction Center [0] and raw data from NOAA for this exact purpose. Does SpaceX not review the data / warnings before launch? There was a G1 warning posted until 21:00 UTC on the launch date: Space Weather Message Code: WARK05 Serial Number: 1635 Issue Time: 2022 Feb 03 1428 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 1634 Valid From: 2022 Feb 03 0…

"Does SpaceX not review the data / warnings before launch?" is peak Hacker News pettiness. Try not to assume the worst, especially when it's pretty silly.

> Try not to assume the worst, especially when it's pretty silly.

I'm just asking questions -- I would be genuinely curious if SpaceX has a system for determining and evaluating risk when it comes to a situation like this. It does seem absurd that they wouldn't review the active warnings prior to launches. What is indisputable here is that they've announced the loss of 40 satellites during an active warning. I think it's valid to wonder what the criteria is for a launch, given that the cost of the launch + payloads is quite high, and the cost of delaying the launch is (relatively) low.

Re: Starlink lost 40 satellites to a geomagnetic storm

#152

Post by TaylorAlexander »

It must be noted that the satellites were not directly damaged by the geomagnetic storm. The storm warmed the atmosphere which caused it to expand, leading to additional drag that prohibited the satellites from leaving their low "safe mode" orbit.

Shortened excerpt: "These storms cause the atmosphere to warm and atmospheric density at our low deployment altitudes to increase.... speed and severity of the storm caused atmospheric drag to increase up to 50 percent.... The Starlink team commanded the satellites into a safe-mode where they would fly edge-on (like a sheet of paper) to minimize drag...

Preliminary analysis show the increased drag at the low altitudes prevented the satellites from leaving safe-mode to begin orbit raising maneuvers, and up to 40 of the satellites will reenter or already have reentered the Earth’s atmosphere. The deorbiting satellites pose zero collision risk with other satellites and by design demise upon atmospheric reentry—meaning no orbital debris is created and no satellite parts hit the ground."

Re: Starlink lost 40 satellites to a geomagnetic storm

#154

Post by trothamel »

markwkw wrote: post #137
cogman10 wrote: post #62

Earlier quoted context omitted.

Yup, spacex stuff is all LEO. Without input it all crashes into the atmosphere in a few years (3 I believe)

I don’t think this is true. Looking at this: https://i.stack.imgur.com/pMchk.jpg from UN, objects above 500km take ~25 years to decay from orbit. They reportedly start at 550km, so I wonder how they hope to achieve 3 years of deorbit without active control.

That's wrong. There were four missions that were deployed to apogees above 300 km, but most are deployed to 250km and below. That means that satellites that fail tend to burn up quite quickly, in a few years.

Here's a chart of deployment apogee and perigee.

https://twitter.com/planet4589/status/1491256299002155012/ph...

Re: Starlink lost 40 satellites to a geomagnetic storm

#155

Post by Shank »

Animats wrote: post #141
Shank wrote: post #102

So…we have the Space Weather Prediction Center [0] and raw data from NOAA for this exact purpose. Does SpaceX not review the data / warnings before launch? There was a G1 warning posted until 21:00 UTC on the launch date: Space Weather Message Code: WARK05 Serial Number: 1635 Issue Time: 2022 Feb 03 1428 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 1634 Valid From: 2022 Feb 03 0…

That was a minor event to everybody else. I checked the PJM power grid alerts, and they didn't issue a geomagnetic disturbance warning. Their last warning was on 11.04.2021, and it didn't reach a level that affected operations.

> That was a minor event to everybody else. I checked the PJM power grid alerts, and they didn't issue a geomagnetic disturbance warning. Their last warning was on 11.04.2021, and it didn't reach a level that affected operations.

I think it's entirely possible that this type of warning would _only_ be relevant to SpaceX, because their satellites are so low and so small. They're going to notice atmospheric drag to a much higher degree by virtue of size and orbital insertion point, compared to other interested Space Weather parties. G1 is relatively minor for most space weather customers, but there are obviously times when G1 conditions aren't observed that they can launch during too.

Re: Starlink lost 40 satellites to a geomagnetic storm

#156

Post by bpodgursky »

wilg wrote: post #147
Shank wrote: post #102

So…we have the Space Weather Prediction Center [0] and raw data from NOAA for this exact purpose. Does SpaceX not review the data / warnings before launch? There was a G1 warning posted until 21:00 UTC on the launch date: Space Weather Message Code: WARK05 Serial Number: 1635 Issue Time: 2022 Feb 03 1428 UTC EXTENDED WARNING: Geomagnetic K-index of 5 expected Extension to Serial Number: 1634 Valid From: 2022 Feb 03 0…

"Does SpaceX not review the data / warnings before launch?" is peak Hacker News pettiness. Try not to assume the worst, especially when it's pretty silly.

It is really up there with the HN classic "Does anyone else think the entire multi billion dollar targeted advertising industry is a scam that doesn't work?"

Re: Starlink lost 40 satellites to a geomagnetic storm

#157

Post by HWR_14 »

ceejayoz wrote: post #138
hypertele-Xii wrote: post #75

Earlier quoted context omitted.

Launching a satellite is already sub $100k. Technology both miniaturizes and industrializes at an exponential rate. Think about how small and cheap computers have become in the span of a hundred years, from "occupies a building and costs a fortune" to "fits in your pocket and everyone can afford one". Sputnik 1, the first satellite ever launched cost 33 billion 1985 US dollars. 45 years later, you can get a cubesat i…

I really don't think Sputnik cost more than the entire Apollo program, nor 8x the cost of the JWST. I can only find a couple of sites saying "33.000 million" for Sputnik's cost, unsourced.

That could be an EU/US issue. In the EU it is common to separate thousands (or millions) with dots, and decimals with commas. In the US it is the other way around. So those sources could be saying (or were read by GP) as 33 thousand million (33 billion) or it could mean 33 million and 0 thousands.

The billion sounds linguistically more correct, but I have no idea if those are inflation adjusted dollars or whatever. It could be an error that telephones around the internet as 33.0 million by the US system then converted to someone in the EU to 33.000 because they misread the number.

Re: Starlink lost 40 satellites to a geomagnetic storm

#158

Post by leoh »

Is anyone else concerned by their statement? i.e. in spite serious engineering efforts to ensure satellites function+orbit or nonfunction+deorbit, they don’t assert or furnish a way of understanding (today or at some future date), that of the 49 satellites:

* how many are functional+orbiting

* how many are nonfunctional+orbiting (i.e. space junk)

* how many are nonfunctional+deorbit(ing|ed)

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