[Starlink] Sunburp kills 40 starlink satellites

Wed Feb 9 14:28:50 EST 2022

At https://www.spacex.com/updates/ (I see no direct link to this news)::::

FEBRUARY 8, 2022

GEOMAGNETIC STORM AND RECENTLY DEPLOYED STARLINK SATELLITES

On Thursday, February 3 at 1:13 p.m. EST, Falcon 9 launched 49 Starlink satellites to low Earth orbit from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida. Falcon 9’s second stage deployed the satellites into their intended orbit, with a perigee of approximately 210 kilometers above Earth, and each satellite achieved controlled flight.

SpaceX deploys its satellites into these lower orbits so that in the very rare case any satellite does not pass initial system checkouts it will quickly be deorbited by atmospheric drag. While the low deployment altitude requires more capable satellites at a considerable cost to us, it’s the right thing to do to maintain a sustainable space environment.

Unfortunately, the satellites deployed on Thursday were significantly impacted by a geomagnetic storm on Friday. These storms cause the atmosphere to warm and atmospheric density at our low deployment altitudes to increase. In fact, onboard GPS suggests the escalation speed and severity of the storm caused atmospheric drag to increase up to 50 percent higher than during previous launches. The Starlink team commanded the satellites into a safe-mode where they would fly edge-on (like a sheet of paper) to minimize drag—to effectively “take cover from the storm”—and continued to work closely with the Space Force’s 18th Space Control Squadron and LeoLabs to provide updates on the satellites based on ground radars.

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. This unique situation demonstrates the great lengths the Starlink team has gone to ensure the system is on the leading edge of on-orbit debris mitigation.

Ouch.

Doc

On Feb 8, 2022, at 8:25 AM, Dave Taht <dave.taht at gmail.com<mailto:dave.taht at gmail.com>> wrote:

i grew up on an obscure british TV show:

https://en.wikipedia.org/wiki/Thunderbirds_(TV_series)

And only today learned there was a remake.

What I don't quite understand is why a full-fledged ground station is
needed to get dropped.  (in a day after they have laser links)

A simple dishy can do 300mbit down and over 20Mbit up. using a 32k
codec that's quite a few voice calls, or cleared transactions.

The difference between zero and some connectivity is quite a lot.

On Tue, Feb 8, 2022 at 7:28 AM Mike Puchol <mike at starlink.sx> wrote:

Hi Christian,

The concern with O3b will be once they launch the inclined orbit mPOWER satellites, which will cause inline events outside the GSO arc. Of the other constellations, OneWeb is a concern on Ka band already, but they only operate above 50º North, where Starlink doesn’t really operate that much yet, Telesat has launched only one test satellite.

It will come for sure, and there will be a requirement for an RF conjunction event management system. IMHO it’s going to be messy before it gets better.

Best,

Mike
On Feb 8, 2022, 14:50 +0100, Christian von der Ropp <cvdr at vdr.net>, wrote:

And to make things even more complicated Starlink also have to avoid emissions within a certain angle towards O3b's satellites in MEO (relatively easy as they are close to the geostationary arc) and to all its LEO competitors with higher ITU priority which would be OneWeb, Telesat Lightspeed, KLEO Connect and before all these a potential European LEO constellation should it use Thales' ITU filings (MCSAT-2 LEO-x) - see https://www.itu.int/en/ITU-R/space/workshops/danang-2015/Documents/Presentations/Yvon%20Henri%20-%20NGSO%20Issues.pdf

The more satellites these LEO competitors deploy, the more in-line events will occur during which Starlink will have to seize emissions - a so far underestimated issue that could severely impair coverage and service availability.

Am 08.02.2022 um 11:11 schrieb Ulrich Speidel:

That's an interesting aspect that I hadn't considered! A quick back-of-the-envelope reveals that the GSO arc is at least 15 times beyond a Starlink LEO satellite, and with Friis propagation, that's about 23 dB in terms of difference in path loss, and thus not as much separation as you'd want. Under ITU regs you're competing with noise, not signal ;-)

Either way, I know it's a contested topic even at the regulatory level.

Tonga is at around 20 deg south so could be using anything from north just over zenith to further south, but as I've pointed out, there are other issues here also.

On 8/02/2022 9:58 pm, Mike Puchol wrote:

The GSO satellite operators, due to the fact that they have been there for eons, plus they cannot move the satellites around, are at a disadvantage with NGSO operators such as Starlink, when it comes to using the same shared spectrum. The Ku band downlink spectrum Starlink uses is the same as your satellite TV, thus, if your Dishy was inline with a Starlink satellite and the line towards the GSO arc, the satellite would kill all satellite TV in your area.

The ITU in its article 22 specifies how NGSO operators must protect GSO operators, by not generating interference above certain power levels to or from the GSO arc. For Dishy, this means it cannot transmit anywhere between the GSO arc elevation and +18° (up), -18° (down).

In Barcelona, the GSO arc due South sits at around 43° in elevation, thus, my Dishy cannot transmit between 25° and 61° in elevation due South. However, the protection band begins around an azimuth of 120°, up to around 240°.

In the Equator, the GSO protection band starts due East, and goes all the way across the sky due West. It also takes out 37° of visible sky at zenith.

Hope this helps!

Best,

Mike
On Feb 8, 2022, 09:49 +0100, Daniel AJ Sokolov <daniel at sokolov.eu.org>, wrote:

On 2022-02-08 at 01:47, Mike Puchol wrote:

the biggest impact on Fiji and Tonga is the GSO protection, which
takes out 36° of usable sky, all the way from East to West.

Ho Mike,

would you please be so kind to explain that a bit more?

Thank you
Daniel
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