Re: Strongly increased chance of satellite reentries the coming days

From: George Roberts via Seesat-l <seesat-l_at_satobs.org>
Date: Thu, 10 Feb 2022 09:10:13 -0500
Deployable drogue chute?  Just anything light weight that greatly 
increases the surface area.

On 2/9/22 16:08, Chris Kuethe via Seesat-l wrote:
> Program could be used more expansively here to include physical design not
> just software. They specifically call out "demisable" design, and I suspect
> they're also including operational techniques such as initial deployment to
> lower altitudes so that even if a spacecraft is catastrophically damaged or
> non-responsive upon deployment it'll naturally decay very quickly. But this
> will be a great chance to see how well this demisable design works.
>
> I'd consider pyrotechnic destruct devices to be non-starters on the
> regulatory front. If the NRO wants to put some thermite on their latest
> bird for security reasons Vandenberg, ATF, FCC, and FAA would probably
> approve it; I can't see the the spooky powers that be giving similar
> approval for 12000 hand grenades to be in orbit, potentially creating more
> space junk or posing a threat to other space assets. I'm not sure how you'd
> reliably burn up a spacecraft in orbit so you get a cloud of soot rather
> than a cloud of shrapnel...
>
>
>
> On Wed, Feb 9, 2022 at 5:25 AM satcom ops via Seesat-l <seesat-l_at_satobs.org>
> wrote:
>
>> Hi
>>
>> According to the operators , they reckon they are programmed to  burn up
>> before "re-entering".
>>
>> Not sure how that works unless they have some sort of pirotechnic device.
>>
>> "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," SpaceX
>> wrote of the satellites' reentry.
>>
>> https://www.space.com/spacex-starlink-satellites-lost-geomagnetic-storm
>>
>> Regards
>>
>> John
>>
>>
>> On 09/02/2022 12:35, Marco Langbroek via Seesat-l wrote:
>>> Helmets on everybody.... ;-)
>>>
>>> There is an increased chance of seeing a reentry the coming days. Some
>>> 40 Starlink satellites from the very recent Feb 3 launch are coming down.
>>>
>>> The reason is a solar storm a day after the launch. This prevented the
>>> satellites, initially deployed in a very low orbit, to raise their
>>> orbits in time.
>>>
>>> So now almost all of them will reenter. It are uncontrolled reentries.
>>>
>>> Some have already reentered (e.g. the Puerto Rico event of Feb 7,
>>> http://www.satobs.org/seesat/Feb-2022/0034.html): many more will over
>>> the coming days.
>>>
>>> This is an update from SpaceX itself on it:
>>>
>>> --------------------------------------------------------------
>>> https://www.spacex.com/updates/
>>>
>>> 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.
>>> --------------------------------------------------------------
>>>
>>> - Marco
>>>
>>>
>>>
>>> -----
>>> Dr Marco Langbroek  -  SatTrackCam Leiden, the Netherlands.
>>> e-mail: sattrackcam_at_langbroek.org
>>>
>>> launchtower:    http://launchtower.langbroek.org
>>> Station (b)log: http://sattrackcam.blogspot.com
>>> Twitter:        _at_Marco_Langbroek
>>> -----
>>> _______________________________________________
>>> Seesat-l mailing list
>>> http://mailman.satobs.org/mailman/listinfo/seesat-l
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>

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Received on Thu Feb 10 2022 - 08:11:22 UTC

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