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 > _______________________________________________ > Seesat-l mailing list > http://mailman.satobs.org/mailman/listinfo/seesat-l > -- GDB has a 'break' feature; why doesn't it have 'fix' too? _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Wed Feb 09 2022 - 15:09:36 UTC
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