I think perhaps tracking potential energy transfer from a collision would be a good baseline?
a BB, moving at 17kph relative to the impact packs quite a wallop. One at 5kph, far less so. Still, that is much smaller than a centimeter. A cosmic ray impact on the wrong transistor can be impactful in different ways. A followon thought is possibly, as satellites are de-orbited would it be possible to take some debris down with them in some way? On Fri, Jul 7, 2023 at 4:28 PM Ulrich Speidel via Starlink <[email protected]> wrote: > > Now there is the misuse of the expression "exponentially" in cases when > people just mean "a bit faster than before". If you have a time series 1, 2, > 4, 6, 8 then you could claim that it's exponential because the first three > terms double each time, yet the last four terms could be used to claim that > it's linear. > > Plus, exponential growth doesn't necessarily mean fast growth. Your 2020 term > deposit for 5 years at 1% interest rate with interest reinvested sees your > money growing exponentially, too. This is perhaps why decision-makers from > the economics sphere tend to get caught out be fast exponential growth (the > sort of growth us science and engineering folk tend to think of). > > Beyond that: I'm not sure that I can make much of orbital maneuver numbers. > Even GEO sats - for which collision probability is very low - undertake > regular corrective maneuvers for station-keeping. For anything further down, > a maneuver could be a short-term evasive action, a longer term orbit > injection or change maneuver, or corrective action to any of these. > > Each maneuver uses some of the satellite's propellant reserve. As a general > rule, a maneuver executed over a longer period of time is more fuel > efficient: A small change in a satellite's trajectory now can lead to a large > change down the time axis, with very little propellant use - think Starlink > satellites transitioning from launch train to final station over months. > Making small corrective adjustments to this over time might bring the total > number of maneuvers up, too. Conversely, large short-term corrections dip > into fuel reserves, which can impact on service life. So you'd really need to > ask which sort of maneuvers these are, and how much each maneuver costs in > terms of service life. > > -- > **************************************************************** > Dr. Ulrich Speidel > > Department of Computer Science > > Room 303S.594 > Ph: (+64-9)-373-7599 ext. 85282 > > The University of Auckland > [email protected] > http://www.cs.auckland.ac.nz/~ulrich/ > **************************************************************** > ________________________________ > From: Starlink <[email protected]> on behalf of David > Lang via Starlink <[email protected]> > Sent: Friday, July 7, 2023 6:02 PM > To: [email protected] <[email protected]> > Cc: [email protected] <[email protected]>; Daniel > AJ Sokolov <[email protected]> > Subject: Re: [Starlink] orbital maneuvers 12 per sat in the last 6 months > > they have been filling shells (altitude sets), so it makes sense for the > numbers > to have been going up. > > we'll have to see if they keep going up as much as they move on to different > altitude shells. > > David Lang > > On Thu, 6 Jul 2023, [email protected] wrote: > > > I think the main point of the article is that the amount of maneuvers needed > > is currently increasing exponentially: "It's been doubling every six months, > > and the problem with exponential trends is that they get to very large > > numbers very quickly." I'm wondering if they are not taking into account the > > massive amount of satellites that have been launched since the previous six > > month report. > > > > I found the semi-annual reports filed w/ the fcc: > > https://licensing.fcc.gov/myibfs/download.do?attachment_key=23204343 and > > https://licensing.fcc.gov/myibfs/download.do?attachment_key=23204338 for gen > > 1 and gen 2 constellations. > > > > Still reading them and haven't found the older ones yet to compare. > > > > > > David Lang via Starlink wrote on 7/6/2023 9:49 PM: > > > >> some people are assuming that more satellites launched will mean more > >> maneuvers needed (not recognizing that what matters is only the things at > >> the same altitude) > >> > >> plus, it's a scary large number :-) > >> > >> David Lang > >> > >> On Thu, 6 Jul 2023, Daniel AJ Sokolov via Starlink wrote: > >> > >>> On 7/6/23 17:54, Dave Taht via Starlink wrote: > >>>> > >>> https://www.space.com/starlink-satellite-conjunction-increase-threatens-space-sustainability > >>>> > >>>> I am under the impression that each sat is capable of about 500 over > >>>> the satellite's lifetime. I am curious as to what they are avoiding. > >>> > >>> Assuming your number of 500 is correct, I don't see any worry here. 12 > >>> moves in 6 months makes 492 in 20.5 years. That is less than 500 and > >>> beyond the lifetime expectation of the satellite anyway. > >>> > >>> A I missing something? > >>> Daniel AJ > >>> _______________________________________________ > >>> Starlink mailing list > >>> [email protected] > >>> https://lists.bufferbloat.net/listinfo/starlink > >>> > >> _______________________________________________ > >> Starlink mailing list > >> [email protected] > >> https://lists.bufferbloat.net/listinfo/starlink > > > > > _______________________________________________ > Starlink mailing list > [email protected] > https://lists.bufferbloat.net/listinfo/starlink -- Podcast: https://www.linkedin.com/feed/update/urn:li:activity:7058793910227111937/ Dave Täht CSO, LibreQos _______________________________________________ Starlink mailing list [email protected] https://lists.bufferbloat.net/listinfo/starlink
