"SpaceX satellites burning up and falling out of orbit after solar storm"
https://www.chron.com/news/space/article/SpaceX-satellites-falling-out-of-orbit-solar-storm-16844807.php

"Up to 40 of the 49 small satellites launched last week have either
reentered the atmosphere and burned up, or are on the verge of doing so,
the company said in an online update Tuesday night."

"SpaceX said a geomagnetic storm last Friday made the atmosphere denser,
which increased the drag on the Starlink satellites, effectively dooming
them."

Oops.

Yup, this is rocket science.

Lynn

In <su14co$rcv$1@dont-email.me> Lynn McGuire <lynnmcguire5@gmail.com> writes:

>"SpaceX satellites burning up and falling out of orbit after solar storm"
>
>https://www.chron.com/news/space/article/SpaceX-satellites-falling-out-of-orbit-solar-storm-16844807.php

[snip]

I say it's aliens.

Keep in mind whenever there's an extinction level event
or other major disaster on the way, it _always_ starts
with some big corporate flunky or gov't mouthpiece
saying there's nothing to worry about.

--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

On 2/9/2022 1:39 PM, danny burstein wrote:
> In <su14co$rcv$1@dont-email.me> Lynn McGuire <lynnmcguire5@gmail.com> writes:
>
>> "SpaceX satellites burning up and falling out of orbit after solar storm"
>>
>> https://www.chron.com/news/space/article/SpaceX-satellites-falling-out-of-orbit-solar-storm-16844807.php
>
> [snip]
>
> I say it's aliens.
>
> Keep in mind whenever there's an extinction level event
> or other major disaster on the way, it _always_ starts
> with some big corporate flunky or gov't mouthpiece
> saying there's nothing to worry about.

Heh !

Lynn

On 09/02/2022 13.39, danny burstein wrote:
> In <su14co$rcv$1@dont-email.me> Lynn McGuire <lynnmcguire5@gmail.com> writes:
>
>> "SpaceX satellites burning up and falling out of orbit after solar storm"
>>
>> https://www.chron.com/news/space/article/SpaceX-satellites-falling-out-of-orbit-solar-storm-16844807.php
>
> [snip]
>
> I say it's aliens.
>
> Keep in mind whenever there's an extinction level event
> or other major disaster on the way, it _always_ starts
> with some big corporate flunky or gov't mouthpiece
> saying there's nothing to worry about.

I don't remember that happening when Chicxulub was inbound.

Just sayin'

--
Michael F. Stemper
Nostalgia just ain't what it used to be.

On Wednesday, February 9, 2022 at 2:24:13 PM UTC-5, Lynn McGuire wrote:
> "SpaceX satellites burning up and falling out of orbit after solar storm"
>
> https://www.chron.com/news/space/article/SpaceX-satellites-falling-out-of-orbit-solar-storm-16844807.php
>
> "Up to 40 of the 49 small satellites launched last week have either
> reentered the atmosphere and burned up, or are on the verge of doing so,
> the company said in an online update Tuesday night."
>
> "SpaceX said a geomagnetic storm last Friday made the atmosphere denser,
> which increased the drag on the Starlink satellites, effectively dooming
> them."
>
> Oops.
>
> Yup, this is rocket science.

Starlink satellites have an deliberately low initial orbit. This allows a 'shakeout'
period during which they are powered up and tested; any duds will deorbit by
themselves pretty quickly; they are designed to burn up completely. They then
use ion thrusters to raise themselves to their operational orbits.

The solar storm warmed the upper atmosphere, puffing it up and, raising the density at which
this initial low orbit was set. Despite orientating them into a low-drag configuration,
many did not survive.

pt

In article <su1de5$mvi$1@dont-email.me>,
Michael F. Stemper <michael.stemper@gmail.com> wrote:
>On 09/02/2022 13.39, danny burstein wrote:
>> In <su14co$rcv$1@dont-email.me> Lynn McGuire <lynnmcguire5@gmail.com> writes:
>>
>>> "SpaceX satellites burning up and falling out of orbit after solar storm"
>>>
>>>
>https://www.chron.com/news/space/article/SpaceX-satellites-falling-out-of-orbit-solar-storm-16844807.php
>>
>> [snip]
>>
>> I say it's aliens.
>>
>> Keep in mind whenever there's an extinction level event
>> or other major disaster on the way, it _always_ starts
>> with some big corporate flunky or gov't mouthpiece
>> saying there's nothing to worry about.
>
>I don't remember that happening when Chicxulub was inbound.
>
>Just sayin'

While absence of evidence is not evidence of absence, we have no
evidence of either corporations or governments in the late
Cretaceous.

--
Dorothy J. Heydt
Vallejo, California
djheydt at gmail dot com
Www.kithrup.com/~djheydt/

Hi all

On Thursday, February 10, 2022 at 6:20:50 AM UTC+2, Dorothy J Heydt wrote:
>
> While absence of evidence is not evidence of absence, we have no
> evidence of either corporations or governments in the late
> Cretaceous.

To be fair as 'Big Ones' go that was pretty much the worst that left any lasting evidence around.

RE SFF: the last episode of TV series Dinosaurs, see: https://en.wikipedia.org/wiki/Dinosaurs_(TV_series)#Series_finale

Not so much a BANG as a whimper.

>
> --
> Dorothy J. Heydt
> Vallejo, California
> djheydt at gmail dot com
> Www.kithrup.com/~djheydt/

Regards
Frank

In article <42f8bb09-202a-4975-8d20-071074e3db27n@googlegroups.com>,
Frank Scrooby <frank.scrooby@gmail.com> wrote:
>To be fair as 'Big Ones' go that was pretty much the worst that left any
>lasting evidence around.

Vredefort would like a word....

(as would Caloris Basin, which scattered a surprising amount of ejecta on Earth
for an impact on Mercury)
--
My reviews can be found at http://jamesdavisnicoll.com/
My tor pieces at https://www.tor.com/author/james-davis-nicoll/
My Dreamwidth at https://james-davis-nicoll.dreamwidth.org/
My patreon is at https://www.patreon.com/jamesdnicoll

In article <su344f$p7i$1@reader1.panix.com>,
jdnicoll@panix.com (James Nicoll) wrote:

> In article <42f8bb09-202a-4975-8d20-071074e3db27n@googlegroups.com>,
> Frank Scrooby <frank.scrooby@gmail.com> wrote:
> >To be fair as 'Big Ones' go that was pretty much the worst that left any
> >lasting evidence around.
>
> Vredefort would like a word....

Not to mention Sudbury and others

>
> (as would Caloris Basin, which scattered a surprising amount of ejecta on
> Earth for an impact on Mercury)

Do you have a reference for this? Or was it just a theoretical
calculation?

--
"We have advanced to new and surprising levels of bafflement."
Imperial Auditor Miles Vorkosigan describes progress in _Komarr_.
�-----------------------------------------------------
Robert Woodward robertaw@drizzle.com

On Wednesday, February 9, 2022 at 2:58:34 PM UTC-7, Michael F. Stemper wrote:
> On 09/02/2022 13.39, danny burstein wrote:

> > Keep in mind whenever there's an extinction level event
> > or other major disaster on the way, it _always_ starts
> > with some big corporate flunky or gov't mouthpiece
> > saying there's nothing to worry about.

> I don't remember that happening when Chicxulub was inbound.
>
> Just sayin'

That's true, but he was only talking about extinction-level
events that happened _after_ the rise of human civilization.

What? There haven't been any? As evidenced by the fact
that we're still here?

Then clearly he is talking about fictional extinction-level
events, probably in the movies.

John Savard

pete...@gmail.com <petertrei@gmail.com> wrote:
>On Wednesday, February 9, 2022 at 2:24:13 PM UTC-5, Lynn McGuire wrote:
>>>https://www.chron.com/news/space/article/SpaceX-satellites-falling-out-of-orbit-solar-storm-16844807.php
>Starlink satellites have an deliberately low initial orbit. This
>allows a 'shakeout' period during which they are powered up and
>tested; any duds will deorbit by themselves pretty quickly; they are
>designed to burn up completely. They then use ion thrusters to raise
>themselves to their operational orbits.
>
>The solar storm warmed the upper atmosphere, puffing it up and,
>raising the density at which this initial low orbit was set. Despite
>orientating them into a low-drag configuration, many did not survive.

IIRC the density was 50% higher than the highest they ever seen, and
the event started after they had launched so they couldn't make any
useful changes. iirc IT was also one of the lowest injections we've
seen for Starlink launches so far.

As I understand it only 9? out of the 49 made it.

It's unclear if the rest were dragged down too far while in low-drag
configuration for the thrusters to get it up OR if they couldn't get
them out of the low-drag configuration, probably due to torque limits.

Both are possible, SpaceX went with much cheaper Krypton based
orbit-raising thrusters despite lower efficiency and because it
wouldn't be possible to buy enough Xenon gas!, and it certainly would
also require significantly more torque than normal to rotate back
against the higher density and everything about these satellites are
hyper-optimized for station keeping where the torque requirement is
very close to zero.

Given that solar activity is still climbing they likely need to reduce
the number of satellites slightly (IE reduce mass) over time to allow
a slightly higher initial orbit.

Well, IIRC at least until the weather improves (IIRC a few months) so
they can launch in a better trajectory again - there's so many
Starlink launches that they've choosen a launch path to reduce the
chance of not being able to launch due to weather despite this hurting
performance (IE less satellites per launch cost).

On Friday, February 11, 2022 at 11:15:08 AM UTC-5, The Horny Goat wrote:
> On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
> <t...@none.invalid> wrote:
>
> >
> >Well, IIRC at least until the weather improves (IIRC a few months) so
> >they can launch in a better trajectory again - there's so many
> >Starlink launches that they've choosen a launch path to reduce the
> >chance of not being able to launch due to weather despite this hurting
> >performance (IE less satellites per launch cost).
> Aren't you basically saying they made a corporate decision to go cheap
> on launch costs and are now getting bitten for what turns out to be
> false economy?

False? Not necessarily. Kr costs around $290/kg, Xe about $1800. I have no idea
how much of either gas would be needed per satellite, but over tens of thousands,
it adds up.

SpaceX charges about 65M per launch, which includes a considerable profit
margin. They lost 40 sats at 200-250k each, or 10M. I suspect SpaceX is out
of pocket to the tune of not more than 50M, which for them is chump change.

Even if they did use Xe instead of Kr, the logical thing would be to build thrusters
with the same power, so it wouldn't have helped.

Pt

The Horny Goat <lcraver@home.ca> wrote:
>On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
><tl@none.invalid> wrote:
>>Well, IIRC at least until the weather improves (IIRC a few months) so
>>they can launch in a better trajectory again - there's so many
>>Starlink launches that they've choosen a launch path to reduce the
>>chance of not being able to launch due to weather despite this hurting
>>performance (IE less satellites per launch cost).
>
>Aren't you basically saying they made a corporate decision to go cheap
>on launch costs and are now getting bitten for what turns out to be
>false economy?

I'm fairly certain it's a deliberate choice they're making and that
they accept the risk. It's possible they "lost" the bet here but it
may also be within calculated risk parameters (see below).

In this case the trigger event happened after the launch, if it had
happened just a few hours earlier they likely would have delayed the
launch and offloaded a few of the satellites to launch in a slightly
higher initial orbit. So, well, oops, but they likely knew that would
happen eventually.

Digging into the specifics:

IIRC the the manufacturing cost of these satellites were below $500k
each quite a while ago, while this could have gone up (added laser
links) we also know that SpaceX had an aspirational goal of $250k per
satellite for the "2.0" variant.

So, guesstimating $10M-$20M production cost for the 40 lost satellites
(out of 49 launched), and they have several months worth of launches
queue up in warehouses. They got a production line spitting them out
in great numbers.

Many have speculated that the internal COST to SpaceX for a Falcon 9
launch with reused core and reused fairings might be as low as $10M,
it's very unlikly to be above $20M.

So, the launch cost probably isn't that far of the cost of the
satellites it carry. Which means increasing the number of satellites
definitely is worthwhile as long as the risks are "low enough".

Staying that close to the edge likely wouldn't be the right call for
anyone else, even for the other "big LEO constellation". It comes from
a combination of owning the launcher and mass-producing a very large
number of light low-cost satellites. They actually have a warehouse
with several months worth of satellites waiting for launches!

Obviously if you're launching an expensive satellite (IIRC most
geostationary satellites cost $150M-$400M) or one with very long
lead-time (most traditional satellites) you would never try to ride
that close to the margin because it would be crazy.

Similarly, SpaceX choose Krypton thrusters instead of Xenon thrusters
which did reduce the cost somewhat (I'm told Xenon gas costs ~10x what
Krypton cost) but! I've also been told that there's considerable doubt
they could even have gotten the required amount of Xenon that this
number of satellites required, note that all these mega constellation
has "50%/100% of the satellites needs to be active before 3/6 years or
the number of satellites will be frozen at the current number".
Meaning at that point only direct replacements can be launched, 1 for
1.

Yes, the FCC can choose waive minor infractions of this but anyone who
asks for that better make sure they're close, trying hard and have an
explaination. Also, all their competitors will likely try to fight any
such waiver in court too.

I don't know how easy it would have been to increase the Xenon
production capacity, but I expect it would push Xenon gas prices up
even higher. Which might well have resulted in additional groups
complaining about SpaceX launch program hurting their profession. And
I expect that say Doctors (it's used in medicine) have WAY more
political clout than astronomers :-)

On Sunday, February 13, 2022 at 4:22:38 PM UTC-6, Torbjorn Lindgren wrote:
> The Horny Goat <lcr...@home.ca> wrote:
> >On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
> ><t...@none.invalid> wrote:
> >>Well, IIRC at least until the weather improves (IIRC a few months) so
> >>they can launch in a better trajectory again - there's so many
> >>Starlink launches that they've choosen a launch path to reduce the
> >>chance of not being able to launch due to weather despite this hurting
> >>performance (IE less satellites per launch cost).
> >
> >Aren't you basically saying they made a corporate decision to go cheap
> >on launch costs and are now getting bitten for what turns out to be
> >false economy?
> I'm fairly certain it's a deliberate choice they're making and that
> they accept the risk. It's possible they "lost" the bet here but it
> may also be within calculated risk parameters (see below).
>
> In this case the trigger event happened after the launch, if it had
> happened just a few hours earlier they likely would have delayed the
> launch and offloaded a few of the satellites to launch in a slightly
> higher initial orbit. So, well, oops, but they likely knew that would
> happen eventually.
>
>
> Digging into the specifics:
>
> IIRC the the manufacturing cost of these satellites were below $500k
> each quite a while ago, while this could have gone up (added laser
> links) we also know that SpaceX had an aspirational goal of $250k per
> satellite for the "2.0" variant.
>
> So, guesstimating $10M-$20M production cost for the 40 lost satellites
> (out of 49 launched), and they have several months worth of launches
> queue up in warehouses. They got a production line spitting them out
> in great numbers.
>
> Many have speculated that the internal COST to SpaceX for a Falcon 9
> launch with reused core and reused fairings might be as low as $10M,
> it's very unlikly to be above $20M.
>
> So, the launch cost probably isn't that far of the cost of the
> satellites it carry. Which means increasing the number of satellites
> definitely is worthwhile as long as the risks are "low enough".
>
> Staying that close to the edge likely wouldn't be the right call for
> anyone else, even for the other "big LEO constellation". It comes from
> a combination of owning the launcher and mass-producing a very large
> number of light low-cost satellites. They actually have a warehouse
> with several months worth of satellites waiting for launches!
>
> Obviously if you're launching an expensive satellite (IIRC most
> geostationary satellites cost $150M-$400M) or one with very long
> lead-time (most traditional satellites) you would never try to ride
> that close to the margin because it would be crazy.
>
>
> Similarly, SpaceX choose Krypton thrusters instead of Xenon thrusters
> which did reduce the cost somewhat (I'm told Xenon gas costs ~10x what
> Krypton cost) but! I've also been told that there's considerable doubt
> they could even have gotten the required amount of Xenon that this
> number of satellites required, note that all these mega constellation
> has "50%/100% of the satellites needs to be active before 3/6 years or
> the number of satellites will be frozen at the current number".
> Meaning at that point only direct replacements can be launched, 1 for
> 1.
>
> Yes, the FCC can choose waive minor infractions of this but anyone who
> asks for that better make sure they're close, trying hard and have an
> explaination. Also, all their competitors will likely try to fight any
> such waiver in court too.
>
> I don't know how easy it would have been to increase the Xenon
> production capacity, but I expect it would push Xenon gas prices up
> even higher. Which might well have resulted in additional groups
> complaining about SpaceX launch program hurting their profession. And
> I expect that say Doctors (it's used in medicine) have WAY more
> political clout than astronomers :-)

On the plus side, since commercial xenon gas is produced by liquification and
fractional distillation from the atmosphere, any xenon expended by satellite
thrusters in low Earth orbit will fall back to Earth and re-enter the supply chain.
Is any significant amount of gas at those altitudes thought to be swept away
from Earth by the solar wind? Do they attempt to scavenge xenon used for
medical purposes?

Peter Wezeman
anti-social Darwinist

On Monday, February 14, 2022 at 11:17:28 AM UTC-5, peterwezeman@hotmail.com wrote:
> On Sunday, February 13, 2022 at 4:22:38 PM UTC-6, Torbjorn Lindgren wrote:
> > The Horny Goat <lcr...@home.ca> wrote:
> > >On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
> > ><t...@none.invalid> wrote:
> > >>Well, IIRC at least until the weather improves (IIRC a few months) so
> > >>they can launch in a better trajectory again - there's so many
> > >>Starlink launches that they've choosen a launch path to reduce the
> > >>chance of not being able to launch due to weather despite this hurting
> > >>performance (IE less satellites per launch cost).
> > >
> > >Aren't you basically saying they made a corporate decision to go cheap
> > >on launch costs and are now getting bitten for what turns out to be
> > >false economy?
> > I'm fairly certain it's a deliberate choice they're making and that
> > they accept the risk. It's possible they "lost" the bet here but it
> > may also be within calculated risk parameters (see below).
> >
> > In this case the trigger event happened after the launch, if it had
> > happened just a few hours earlier they likely would have delayed the
> > launch and offloaded a few of the satellites to launch in a slightly
> > higher initial orbit. So, well, oops, but they likely knew that would
> > happen eventually.
> >
> >
> > Digging into the specifics:
> >
> > IIRC the the manufacturing cost of these satellites were below $500k
> > each quite a while ago, while this could have gone up (added laser
> > links) we also know that SpaceX had an aspirational goal of $250k per
> > satellite for the "2.0" variant.
> >
> > So, guesstimating $10M-$20M production cost for the 40 lost satellites
> > (out of 49 launched), and they have several months worth of launches
> > queue up in warehouses. They got a production line spitting them out
> > in great numbers.
> >
> > Many have speculated that the internal COST to SpaceX for a Falcon 9
> > launch with reused core and reused fairings might be as low as $10M,
> > it's very unlikly to be above $20M.
> >
> > So, the launch cost probably isn't that far of the cost of the
> > satellites it carry. Which means increasing the number of satellites
> > definitely is worthwhile as long as the risks are "low enough".
> >
> > Staying that close to the edge likely wouldn't be the right call for
> > anyone else, even for the other "big LEO constellation". It comes from
> > a combination of owning the launcher and mass-producing a very large
> > number of light low-cost satellites. They actually have a warehouse
> > with several months worth of satellites waiting for launches!
> >
> > Obviously if you're launching an expensive satellite (IIRC most
> > geostationary satellites cost $150M-$400M) or one with very long
> > lead-time (most traditional satellites) you would never try to ride
> > that close to the margin because it would be crazy.
> >
> >
> > Similarly, SpaceX choose Krypton thrusters instead of Xenon thrusters
> > which did reduce the cost somewhat (I'm told Xenon gas costs ~10x what
> > Krypton cost) but! I've also been told that there's considerable doubt
> > they could even have gotten the required amount of Xenon that this
> > number of satellites required, note that all these mega constellation
> > has "50%/100% of the satellites needs to be active before 3/6 years or
> > the number of satellites will be frozen at the current number".
> > Meaning at that point only direct replacements can be launched, 1 for
> > 1.
> >
> > Yes, the FCC can choose waive minor infractions of this but anyone who
> > asks for that better make sure they're close, trying hard and have an
> > explaination. Also, all their competitors will likely try to fight any
> > such waiver in court too.
> >
> > I don't know how easy it would have been to increase the Xenon
> > production capacity, but I expect it would push Xenon gas prices up
> > even higher. Which might well have resulted in additional groups
> > complaining about SpaceX launch program hurting their profession. And
> > I expect that say Doctors (it's used in medicine) have WAY more
> > political clout than astronomers :-)
> On the plus side, since commercial xenon gas is produced by liquification and
> fractional distillation from the atmosphere, any xenon expended by satellite
> thrusters in low Earth orbit will fall back to Earth and re-enter the supply chain.
> Is any significant amount of gas at those altitudes thought to be swept away
> from Earth by the solar wind? Do they attempt to scavenge xenon used for
> medical purposes?

Krypton is present in the atmosphere at about 1 ppm, while Xenon is about
87 ppb. Production of both is as a byproduct of making liquid oxygen.

That's raises an interesting little wrinkle. Its rumored that SpaceX is looking
at building its own LOX plant at Boca Chica. If that's the case, it may be able
to produce its own Kr as well.

I saw a stackexchange BoE calculation that suggested that each starlink
satellite needed the delta-V available from 4.8 kg of Kr. Their ionization
potential is similar, so the drop in efficiency isn't that great. I think that
means similar masses required as well.

pt

On 2/14/2022 1:27 PM, pete...@gmail.com wrote:
> On Monday, February 14, 2022 at 11:17:28 AM UTC-5, peterwezeman@hotmail.com wrote:
>> On Sunday, February 13, 2022 at 4:22:38 PM UTC-6, Torbjorn Lindgren wrote:
>>> The Horny Goat <lcr...@home.ca> wrote:
>>>> On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
>>>> <t...@none.invalid> wrote:
>>>>> Well, IIRC at least until the weather improves (IIRC a few months) so
>>>>> they can launch in a better trajectory again - there's so many
>>>>> Starlink launches that they've choosen a launch path to reduce the
>>>>> chance of not being able to launch due to weather despite this hurting
>>>>> performance (IE less satellites per launch cost).
>>>>
>>>> Aren't you basically saying they made a corporate decision to go cheap
>>>> on launch costs and are now getting bitten for what turns out to be
>>>> false economy?
>>> I'm fairly certain it's a deliberate choice they're making and that
>>> they accept the risk. It's possible they "lost" the bet here but it
>>> may also be within calculated risk parameters (see below).
>>>
>>> In this case the trigger event happened after the launch, if it had
>>> happened just a few hours earlier they likely would have delayed the
>>> launch and offloaded a few of the satellites to launch in a slightly
>>> higher initial orbit. So, well, oops, but they likely knew that would
>>> happen eventually.
>>>
>>>
>>> Digging into the specifics:
>>>
>>> IIRC the the manufacturing cost of these satellites were below $500k
>>> each quite a while ago, while this could have gone up (added laser
>>> links) we also know that SpaceX had an aspirational goal of $250k per
>>> satellite for the "2.0" variant.
>>>
>>> So, guesstimating $10M-$20M production cost for the 40 lost satellites
>>> (out of 49 launched), and they have several months worth of launches
>>> queue up in warehouses. They got a production line spitting them out
>>> in great numbers.
>>>
>>> Many have speculated that the internal COST to SpaceX for a Falcon 9
>>> launch with reused core and reused fairings might be as low as $10M,
>>> it's very unlikly to be above $20M.
>>>
>>> So, the launch cost probably isn't that far of the cost of the
>>> satellites it carry. Which means increasing the number of satellites
>>> definitely is worthwhile as long as the risks are "low enough".
>>>
>>> Staying that close to the edge likely wouldn't be the right call for
>>> anyone else, even for the other "big LEO constellation". It comes from
>>> a combination of owning the launcher and mass-producing a very large
>>> number of light low-cost satellites. They actually have a warehouse
>>> with several months worth of satellites waiting for launches!
>>>
>>> Obviously if you're launching an expensive satellite (IIRC most
>>> geostationary satellites cost $150M-$400M) or one with very long
>>> lead-time (most traditional satellites) you would never try to ride
>>> that close to the margin because it would be crazy.
>>>
>>>
>>> Similarly, SpaceX choose Krypton thrusters instead of Xenon thrusters
>>> which did reduce the cost somewhat (I'm told Xenon gas costs ~10x what
>>> Krypton cost) but! I've also been told that there's considerable doubt
>>> they could even have gotten the required amount of Xenon that this
>>> number of satellites required, note that all these mega constellation
>>> has "50%/100% of the satellites needs to be active before 3/6 years or
>>> the number of satellites will be frozen at the current number".
>>> Meaning at that point only direct replacements can be launched, 1 for
>>> 1.
>>>
>>> Yes, the FCC can choose waive minor infractions of this but anyone who
>>> asks for that better make sure they're close, trying hard and have an
>>> explaination. Also, all their competitors will likely try to fight any
>>> such waiver in court too.
>>>
>>> I don't know how easy it would have been to increase the Xenon
>>> production capacity, but I expect it would push Xenon gas prices up
>>> even higher. Which might well have resulted in additional groups
>>> complaining about SpaceX launch program hurting their profession. And
>>> I expect that say Doctors (it's used in medicine) have WAY more
>>> political clout than astronomers :-)
>> On the plus side, since commercial xenon gas is produced by liquification and
>> fractional distillation from the atmosphere, any xenon expended by satellite
>> thrusters in low Earth orbit will fall back to Earth and re-enter the supply chain.
>> Is any significant amount of gas at those altitudes thought to be swept away
>> from Earth by the solar wind? Do they attempt to scavenge xenon used for
>> medical purposes?
>
> Krypton is present in the atmosphere at about 1 ppm, while Xenon is about
> 87 ppb. Production of both is as a byproduct of making liquid oxygen.
>
> That's raises an interesting little wrinkle. Its rumored that SpaceX is looking
> at building its own LOX plant at Boca Chica. If that's the case, it may be able
> to produce its own Kr as well.
>
> I saw a stackexchange BoE calculation that suggested that each starlink
> satellite needed the delta-V available from 4.8 kg of Kr. Their ionization
> potential is similar, so the drop in efficiency isn't that great. I think that
> means similar masses required as well.
>
> pt

The EPA is forcing SpaceX to move the Boca Chica operations to Florida.
https://spacenews.com/spacex-considers-shifting-starship-testing-to-florida/

Lynn

On Monday, February 14, 2022 at 3:09:52 PM UTC-5, Lynn McGuire wrote:
> On 2/14/2022 1:27 PM, pete...@gmail.com wrote:
> > On Monday, February 14, 2022 at 11:17:28 AM UTC-5, peterw...@hotmail.com wrote:
> >> On Sunday, February 13, 2022 at 4:22:38 PM UTC-6, Torbjorn Lindgren wrote:
> >>> The Horny Goat <lcr...@home.ca> wrote:
> >>>> On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
> >>>> <t...@none.invalid> wrote:
> >>>>> Well, IIRC at least until the weather improves (IIRC a few months) so
> >>>>> they can launch in a better trajectory again - there's so many
> >>>>> Starlink launches that they've choosen a launch path to reduce the
> >>>>> chance of not being able to launch due to weather despite this hurting
> >>>>> performance (IE less satellites per launch cost).
> >>>>
> >>>> Aren't you basically saying they made a corporate decision to go cheap
> >>>> on launch costs and are now getting bitten for what turns out to be
> >>>> false economy?
> >>> I'm fairly certain it's a deliberate choice they're making and that
> >>> they accept the risk. It's possible they "lost" the bet here but it
> >>> may also be within calculated risk parameters (see below).
> >>>
> >>> In this case the trigger event happened after the launch, if it had
> >>> happened just a few hours earlier they likely would have delayed the
> >>> launch and offloaded a few of the satellites to launch in a slightly
> >>> higher initial orbit. So, well, oops, but they likely knew that would
> >>> happen eventually.
> >>>
> >>>
> >>> Digging into the specifics:
> >>>
> >>> IIRC the the manufacturing cost of these satellites were below $500k
> >>> each quite a while ago, while this could have gone up (added laser
> >>> links) we also know that SpaceX had an aspirational goal of $250k per
> >>> satellite for the "2.0" variant.
> >>>
> >>> So, guesstimating $10M-$20M production cost for the 40 lost satellites
> >>> (out of 49 launched), and they have several months worth of launches
> >>> queue up in warehouses. They got a production line spitting them out
> >>> in great numbers.
> >>>
> >>> Many have speculated that the internal COST to SpaceX for a Falcon 9
> >>> launch with reused core and reused fairings might be as low as $10M,
> >>> it's very unlikly to be above $20M.
> >>>
> >>> So, the launch cost probably isn't that far of the cost of the
> >>> satellites it carry. Which means increasing the number of satellites
> >>> definitely is worthwhile as long as the risks are "low enough".
> >>>
> >>> Staying that close to the edge likely wouldn't be the right call for
> >>> anyone else, even for the other "big LEO constellation". It comes from
> >>> a combination of owning the launcher and mass-producing a very large
> >>> number of light low-cost satellites. They actually have a warehouse
> >>> with several months worth of satellites waiting for launches!
> >>>
> >>> Obviously if you're launching an expensive satellite (IIRC most
> >>> geostationary satellites cost $150M-$400M) or one with very long
> >>> lead-time (most traditional satellites) you would never try to ride
> >>> that close to the margin because it would be crazy.
> >>>
> >>>
> >>> Similarly, SpaceX choose Krypton thrusters instead of Xenon thrusters
> >>> which did reduce the cost somewhat (I'm told Xenon gas costs ~10x what
> >>> Krypton cost) but! I've also been told that there's considerable doubt
> >>> they could even have gotten the required amount of Xenon that this
> >>> number of satellites required, note that all these mega constellation
> >>> has "50%/100% of the satellites needs to be active before 3/6 years or
> >>> the number of satellites will be frozen at the current number".
> >>> Meaning at that point only direct replacements can be launched, 1 for
> >>> 1.
> >>>
> >>> Yes, the FCC can choose waive minor infractions of this but anyone who
> >>> asks for that better make sure they're close, trying hard and have an
> >>> explaination. Also, all their competitors will likely try to fight any
> >>> such waiver in court too.
> >>>
> >>> I don't know how easy it would have been to increase the Xenon
> >>> production capacity, but I expect it would push Xenon gas prices up
> >>> even higher. Which might well have resulted in additional groups
> >>> complaining about SpaceX launch program hurting their profession. And
> >>> I expect that say Doctors (it's used in medicine) have WAY more
> >>> political clout than astronomers :-)
> >> On the plus side, since commercial xenon gas is produced by liquification and
> >> fractional distillation from the atmosphere, any xenon expended by satellite
> >> thrusters in low Earth orbit will fall back to Earth and re-enter the supply chain.
> >> Is any significant amount of gas at those altitudes thought to be swept away
> >> from Earth by the solar wind? Do they attempt to scavenge xenon used for
> >> medical purposes?
> >
> > Krypton is present in the atmosphere at about 1 ppm, while Xenon is about
> > 87 ppb. Production of both is as a byproduct of making liquid oxygen.
> >
> > That's raises an interesting little wrinkle. Its rumored that SpaceX is looking
> > at building its own LOX plant at Boca Chica. If that's the case, it may be able
> > to produce its own Kr as well.
> >
> > I saw a stackexchange BoE calculation that suggested that each starlink
> > satellite needed the delta-V available from 4.8 kg of Kr. Their ionization
> > potential is similar, so the drop in efficiency isn't that great. I think that
> > means similar masses required as well.
> >
> > pt
> The EPA is forcing SpaceX to move the Boca Chica operations to Florida.
>
> https://spacenews.com/spacex-considers-shifting-starship-testing-to-florida/

I watched the presentation.

Its hardly a settled matter. The EPA should issue a decision in March as to
whether a new, full EIS (Environmental Impact Statement) is needed. If it
does, AND the EIS nixes regular orbital launches from Boca Chica, SpaceX
would have to use the site its already building at KSC. It may be able to continue
some level of testing at BC.

SpaceX is also repurposing two oil platforms as floating launch facilities.

pt

Lynn McGuire <lynnmcguire5@gmail.com> writes:
>On 2/14/2022 1:27 PM, pete...@gmail.com wrote:
>> On Monday, February 14, 2022 at 11:17:28 AM UTC-5, peterwezeman@hotmail.com wrote:

>>
>> I saw a stackexchange BoE calculation that suggested that each starlink
>> satellite needed the delta-V available from 4.8 kg of Kr. Their ionization
>> potential is similar, so the drop in efficiency isn't that great. I think that
>> means similar masses required as well.
>>
>> pt
>
>The EPA is forcing SpaceX to move the Boca Chica operations to Florida.

That's incorrect. That's what we call "yellow journalism", lying in the
headline to drive traffic.

"SpaceX is prepared to shift testing of its Starship next-generation
launch vehicle from Texas to Florida if there are extended delays
in an ongoing environmental review, company founder and chief
executive Elon Musk said Feb. 10."

That's just Musk being Musk.

On 2/11/22 09:20, pete...@gmail.com wrote:
> On Friday, February 11, 2022 at 11:15:08 AM UTC-5, The Horny Goat wrote:
>> On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
>> <t...@none.invalid> wrote:
>>
>>>
>>> Well, IIRC at least until the weather improves (IIRC a few months) so
>>> they can launch in a better trajectory again - there's so many
>>> Starlink launches that they've choosen a launch path to reduce the
>>> chance of not being able to launch due to weather despite this hurting
>>> performance (IE less satellites per launch cost).
>> Aren't you basically saying they made a corporate decision to go cheap
>> on launch costs and are now getting bitten for what turns out to be
>> false economy?
>
> False? Not necessarily. Kr costs around $290/kg, Xe about $1800. I have no idea
> how much of either gas would be needed per satellite, but over tens of thousands,
> it adds up.
>
> SpaceX charges about 65M per launch, which includes a considerable profit
> margin. They lost 40 sats at 200-250k each, or 10M. I suspect SpaceX is out
> of pocket to the tune of not more than 50M, which for them is chump change.
>
> Even if they did use Xe instead of Kr, the logical thing would be to build thrusters
> with the same power, so it wouldn't have helped.
>
> Pt
I am guessing here since I wasn't a propulsion guy. I was a flight
software guy. It could be that the motors for krypton weighed more. But
bigger tanks are required, so maybe not. But I found the following link
on Stack Exchange that has some interesting stuff:
https://space.stackexchange.com/questions/36165/why-will-starlink-satellites-use-krypton-instead-of-xenon-for-electric-propulsio

It may be faulty.

--
Dave Scruggs
Captain, Boulder Creek Fire (Retired)
Sr. Software Engineer - Stellar Solutions (Definitely Retired)

On 2/14/2022 2:56 PM, J. Clarke wrote:
> On Mon, 14 Feb 2022 14:09:49 -0600, Lynn McGuire
> <lynnmcguire5@gmail.com> wrote:
>
>> On 2/14/2022 1:27 PM, pete...@gmail.com wrote:
>>> On Monday, February 14, 2022 at 11:17:28 AM UTC-5, peterwezeman@hotmail.com wrote:
>>>> On Sunday, February 13, 2022 at 4:22:38 PM UTC-6, Torbjorn Lindgren wrote:
>>>>> The Horny Goat <lcr...@home.ca> wrote:
>>>>>> On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
>>>>>> <t...@none.invalid> wrote:
>>>>>>> Well, IIRC at least until the weather improves (IIRC a few months) so
>>>>>>> they can launch in a better trajectory again - there's so many
>>>>>>> Starlink launches that they've choosen a launch path to reduce the
>>>>>>> chance of not being able to launch due to weather despite this hurting
>>>>>>> performance (IE less satellites per launch cost).
>>>>>>
>>>>>> Aren't you basically saying they made a corporate decision to go cheap
>>>>>> on launch costs and are now getting bitten for what turns out to be
>>>>>> false economy?
>>>>> I'm fairly certain it's a deliberate choice they're making and that
>>>>> they accept the risk. It's possible they "lost" the bet here but it
>>>>> may also be within calculated risk parameters (see below).
>>>>>
>>>>> In this case the trigger event happened after the launch, if it had
>>>>> happened just a few hours earlier they likely would have delayed the
>>>>> launch and offloaded a few of the satellites to launch in a slightly
>>>>> higher initial orbit. So, well, oops, but they likely knew that would
>>>>> happen eventually.
>>>>>
>>>>>
>>>>> Digging into the specifics:
>>>>>
>>>>> IIRC the the manufacturing cost of these satellites were below $500k
>>>>> each quite a while ago, while this could have gone up (added laser
>>>>> links) we also know that SpaceX had an aspirational goal of $250k per
>>>>> satellite for the "2.0" variant.
>>>>>
>>>>> So, guesstimating $10M-$20M production cost for the 40 lost satellites
>>>>> (out of 49 launched), and they have several months worth of launches
>>>>> queue up in warehouses. They got a production line spitting them out
>>>>> in great numbers.
>>>>>
>>>>> Many have speculated that the internal COST to SpaceX for a Falcon 9
>>>>> launch with reused core and reused fairings might be as low as $10M,
>>>>> it's very unlikly to be above $20M.
>>>>>
>>>>> So, the launch cost probably isn't that far of the cost of the
>>>>> satellites it carry. Which means increasing the number of satellites
>>>>> definitely is worthwhile as long as the risks are "low enough".
>>>>>
>>>>> Staying that close to the edge likely wouldn't be the right call for
>>>>> anyone else, even for the other "big LEO constellation". It comes from
>>>>> a combination of owning the launcher and mass-producing a very large
>>>>> number of light low-cost satellites. They actually have a warehouse
>>>>> with several months worth of satellites waiting for launches!
>>>>>
>>>>> Obviously if you're launching an expensive satellite (IIRC most
>>>>> geostationary satellites cost $150M-$400M) or one with very long
>>>>> lead-time (most traditional satellites) you would never try to ride
>>>>> that close to the margin because it would be crazy.
>>>>>
>>>>>
>>>>> Similarly, SpaceX choose Krypton thrusters instead of Xenon thrusters
>>>>> which did reduce the cost somewhat (I'm told Xenon gas costs ~10x what
>>>>> Krypton cost) but! I've also been told that there's considerable doubt
>>>>> they could even have gotten the required amount of Xenon that this
>>>>> number of satellites required, note that all these mega constellation
>>>>> has "50%/100% of the satellites needs to be active before 3/6 years or
>>>>> the number of satellites will be frozen at the current number".
>>>>> Meaning at that point only direct replacements can be launched, 1 for
>>>>> 1.
>>>>>
>>>>> Yes, the FCC can choose waive minor infractions of this but anyone who
>>>>> asks for that better make sure they're close, trying hard and have an
>>>>> explaination. Also, all their competitors will likely try to fight any
>>>>> such waiver in court too.
>>>>>
>>>>> I don't know how easy it would have been to increase the Xenon
>>>>> production capacity, but I expect it would push Xenon gas prices up
>>>>> even higher. Which might well have resulted in additional groups
>>>>> complaining about SpaceX launch program hurting their profession. And
>>>>> I expect that say Doctors (it's used in medicine) have WAY more
>>>>> political clout than astronomers :-)
>>>> On the plus side, since commercial xenon gas is produced by liquification and
>>>> fractional distillation from the atmosphere, any xenon expended by satellite
>>>> thrusters in low Earth orbit will fall back to Earth and re-enter the supply chain.
>>>> Is any significant amount of gas at those altitudes thought to be swept away
>>>> from Earth by the solar wind? Do they attempt to scavenge xenon used for
>>>> medical purposes?
>>>
>>> Krypton is present in the atmosphere at about 1 ppm, while Xenon is about
>>> 87 ppb. Production of both is as a byproduct of making liquid oxygen.
>>>
>>> That's raises an interesting little wrinkle. Its rumored that SpaceX is looking
>>> at building its own LOX plant at Boca Chica. If that's the case, it may be able
>>> to produce its own Kr as well.
>>>
>>> I saw a stackexchange BoE calculation that suggested that each starlink
>>> satellite needed the delta-V available from 4.8 kg of Kr. Their ionization
>>> potential is similar, so the drop in efficiency isn't that great. I think that
>>> means similar masses required as well.
>>>
>>> pt
>>
>> The EPA is forcing SpaceX to move the Boca Chica operations to Florida.
>>
>> https://spacenews.com/spacex-considers-shifting-starship-testing-to-florida/
>
> No, the EPA is not. The FAA has its finger firmly up its butt
> concerning the environmental review, and SpaceX is getting sick of
> waiting for them to pull it out.

You are correct.

Lynn

On Monday, February 14, 2022 at 3:57:03 PM UTC-5, J. Clarke wrote:
> On Mon, 14 Feb 2022 14:09:49 -0600, Lynn McGuire
> <lynnmc...@gmail.com> wrote:
>
> >On 2/14/2022 1:27 PM, pete...@gmail.com wrote:
> >> On Monday, February 14, 2022 at 11:17:28 AM UTC-5, peterw...@hotmail.com wrote:
> >>> On Sunday, February 13, 2022 at 4:22:38 PM UTC-6, Torbjorn Lindgren wrote:
> >>>> The Horny Goat <lcr...@home.ca> wrote:
> >>>>> On Fri, 11 Feb 2022 12:35:59 -0000 (UTC), Torbjorn Lindgren
> >>>>> <t...@none.invalid> wrote:
> >>>>>> Well, IIRC at least until the weather improves (IIRC a few months) so
> >>>>>> they can launch in a better trajectory again - there's so many
> >>>>>> Starlink launches that they've choosen a launch path to reduce the
> >>>>>> chance of not being able to launch due to weather despite this hurting
> >>>>>> performance (IE less satellites per launch cost).
> >>>>>
> >>>>> Aren't you basically saying they made a corporate decision to go cheap
> >>>>> on launch costs and are now getting bitten for what turns out to be
> >>>>> false economy?
> >>>> I'm fairly certain it's a deliberate choice they're making and that
> >>>> they accept the risk. It's possible they "lost" the bet here but it
> >>>> may also be within calculated risk parameters (see below).
> >>>>
> >>>> In this case the trigger event happened after the launch, if it had
> >>>> happened just a few hours earlier they likely would have delayed the
> >>>> launch and offloaded a few of the satellites to launch in a slightly
> >>>> higher initial orbit. So, well, oops, but they likely knew that would
> >>>> happen eventually.
> >>>>
> >>>>
> >>>> Digging into the specifics:
> >>>>
> >>>> IIRC the the manufacturing cost of these satellites were below $500k
> >>>> each quite a while ago, while this could have gone up (added laser
> >>>> links) we also know that SpaceX had an aspirational goal of $250k per
> >>>> satellite for the "2.0" variant.
> >>>>
> >>>> So, guesstimating $10M-$20M production cost for the 40 lost satellites
> >>>> (out of 49 launched), and they have several months worth of launches
> >>>> queue up in warehouses. They got a production line spitting them out
> >>>> in great numbers.
> >>>>
> >>>> Many have speculated that the internal COST to SpaceX for a Falcon 9
> >>>> launch with reused core and reused fairings might be as low as $10M,
> >>>> it's very unlikly to be above $20M.
> >>>>
> >>>> So, the launch cost probably isn't that far of the cost of the
> >>>> satellites it carry. Which means increasing the number of satellites
> >>>> definitely is worthwhile as long as the risks are "low enough".
> >>>>
> >>>> Staying that close to the edge likely wouldn't be the right call for
> >>>> anyone else, even for the other "big LEO constellation". It comes from
> >>>> a combination of owning the launcher and mass-producing a very large
> >>>> number of light low-cost satellites. They actually have a warehouse
> >>>> with several months worth of satellites waiting for launches!
> >>>>
> >>>> Obviously if you're launching an expensive satellite (IIRC most
> >>>> geostationary satellites cost $150M-$400M) or one with very long
> >>>> lead-time (most traditional satellites) you would never try to ride
> >>>> that close to the margin because it would be crazy.
> >>>>
> >>>>
> >>>> Similarly, SpaceX choose Krypton thrusters instead of Xenon thrusters
> >>>> which did reduce the cost somewhat (I'm told Xenon gas costs ~10x what
> >>>> Krypton cost) but! I've also been told that there's considerable doubt
> >>>> they could even have gotten the required amount of Xenon that this
> >>>> number of satellites required, note that all these mega constellation
> >>>> has "50%/100% of the satellites needs to be active before 3/6 years or
> >>>> the number of satellites will be frozen at the current number".
> >>>> Meaning at that point only direct replacements can be launched, 1 for
> >>>> 1.
> >>>>
> >>>> Yes, the FCC can choose waive minor infractions of this but anyone who
> >>>> asks for that better make sure they're close, trying hard and have an
> >>>> explaination. Also, all their competitors will likely try to fight any
> >>>> such waiver in court too.
> >>>>
> >>>> I don't know how easy it would have been to increase the Xenon
> >>>> production capacity, but I expect it would push Xenon gas prices up
> >>>> even higher. Which might well have resulted in additional groups
> >>>> complaining about SpaceX launch program hurting their profession. And
> >>>> I expect that say Doctors (it's used in medicine) have WAY more
> >>>> political clout than astronomers :-)
> >>> On the plus side, since commercial xenon gas is produced by liquification and
> >>> fractional distillation from the atmosphere, any xenon expended by satellite
> >>> thrusters in low Earth orbit will fall back to Earth and re-enter the supply chain.
> >>> Is any significant amount of gas at those altitudes thought to be swept away
> >>> from Earth by the solar wind? Do they attempt to scavenge xenon used for
> >>> medical purposes?
> >>
> >> Krypton is present in the atmosphere at about 1 ppm, while Xenon is about
> >> 87 ppb. Production of both is as a byproduct of making liquid oxygen.
> >>
> >> That's raises an interesting little wrinkle. Its rumored that SpaceX is looking
> >> at building its own LOX plant at Boca Chica. If that's the case, it may be able
> >> to produce its own Kr as well.
> >>
> >> I saw a stackexchange BoE calculation that suggested that each starlink
> >> satellite needed the delta-V available from 4.8 kg of Kr. Their ionization
> >> potential is similar, so the drop in efficiency isn't that great. I think that
> >> means similar masses required as well.
> >>
> >> pt
> >
> >The EPA is forcing SpaceX to move the Boca Chica operations to Florida.
> >
> >https://spacenews.com/spacex-considers-shifting-starship-testing-to-florida/
> No, the EPA is not. The FAA has its finger firmly up its butt
> concerning the environmental review, and SpaceX is getting sick of
> waiting for them to pull it out.

It's also worth noting that there's a lot of bad feelings between Musk and Biden
these days, and the FAA and EPA know that harassing SpaceX won't get any
White House pushback.

pt

On Tuesday, February 15, 2022 at 2:56:15 AM UTC-5, The Horny Goat wrote:
> On Sun, 13 Feb 2022 22:22:34 -0000 (UTC), Torbjorn Lindgren
> <t...@none.invalid> wrote:
>
> >>Aren't you basically saying they made a corporate decision to go cheap
> >>on launch costs and are now getting bitten for what turns out to be
> >>false economy?
> >
> >I'm fairly certain it's a deliberate choice they're making and that
> >they accept the risk. It's possible they "lost" the bet here but it
> >may also be within calculated risk parameters (see below).
> >
> >In this case the trigger event happened after the launch, if it had
> >happened just a few hours earlier they likely would have delayed the
> >launch and offloaded a few of the satellites to launch in a slightly
> >higher initial orbit. So, well, oops, but they likely knew that would
> >happen eventually.
> That sounds a LOT like what was being said after January 1986 other
> than that no human lives were lost and no macabre jokes like "NASA
> stands for Need Another Seven Astronauts" are being said.

It's the way Musk likes to do things. He's not afraid to take calculated
risks, and have very public failures if doing so means he moves ahead.
It's the 'move quickly and break stuff' Silicon Valley mentality. These
failures are just part of doing business, and he won't be fired for them.

The only people he has to justify himself to are his insurers, who know
all about calculated risks.

Here's a fun compilation of Starship tests:
https://www.youtube.com/watch?v=ztHUxBduRmE

pt

On 2/15/2022 10:14 AM, pete...@gmail.com wrote:
> On Tuesday, February 15, 2022 at 2:56:15 AM UTC-5, The Horny Goat wrote:
>> On Sun, 13 Feb 2022 22:22:34 -0000 (UTC), Torbjorn Lindgren
>> <t...@none.invalid> wrote:
>>
>>>> Aren't you basically saying they made a corporate decision to go cheap
>>>> on launch costs and are now getting bitten for what turns out to be
>>>> false economy?
>>>
>>> I'm fairly certain it's a deliberate choice they're making and that
>>> they accept the risk. It's possible they "lost" the bet here but it
>>> may also be within calculated risk parameters (see below).
>>>
>>> In this case the trigger event happened after the launch, if it had
>>> happened just a few hours earlier they likely would have delayed the
>>> launch and offloaded a few of the satellites to launch in a slightly
>>> higher initial orbit. So, well, oops, but they likely knew that would
>>> happen eventually.
>> That sounds a LOT like what was being said after January 1986 other
>> than that no human lives were lost and no macabre jokes like "NASA
>> stands for Need Another Seven Astronauts" are being said.
>
> It's the way Musk likes to do things. He's not afraid to take calculated
> risks, and have very public failures if doing so means he moves ahead.
> It's the 'move quickly and break stuff' Silicon Valley mentality. These
> failures are just part of doing business, and he won't be fired for them.
>
> The only people he has to justify himself to are his insurers, who know
> all about calculated risks.
>
> Here's a fun compilation of Starship tests:
> https://www.youtube.com/watch?v=ztHUxBduRmE
>
> pt

When I worked for TXU (the largest electricity company in Texas) back in
the 1980s, our insurance deductible was $30 million. We managed to nail
it at least once during the eight years I worked there.
https://www.upi.com/Archives/1987/02/17/An-electrical-power-plant-disabled-by-an-explosion-and/1253540536400/

We knew what caused the explosion and six hour fire. One of the low
pressure steam turbines threw an 18 inch long last row minus one blade
at 3,600 rpm. The subsequent vibrations caused the hydrogen seals on
the 350 MW generator to fail. And then the fire started and was fed by
the DC turbine lube oil pump with 10,000 gallons of lube oil for six hours.

Lynn

On 2/15/22 12:59, Lynn McGuire wrote:
> On 2/15/2022 10:14 AM, pete...@gmail.com wrote:
>> On Tuesday, February 15, 2022 at 2:56:15 AM UTC-5, The Horny Goat wrote:

Stuff deleted

>
> When I worked for TXU (the largest electricity company in Texas) back in
> the 1980s, our insurance deductible was $30 million.  We managed to nail
> it at least once during the eight years I worked there.
>
> https://www.upi.com/Archives/1987/02/17/An-electrical-power-plant-disabled-by-an-explosion-and/1253540536400/
>
>
> We knew what caused the explosion and six hour fire.  One of the low
> pressure steam turbines threw an 18 inch long last row minus one blade
> at 3,600 rpm.  The subsequent vibrations caused the hydrogen seals on
> the 350 MW generator to fail.  And then the fire started and was fed by
> the DC turbine lube oil pump with 10,000 gallons of lube oil for six hours.
>
> Lynn

I would NOT have wanted to work that fire. Way too explosive with
invisible flame (hydrogen!) and too much mythel-eythel bad stuff.

--
Dave Scruggs
Captain, Boulder Creek Fire (Retired)
Sr. Software Engineer - Stellar Solutions (Definitely Retired)

The Horny Goat <lcraver@home.ca> wrote:
>On Sun, 13 Feb 2022 22:22:34 -0000 (UTC), Torbjorn Lindgren
><tl@none.invalid> wrote:
>>>Aren't you basically saying they made a corporate decision to go cheap
>>>on launch costs and are now getting bitten for what turns out to be
>>>false economy?
>>
>>I'm fairly certain it's a deliberate choice they're making and that
>>they accept the risk. It's possible they "lost" the bet here but it
>>may also be within calculated risk parameters (see below).
>>
>>In this case the trigger event happened after the launch, if it had
>>happened just a few hours earlier they likely would have delayed the
>>launch and offloaded a few of the satellites to launch in a slightly
>>higher initial orbit. So, well, oops, but they likely knew that would
>>happen eventually.
>
>That sounds a LOT like what was being said after January 1986 other
>than that no human lives were lost and no macabre jokes like "NASA
>stands for Need Another Seven Astronauts" are being said.

No, the triggers for both Challenger (1986, O-ring seals) and Columbia
(2003, foam vs fragile heat tiles) were known for YEARS before the
respective disasters!

It just was ignore because it didn't blow up in their face so they
kept pushing the boundary harder until it DID! - I think the relevant
quote is "normalisation of deviance".

In comparison this event actually did catch everyone by surprise, no
one has documented an event of this nature. Admittedly that's partly
because no one use orbits that low but still, rather different. But
the risk was definitely known.

In this case SpaceX decided to go with the a slightly riskier (IE
lower) initial orbit for SpaceX based on the fact that it allowed them
to put a few more satellites on each launch.

As I noted in the part you cut out SpaceX decisions wouldn't make
sense for expensive ($100M+) or long-leadtime satellites, nor for
launches where humans would be involved.

But as I mentioned the Starlink satellites are very different to those
or for that matter the Space Shuttle, it's BULK product that is mass
produced (100+ per month IIRC), are relatively cheap (<$500k), doesn't
involve human lives and SpaceX has more than hundred of them waiting
to get launched in warehouse. Heck, the main reason they're not
churning out even more satellites is well, it makes no sense to ramp
up product any further since they can't launch fast enough anyway!

So, given this situation it seems a perfectly valid engineering
trade-off for them to make and as I'll detail below it's likely SpaceX
are at worst roughly even.

Evaluting SpaceX's "gamble" - AKA let's do the MATH:

My best guess is that for a "safe" altitude they would have launched
two less satellites for the recent launches (49 satellites) and two to
three less for the earlier bigger launches (60 satellites).

SpaceX has done 39 Starlink launches, not counting the two test
satellites. Arguably the first launch with 0.9 satellites shouldn't
count either, so lets go with 38.

They never lost any satellites to this before, so at worst they lost
40 satellites on 38 launches. Some sources suggest they may have
recovered two more satellites which would make it 38 lost on 38
launches.

So, averaged out that's 1.05 (or 1.0) satellites "lost" per launch.

The actual calculus is more complicated given that they've reduced the
satellite count to allow for external paying ride-share satellites on
3 of these 38 launches and they've also launched 10 Starlink
satellites on the Transporter-1 launch which isn't included at all in
this.

Also, as time has gone past they've slightly reduced the initial
launch altitude (AKA increased the risk) but for a
back-of-the-envolope calculation 40/38 or 38/38 is good enough!

So, likely at best they would likely have been very slightly ahead if
they had reduced the payload with one satellite per launch AND that
reduction had been enough to avoid this loss completely, which is
questionable.

And if they instead choosen an orbit high enough to be completely safe
by dropping 2-3 satellites per launch they would be well behind the
current total, despite not loosing any to atmospheric drag.

So, the result is somehwre between "very slight behind" to "far
ahead", that seems a decent to good outcome to me.

Obviously this calculus could change over time but there's no reason
to believe this "gamble" isn't one SpaceX is going to "win" in the
long run, and more importantly they can do it without pretty much ANY
risk of it hurting them badly so why not go with what the numbers say
is likely to give the best result.