
ESA satellite dodges 'mega constellation' - baud147258
https://www.theregister.co.uk/2019/09/02/esa_starlink/
======
TeMPOraL
Two things from this article that surprised me:

> _The ESA operations team confirmed that this morning 's manoeuvre took place
> approximately half an orbit before the potential pileup._

Half an orbit is _mightily late_. It's a last minute emergency correction in
space terms. Given that both Aeolus and Starlink satellites are active
missions, how come they didn't realize and correct this sooner?

And related:

> _If plans to orbit thousands more satellites (to bring broadband to remote
> areas, or inflict it on air-travellers, for example) come to fruition, the
> ESA team reckons that things will need to be a lot more automated._

Maybe it's because I didn't get far enough in the space industry handbook I'm
reading, but I was _sure_ orbital tracking and detecting potential collisions
was automated already. There should be continuously running simulations that
are constantly fed fresh TLEs from tracking stations, that check whether or
not anything is going to collide with anything else in the nearby future.

~~~
benjymo
According to the other article I read about it
([https://www.forbes.com/sites/jonathanocallaghan/2019/09/02/s...](https://www.forbes.com/sites/jonathanocallaghan/2019/09/02/spacex-
refused-to-move-a-starlink-satellite-at-risk-of-collision-with-a-european-
satellite/)) they knew about it earlier but Starlink refused to move their
satelite.

~~~
hoseja
So, they were playing chicken? And Starlink won?

~~~
manicdee
No.

Jonathan O’Callaghan published his extremely biased and inflammatory clickbait
before waiting for SpaceX to present their side of the story (time from ESA
tweet to Jonathan’s story was about three hours).

What actually happened is that SpaceX communicated their intention to take no
action based on a much earlier estimate of extremely low collision risk. A
later update from the US Air Force got lost in the mail filter, so SpaceX
never read it otherwise they would have contacted ESA immediately.

Here is Loren Grush with a more mature and less inflammatory take on the
topic: [https://www.theverge.com/2019/9/3/20847243/spacex-
starlink-s...](https://www.theverge.com/2019/9/3/20847243/spacex-starlink-
satellite-european-space-agency-aeolus-conjunction-space-debris)

In time we will get a more thorough understanding of what happened, but the
ESA’s fundamental point is emphasised by SpaceX’s experience: having to
coordinate satellite operations through email that is handled by humans is
fundamentally unworkable, and something needs to be done about automating
everything before the megaconstellations take to the sky.

------
russdill
From the author of a Forbes article on the same subject:

[https://twitter.com/Astro_Jonny/status/1168859502067834881](https://twitter.com/Astro_Jonny/status/1168859502067834881)

"Just to quickly clarify again @FastCompany et al, ESA did NOT ask SpaceX to
move. SpaceX simply said they would not move their #Starlink satellite,
necessitating an evasive manoeuvre from #Aeolus."

[https://twitter.com/Astro_Jonny/status/1168833920118480898](https://twitter.com/Astro_Jonny/status/1168833920118480898)

"I'm not sure on the exact timeline but yes, ESA was alerted to the event five
days before. Three days prior, they noted a raised collision risk. One day
before, they decided to move. SpaceX sent one email saying they had no plans
to manoeuvre."

~~~
manicdee
That was published before the author had any response from SpaceX (it looks
like he gave them an hour or two to respond before publishing).

Here’s Loren Grush with more info:
[https://www.theverge.com/2019/9/3/20847243/spacex-
starlink-s...](https://www.theverge.com/2019/9/3/20847243/spacex-starlink-
satellite-european-space-agency-aeolus-conjunction-space-debris)

------
case_187
This is hardly a 'first'. ESA felt their satellite was being obstructed by
SpaceX who moved into the space much later and didn't act responsibly as they
should have. So ESA decided to send out a press release.

~~~
ovi256
Yeah, you can feel the bad blood behind the press release.

Basically ESA nicely asked SpaceX to maneuver their sat and shorten its
lifetime - they don't have a legal basis or enforcement mechanism anyway.
SpaceX pretended not to hear until it was too late and ESA went ahead with
their contingency plan of burning their own sat's fuel and lifetime instead.

~~~
russdill
If it was really about burning fuel, ESA would not have waited until half an
orbit before. The longer you wait, the more you have to burn.

~~~
tehbeard
Not really.

a. They did an altitude increase. There's no real gains from an earlier burn
that one might get when doing something like a hohmann transfer.

b. Half an orbit before out means more/better telemetry to work with.

c. They are from a quick google, well within the range where atmospheric drag
plays a role, and you need to do station keeping. leaving it this late means
you don't "waste" fuel from drag.

Admittedly, my only credentials for this are a few thousand hours in KSP and
reading around the subject. Anyone with a proper degree on this is welcome to
correct me.

~~~
russdill
In that case they were simply adjusting their station keeping schedule and
minimum (if any) fuel would be wasted.

If that wasn't the case, they could raise or lower the altitude slightly
several orbits before the "event" causing them to arrive at the intersection
point earlier or later. For a desired time delta, the sooner your perform your
altitude change the smaller the changed required.

------
grecy
This all happened at 320km, which is way below the Starlink constellation
operating elevation. So the satellite in question is either one that is
undergoing de-orbit testing, or is not functioning correctly which likely
means SpaceX couldn't move it if they wanted to.

Very, very misleading to say the ESA had to dodge the "mega constellation".

~~~
S_A_P
The register does seem to have a penchant for hyperbole.

~~~
EdwardDiego
Penchant? It's why they get out of bed in the morning.

------
gpm
> Hmmm. We move our satellites on average once a week and don't put out a
> press release to say who we maneuvered around...

\-
[https://twitter.com/IridiumBoss/status/1168582141128650753](https://twitter.com/IridiumBoss/status/1168582141128650753)

> Normal part of flying satellites (or should be). Does BA announce every time
> one of its airplanes steers around a Ryanair aircraft?

\-
[https://twitter.com/IridiumBoss/status/1168607146646364160](https://twitter.com/IridiumBoss/status/1168607146646364160)

CEO of Iridium, an existing not-mega constellation that Starlink is arguably
going to make obsolete. When a competitor is coming in and calling this
unnecessary drama, you have to wonder if the ESA has a leg to stand on or is
doing this for political pandering.

They have lots of political reasons to do this too. Attempting to acquire more
regulatory authority. Attempting to acquire funding for projects like AI
collision avoidance
([https://twitter.com/esaoperations/status/1168540912282165248](https://twitter.com/esaoperations/status/1168540912282165248)).
Maybe even attempting to slow down a competitor to their Ariane rocket
family...

PS. the other recent tweets by the CEO of iridium are also interesting and
relevant:
[https://twitter.com/IridiumBoss/with_replies](https://twitter.com/IridiumBoss/with_replies)

------
Deukhoofd
This article has some questionable word choices.

"We contacted SpaceX to get its take on ESA's _antics_ , but nothing has yet
emerged from Musk's media _orifice_ "

"In 2018, the _boffins_ keeping track of things"

Is this considered professional journalism nowadays?

~~~
ISL
Many British publications use the term.

boffin: Noun (British informal) A person engaged in scientific or technical
research. [1]

It appears regularly in the Economist, too [2].

[1]
[https://www.lexico.com/en/definition/boffin](https://www.lexico.com/en/definition/boffin)

[2] [https://www.economist.com/middle-east-and-
africa/2019/08/08/...](https://www.economist.com/middle-east-and-
africa/2019/08/08/how-africa-can-encourage-home-grown-maths-boffins)

~~~
codeulike
You don't often hear Orifice though

------
gpm
> Our starlink team last exchanged an email with the Aeolus operations team on
> August 28, when the probability of a collision was only in the 2.2e-5 range
> (or 1 in 50k), well below the 1e-4 (or 1 in 10k) industry standard threshold
> and 75 time slower than the final estimate. At that point, both SpaceX and
> ESA determined a maneuver was not necessary. Then, the U.S. Air Force's
> updates showed the probability increased to 1.69e-3 (or more than 1 in 10k)
> but a bug in our on-call paging system prevented the Starlink operator from
> seeing the follow on correspondence on this probability increase - SpaceX is
> still investigating the issue and will implement corrective actions.
> However, had the Starlink operator seen the correspondence, we would have
> coordinated with ESA to determine best approach with their continuing with
> their maneuver or our performing a maneuver."

Reportedly an official SpaceX Statement (typos are probably mine)

[https://twitter.com/lorengrush/status/1168917747109191681?s=...](https://twitter.com/lorengrush/status/1168917747109191681?s=21)

------
emiliobumachar
"[...]but nothing has yet emerged from Musk's media orifice."

Typo or colorful word choice?

~~~
SiempreViernes
You don't know _The Register_? Take a look at the rest of the site: wordplay
like that is their chosen style.

------
lokimedes
While space may be infinite, the parking spots closest to the door ain’t - why
are we even talking about letting commercial entities taking up so much LEO
space without some kind of ride share clause? This is ESA we are talking
about, a pan-national agency working solely for the common good of humanity.
Should they move for a prototype of the next AT&T global monopoly?

