SpaceX Starlink Near Collision with ESA Satellite | SpaceX Missed the Collision Warning!
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The European Space Agency (ESA) has published
an unusual press release – specifically blaming SpaceX’s nascent Starlink constellation
for a collision avoidance maneuver recently performed by Aeolus, a scientific spacecraft
in low Earth orbit (LEO). SpaceX reportedly refused to move its Starlink
satellite, triggering the maneuver. In a series of tweets from its ESA Operations
account, the agency said the Aeolus satellite performed a maneuver to avoid a potential
close approach to a Starlink satellite, which it identified in one graphic as Starlink 44. The incident took place 320 kilometers above
Earth as the two orbital paths of the two vehicles intercepted each other. No one wants a collision, since these satellites
are moving through space at several thousands of miles per hour. At those speeds, an impact can cause spacecraft
to break apart into hundreds of pieces. The resulting high-speed junk could potentially
run into other satellites, possibly creating more dangerous debris. “Experts in ESA SpaceDebris team calculated
the risk of collision between these two active satellites, determining the safest option
for Aeolus would be to increase its altitude and pass over the SpaceX satellite,” the
agency stated in one tweet. That maneuver took place about half an orbit
before closest approach, and the agency confirmed that the spacecraft was operating normally
after the time of closest approach. According to a list of conjunctions called
the Satellite Orbital Conjunction Reports Assessing Threatening Encounters in Space
(SOCRATES), maintained by the Center for Space Standards & Innovation, Aeolus was predicted
to have a close approach shortly after 7 a.m. Eastern Sept. 2 with a satellite identified
as Starlink44. The two satellites were predicted to come
within about four kilometers of each other, at a relative velocity of 14.4 kilometers
per second. From the perspective of ESA sourced information,
SpaceX certainly appears to be in the wrong in this case. However, the current story is extremely patchy,
and more information is needed to paint a true-to-life picture of events. In this Video Engineering Today will discuss
why ESA’s Aeolus SatellitePerforms Evasive maneuver to Dodge SpaceX Starlink 44 Satellite
After Missed Message. Was SpaceX’s refusal to move based on an
inability to move one of the two satellites it is intentionally deorbiting? Is SpaceX Company simply confident in what
it has described as a suite of autonomous collision avoidance hardware and software
installed on each Starlink satellite? Let’s get into details. According to Holger Krag, head of the Space
Debris Office at ESA, the risk of collision between the two satellites was 1 in 1,000
– ten times higher than the threshold that requires a collision avoidance maneuver. However, despite Aeolus occupying this region
of space nine months before Starlink 44, SpaceX declined to move their satellite after the
two were alerted to the impact risk by the U.S. military, who monitor space traffic. “Based on this we informed SpaceX, who replied
and said that they do not plan to take action,” says Krag, who said SpaceX informed them via
email – the first contact that had been made with SpaceX, despite repeated attempts
by Krag and his team to get in touch since Starlink launched. “It was at least clear who had to react. So we decided to react because the collision
was close to 1 in 1,000, which was ten times higher than our threshold.” The SpaceX satellites should have automated
collision avoidance systems, but this system was not used and it’s not clear why. Krag suspected it could be something to do
with SpaceX’s electric propulsion system, which “maybe is not reacting so fast”
as the chemical propulsion on board Aeolus. The Aeolus satellite, weighing in at more
than 1,300 kilograms, was launched on August 22, 2018, is in an orbit between 308 and 314
kilometers high. Whereas SpaceX launched its first batch of
60 Starlink satellites on May 23 this year. While most of those had their orbits raised
from 440 kilometers to 550 kilometers, but the Starlink44 satellite is in an orbit much
lower than most of the rest of the 60 Starlink satellites. According to the Space Track database maintained
by the U.S. Air Force, Starlink 44 is in an orbit that varies between 311 and 345 kilometers. SpaceX announced in June that it planned to
intentionally deorbit two of the Starlink satellites as test of the spacecraft’s propulsion
system, suggesting Starlink 44 may be one of those satellites. SpaceX also said in June that three of the
60 satellites had failed to respond to commands and were presumed dead. SpaceX has said it plans to use autonomous
systems to avoid collisions. “Our satellites automatically maneuver around
any orbital debris,” SpaceX Chief Executive Elon Musk said in a call with reporters in
May, shortly before the first Starlink launch. “I think we’ve got a really good solution
for making sure that we do not create orbital debris,” he added, also noting that the
relatively low altitude of the Starlink satellites limits their orbital lifetime. It wasn’t clear if that autonomous avoidance
system was active on the Starlink satellite projected to come close to Aeolus, or any
other active Starlink satellites. Thus Starlink 44 entered a region of space
that Aeolus had occupied first. However, there are no rules in space that
require one or another operator to move their satellite when there is a risk of collision. This, says Krag, is something that ESA hopes
will be addressed in the near future. “There are no rules in space,” he says. “Nobody did anything wrong. Space is there for everybody to use. There’s no rule that somebody was first
here. Basically on every orbit you can encounter
other objects. Space is not organized. And so we believe we need technology to manage
this traffic.” According to ESA this is the first time that
it has ever had to reposition one of its satellites to avoid an object belonging to a mega constellation. However, the agency has had to alter the trajectory
of its LEO orbiters many times in the past to avoid other potential hazards. Last year alone ESA performed 28 collision
avoidance maneuvers, largely in an effort to keep its probes safe from defunct satellites
or debris. It is extremely rare for the threat to be
posed by an intact satellite, let alone an operational one. Sadly, however, these events are likely to
become much more common as access to space becomes cheaper. “We see it as part of our changing environment,”
says Stijn Lemmens, a space debris analyst at ESA. “We want to raise awareness in this sense,
that there’s quite a bit of work that needs to be done on how to make sure that these
type of operations will run smoothly in the future.” Collisions between satellites are not unheard
of; perhaps the most famous incident was between the US Iridium 33 satellite and the defunct
Russian Kosmos-2251 satellite in 2009, which resulted in thousands of pieces of debris. And many have noted that our systems in place
today are simply not adequate to cope with upcoming mega constellations like Starlink,
which will far exceed the number of 2,000 active satellites currently in orbit. “The February 2009 collision between Iridium
33 and Kosmos-2251 was actually predicted, with a miss distance of 584 meters, but that
was less than the prediction formal error, and so evasive action was not taken,” says
Marshall Eubanks from Space Initiatives. “The existing satellite tracking system
is not intended to handle the mega constellations being planned and deployed, and new thinking
is going to be required to allow the industry to continue to grow.” SpaceX alone plans to launch a total of 12,000
Starlink satellites into orbit in the coming years, with considerable concerns about how
busy Earth orbit will become. ESA, in its series of tweets about the maneuver,
suggested that the “manual” approach to avoiding the potential collision will not
be sustainable, once more satellites like those in Starlink and other planned mega constellations,
are in orbit. “These avoidance maneuvers take a lot of
time to prepare – from determining the future orbital positions of all functioning spacecraft,
to calculating the risk of collision and potential outcomes of different actions,” the agency
said. ESA said it’s looking to rely more on artificial
intelligence to decide whether, and how, to perform avoidance maneuvers in the future,
and has a proposal to fund such work for the agency’s member states to consider at the
Space19+ ministerial meeting in November. That is part of a broader “Space Safety”
initiative that also includes improved forecasting of space weather and a planetary defense mission
called Hera. Licenses filed by SpaceX suggest they are
planning four more Starlink launches by the end of 2019, which could total at least an
additional 240 satellites if they continue to launch 60 on each Falcon 9 rocket. The first launch is expected no earlier than
October 10, with subsequent launches in October, November, and December. Other companies like OneWeb, Amazon, and Kepler
Communications also have plans for thousands of space internet satellites. SpaceX has so far remained tight-lipped on
how it will handle the growing concerns around its Starlink constellation, including collision
avoidance maneuvers and concerns from the astronomy community. As for this most recent incident, Krag and
his team just hope that SpaceX will be more responsive in the future, so that situations
can be avoided when more Starlink satellites are launched, and more stringent rules are
put in place. “We are not upset by them saying they wouldn’t
move,” says Krag. “My concern is how often will we have such
events in the future? These are just two satellites. Now they will add several thousand, and they
will also be disposed and end up at various altitudes. And there’s no rule or law on how to react,
it’s all goodwill. “What I want is an organized way of doing
space traffic. It must be clear when you have such a situation
who has to react. And of course automating the system. It cannot be when we have 10,000 satellites
in space that there are operators writing the email what to do. This is not how I imagine modern spaceflight. While ESA sounded worried about the close
approach, others in the industry were nonplussed by the attention it received. “Hmmm. We move our satellites on average once a week
and don’t put out a press release to say who we maneuvered around,” tweeted Matt
Desch, chief executive of Iridium, which operates a constellation of 75 next-generation satellites
in low Earth orbit. Desch, though, has previously expressed concerns
about threats to space sustainability caused from mega constellations, particularly if
those satellites have high failure rates. “We are creating an environment that may
make LEO an environment that isn’t sustainable,” he warned at a June forum organized by the
Secure World Foundation. He added then, though, that he was happy that
SpaceX decided to place its Starlink satellites in a lower orbit than originally proposed,
which means they will stay in orbit for a shorter period even if not deliberately deorbited. “It’s a very responsible decision”.

24 thoughts on “SpaceX Starlink Near Collision with ESA Satellite | SpaceX Missed the Collision Warning!

  1. Why is it only news when it involves one of Musk's companies?
    One or two satellites are destroyed every year, and others are damaged.
    Over 300K close calls every year.

  2. One big difference between old-school ESA and top-notch SpaceX: ESA is getting nervous when another satellite comes close to about 4km, because THEY need to MANUALLY PLAN a maneuver to get to a "safe" distance. SpaceX on the other hand, wether they missed a warning e-mail or not, already have systems onboard the satellites to automatically detect and avoid collision hazards, thus, they DON'T NEED to plan far ahead and they DON'T NEED to keep such large safety marings like ESA is used to.

  3. So it would have, probably, missed. Ok? Keep tracking, build data and find out if this will happen again. Thought we were ahead of this.

  4. first warning, for witch Spacex reply was not 1:1000 but 1:50000. at that odd no moving is required. the other mail from ESA where not receive, mail bug!

  5. If you don't like the title…. If you don't like stories that are unfavorable to a Musk company… Get used to it now. I learned more in 20 seconds of a Scott Manley video about this subject than I did in all 13:23 of this video, and I could only stand to watch about 1:36 of it.

  6. 4 kilometers = about 2.5 miles
    SpaceX refused to alter the course of Starlink 44. It appears that SpaceX either does not have the ability to alter course in short notice or just felt that SpaceX could just bully ESA into altering it's satellite's course in order to avoid collusion, being that the ESA satellite is probably more expensive than Starlink 44!
    One my wonder what will happen if SpaceX playing chicken with other satellites, if they also refuse to alter their satellites course!

  7. With the plan to deploy thousands of Starlink satellite, there's a chance of a collision with satellites other than Starlink.

  8. its surprising that a small satellite would have the capabilities to track other small objects when fast speeds/ distances are involved — Wow

  9. Hey, I think SpaceX, NASA etc+ should increase customer service standards via communications through Internet, telephone etc+ to human's, corporations, institutions & be more user friendly towards everyone in every aspects/perspective. (◕ᴗ◕✿) 🌸🦋+🍬…

  10. What a click-bait title! The video itself states that these "near misses" are common, and are usually handled internally and successfully all the time! Just another "let's pathologize SpaceX" video.

  11. So no crash, bang, wallop. Fish bait. Satellites die each years, leaving even more junk behind, some used to be recovered and refurbished, but the space shuttle programme has ended. Close collisions are known so why highlight SpaceX?

  12. The issue is he wants to send 1000 starlink satellites, I hope they burn out on earth atmosphere otherwise they are a problem for the world…

  13. Esa: excuse me mr. SpaceX, the odds of a collision are approaching approximately 1000 to 1…
    Elon: bitch relax. Never tell me the odds. Gwen hold my beer…

  14. Thanks for the video, I think it is generally positive that ESA made public what took place. Firstly collision avoidance manoeuvres between active spacecraft and debris have become relatively common in the last 15 years. Whereas before this time there was very little coordination, perhaps only by telephone, and few processes were in place. Currently collision avoidance manoeuvres between active spacecraft are rare, but presumably will become more common in the future if systems such as One Web and Starlink are successful. Therefore there will need to be some decision by the operators, which spacecraft manoeuvres as the risk of collision may actually increase if both manoeuvre in the same direction. In terms of fuel efficiency it is preferable to perform a small manoeuvre earlier, so perhaps in the working day before the conjunction is forecast to take place. Whereas I assume the ADM Aeolus flight control team could not decide whether to wait for the Starlink satellite to autonomously manoeuvre or perform their own manoeuvre manually. Eventually it appears ESA instructed their flight control team to perform a collision avoidance manoeuvre unusually late and therefore consume more propellant than usual. Also bear in mind that unlike Starlink, most spacecraft have no autonomy in this area, so collision avoidance manoeuvres can involve staff being called in in the middle of the night and accidentally manoeuvre towards some other debris or struggle with ground system problems. ADM Aeolus is a unique spacecraft that took 10-15 years to develop and launch, whereas SpaceX have already launched more than 60 Starlinks, so losing one is perhaps not such an issue. At the unusually low altitude that the incident took place, any debris generated by a collision would reenter the atmosphere within a few years to decades, whereas a collision at a higher orbit, say above the commonly used 850km altitude could take decades to centuries to reenter. Therefore really I think operators are going to have to figure out how to communicate with one another, so that a decision can be made a day or so before the conjunction between the two objects is forecast. With debris the decision process is understood, based on CSpOC data if the probability of collision is worse than 1/10000 the operator should consider manoeuvring their spacecraft. However with 2 active spacecraft, then which party takes the decision to manoeuvre?

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