12 ms·

Starlink plans to deploy 12,000 - 42,000 satellites. What if two competitors want to do the same? Can the low earth orbit handle 150,000 satellites that turn in

Starlink plans to deploy 12,000 - 42,000 satellites. What if two competitors want to do the same? Can the low earth orbit handle 150,000 satellites that turn into space debris at some point?

Armisael16 3y ago
Yes.
panick21_ 3y ago
The waste, waste majority of sats never turn into space debris. Every single sat that launches today in the West has a deorbit planned. The only sat that turn into space debris will be those that brake unexpectitly and totally unrecoverable. And the Starlink sats are so low that they dont really turn very meaningful debris ever. And in general, yes LEO can handle millions of sats. We have like 150k cars in a single tiny country on earth right now.
- wyldfire 3y ago
  Freudian slip.
  - elwell 3y ago
    It's just phonetically in a german accent.
    - panick21_ 3y ago
      Damn, you are on the spot. German is my first language and I have dyslexia.
- 3cats-in-a-coat 3y ago
  Cars don’t constantly move thousands miles an hour uncontrollably
  - simple-thoughts 3y ago
    Cars also don’t move in easily predicted patterns for decades without turning from their predetermined path.
    - mabbo 3y ago
      They sort of do though. Cars, for the most part, follow the road and the direction they're already going. They (usually) signal if they're about to make changes. And to be safe, we've built an arrangement that they only travel on these specific paths at specific speeds, modifying their speed to match the other cars they might hit. The challenge with satellites is that steering is hard and very limited. And they don't have brakes they can slam to come to a stop if they need to suddenly avoid a collision.
      - panick21_ 3y ago
        It is well known that potential points of conflict are a huge issue. That's why a round about is safer then intersection. > And to be safe Tell that to the 40k people killed and the millions hurt by cars in the US alone. Cars constantly turn and intersect routes with other cars without any planning, even if perfectly handled and most of time they are not. > The challenge with satellites is that steering is hard and very limited. And they don't have brakes they can slam to come to a stop if they need to suddenly avoid a collision. They don't need to break, they just need to know the position of speed of other objects and correct position ahead of time. The only reason why this is even a program at all is because only the US has even minimally invested in monitoring. If each nation just did the same our accuracy would be far, far higher and things would be way better. So, as of now, we have minimally invested in solving this problem and it isn't a big issue. Slightly more investment (that is justified if we 10-100-1000x the amount of sats) is required eventually. But compared to what it takes to make cars not crash into each other its nothing. (Unless its like US infrastructure design that seems to want to make cars crash into things, but I hope in Space we can avoid that)
      - starbase 3y ago
        Cool thing about satellites is if you're on the same path, you must also be going the same speed. Collision avoidance in LEO is quite elegant. When two satellites are predicted to pass uncomfortably close to one another, one satellite will fire its station keeping thrusters to raise its orbit above the other. No brakes or swerving needed, just a slight push well ahead of time. Starlink sats do this over 1000 times per week. Even better, energy used for avoidance reduces energy needed for station keeping on a 1:1 basis. Avoidance maneuvers are effectively free.
- Jeff_Brown 3y ago
  > the Starlink sats are so low that they dont really turn very meaningful debris ever. Is that right? Scientific American seemed to think it could be a problem in 2019[1]. Space.com says Starlink satellites orbit at an altitude of about 342 miles (550 kilometers)[2]. And the Wikipedia article on Kessler Syndrome[3] (which is a chain reaction of satellite debris) mentions an incident at 555km that was problematic: "In 1985, the first anti-satellite (ASAT) missile was used in the destruction of a satellite. The American 1985 ASM-135 ASAT test was carried out, in which the Solwind P78-1 satellite flying at an altitude of 555 kilometres was struck by the 14-kilogram payload at a velocity of 24,000 kilometres per hour (15,000 mph; 6.7 km/s). When NASA learned of U.S. Air Force plans for the Solwind ASAT test, they modeled the effects of the test and determined that debris produced by the collision would still be in orbit late into the 1990s. It would force NASA to enhance debris shielding for its planned space station." [1] https://www.scientificamerican.com/article/spacexs-starlink-could-cause-cascades-of-space-junk/ https://www.scientificamerican.com/article/spacexs-starlink-... [2] https://www.space.com/spacex-starlink-satellites.html https://www.space.com/spacex-starlink-satellites.html [3] https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome
  - nordsieck 3y ago
    Space junk at that altitude does turn into debris, but it tends to deorbit on its own in around 5-10 years. The real danger is space junk that's at much higher altitudes. OneWeb and Telesat Lightspeed (in planning) operate at 1000+ km, where space junk will take 1000+ years to deorbit on its own. And OneWeb has already had a satellite failure where it can't deorbit the satellite.
  - montagg 3y ago
    I don’t have references for this, but my understanding is that you have more to worry about space debris that is higher/faster than lower/slower. The atmospheric drag is such that any out of control craft at [some threshold] or under will deorbit themselves fairly quickly, and the debris will burn up entirely. I believe that threshold is around 450-500km, but it’s also probably not a literal height, more of a gradient of risk. Higher/faster, they will be up there for longer (years? decades?) and it’s harder to predict where any broken pieces will go over time.
- idlewords 3y ago
  Except that all distinct orbits at the same altitude eventually collide.
  - deleted 3y ago
    [deleted]
  - rdlw 3y ago
    What do you mean? If they're both circular orbits, they'll have the same period, so they'll never collide—they'll always be on opposite sides of the Earth. In fact, this goes for any two orbits with identical periods.
    - InspiredIdiot 3y ago
      Once anything collides with anything in orbit it has a slightly different trajectory. Any movement up or down will make its orbit more ellipsoidal than the original orbit. Also the atmosphere moves up and down in response to solar wind and therefore varies in both time and space. Atmospheric drag is apparently still a factor up to 600km https://www.swpc.noaa.gov/impacts/satellite-drag https://www.swpc.noaa.gov/impacts/satellite-drag Debris in a crowded orbit will eventually collide, no matter how synchronized it all was initially.
      - aledalgrande 3y ago
        From the article you linked: > Debris between 1 cm and 10 cm (approximately 500,000), referred to as the “lethal” population, are the most concerning as they cannot be tracked or cataloged and can cause catastrophic damage when colliding with a satellite. Objects smaller than 1 cm (approximately 135 million measuring from 1mm to 1cm, and many more smaller than 1 mm) that could disable a satellite upon impact are termed the “risk” population
    - jacquesm 3y ago
      There is no such thing as an identical period. It may seem identical when you compare them casually but over time the little differences add up and sooner or later the two will intersect, unless either one of the two moves to a different orbit or de-orbits. Satellite orbits are not locked together by magic, they are all independent of each other.
- deleted 3y ago
  [deleted]
- deleted 3y ago
  [deleted]
- youngtaff 3y ago
  Yeh, but what happens when they all burn up? It’s pollution of the upper atmosphere on a huge scale and we don’t know what side effects that will produce
b33j0r 3y ago
LEO is big, but only a few orbits are desirable and all circular orbits at the same altitude cross twice, by definition. It’s like slot cars, but much lower probability of an “intersection event.” That’s fun! Of course, we do already have something analogous to FAA altitude separations. But that requires everyone everywhere to cooperate in real-time, and mandates some degree of maneuverability. I guess orbital decay is only a concern for aircraft when they aren’t trying to land. What you have to watch out for is the eventual rise of the Kessler Cult, who (according to me) will seek to block all access to space intentionally ;)
- ghaff 3y ago
  You also have people who would largely prioritize for astronomical observations over rural internet—perhaps because they think people should be living in cities anyway. I’m only being mildly sarcastic.
  - b33j0r 3y ago
    The needs of the many outweigh the needs of the few. (They can just be awfully hard to count, no matter who counts.)
    - reaperducer 3y ago
      The needs of the many outweigh the needs of the few. Glad to hear it! Because I know a large family that doesn't have a computer. I'll send you their address so you can mail them yours!
      - jpc0 3y ago
        These families surely own a smartphone? You know the powerful computer in your pocket you potentially used to browse this website.
        reaperducer 3y ago
        These families surely own a smartphone? You know the powerful computer in your pocket you potentially used to browse this website. You think that all government, education, banking, employment, and healthcare web sites work on phones or have apps? That's adorable!
alden5 3y ago
Starlink satellites only last about 5 years before they run out of gas and are decommissioned with an end of life maneuver which sets them on course to burn up in the earth's atmosphere. I doubt many others besides maybe amazon will want to launch satellites at the same height as spacex's, especially considering how insanely expensive and complicated launching something like the starlink network is. Another point to consider is how small they are compared to the area they occupy, they have plenty of room to spread out and they're constantly monitored to calculate the probability that they might collide.
jdjdjdhhd 3y ago
China is already planning something similar: https://www.wsj.com/articles/china-seeks-to-counter-musks-starlink-with-own-satellite-network-ca94aa52 https://www.wsj.com/articles/china-seeks-to-counter-musks-st...

Starlink plans to deploy 12,000 - 42,000 satellites. What if two competitors want to do the same? Can the low earth orbit handle 150,000 satellites that turn into space debris at some point?

Armisael16 3y ago

Yes.

panick21_ 3y ago

The waste, waste majority of sats never turn into space debris. Every single sat that launches today in the West has a deorbit planned. The only sat that turn into space debris will be those that brake unexpectitly and totally unrecoverable. And the Starlink sats are so low that they dont really turn very meaningful debris ever. And in general, yes LEO can handle millions of sats. We have like 150k cars in a single tiny country on earth right now.

wyldfire 3y ago
Freudian slip.
- elwell 3y ago
  It's just phonetically in a german accent.
  - panick21_ 3y ago
    Damn, you are on the spot. German is my first language and I have dyslexia.
3cats-in-a-coat 3y ago
Cars don’t constantly move thousands miles an hour uncontrollably
- simple-thoughts 3y ago
  Cars also don’t move in easily predicted patterns for decades without turning from their predetermined path.
  - mabbo 3y ago
    They sort of do though. Cars, for the most part, follow the road and the direction they're already going. They (usually) signal if they're about to make changes. And to be safe, we've built an arrangement that they only travel on these specific paths at specific speeds, modifying their speed to match the other cars they might hit. The challenge with satellites is that steering is hard and very limited. And they don't have brakes they can slam to come to a stop if they need to suddenly avoid a collision.
    - panick21_ 3y ago
      It is well known that potential points of conflict are a huge issue. That's why a round about is safer then intersection. > And to be safe Tell that to the 40k people killed and the millions hurt by cars in the US alone. Cars constantly turn and intersect routes with other cars without any planning, even if perfectly handled and most of time they are not. > The challenge with satellites is that steering is hard and very limited. And they don't have brakes they can slam to come to a stop if they need to suddenly avoid a collision. They don't need to break, they just need to know the position of speed of other objects and correct position ahead of time. The only reason why this is even a program at all is because only the US has even minimally invested in monitoring. If each nation just did the same our accuracy would be far, far higher and things would be way better. So, as of now, we have minimally invested in solving this problem and it isn't a big issue. Slightly more investment (that is justified if we 10-100-1000x the amount of sats) is required eventually. But compared to what it takes to make cars not crash into each other its nothing. (Unless its like US infrastructure design that seems to want to make cars crash into things, but I hope in Space we can avoid that)
    - starbase 3y ago
      Cool thing about satellites is if you're on the same path, you must also be going the same speed. Collision avoidance in LEO is quite elegant. When two satellites are predicted to pass uncomfortably close to one another, one satellite will fire its station keeping thrusters to raise its orbit above the other. No brakes or swerving needed, just a slight push well ahead of time. Starlink sats do this over 1000 times per week. Even better, energy used for avoidance reduces energy needed for station keeping on a 1:1 basis. Avoidance maneuvers are effectively free.
Jeff_Brown 3y ago
> the Starlink sats are so low that they dont really turn very meaningful debris ever. Is that right? Scientific American seemed to think it could be a problem in 2019[1]. Space.com says Starlink satellites orbit at an altitude of about 342 miles (550 kilometers)[2]. And the Wikipedia article on Kessler Syndrome[3] (which is a chain reaction of satellite debris) mentions an incident at 555km that was problematic: "In 1985, the first anti-satellite (ASAT) missile was used in the destruction of a satellite. The American 1985 ASM-135 ASAT test was carried out, in which the Solwind P78-1 satellite flying at an altitude of 555 kilometres was struck by the 14-kilogram payload at a velocity of 24,000 kilometres per hour (15,000 mph; 6.7 km/s). When NASA learned of U.S. Air Force plans for the Solwind ASAT test, they modeled the effects of the test and determined that debris produced by the collision would still be in orbit late into the 1990s. It would force NASA to enhance debris shielding for its planned space station." [1] https://www.scientificamerican.com/article/spacexs-starlink-could-cause-cascades-of-space-junk/ https://www.scientificamerican.com/article/spacexs-starlink-... [2] https://www.space.com/spacex-starlink-satellites.html https://www.space.com/spacex-starlink-satellites.html [3] https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome
- nordsieck 3y ago
  Space junk at that altitude does turn into debris, but it tends to deorbit on its own in around 5-10 years. The real danger is space junk that's at much higher altitudes. OneWeb and Telesat Lightspeed (in planning) operate at 1000+ km, where space junk will take 1000+ years to deorbit on its own. And OneWeb has already had a satellite failure where it can't deorbit the satellite.
- montagg 3y ago
  I don’t have references for this, but my understanding is that you have more to worry about space debris that is higher/faster than lower/slower. The atmospheric drag is such that any out of control craft at [some threshold] or under will deorbit themselves fairly quickly, and the debris will burn up entirely. I believe that threshold is around 450-500km, but it’s also probably not a literal height, more of a gradient of risk. Higher/faster, they will be up there for longer (years? decades?) and it’s harder to predict where any broken pieces will go over time.
idlewords 3y ago
Except that all distinct orbits at the same altitude eventually collide.
- deleted 3y ago
  [deleted]
- rdlw 3y ago
  What do you mean? If they're both circular orbits, they'll have the same period, so they'll never collide—they'll always be on opposite sides of the Earth. In fact, this goes for any two orbits with identical periods.
  - InspiredIdiot 3y ago
    Once anything collides with anything in orbit it has a slightly different trajectory. Any movement up or down will make its orbit more ellipsoidal than the original orbit. Also the atmosphere moves up and down in response to solar wind and therefore varies in both time and space. Atmospheric drag is apparently still a factor up to 600km https://www.swpc.noaa.gov/impacts/satellite-drag https://www.swpc.noaa.gov/impacts/satellite-drag Debris in a crowded orbit will eventually collide, no matter how synchronized it all was initially.
    - aledalgrande 3y ago
      From the article you linked: > Debris between 1 cm and 10 cm (approximately 500,000), referred to as the “lethal” population, are the most concerning as they cannot be tracked or cataloged and can cause catastrophic damage when colliding with a satellite. Objects smaller than 1 cm (approximately 135 million measuring from 1mm to 1cm, and many more smaller than 1 mm) that could disable a satellite upon impact are termed the “risk” population
  - jacquesm 3y ago
    There is no such thing as an identical period. It may seem identical when you compare them casually but over time the little differences add up and sooner or later the two will intersect, unless either one of the two moves to a different orbit or de-orbits. Satellite orbits are not locked together by magic, they are all independent of each other.
deleted 3y ago
[deleted]
deleted 3y ago
[deleted]
youngtaff 3y ago
Yeh, but what happens when they all burn up? It’s pollution of the upper atmosphere on a huge scale and we don’t know what side effects that will produce

b33j0r 3y ago

LEO is big, but only a few orbits are desirable and all circular orbits at the same altitude cross twice, by definition. It’s like slot cars, but much lower probability of an “intersection event.” That’s fun! Of course, we do already have something analogous to FAA altitude separations. But that requires everyone everywhere to cooperate in real-time, and mandates some degree of maneuverability. I guess orbital decay is only a concern for aircraft when they aren’t trying to land. What you have to watch out for is the eventual rise of the Kessler Cult, who (according to me) will seek to block all access to space intentionally ;)

ghaff 3y ago
You also have people who would largely prioritize for astronomical observations over rural internet—perhaps because they think people should be living in cities anyway. I’m only being mildly sarcastic.
- b33j0r 3y ago
  The needs of the many outweigh the needs of the few. (They can just be awfully hard to count, no matter who counts.)
  - reaperducer 3y ago
    The needs of the many outweigh the needs of the few. Glad to hear it! Because I know a large family that doesn't have a computer. I'll send you their address so you can mail them yours!
    - jpc0 3y ago
      These families surely own a smartphone? You know the powerful computer in your pocket you potentially used to browse this website.
      - reaperducer 3y ago
        These families surely own a smartphone? You know the powerful computer in your pocket you potentially used to browse this website. You think that all government, education, banking, employment, and healthcare web sites work on phones or have apps? That's adorable!

alden5 3y ago

Starlink satellites only last about 5 years before they run out of gas and are decommissioned with an end of life maneuver which sets them on course to burn up in the earth's atmosphere. I doubt many others besides maybe amazon will want to launch satellites at the same height as spacex's, especially considering how insanely expensive and complicated launching something like the starlink network is. Another point to consider is how small they are compared to the area they occupy, they have plenty of room to spread out and they're constantly monitored to calculate the probability that they might collide.

jdjdjdhhd 3y ago

China is already planning something similar: https://www.wsj.com/articles/china-seeks-to-counter-musks-starlink-with-own-satellite-network-ca94aa52 https://www.wsj.com/articles/china-seeks-to-counter-musks-st...