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Space

SpaceX Rocket Launches Starlink Satellites On Record-Breaking 17th Flight (space.com) 46

SpaceX just extended its Falcon 9 rocket-reuse record. Space.com reports: The Falcon 9 lifted off from Cape Canaveral Space Force Station in Florida on Tuesday at 11:38 p.m. EDT (0338 GMT Sept. 20), carrying 22 of SpaceX's Starlink internet satellites toward low Earth orbit (LEO). The rocket's first stage came back to Earth 8.5 minutes after launch, landing on a SpaceX drone ship stationed at sea. It was the 17th liftoff and landing for this Falcon 9's first stage, according to a SpaceX mission description.

Those figures are unprecedented; the previous mark was 16, held by two different Falcon 9 boosters. The 22 Starlink satellites, meanwhile, deployed from the Falcon 9's upper stage 62.5 minutes after launch as planned. Tuesday night's liftoff extended another record as well: It was SpaceX's 65th orbital mission of the year. The company's previous mark, 61, was set in 2022.
You can watch a recorded video of the launch here.
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SpaceX Rocket Launches Starlink Satellites On Record-Breaking 17th Flight

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  • Apparently the starlinks only last 2 years.

    Is it worth it in cost of resources and emissions?
    • by backslashdot ( 95548 ) on Thursday September 21, 2023 @02:22AM (#63865018)

      Apparently the starlinks only last 2 years.

      Is it worth it in cost of resources and emissions?

      It's 5 to 7 years. Once they get Starship working they'll need fewer launches annually to keep replenishing the network. They already generate nearly $2 billion in subscriber fees.

      • With Starship they'll also be able to send up more propellant in the satellites so they can maintain orbit for longer. Starship is going to absolutely revolutionize Starlink and orbital operations in general.

      • Why do they only last 5 to 7 years, and what happens with the satellites when they reach end of life? Do they fall down and burn in the atmosphere? Or do they stay up there as zombie satellites?
        Or do they only last 5 to 7 years because they fall back to Earth?

        • by ls671 ( 1122017 )

          I assume it's over when they run out of fuel. Then, friction in low orbit slows them down and they fall back to Earth and since they are small, I would assume they completely burn up.

          • Then, friction in low orbit slows them down and they fall back to Earth

            Friction in orbit actually speeds up satellites. It loses energy but this causes it to fall into a lower orbit where it has a higher speed. It's counterintuitive but the loss in gravitational potential energy more than makes up for the energy lost to friction which causes the satellite to actually gain speed.

            • by ls671 ( 1122017 )

              I don't understand how it could gain absolute speed. It would make sense that it gains speed relatively to the Earth surface although, e.g. rotate with a shorter period around the Earth (angular speed let's call it) but not absolute speed. Also, I would think it would only gain "angular speed" at the beginning to eventually also lose "angular speed" when it gets to denser part of the atmosphere.

              Can you elaborate on this? Thanks, interesting point!

              • What is absolute speed?

                • by ls671 ( 1122017 )

                  For the purpose of my post, let's say you would feel a deceleration or acceleration if you were in the satellite when its speed changes. I just used "absolute speed" to contrast with "angular speed" or the speed relative to the Earth surface. Of course with the same kinetic energy, the satellite would seem to go faster relative to the Earth surface on lower orbits until the atmosphere decelerate it. I don't see how the satellite could accelerate although or how you could feel an acceleration if you were ins

              • I don't understand how it could gain absolute speed. It would make sense that it gains speed relatively to the Earth surface

                The speed of the Earth's surface is utterly irrelevant to this since it depends on where you are on the Earth which has nothing to do with a spacecraft in orbit. There is no "absolute" speed since there is no way to define a unique rest frame - this is one of the key postulates of relativity.

                I think what you mean is how can it gain speed relative to the centre of mass of the Earth. Effectively what happens when a satellite encounters friction is that its orbital trajectory is changed. This causes it to

        • by beelsebob ( 529313 ) on Thursday September 21, 2023 @05:20AM (#63865144)

          They run out of fuel and deorbit. IIRC they use the last of their fuel to accelerate their deorbit.

        • Just before the fuel runs out, the satellite deorbits itself.

        • by RobinH ( 124750 )
          These satellites they're launching 22 at a time are the second generation, which are significantly upgraded from the first. I think that while they're still innovating the technology it doesn't make sense to leave them up there really long. Once the technology is more mature it might make more sense to launch a later version that stays up for 10 or 15 years. Given the rapid increase in bandwidth we're seeing, even that duration seems unreasonable right now.
        • by nbvb ( 32836 )

          They deorbit naturally - gravity at 300mi LEO is still relatively strong - and then burn up completely. It's happened many times already with Starlink sats - there was a batch that were wrecked by a geomagnetic storm and they all deorbited naturally. There have been other satellites that have failed out along the way too.

          The materials chosen are designed so they burn up completely on re-entry and pose zero risk on the ground.

          Kinda cool - satellites that self-cleanse themselves out of existence at the end

          • by tragedy ( 27079 )

            They deorbit naturally - gravity at 300mi LEO is still relatively strong

            Just to be clear, while gravity certainly plays a role in de-orbiting, the actual reason they deorbit is because of air friction. If there were no air friction in LEO, then the satellites could be expected to stay up indefinitely, regardless of the strength of gravity at that altitude. There could be other factors that influence them in orbit such as tidal forces, etc. but the air friction is definitely the largest influence by far.

        • They are in Low Earth Orbit. They will fall out of orbit and burn up within months of losing propulsion.

          This is by design. If anything goes wrong, they don't stay in orbit for long, thus minimizing the orbital trash (ne Kessler syndrome) contribution.

          They are small. This limits the amount of fuel each can carry. It also reduces the cost to orbit, and improves coverage (less users per satellite).

          They burn up completely in the atmosphere upon re-entry. The total amount of atmospheric residue they contrib

      • No same launch cadence starship is launching version 2 od starlink. Bigger everything. Plus better interconnections. So launch rate isnt going to change much. But everything else will improve

        The trick. Amazons kupier is doomed as no one else can come close to that launch rate.

        • There's a reason Amazon was recently sued by shareholders [spacenews.com] for refusing to use SpaceX (which can, has, and does launch competitor satellites), instead choosing ULA's Vulcan (hasn't flown yet and relies on Blue Origin for engines in an unproven production process), Blue Origin's New Glenn (hasn't flown yet, not even a prototype built, will need lots of engines from a line with contractual obligations to ULA), and ArianeSpace's Ariane 6 (expensive and uncertain development timeline).

    • If SpaceX launched a Falcon 9 every day, its emissions would be equivalent to around 0.015% of the fuel used by commercial aviation in the same time. (Based on numbers pulled from ChatGPT)
      Are vacations worth the cost of resources and emissions?

      • If SpaceX launched a Falcon 9 every day, its emissions would be equivalent to around 0.015% of the fuel used by commercial aviation in the same time. (Based on numbers pulled from ChatGPT) Are vacations worth the cost of resources and emissions?

        You are comparing 1 flight to tens of thousands of flights. From (https://www.statista.com/statistics/564769/airline-industry-number-of-flights/) we can get a rough average of 30 million flights a year. Divide that by 365 gives 82,191.78, We'll call it 80,000 a day to make it simpler. Take your 0.015 and multiply the two and we get 1,200 plane trips per falcon trip.

        What was the point you were trying to make?

        • No, you get 12 plane trips, you seem to have missed the percent sign.
          My point is, I think putting up satellites that provide global internet coverage to areas that were previously inaccessible, including improving the bandwidth in these airplanes, for longer than the 2 years parent claims, is worth the cost of resources and emissions, and maybe the concern over those resources might be better directed at an issue that is many orders of magnitude greater, like air travel.

          • yeah, but elon man bad.

          • by tragedy ( 27079 )

            No, you get 12 plane trips, you seem to have missed the percent sign.

            That does put things in perspective. Another thing to put it into perspective is to consider how often SpaceX launches (60 launches in 2022, so about once a week) and how many people work there (13,000+) and how long their commute is (average commute is 41 miles). So, that means that for every rocket launch at SpaceX, employees drive around 13,000X5X41 miles=2,665,000 miles. At an average fuel consumption of say 26 mpg, that's 102,500 gallons of gasoline. A Falcon 9 holds 123.5 tons of RP-1, which is basica

            • by ceoyoyo ( 59147 )

              It's also pretty vague.

              A Falcon rocket holds 147 000 kg of kerosene. So a Falcon launch is roughly equivalent to a single 777-300 (137 000 kg of Jet-A) or 747 (184 000 kg) flight.

              • by tragedy ( 27079 )

                147 000 kg of kerosene, or 147 tons. Slightly different from the 123.5 tons I found, but it looks like that was just for first stage and your number was first plus second stage. Still, only a 19% difference. So, there's still approximately double the emissions from the employees at SpaceX driving to and from work. I would have compared to flights they take, but I'm not sure how many of them fly every week. Probably less than a full plane load every rocket launch. Ultimately, whichever way you look at it, th

    • by Tx ( 96709 ) on Thursday September 21, 2023 @03:24AM (#63865080) Journal

      Emissions? If SpaceX achieve their goal of 100 launches per year (unlikely this year), and given that a Falcon 9 holds 155870kg of RP1 (1st and 2nd stage), that would be 15587000kg per year. Worldwide jet fuel consumption is 431878550000kg per year. So SpaceX would be using 0.000036 the amount of fuel of the aviation industry. I don't know what the relative fuel efficiencies of Merlin engines versus typical jet engines, but given that fuel efficiency is a key parameter in both cases, wherever it is in the likely range of values, that translates to a very small amount of emissions. Moreover, Starship, New Glenn, and many other next generation rockets, run on methane, with the express thought that they could run on green methane, and so be carbon neutral. Likewise, hydrogen-fuelled rockets could run on green hydrogen, as their only significant emission is from the hydrogen production. So there's zero reason to be concerned about emissions from spaceflight.

      P.S. - SpaceX launches more rockets than the rest of the world put together; I can't be bothered running numbers for a ton of other rockets, but you could just double SpaceX's numbers to approximate the entire spaceflight industry.

      • I donâ(TM)t think 100 this year is unlikely. First, weâ(TM)re at 3/4 of the way through the year, and 2/3 of the 100 launches. Even if they maintain the âoecurrent rateâ theyâ(TM)d come close - 88 launches. Second though, theyâ(TM)re accelerating. At the start of the year, the launch cadence was roughly one launch every 6 days. Theyâ(TM)re currently down to one launch every 3 days. At that rate theyâ(TM)ll get to 100. The reality though is that theyâ(TM)re

        • by nucrash ( 549705 )

          All depends on what type of launches. Vandenberg's cadence is still around 10 days. SLC-40 is about every 4 days with the exception of weather and LC-39A depends on what is launching will depend on the cadence. Falcon Heavy launches and Crewed launches take longer due to complexity and sensitivity of the nature. Psyche Mission looks to have Pad 39A occupied and doesn't launch until October 5th.

          If SpaceX can continue to increase their cadence and even get some missions running in 3 days, they might make 1

    • Apparently the starlinks only last 2 years. Is it worth it in cost of resources and emissions?

      Why don't we ask the taxpayer if paying for a terrestrial broadband rollout again to liars who will pocket that money instead, will be worth it again.

      Perhaps then we can accurately bitch about the cost of those making actual progress.

    • Comment removed based on user account deletion
    • > Apparently the starlinks only last 2 years

      What made you think that?

    • Your question about ROI is valid. Your question about "emissions" is detached from reality. Only someone who can't do basic math or who is trying to discredit the entire issue of emissions would say something that stupid.
  • by account_deleted ( 4530225 ) on Thursday September 21, 2023 @07:29AM (#63865266)
    Comment removed based on user account deletion
  • SpaceX continues to break records in spaceflight with its Falcon 9 rocket. Achieving its 17th successful landing and deploying 22 Starlink satellites, SpaceX is setting a high bar for the industry's reliability and launch frequency. YEAH !!!!!!!!!!!!!!!!!!

The unfacts, did we have them, are too imprecisely few to warrant our certitude.

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