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Space

SpaceX Launches 60 More Starlink Satellites and Achieves a Reusability Record For a Falcon 9 Booster (techcrunch.com) 63

SpaceX launched its second Falcon 9 rocket in the span of just four days on Wednesday at 9:25 PM EDT (6:25 PM PDT). This one was carrying 60 more satellites for its Starlink constellation, which will bring the total currently in operation on orbit to 480. From a report: The launch took off from Florida, where SpaceX's first astronaut launch took place on Saturday for the final demonstration mission of its Crew Dragon to fulfill the requirements of NASA's Commercial Crew human-rating process. Today's launch didn't include any human passengers, but it did fly that next big batch of Starlink broadband internet satellites, as mentioned. Those will join the other Starlink satellites in low Earth orbit, forming part of a network that will eventually serve to provide high-bandwidth, reliable internet connectivity, particularly in underserved areas where terrestrial networks either aren't present or don't offer high-speed connections. This launch included a test of a new system that SpaceX designed in order to hopefully improve an issue its satellites have had with nighttime visibility from Earth. The test Starlink satellite, one of the 60, has a visor system installed that it can deploy post-launch in order to block the sun from reflecting off its communication antenna surfaces. If it works as designed, it should greatly reduce sunlight reflected off the satellite back to Earth, and SpaceX will then look to make it a standard part of its Starlink satellite design going forward.
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SpaceX Launches 60 More Starlink Satellites and Achieves a Reusability Record For a Falcon 9 Booster

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  • by Rei ( 128717 ) on Thursday June 04, 2020 @11:19AM (#60145016) Homepage

    Last year Gwynne said that they needed "up to 8 launches" before they can start opening up to customers within specific latitude ranges. That was #7. Of course, even after #8 you still need to wait weeks for the satellites to reach their target orbits. But Starlink should be getting close to going operational now.

    • by Rei ( 128717 )

      (Launch #8 should be in just a couple weeks). I'm not sure how much overhead time they'll need after that, but I wouldn't be surprised to see Starlink open to customers a few months from now.

    • by lgw ( 121541 )

      Really looking forward to it. Somewhat surprisingly I don't have any problem with my ISP, but we all know that can change overnight. Having a backup option would be great. Having non-phone internet if the power goes out would also be great.

  • i guess the ocean landing isn't so hard anymore lol
    • by crow ( 16139 )

      Well, one leg was outside the circle, so they almost missed. If it were outside in a different direction, it would have been off the barge. They're not perfect yet.

      • by Rei ( 128717 )

        I wrote below about how it wasn't a perfectly centred landing, but I think calling it "almost missed" is overstating it. One can see the rocket here [youtu.be]; it's still quite a ways from "off the barge".

        But as noted before, SpaceX wants to get the accuracy high enough that they don't even need legs, that they can consistently just touch back down on a launch mount. They're certainly not there yet.

        • One can see the rocket here

          Wow, is this the first time there was no ground signal drop during the landing? I don't recall that from the past.

          • by Rei ( 128717 )

            It surprised me too. About a third of the time the signal is sustained for landing, but there's usually dropoffs at some point during the sequence. A fully sustained signal is really unusual.

            Wonder if they've changed up their approach.

            • by crow ( 16139 )

              Maybe different equipment since they use Of Course I Still Love you more often?

              • Maybe they're using Starlink to send the video now! The system is not live for customers yet but SpaceX is testing it.
                • by crow ( 16139 )

                  That's unlikely. The Starlink coverage is supposed to be best farther north. Also, the current version does not have relays between satellites yet, so it only works if you're talking to a satellite that is also talking to a ground station. Both of those factors suggest that Starlink isn't the right solution yet.

            • Maybe they've just stopped broadcasting it completely live and have introduced a small buffer to ride out the interruptions. Frankly I don't know why they didn't do that from the start ...

            • by torkus ( 1133985 )

              I cant find the video at the moment but the explanation is pretty simple:

              They stream the video via satellite feed which requires a rather precise lock-on by the sending antenna. When a huge rocket thunders down towards your barge, it vibrates and moves more than the compensating mechanism can handle. That breaks the signal lock and...loss of feed. It's queued locally of course, so once the feed is restored it's send on and we get to see it shortly after the fact.

              There's been suggested ways to work around

          • by mspohr ( 589790 )

            AFAIK there is always a signal drop during the landing... at least for every landing I have watched.

        • by crow ( 16139 )

          Yes. Look at where it's outside the line. Imagine a larger circle big enough for it to be just inside. It looks to me like that circle would go just off the edge of the barge. Something like 95% of the circumference would be on the barge, but not all.

          So this accuracy may have a one in twenty failure rate. I'm also wondering if Of Course I Still Love You might be slightly wider.

          Or maybe my spacial reasoning is off, but it's close.

          • by Rei ( 128717 )

            I can see your argument, but I think your "1 in 20" notion is really overstating it. It'd have to be oriented right at one of the two extreme points, and be rotated just right so that one leg reaches out as far as possible, and even then it'd just be a "maybe". One that could be remedied with foldout pad extensions at that point.

            But yeah... "landed within tolerance", but not pinpoint.

            • by Rei ( 128717 )

              Actually, rewatching it closer, it actually landed much more centred, with the outermost foot just touching the circle, from the inside. It then however drifted out of the circle before it settled.

              • by crow ( 16139 )

                Good point. If it had bumped the edge in that drifting, would it have tipped over or stopped? Hard to say.

                Anyway, I'm very glad they recovered it. These rocket landings are straight out of science fiction, and I'm always amazed.

                • by Rei ( 128717 )

                  In theory, if it began to tilt, the cold gas thrusters should have attempted to right it (if they had any propellant left over, which they usually have some margin).

                  That's in theory, at least. That'd certainly be a new edge case to see what happens... ;)

        • by lgw ( 121541 )

          Do you think they can ever get there with a suicide burn? If your last minute data about winds and the motion of the barge is off a little, there's just no way to correct. I figure at some point some point at least Super Heavy will be able to hover and adjust - it's, well, super heavy, and they just need one engine that can throttle low enough.

          • last minute data about winds and the motion of the barge is off a little, there's just no way to correct

            But high speed of approach *decreases* the effect of wind, since wind can now only act on the booster for a very limited time. The effect of barge motion is compensated by high precision of GPS and by the barge being equipped with positional thrusters.

          • by Rei ( 128717 )

            You know, it's hard to say. I don't how know precisely they can constrain all of the parameters with the current F9 design. That said, there's certainly ways they could modify designs to make that task easier. For example, with Starship, they've talked about not merely having cold gas thrusters for attitude control, but outright methalox hot gas thrusters - much higher thrust. So I'd suspect that they could feather positioning and momentum pretty tightly with them, so long as the response rate is fast en

            • Might be easier to just get a bigger barge.
              • by Rei ( 128717 )

                They want to be able to land back on the launch mounts for two main reasons. One, it makes for faster reuse. Two, it lets them omit the legs, which saves significant mass.

                • by torkus ( 1133985 )

                  They want to be able to land back on the launch mounts for two main reasons. One, it makes for faster reuse. Two, it lets them omit the legs, which saves significant mass.

                  They want to come back to the launch facility, but they'd still need to mount the rocket on the launch pad. The legs aren't designed to hold the fully fueled weight and the rocket needs to be returned to the hold-down points with far greater precision than is practical for a landing rocket (or plane for that matter).

            • by lgw ( 121541 )

              It just occurred to me that maybe this is an ulterior motive for the Moonship design. Those new midship thrusters would be great for a small adjustment during the landing burn. Not sure the weight would be worth it, but then I don't know how heavy they will be.

              • by Rei ( 128717 )

                Yeah, we really know nothing about the design of these thrusters to get a sense of their mass. I expect a lot of creativity when it comes to them. If they're dealing with liquids (will they be dealing with liquids?), electric turbopumps ala Electron would make good sense, since they can throttle up and down extremely rapidly (and they already have a giant battery pack for the fins, so power limits will not be a factor, only energy reserves, and that only if we assume no dynamo on the raptors or elsewhere).

      • Just before it lands, you can see the wear pattern on the deck of the barge.
        It is not in the center of the circle and it pretty much right where the booster landed.
        We might be reading more into the circle than we should be.

        It is amazing that they can do this. That stage is huge but the video makes it
        look like a model rocket. I fail to see why people are so drawn to find
        something to critique every SpaceX operation. They are the best of the best.

    • by Rei ( 128717 ) on Thursday June 04, 2020 @11:34AM (#60145066) Homepage

      They did lose one several launches ago due to incorrect wind data. And the last time they tried to land a 5-reuse booster, it failed - not due to wear from five reuses, but rather, due to some residual isopropyl alcohol cleaning fluid that had gotten trapped in a sensor dead leg (a dead-end path off of a pipe, to get static conditions for taking readings). And even this most recent landing wasn't spot-on dead centre in the pad - certainly not a "near miss", but they want the level of accuracy where they can touchdown a rocket straight back on its launch mounts without even needing landing legs.

      They're still learning and working towards airplane-level recovery rates and pinpoint accuracy. With as impressive as their progress has been ("almost always" recovering the boosters), they're not there yet.

      • And even this most recent landing wasn't spot-on dead centre in the pad - certainly not a "near miss", but they want the level of accuracy where they can touchdown a rocket straight back on its launch mounts without even needing landing legs.

        They also appear to be using Starlink launches to test the practical limits of recovery. They have launched Starlink with the oldest boosters using aggressive flight profiles that impart more energy to the satellites with less fuel remaining for landing. At least it appears that way.

      • Incorrect wind data or out of boundary wind data? I thought the landing zone conditions scrapped that one.

    • It may still be hard, but it is probably safer than landing it within 10 miles of a town.

      It is like setting up a firing range, you don't design it for the bullet to hit the target, but account for someone missing badly.

      • It is like setting up a firing range, you don't design it for the bullet to hit the target, but account for someone missing badly.

        You, sir, will never make it as a middle manager!

        • by lgw ( 121541 )

          True enough, to make it to middle manager you need to be sure your bullets will hit the target (who is, of course, the current middle manager of the position you want).

        • by cusco ( 717999 )

          IMOHO that should be considered a compliment.

      • by torkus ( 1133985 )

        The preference is to land back at the launch facility. Doing so requires significantly more fuel left over from the launch which limits payloads though.

  • They always end their broadcasts before the fairing recovery attempts, saying that they'll keep us posted on social media, but then they never tweet about it. I assume that means they failed on both catches, but I can't find anything online to confirm that.

    With all the attempts they've made, I'm beginning to wonder if their approach is flawed, and they need to work on some significant design changes to get to consistent fairing recovery.

    • I thought the one that launched the dragon capsule succeeded? Though I read they said they did - I don't recall seeing video.

    • by Rei ( 128717 )

      Honestly, I wonder how much they even care at this point. Falcon 9 is obsolete. It just exists to function as a reliable workhorse until Starship takes over. Starship doesn't jettison fairings; there's only two components to the spacecraft (the upper and lower stages), and both reenter / land in powered flight.

      So while there's still a lot for them to learn about how to improve accuracy, maintenance / reuse, reentry limits, experience with manned spaceflight, etc.... developing a tech base for better fairing

      • That's a rather bold statement and one that I would argue isn't backed up by the facts.

        Starship is proceeding, but they definitely have to stop blowing up. Along with that, I haven't seen a schedule Musk is working to on Starship so I have no idea when we'll see it actually flying into orbit.

        Regardless, with Falcon I would think that the competition using expendable boosters would be waning but there are almost two dozen companies out there coming up with boosters that are designed to fall into the ocean w

      • Re:Fairing Recovery? (Score:4, Informative)

        by im_thatoneguy ( 819432 ) on Thursday June 04, 2020 @01:28PM (#60145588)

        Honestly, I wonder how much they even care at this point.

        Elon hinted that refurbishment was about $1m.
        Fairings cost $6m.
        2nd Stage ~$10m.
        Fuel 0.3m

        $6m / $17.3m = ~1/3rd of Starlink launch hard costs.

        I would say they probably care a good bit. They just raised $500 million. If they want to launch once a week that's 52 weeks * $6m = $312 million in fairings. Recovering fairings alone would mean they don't need to sell 300 million in equity every year.

        • by bgarcia ( 33222 )
          They're happy to fish the fairings out of the ocean and re-use them for starlink launches.

          Other customers don't want their sensitive satellites exposed to salt water remnants, so they can only really be re-used for starlink launches.
      • Falcon 9 is not obsolete now, and won't be when they lash 6 to the SH to up the payload

    • by lgw ( 121541 )

      They do catch the fairing in a net from time to time, but I don't think it's near half yet. However, they've gotten good at fishing them out of the ocean. Wish they were more forthcoming about it.

    • They always end their broadcasts before the fairing recovery attempts, saying that they'll keep us posted on social media, but then they never tweet about it. I assume that means they failed on both catches, but I can't find anything online to confirm that.

      They've caught enough of them that they've actually reflown a pair of them now.

      As Rei points out, SpaceX intends to retire the entire Falcon 9 launch platform. As always, they're overly optimistic about how soon. They are guaranteed to be manufacturing Falcon 9s for years to come, since NASA has the option to buy up to 6 launches for Commercial Crew, which require Falcon 9s. That's typically two per year, so SpaceX will be making Falcon 9s until at least 2024 (or at least making that many and warehousing

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