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Pretty impressive. The engineering team at SpaceX is really something. Some thoughts; The 'chopsticks catch' was amazing to watch. Seems like it adds a lot of

Pretty impressive. The engineering team at SpaceX is really something. Some thoughts; The 'chopsticks catch' was amazing to watch. Seems like it adds a lot of risk and clearly the booster needs additional fire suppression systems :-) perhaps the tower could mount something that sprays the booster like the barges have for the F9 boosters. The heatshield held out for a much longer time, the asymmetric heating on the flaps was interesting. I had guessed that all four flaps would have equivalent heating based on an approach that was basically that side of the rocket perpendicular to the flow but it seems like that isn't the case. Still it seems like they are close to having something workable here. The detonation at the end was pretty spectacular too, but I suspect that structurally the tanks failed as the rocket hit the water vs anything that was an engineering failure. Engineering it to be strong enough to land on water would presumably compromise the cargo to orbit number. The use of Starlink was really interesting. The ability to get live video for the entire re-entry is pretty game changing for engineering. I'd guess there are even more 'views' than they showed (there would be if I were running things :-)) but overall that capability is something that really helps evaluate the changes made. I can easily imagine that flight 6 will be nominal end to end without any unintended damage. That would enable, perhaps, one of their 'massive' Starlink missions to test cargo delivery. It will also start to give us some better numbers on exactly how much cargo Starship can put in orbit in 'full reuse' mode which is essential if they want to create a fueling station on orbit for the Artemis program. Again, hats off to engineering at SpaceX, y'all did good.

nordsieck 2y ago
> The detonation at the end was pretty spectacular too, but I suspect that structurally the tanks failed as the rocket hit the water vs anything that was an engineering failure. It's possible that SpaceX programed the AFTS to trigger some time after the rocket touched down in the water. Just to make sure that it completely submerges quickly. > I can easily imagine that flight 6 will be nominal end to end without any unintended damage. I think it depends on what you mean by "nominal". SpaceX ultimately wants to catch the 2nd stage as well. I suspect that they are a ways off of that, since it would have to approach over land. The FAA is going to need to have very high confidence that it will do exactly what it's designed to do before they're going to allow that.
- 317070 2y ago
  > Just to make sure that it completely submerges quickly. Why would they want to do that? (genuinly curious). I reckon there would be a lot of useful data left if they could recover or even just inspect the remains. The remains are one big tank, so it would have floated.
  - eco 2y ago
    No doubt it would be very useful to recover. SpaceX isn't the only one who could pluck it out of the Indian ocean though. You don't want to leave a prototype for the most advanced Spacecraft ever made just sitting around for competitors to grab (most notably China which is currently speed running SpaceX-like designs).
    - creer 2y ago
      It landed right next to their own camera-bearing buoy. You can bet their own recovery ship was right nearby. And with access to radio control too. Likely with a couple US military ships on hand too.
      - wiz21c 2y ago
        I certainly hope so. Ocean are polluted enough and although such a ship is just a, well, drop in the ocean, the ideq of accepting to pollute more is unbearable to me, especially for a world class company like SpaceX...
        EnigmaFlare 2y ago
        [dead]
        dzhiurgis 2y ago
        Other than some electronics it's actually pretty clean vehicle - methane will gas off, steel will quickly disintegrate in water, there isn't tons of plastic or paint.
        2y ago
Isamu 2y ago
I imagine that they will be their own first customer - putting Starlink satellites into orbit while they are gaining confidence in the reliability of the system for external customers. They have to prove out the landing of the second stage, either with another catch or with landing gear, which they need for the lunar lander anyway.
- ericcumbee 2y ago
  I think that has always been the plan. the V2 starlink sats were designed to fly on Starship. When Starship wasn't coming along as planned they shoe horned the guts of the V2 on to a smaller sat that became the V2 Mini.
- norman784 2y ago
  If Im not mistaken, they already delivered a payload in one of the previous flights, because they cut the transmission for a while and didn’t show the payload bay like one previous flight.
  - oceanplexian 2y ago
    I’m not sure they are, if only because of the altitude. They only took Starship up to 200km, Starlink are nearly double that so while they do have thrusters that’s quite the distance. Starship is not really in a true orbit, I forget the exact terminology but the trajectory is designed to re-enter regardless of what happens with the the flight.
    - ViewTrick1002 2y ago
      It is in an suborbital trajectory but with enough energy to be equivalent to reaching orbit. Think of it as instead of thrusting perpendicular to gravity for the most optimal energy usage Starship instead points its nose up gaining more altitude but now lacks the speed to miss earth as it comes down.
    - m4rtink 2y ago
      They actually made use of this this flight again - eq. they still did not perform a deorbit burn this flight & let the trajectory to pull them down to the atmosphere.
creer 2y ago
They showed 4 streams at once during some of the reentry. One view of each control surface. They may have had still more views but just that 4 was a first.
- creer 2y ago
  Wait, that was 5 views no? Facing four fins, plus one fin from the front.
- asdf123qweasd 2y ago
  Imagine, linking that video into a 360° virtual cockpit As if you were inside a booster made from glass.
ninetyninenine 2y ago
>The heatshield held out for a much longer time, the asymmetric heating on the flaps was interesting. I had guessed that all four flaps would have equivalent heating based on an approach that was basically that side of the rocket perpendicular to the flow but it seems like that isn't the case. Still it seems like they are close to having something workable here. Heat shielding didn't look relevant at this section of the flight at all. The booster didn't have any shielding.
- Narishma 2y ago
  They're talking here about Starship, not the booster.
  - ninetyninenine 2y ago
    How does this logically make sense? They said "it looks like the heat shield held out". Where was a heat shield holding out?
    - kortilla 2y ago
      On starship. Believe it or not, Chuck’s comment was about both booster and starship
      - ninetyninenine 2y ago
        And I’m saying he’s wrong no heat shield held out to anything. The booster never travelled fast enough to need heat shielding ever. Only the starship needs it. If chuck is talking about both likely he doesn’t know what he’s talking about.
        kortilla 2y ago
        Dude you are having trouble reading. His comment first talked about booster and then talked about starship. It’s not that difficult to follow.
- 2y ago
cpeterso 2y ago
What’s the advantage of catching the booster over landing it in the ground? Catching it seems like an extra complication.
- bagels 2y ago
  You save the mass of the landing systems, you get to have all that mass on the ground and not have to lift it into space. Dramatically improves the performance of the rocket.
- __d 2y ago
  I can speculate ... I think the primary reason would be that landing legs are heavy, and it wastes performance to carry them. If your landing mechanism is mostly on the ground, you get that performance back. Secondary reasons might include that it's simpler to get the booster right back to the pad. Once things have settled into an operational cadence, it's likely feasible to lower and lock the booster onto the stool, stack a ship on top, refuel, and relaunch -- no more messing around with barges, transport, weather issues, etc.
  - MPSimmons 2y ago
    To my knowledge, you're right, but in reverse order. I believe the driving force is time, rather than mass overhead, but certainly both play a large part.
  - btilly 2y ago
    Your primary reason matches what SpaceX themselves have said. You either need to be strong enough to handle the shock of inpact, or need to spread the impact over time. Building either into the rocket adds a lot of mass. Landing on a device that spreads out the shock moves that weight to the static landing platform.
  - XorNot 2y ago
    It's worth noting that at least 1 Falcon 9 core probably got trashed not from the landing, but from rough seas - so cutting out the ground logistics chain adds resiliency.
rkagerer 2y ago
Seems like it adds a lot of risk I'm actually wondering about that. If I understand correctly, the arms can move up and down, and pivot around the tower. This allows them to correct for some error in the rocket trajectory and also (presumably) "soften" the final contact. Between the nozzles and the arms, it gives SpaceX a lot of degrees of freedom in the final seconds (you can see how the booster kind of "hovered" right at the end) and in certain respects might even offer more forgiveness than the hard ground. Could it smash into the tower? For sure. Would that be more dangerous than smashing into the pad? I don't know. It's a new technique with which we don't have a lot of experience.
- ChuckMcM 2y ago
  My thought (admittedly not well developed) is that smashing into a landing pad of concrete can damage that pad but it can be quickly repaired without affecting the ability to launch future rockets. If you damage the launch tower significantly you're going to have to suspend launches from it until you fix it. So the "higher risk" is more critical assets offline in the event of a non-optimal return.
  - rkagerer 2y ago
    Understood, although weren't they out of commission for a really long time anyway the last time they damaged their launchpad?
    - pfdietz 2y ago
      That was a launch pad, not a recovery pad. The launch pad has to be engineered to survive full thrust from all the engines, and for a rather long time as the loaded vehicle accelerates upward.
      - rkagerer 2y ago
        Thanks for clarifying!
  - ocdtrekkie 2y ago
potato3732842 2y ago
>The 'chopsticks catch' was amazing to watch. Seems like it adds a lot of risk and clearly the booster needs additional fire suppression systems :-) perhaps the tower could mount something that sprays the booster like the barges have for the F9 boosters. There's no reason to reinvent the airport firetruck.
- kortilla 2y ago
  The airport fire truck can’t control fires 250ft in the air
  - potato3732842 2y ago
    It's pushing the limits but it's close enough to existing capability to be a pretty easy ask.
- CydeWeys 2y ago
  Unless you're gonna make it fully automated, it's not gonna work here as it can't be within kilometers of the landing site during landing in case there's a catastrophic failure.
- nine_k 2y ago
  > no reason to reinvent the airport firetruck. There is. The booster is high above, and is larger than basically any aircraft. There's no flat concrete airfield around either. I would suggest blowing CO2 or nitrogen through pipes positioned at the right height on the tower.
  - adastra22 2y ago
    It’s not going to burn like that in production.
- Cthulhu_ 2y ago
  Why would you use a firetruck if you could also run a hose up the tower and get it right where it's needed?
Jugurtha 2y ago
I'm wondering if they'll be using the vertical equivalent of arresting gear on aircraft carriers[0]. See when fighter jets land on aircraft carriers? There's a cable that decelerates them. That, but for vertical landing. The way these chopsticks are set forces the booster into a dangerous, snake like maneuver (a SnakeX maneuver) at the last second from a vertical setting, to get into the chopsticks. This maneuver is due to the fact chopsticks are short and the booster has to land on one point in space. No degrees of freedom. Now, imagine if the chopsticks were long. The booster wouldn't have to land at one specific point, but it could now land on a line. One degree of freedom. Now replace the long chopsticks with cables, and then add another pair of cables perpendicular to them. So you have a pair of parallel cables perpendicular to a second pair of parallel cables. Now the booster doesn't have to land on a line, but can land anywhere in the grid that's covered by the cables. Two degrees of freedom. Pushing this thought leads to having a sort of iris diaphragm, like the ones in optics, but an iris diaphragm of cables. The diaphragm is open when the booster is about to land, then closes in quickly. Imagine this[1], but it's cables cinching in. Now, it's a diaphragm of cables, not a diaphragm of rigid beams, so I imagine the deceleration to be even smoother as the cables elongate, and an additional system of springs and dampers to counter the weight of the booster. The booster is vertical and stays vertical. Granted, an unstable equilibrium, but it beats doing the SnakeX maneuver to get to the chopsticks, and that's another story. Now, imagine the iris cable diaphragm can move up and down like equipment handling containers, and now you have three degrees of freedom. That's less control to worry about on the booster's side at the worst possible moment, landing, where you can't make adjustments anymore. This not only means being more forgiving on mistakes related to position, but also on speed and angle. The diaphragm catches the booster at any angle, and given that it cinches way above the center of gravity, the booster goes back to a more stable vertical position. For the fire, maybe you just need a big hole down there. - [0]: https://en.wikipedia.org/wiki/Arresting_gear https://en.wikipedia.org/wiki/Arresting_gear - [1]: https://en.wikipedia.org/wiki/File:Iris_Diaphragm.gif https://en.wikipedia.org/wiki/File:Iris_Diaphragm.gif
- T-A 2y ago
  That's how the Chinese are planning to do it: https://youtu.be/OYWBmu6H0ik?feature=shared&t=35 https://youtu.be/OYWBmu6H0ik?feature=shared&t=35
mhandley 2y ago
As to whether catching the booster adds risk - I'm not sure it does. First, to the extent the booster is out of position in the x (sideways) direction, the chopsticks can move to accomodate error. But actually I think this dimension is the easiest of the three, as the booster has plenty to time to null any error in this dimension. In the y direction (direction of travel towards the tower), the rails on the chopsticks can cope with the booster touching down along quite a long distance. But importantly, they appear to be smooth, so the pins can initially skid along them and then the booster can swing if it has not fully nulled any horizontal movement. In contrast, if the booster used legs and has not yet fully nulled any horizontal motion at touchdown, there is a greater risk of breaking a leg or simply tipping over. And in the z direction, it should be possible for the chopsticks can absorb more vertical motion than legs can absorb, because you can easily build in huge springs/dampers/etc into the ground equipment without concern about mass. Catching also puts the booster in tension rather than compression - it's easier to be rigid in tension than compression. Finally, if legs were used, the engines would have to get close to the ground during landing, so reflected shock from the ground could cause damage. I know Falcon 9 does this, but the area of the base of Starship is much greater, so there's effectively less room for the reflected energy to escape. Catching completely removes this risk. On balance, I think they would have better chance of success for each mission by catching. The main downside would be if you fail to catch, you may need to build a new tower, whereas a flat pad would be cheaper and easier to repair.
- LorenPechtel 2y ago
  And with a barge recovery the legs must have enough spring to deal with waves. The tower doesn't move, they can get a lower landing velocity.
- was_a_dev 2y ago
  The most challenging axis in my opinion is the roll axis of Super Heavy, if there is a roll angle error, the pins could not sit properly on the chopsticks and the whole booster slides off.
  - didgeoridoo 2y ago

nordsieck 2y ago

> The detonation at the end was pretty spectacular too, but I suspect that structurally the tanks failed as the rocket hit the water vs anything that was an engineering failure. It's possible that SpaceX programed the AFTS to trigger some time after the rocket touched down in the water. Just to make sure that it completely submerges quickly. > I can easily imagine that flight 6 will be nominal end to end without any unintended damage. I think it depends on what you mean by "nominal". SpaceX ultimately wants to catch the 2nd stage as well. I suspect that they are a ways off of that, since it would have to approach over land. The FAA is going to need to have very high confidence that it will do exactly what it's designed to do before they're going to allow that.

317070 2y ago
> Just to make sure that it completely submerges quickly. Why would they want to do that? (genuinly curious). I reckon there would be a lot of useful data left if they could recover or even just inspect the remains. The remains are one big tank, so it would have floated.
- eco 2y ago
  No doubt it would be very useful to recover. SpaceX isn't the only one who could pluck it out of the Indian ocean though. You don't want to leave a prototype for the most advanced Spacecraft ever made just sitting around for competitors to grab (most notably China which is currently speed running SpaceX-like designs).
  - creer 2y ago
    It landed right next to their own camera-bearing buoy. You can bet their own recovery ship was right nearby. And with access to radio control too. Likely with a couple US military ships on hand too.
    - wiz21c 2y ago
      I certainly hope so. Ocean are polluted enough and although such a ship is just a, well, drop in the ocean, the ideq of accepting to pollute more is unbearable to me, especially for a world class company like SpaceX...
      - EnigmaFlare 2y ago
        [dead]
      - dzhiurgis 2y ago
        Other than some electronics it's actually pretty clean vehicle - methane will gas off, steel will quickly disintegrate in water, there isn't tons of plastic or paint.
      - 2y ago

Isamu 2y ago

I imagine that they will be their own first customer - putting Starlink satellites into orbit while they are gaining confidence in the reliability of the system for external customers. They have to prove out the landing of the second stage, either with another catch or with landing gear, which they need for the lunar lander anyway.

ericcumbee 2y ago
I think that has always been the plan. the V2 starlink sats were designed to fly on Starship. When Starship wasn't coming along as planned they shoe horned the guts of the V2 on to a smaller sat that became the V2 Mini.
norman784 2y ago
If Im not mistaken, they already delivered a payload in one of the previous flights, because they cut the transmission for a while and didn’t show the payload bay like one previous flight.
- oceanplexian 2y ago
  I’m not sure they are, if only because of the altitude. They only took Starship up to 200km, Starlink are nearly double that so while they do have thrusters that’s quite the distance. Starship is not really in a true orbit, I forget the exact terminology but the trajectory is designed to re-enter regardless of what happens with the the flight.
  - ViewTrick1002 2y ago
    It is in an suborbital trajectory but with enough energy to be equivalent to reaching orbit. Think of it as instead of thrusting perpendicular to gravity for the most optimal energy usage Starship instead points its nose up gaining more altitude but now lacks the speed to miss earth as it comes down.
  - m4rtink 2y ago
    They actually made use of this this flight again - eq. they still did not perform a deorbit burn this flight & let the trajectory to pull them down to the atmosphere.

creer 2y ago

They showed 4 streams at once during some of the reentry. One view of each control surface. They may have had still more views but just that 4 was a first.

creer 2y ago
Wait, that was 5 views no? Facing four fins, plus one fin from the front.
asdf123qweasd 2y ago
Imagine, linking that video into a 360° virtual cockpit As if you were inside a booster made from glass.

ninetyninenine 2y ago

>The heatshield held out for a much longer time, the asymmetric heating on the flaps was interesting. I had guessed that all four flaps would have equivalent heating based on an approach that was basically that side of the rocket perpendicular to the flow but it seems like that isn't the case. Still it seems like they are close to having something workable here. Heat shielding didn't look relevant at this section of the flight at all. The booster didn't have any shielding.

Narishma 2y ago
They're talking here about Starship, not the booster.
- ninetyninenine 2y ago
  How does this logically make sense? They said "it looks like the heat shield held out". Where was a heat shield holding out?
  - kortilla 2y ago
    On starship. Believe it or not, Chuck’s comment was about both booster and starship
    - ninetyninenine 2y ago
      And I’m saying he’s wrong no heat shield held out to anything. The booster never travelled fast enough to need heat shielding ever. Only the starship needs it. If chuck is talking about both likely he doesn’t know what he’s talking about.
      - kortilla 2y ago
        Dude you are having trouble reading. His comment first talked about booster and then talked about starship. It’s not that difficult to follow.
2y ago

cpeterso 2y ago

What’s the advantage of catching the booster over landing it in the ground? Catching it seems like an extra complication.

bagels 2y ago
You save the mass of the landing systems, you get to have all that mass on the ground and not have to lift it into space. Dramatically improves the performance of the rocket.
__d 2y ago
I can speculate ... I think the primary reason would be that landing legs are heavy, and it wastes performance to carry them. If your landing mechanism is mostly on the ground, you get that performance back. Secondary reasons might include that it's simpler to get the booster right back to the pad. Once things have settled into an operational cadence, it's likely feasible to lower and lock the booster onto the stool, stack a ship on top, refuel, and relaunch -- no more messing around with barges, transport, weather issues, etc.
- MPSimmons 2y ago
  To my knowledge, you're right, but in reverse order. I believe the driving force is time, rather than mass overhead, but certainly both play a large part.
- btilly 2y ago
  Your primary reason matches what SpaceX themselves have said. You either need to be strong enough to handle the shock of inpact, or need to spread the impact over time. Building either into the rocket adds a lot of mass. Landing on a device that spreads out the shock moves that weight to the static landing platform.
- XorNot 2y ago
  It's worth noting that at least 1 Falcon 9 core probably got trashed not from the landing, but from rough seas - so cutting out the ground logistics chain adds resiliency.

rkagerer 2y ago

Seems like it adds a lot of risk I'm actually wondering about that. If I understand correctly, the arms can move up and down, and pivot around the tower. This allows them to correct for some error in the rocket trajectory and also (presumably) "soften" the final contact. Between the nozzles and the arms, it gives SpaceX a lot of degrees of freedom in the final seconds (you can see how the booster kind of "hovered" right at the end) and in certain respects might even offer more forgiveness than the hard ground. Could it smash into the tower? For sure. Would that be more dangerous than smashing into the pad? I don't know. It's a new technique with which we don't have a lot of experience.

ChuckMcM 2y ago
My thought (admittedly not well developed) is that smashing into a landing pad of concrete can damage that pad but it can be quickly repaired without affecting the ability to launch future rockets. If you damage the launch tower significantly you're going to have to suspend launches from it until you fix it. So the "higher risk" is more critical assets offline in the event of a non-optimal return.
- rkagerer 2y ago
  Understood, although weren't they out of commission for a really long time anyway the last time they damaged their launchpad?
  - pfdietz 2y ago
    That was a launch pad, not a recovery pad. The launch pad has to be engineered to survive full thrust from all the engines, and for a rather long time as the loaded vehicle accelerates upward.
    - rkagerer 2y ago
      Thanks for clarifying!
- ocdtrekkie 2y ago

potato3732842 2y ago

>The 'chopsticks catch' was amazing to watch. Seems like it adds a lot of risk and clearly the booster needs additional fire suppression systems :-) perhaps the tower could mount something that sprays the booster like the barges have for the F9 boosters. There's no reason to reinvent the airport firetruck.

kortilla 2y ago
The airport fire truck can’t control fires 250ft in the air
- potato3732842 2y ago
  It's pushing the limits but it's close enough to existing capability to be a pretty easy ask.
CydeWeys 2y ago
Unless you're gonna make it fully automated, it's not gonna work here as it can't be within kilometers of the landing site during landing in case there's a catastrophic failure.
nine_k 2y ago
> no reason to reinvent the airport firetruck. There is. The booster is high above, and is larger than basically any aircraft. There's no flat concrete airfield around either. I would suggest blowing CO2 or nitrogen through pipes positioned at the right height on the tower.
- adastra22 2y ago
  It’s not going to burn like that in production.
Cthulhu_ 2y ago
Why would you use a firetruck if you could also run a hose up the tower and get it right where it's needed?

Jugurtha 2y ago

I'm wondering if they'll be using the vertical equivalent of arresting gear on aircraft carriers[0]. See when fighter jets land on aircraft carriers? There's a cable that decelerates them. That, but for vertical landing. The way these chopsticks are set forces the booster into a dangerous, snake like maneuver (a SnakeX maneuver) at the last second from a vertical setting, to get into the chopsticks. This maneuver is due to the fact chopsticks are short and the booster has to land on one point in space. No degrees of freedom. Now, imagine if the chopsticks were long. The booster wouldn't have to land at one specific point, but it could now land on a line. One degree of freedom. Now replace the long chopsticks with cables, and then add another pair of cables perpendicular to them. So you have a pair of parallel cables perpendicular to a second pair of parallel cables. Now the booster doesn't have to land on a line, but can land anywhere in the grid that's covered by the cables. Two degrees of freedom. Pushing this thought leads to having a sort of iris diaphragm, like the ones in optics, but an iris diaphragm of cables. The diaphragm is open when the booster is about to land, then closes in quickly. Imagine this[1], but it's cables cinching in. Now, it's a diaphragm of cables, not a diaphragm of rigid beams, so I imagine the deceleration to be even smoother as the cables elongate, and an additional system of springs and dampers to counter the weight of the booster. The booster is vertical and stays vertical. Granted, an unstable equilibrium, but it beats doing the SnakeX maneuver to get to the chopsticks, and that's another story. Now, imagine the iris cable diaphragm can move up and down like equipment handling containers, and now you have three degrees of freedom. That's less control to worry about on the booster's side at the worst possible moment, landing, where you can't make adjustments anymore. This not only means being more forgiving on mistakes related to position, but also on speed and angle. The diaphragm catches the booster at any angle, and given that it cinches way above the center of gravity, the booster goes back to a more stable vertical position. For the fire, maybe you just need a big hole down there. - [0]: https://en.wikipedia.org/wiki/Arresting_gear https://en.wikipedia.org/wiki/Arresting_gear - [1]: https://en.wikipedia.org/wiki/File:Iris_Diaphragm.gif https://en.wikipedia.org/wiki/File:Iris_Diaphragm.gif

T-A 2y ago
That's how the Chinese are planning to do it: https://youtu.be/OYWBmu6H0ik?feature=shared&t=35 https://youtu.be/OYWBmu6H0ik?feature=shared&t=35

mhandley 2y ago

As to whether catching the booster adds risk - I'm not sure it does. First, to the extent the booster is out of position in the x (sideways) direction, the chopsticks can move to accomodate error. But actually I think this dimension is the easiest of the three, as the booster has plenty to time to null any error in this dimension. In the y direction (direction of travel towards the tower), the rails on the chopsticks can cope with the booster touching down along quite a long distance. But importantly, they appear to be smooth, so the pins can initially skid along them and then the booster can swing if it has not fully nulled any horizontal movement. In contrast, if the booster used legs and has not yet fully nulled any horizontal motion at touchdown, there is a greater risk of breaking a leg or simply tipping over. And in the z direction, it should be possible for the chopsticks can absorb more vertical motion than legs can absorb, because you can easily build in huge springs/dampers/etc into the ground equipment without concern about mass. Catching also puts the booster in tension rather than compression - it's easier to be rigid in tension than compression. Finally, if legs were used, the engines would have to get close to the ground during landing, so reflected shock from the ground could cause damage. I know Falcon 9 does this, but the area of the base of Starship is much greater, so there's effectively less room for the reflected energy to escape. Catching completely removes this risk. On balance, I think they would have better chance of success for each mission by catching. The main downside would be if you fail to catch, you may need to build a new tower, whereas a flat pad would be cheaper and easier to repair.

LorenPechtel 2y ago
And with a barge recovery the legs must have enough spring to deal with waves. The tower doesn't move, they can get a lower landing velocity.
was_a_dev 2y ago
The most challenging axis in my opinion is the roll axis of Super Heavy, if there is a roll angle error, the pins could not sit properly on the chopsticks and the whole booster slides off.
- didgeoridoo 2y ago