4 ms·
What’s the advantage of catching the booster over landing it in the ground? Catching it seems like an extra complication.
by 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 agoYou 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 agoI 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 agoTo 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 agoYour 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 agoIt'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.
- Gare 2y agoFalcon 9 can land on land just fine (and it was done multiple times on less demanding missions). Landing on barge gives it extra performance.
- wcoenen 2y agoThe rocket equation implies that if you want to maximize the delta-v a rocket gets out of a certain amount of fuel, then you should get the dry mass as close to zero as possible. Eliminating landing legs helps a lot.
- _dain_ 2y agoWhy send the landing mechanism to space when it isn't needed there? Whatever kit you put on a rocket has to be brutally miniaturized to limit how much you eat into the payload mass. Also has to be rugged enough to withstand tremendous vibrations and thermal stresses. That adds cost and more points of failure. You want to move as much of the complexity off the rocket as possible. Then doesn't matter if the catching mechanism on the launch tower is big and heavy.
- deelowe 2y agoI thought it was so they can name make the booster body thinner relying more on the fuel for structural rigidity.
- syncsynchalt 2y ago1) legs are heavy 2) empty rockets are stronger in tension than compression 3) the booster is large enough to make (1) and (2) matter more than they did for Falcon 9.
- boxed 2y agoThe reflected sound of the engines is enough to destroy the engines, ironically. That's also why the launch mount is so high. You'd need truly enormous legs, which wouldn't work for weight.
- m4rtink 2y agoThe load for landing and almost empty booster would be less, but otherwise yes, it would be much more than the single Merlin engine on the Falcon 9, with all associated issues (local scorching/spalling of the pad, acoustic issues, extra weight, longer turnaround, etc.).