The rocket exploded because it fell over, not the other way around. Had one of the landing gears not malfunctioned, it would have been fine.
SpaceX Falcon rocket explodes on landing after delivering satellite to space
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Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#42Could someone explain to me why they attempt this? Wouldn't inflating a set of floating devices when it goes down the ocean an easier way of retrieving it? Or something other than this REALLY HARD TO PULL OFF maneuver? Genuinely interested.
The corrosion from the salt water would completely ruin the engines, obviating any benefits from returning the first stage.
Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#43Could someone explain to me why they attempt this? Wouldn't inflating a set of floating devices when it goes down the ocean an easier way of retrieving it? Or something other than this REALLY HARD TO PULL OFF maneuver? Genuinely interested.
Rockets have always been able to land in the ocean more or less intact (i.e. without disintegrating). However, if the rocket is dipped in salt water, the restoration would be enormously expensive, so it needs to stay dry to be re-used.
Of course, you could just try to land it vertically on the water on some cushion and have more cushions deploy to make it tip over horizontally and float (all the time staying above the surface of the ocean). Such a solution isn't as compatible with recovery on dry land. If you want to do e.g. space tourism missions and land on dry land, the vertical landing seems better.
Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#44SpaceX actually got very close to sticking this landing. Sea conditions were reasonably rough, with 3-meter waves. It's also the first time SpaceX launches in fog, IIRC. Everything about the landing except the stuck leg seemed to be perfect. So IMHO, the fact that the rocket exploded is not the most pertinent fact about this experiment. The main piece of news is that SpaceX is exceedingly likely to be able to recover…
As a former gymnast, I like the sticking the landing analogy but a human (even on an unstable mat) has far more control over their balance point (we do much of our balancing by bending at the waist - if only the rocket had one).
In any case, I agree that this was very close. I've also spent a reasonable amount of time on "big water" and was specifically watching the attitude of the landing deck with respect to the horizon. I didn't see much movement of the barge (but that doesn't mean there wasn't some instantaneous movement that together with the force of landing exceeded the leg's load rating).
The other thing that's struck me is that the SSTO advocates could end up becoming irrelevant. Who's going to argue we need SSTO at all if we can recover and reuse all the stages anyway? Multiple stages will remain dramatically more efficient (Yes - I know we don't get space planes with two hour flight times from New York to Tokyo quite as easily).
Finally ... I just have to say "I LOVE THIS". I remember as a child watching the Apollo missions and, as an engineer, I haven't been this excited about a project for a long time. Isn't this exactly the type of thing we can rally humanity around? Who's going to argue that it's not a great accomplishment?
Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#45Would it be possible to have locking mechanisms directly in the dock itself?
ie. maybe the rocket descends several feet INTO the dock into a hole which then locks around the body of the rocket?
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==||== dock (which opens wide for decent and then closes)
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^^Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#46Could someone explain to me why they attempt this? Wouldn't inflating a set of floating devices when it goes down the ocean an easier way of retrieving it? Or something other than this REALLY HARD TO PULL OFF maneuver? Genuinely interested.
Two main reasons I can think of:
1) Sea water is extremely corrosive. If your booster takes a dunk in the drink, it's going to be very hard to refurbish for another launch. Lots of components (electronics, valves, etc) would need to be replaced and the structural integrity of the tanks themselves may be compromised by rust.
2) Flotation devices attached to the booster = extra payload. It would be the canvas/dinghys AND compressed gas canisters for inflating them. This is arguably (a lot?) more weight than just landing struts + fins. Any extra payload on a rocket represents a massive cost and means less stuff you can haul for paying customers.
Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#47Could someone explain to me why they attempt this? Wouldn't inflating a set of floating devices when it goes down the ocean an easier way of retrieving it? Or something other than this REALLY HARD TO PULL OFF maneuver? Genuinely interested.
Or even a different kind of barge. A floating 'jar' rather than a flat surface, the thing could tip and not fall all the way.
Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#48Earlier quoted context omitted.
They want to use this tech to eventually land rockets on other planets so the rocket needs to be able to land upright. Short term it might be easier to land on inflatables but they're looking at the bigger picture.
No, its just not possible to maintain the integrity of the rocket if you're going to somehow lay it down on an inflatable. How could an inflatable withstand the temperature of the firing engines?
For weight, the sides of a rocket are very thin. Think tin can. Vertical is OK but horizontal can't work.
Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#49That was pretty much exactly what I expected to see from the video given the description of a broken landing leg yesterday. Elon's twitter comment about the ice is interesting because it adds some interesting twists. If the stage is icing up as it descends it would change the mass calculation, however it does not seem to shed ice when it lands in the video. He suggested that ice at launch may have interfered with leg…
In an earlier re-entry video, the camera lens ices up during the re-entry burn, presumably due to water from the engine exhaust. So I don't think that re-entry is necessarily enough to heat up the stage enough to melt all the ice on it.
Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space
#50Earlier quoted context omitted.
Yeah, I don't understand why they won't keep landing them on the ground like everyone else does. It's not like there's not enough space on Earth.
So if you launch out of Cali going west and separate stage 2 300 miles out.... What is under you to land on?
I assume the parent poster meant that the launch should take place from somewhere on earth where there is earth 2300 miles out. It's likely not convenient to do so, at least not for all launch directions.