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SpaceX Falcon rocket explodes on landing after delivering satellite to space

bbc.com

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Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#121

Post by AaronM »

valhalla wrote: post #118
startupfounder wrote: post #51

Earlier quoted context omitted.

Salt water isn't good for rockets. Once you solve this really hard problem of landing a rocket on a barge on a dynamic ocean you have a real competitive advantage.

Is that the reason they've been using the barges for landing? I'd always assumed they were just being extra cautious since it could endanger civilians or crew if the reusable stage was supposed to land on solid earth. I'd imagine that the barge landings introduce a lot of uncertainty and complicating factors that are impossible to completely nullify. High waves and (comparatively) strong open-ocean winds seem (to me…

Some flights wouldn't have enough fuel to make it back to the launch site. That's the reason I've seen. There is also a large amount of water, so that increases the places you can land.

Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#122

Post by Dylan16807 »

benjaminl wrote: post #106
bantunes wrote: post #25

Could 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 key thing to remember about rockets is that they are incredibly fragile. The rocket is about 15 stories tall and is designed for force to only be applied at the end either via the rocket engines or the landing gear. Any type of lateral forces will irreversibly damage the rocket. As an illustration, extreme care is taken when the rocket needs to be transported on its side. Some rockets, not the Falcon 9, can't eve…

While that's true, the metal tube is not the part that's expensive to build.

Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#124

Post by marshray »

rplnt wrote: post #2

Technically, it exploded well before it delivered the satellite. edit to add some facts since this seems to be getting downvoted pretty quickly: Stage 1 landed and exploded at around T+10min, the satellite was deployed at T+56min. This was just two minutes after it was delivered on its final orbit. Both of those could be considered "delivered to space", neither of which happened before the failed landing.

I think this is an interesting point. While I don't think we ought to rush out and change our terminology, I had not heard this anywhere else.

Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#125

Post by Dylan16807 »

Grue3 wrote: post #94
dkbrk wrote: post #61

Earlier quoted context omitted.

> like everyone else does Nobody else does this. I have absolutely no idea what you could possibly be referring to. SpaceX lands on land preferably when it is an option. > I don't understand why they won't keep landing them on the ground ... It's not like there's not enough space on Earth As a general rule, you not understanding the reason for something does not mean there is not a good reason. For reference, see the…

>Nobody else does this. I have absolutely no idea what you could possibly be referring to. Believe it or not, we've been landing spacecraft for decades. Does "space shuttle" ring a bell?

The shuttle throws its lower stages into the ocean.

Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#126

Post by JoblessWonder »

baq wrote: post #117
mikeash wrote: post #108

Earlier quoted context omitted.

"Explodes after landing" would be more accurate, I think.

and the "explosion" is borderline, it's very close to just "burns really fast", especially when you see what's left after the fire goes out: https://pbs.twimg.com/media/CY8-PdyU0AABqaa.jpg:large (there's quite a lot of rocket left)

The video pretty clearly shows/sounds like an explosion. Not a huge one, but one none the less.

Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#127

Post by Animats »

This is progress. They got a good landing, then the landing gear collapsed, and not because of a hard landing. Next time they'll have a design that forces the landing gear down and locked, ice or no ice. Somewhere down in Hawthorne, someone is probably freezing one of those mechanisms in a cold chamber right now.

This is way better than back in July, when the booster blew up because of a strut failure. That was a major quality control failure.

Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#128

Post by Rhinobird »

smoyer wrote: post #44
marvin wrote: post #8

SpaceX 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 ho…

I read somewhere, that the new first stage can do SSTO unloaded.

Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#129

Post by jadyoyster »

jbooth wrote: post #88
CarolineW wrote: post #86

Earlier quoted context omitted.

From Wikipedia: The project's long-term objectives include returning a launch vehicle first stage to the launch site in minutes and to return a second stage to the launch pad following orbital realignment with the launch site and atmospheric reentry in up to 24 hours. https://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_... However, from other sources: SpaceX would love to recover the second stage, which they…

Seems way harder for way lower returns to recover the second stage. Only 1 engine instead of 9, and you're recovering from orbital velocity which opens up several new cans of worms. Would they need heat shielding? The extra weight there might blow away any cost savings from recovering the engine.

Heat shielding is needed, as well as extra landing engines that work outside of vacuum, since the second stage engine would destroy itself under atmospheric pressure. It's easy to see how quickly you start to get dimishing returns, but it would be cool if they could pull it off.

Re: SpaceX Falcon rocket explodes on landing after delivering satellite to space

#130

Post by eric_h »

tetraodonpuffer wrote: post #56
jsumrall wrote: post #41

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.

yeah, it feels the title this time should be rocket explodes AFTER landing, to give a better feeling of how close this was

especially since it seems to have hit the bullseye on the center of the barge (maybe missed dead center by a few inches).
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