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Watch the SpaceX Falcon Heavy Rocket Launch Today

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Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#81

Post by lmm »

the8472 wrote: post #70
Robotbeat wrote: post #37

Falcon Heavy is just a toe in the door of super heavy launch. BFR will have 31 engines at liftoff compared to Falcon Heavy's 27. BFR will be about twice the thrust of Falcon Heavy, and most importantly BFR is not just a launch vehicle (which gives SpaceX a big edge in deploying megaconstellations of low-latency internet satellites), but the upper stage part will be a spacecraft capable of reentering the Earth's atmos…

It might be a "build it and they will come" thing, but what is the current market for super-heavy payloads?

At the moment? Large satellites, ISS modules, one-off scientific missions (e.g. Mars rovers, JWST, a mooted Europa mission).

Musk has said BFR is very much about Mars colonisation.

Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#82

Post by Klathmon »

arnaud12 wrote: post #61
Klathmon wrote: post #8

I can't put into words how excited I am for this launch today. I remember back in 2012 where spacex was still a laughingstock. The idea of landing a rocket from a private company was a joke. But SpaceX always did one thing right, they made many care about space again. They broadcast their launches, made a bit of a show of it, and they weren't ashamed of their failures. Then they started breaking milestones. They incr…

I find the first stage recovery very impressive too, but did they manage to reduce the launch cost since they started reusing the rockets?

Yes, significantly. I don't have numbers on hand right now, but I believe it has been a large success in that department.

Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#83

Post by ryanwaggoner »

Faaak wrote: post #63
VikingCoder wrote: post #24

A thought I've had about SpaceX, Crazy Horse Memorial, and 9/11... They were all once the kind of things that only nation-states could accomplish... Putting up massive payloads into space, building huge monuments, and killing thousands of people. We've made all kinds of things easier to do - some good, some bad. I hope we continue to grow into our capabilities a bit more smoothly than we seem to be, right now...

I think there's a little difference between thousands of engineers building a rocket and 4 idiots crashing a plane down…

As horrific as 9/11 was, it’s not fair to characterize it as 4 idiots bringing down a plane.

It was 19 people who led a coordinated attack that took hundreds of people, millions of dollars, and years to plan and execute. In the process, they brought down 4 airplanes, damaged the pentagon, and toppled TWO skyscrapers, killing thousands of people in the process.

Looking back at the 17 years since, they indirectly started multiple wars, toppled governments, inspired a generation of terrorists, and changed the geopolitical situation in the Middle East for decades, at least.

Again, it was horrible and we should condemn it, but it was also a lot more strategically impressive and impactful than you’re making it out to be.

Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#84

Post by thaumaturgy »

verytrivial wrote: post #57
pensivemood wrote: post #23

Earlier quoted context omitted.

>I remember clearly thinking the whole idea of landing the booster as being completely unrealistic, verging on not possible Please share why you thought it was not possible. Just curious.

Where to start‽ (These are my recollections, perhaps wrong of course): - The wafer thin margin of actual payload that the booster put up now being shared with landing fuel - Engine restart after launch - Re-entry forces on the engines - The fact (perhaps since addressed) that a single Merlin puts out more thrust at near minimum throttle than the dry mass of the booster itself. Think about that last one. If you start…

I'm not sure I've ever thought it was impossible -- I've learned to be more circumspect about that kind of thing as I'm nearing 40 -- but I tried imagining the fine detail engineering that would be required to do it and was totally overwhelmed.

I mean, take a yardstick or short rod or something, and try to balance it upright on the tip of your finger. That's basically what they're doing, but with a -rocket-. It's amazing.

Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#85

Post by Symmetry »

Remember that Elon is saying there's even odds the rocket explodes. 2 failures in the first 10 launches is par for the course for new rockets. You can do better by being paranoid like ULA but that slows down innovation which is not the tradeoff SpaceX is going to take.

Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#87

Post by TeMPOraL »

thaumaturgy wrote: post #84
verytrivial wrote: post #57

Earlier quoted context omitted.

Where to start‽ (These are my recollections, perhaps wrong of course): - The wafer thin margin of actual payload that the booster put up now being shared with landing fuel - Engine restart after launch - Re-entry forces on the engines - The fact (perhaps since addressed) that a single Merlin puts out more thrust at near minimum throttle than the dry mass of the booster itself. Think about that last one. If you start…

I'm not sure I've ever thought it was impossible -- I've learned to be more circumspect about that kind of thing as I'm nearing 40 -- but I tried imagining the fine detail engineering that would be required to do it and was totally overwhelmed. I mean, take a yardstick or short rod or something, and try to balance it upright on the tip of your finger. That's basically what they're doing, but with a -rocket-. It's ama…

The rocket has its center of mass very low during landing, as it's mostly an empty shell by this point, with heavy engines at the bottom. So take a meter tape, pull it out a bit, lock and try to balance that. Much easier, right?

The magic is in a) ensuring the whole construct survives reentry, and b) timing the landing burn - even a single Merlin engine is too powerful for the almost empty rocket to hover, so they need to zero out their velocity at precisely the moment they're hitting the ground. There's no second attempt.

Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#88

Post by cr0sh »

michrassena wrote: post #43
TeMPOraL wrote: post #29

Earlier quoted context omitted.

Not parent, but I was surprised when I first heard of it. I thought it must be infeasible - in retrospect, for no reason other than vertical-standing rockets are associated with kitschy cover arts of old sci-fi stories. It didn't fit the more modern sci-fi aesthetics I grew in. Since realizing that I became more wary of unconscious biases picked up from environment, and how they affect what I think is technologically…

Perhaps I grew up in a different era, but it's precisely that same aesthetic which makes me see these landings as futuristic because they align so well with those images. The ascent into space looks like a massive show of raw power, and in contrast these vertical landings look so graceful and controlled.

> The ascent into space looks like a massive show of raw power, and in contrast these vertical landings look so graceful and controlled.

Personally, I think both are a "massive show of raw power" - both literally and figuratively.

Literally goes without explanation. But what I mean of the word "figuratively" is that it shows our capability as a species to fully harness our intellect, knowledge, and emotions to do this kind of engineering, despite knowing it can all go horribly wrong (especially in the case of manned space flight).

Certainly there are many other drivers to why we do this (profit in the case of SpaceX certainly is a great one), but part of it is also to show ourselves we can push beyond what seemed or seems impossible at times, and make it routine, and eventually both practical and relatively "safe" (always knowing it might never be perfect).

Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#89

Post by ChuckMcM »

pensivemood wrote: post #23
verytrivial wrote: post #16

Earlier quoted context omitted.

I remember clearly thinking the whole idea of landing the booster as being completely unrealistic, verging on not possible. I'm really pleased to have been utterly wrong. And 2/3rds of the boosters in today's test have already been into space. Mind blowing. Congratulations to all the hard working engineers at SpaceX!

>I remember clearly thinking the whole idea of landing the booster as being completely unrealistic, verging on not possible Please share why you thought it was not possible. Just curious.

I know that many aerospace engineers were skeptical it would be possible to achieve ignition when facing "backwards" during hypersonic flight. No way to get the right mixture in exhaust chamber.

Re: Watch the SpaceX Falcon Heavy Rocket Launch Today

#90

Post by chasd00 »

angrygoat wrote: post #45
chasd00 wrote: post #21

Earlier quoted context omitted.

hah i felt the same way. I remember when the Sky Crane was used to put Curiosity down on Mars, I thought there's just no freaking way that's going to work but they pulled it off. When SpaceX started talking about landing boosters I shook my head again but then they did it. The older I get the more blown away (and humbled) I am at what people are capable of achieving. On a lighter note there's a Simpons line when Home…

nitpick - it was Curiosity that came down on Mars using a sky crane, Odyssey was an earlier mission

thanks, i updated my post
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