71–80 of 142 posts
Not trying to nit-pick, just trying to confirm my own understanding. But actually, accelerating a mass from 1000km/hr to 2000km/hr should take three times as much energy as from 0km/hr to 1000km/hr, right? I assume the quantity of "four times as much" was just used to get across the notion of energy being proportional to the square of velocity.
If we can land the rocket accurately enough to put it down on a tiny barge only slightly larger than the rocket itself, then why do we need to tolerate the weight of the landing legs? We already have industrial robots that can move and grasp heavy weights relatively quickly over distances of several metres -- it doesn't take much imagination to conceive of a similar contraption being used to arrest the descent of the…
Every time these discussions come up, people immediately come up with "other" suggestions for landing. Parachutes, "catching" devices, etc. etc. It all comes down to one thing, and one thing only. Whatever the solution, it has to work on other planets with no infrastructure on that planet, and it has to leave the booster in a state that it's ready to go again with only a fuel fill up.
Elon's whole gravity explanation is essentially a textual version of this excellent video/demonstration: https://www.youtube.com/watch?v=MTY1Kje0yLg (19 million views). Highly recommended, very memorable.
Yep, came here to post this. The funny thing is that there was a post about that video a while back, and the HN crowd criticized it pretty heavily for being a bad way to explain gravity. But... whatever. :)
Nice article, but I couldn't pass up a chance to correct Elon Musk's math: It is important to note that the amount of energy needed to achieve a given velocity increases with the square, so going from 1000 km/h to 2000 km/h takes four times as much energy as going from 0 km/h to 1000 km/h, not twice as much. Three times, not four--you already spent a quarter of the energy getting to 1000 km/h. Getting the rest of the…
Earlier quoted context omitted.
SpaceX own the first stage. You pay to get your payload delivered to a specified orbit. You don't actually buy the rocket. It's like flying, you buy a ticket, not the plane.
Just for reference, I got an inside look at what it took to get OSCAR16[1] launched and it isn't like flying :-). Now I don't doubt things are more streamlined now but every launch starts with a basic contract and that contract has to cover everything from contingencies to insurance to liability to disposal. Trying to search for a boilerplate launch contract I found an article[1] where it discusses that Spaceflight I…
Earlier quoted context omitted.
Every time these discussions come up, people immediately come up with "other" suggestions for landing. Parachutes, "catching" devices, etc. etc. It all comes down to one thing, and one thing only. Whatever the solution, it has to work on other planets with no infrastructure on that planet, and it has to leave the booster in a state that it's ready to go again with only a fuel fill up.
I was under the assumption the primary reason is reusability on earth only. This would drastically reduce the cost for building new rockets and would decrease turn around time for new launches. Having it work on other planets is a nice plus but there's no demand for that and likely wont be for decades.
Elon has made it very, very clear and continues to reiterate.
The entire purpose of SpaceX is to get to Mars.
Launching satellites and other near-earth stuff is nothing more than a needed step to achieve the goal.
The article mentions that the water landing requires less fuel to return the rocket because it doesn't have to spend fuel overcoming its initial ballistic trajectory. In the water landing scenario, how far away from the launchpad is the landing barge? I'm wondering about the economics of launching from a site where your first stage trajectory is entirely overland, to avoid the complications of landing on a barge that…
Clearly this man's intellect is through the roof. Reading this post and him explaining these concepts in such first-principle terms (despite not being a physicist/rocket engineer) indicates his in-depth understanding (nothing new there). I know he has a Bachelors in Physics but bear with me. But, I'm just in awe and I keep thinking 'how does he do it?'. He's running two intensely technical and risky companies. Yet he…
Also, he does have an undergrad degree in physics, and was accepted to a physics PhD program at Stanford.
The guy's incredibly impressive, but there are many almost-Elons. It's not like he's an alien or a superhuman.
Clearly this man's intellect is through the roof. Reading this post and him explaining these concepts in such first-principle terms (despite not being a physicist/rocket engineer) indicates his in-depth understanding (nothing new there). I know he has a Bachelors in Physics but bear with me. But, I'm just in awe and I keep thinking 'how does he do it?'. He's running two intensely technical and risky companies. Yet he…
In most companies the "Posts from the CEO" are a group effort (at my last company I wrote multiple statements that were supposedly from our CEO). What you're attributing to a single person is actually the work of many. This leads to your question: > But, I'm just in awe and I keep thinking 'how does he do it?'. What can us, mere mortals learn from him? We can't change our baseline raw intelligence (which effects how…
This is what crops up again and again when looking at these performance outliers.
Clearly this man's intellect is through the roof. Reading this post and him explaining these concepts in such first-principle terms (despite not being a physicist/rocket engineer) indicates his in-depth understanding (nothing new there). I know he has a Bachelors in Physics but bear with me. But, I'm just in awe and I keep thinking 'how does he do it?'. He's running two intensely technical and risky companies. Yet he…