271–280 of 391 posts
What you don't get a sense for in the video is the size of this thing... It's absolutely bonkers. 9m (30 ft) in diameter 50m (160 ft) in height (or would be with the nose-cone) That's the height of a 12-story building. And this is the upper stage of the full rocket.
Construction equipment for scale: https://s.yimg.com/ny/api/res/1.2/mz7KZlvgwTBa5cs4xfM_aA--~A...
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I agree. For a space craft that did it's 150m "hop" in 1992 it was even more impressive (especially considering how much the computers and IMU weighed in that thing!) I'm not convinced though that it ever really to achieve it's SSTO goals and still land it. With on orbit refueling perhaps (as could Starship in a similar scenario). It was also shooting for much lower mass to LEO.
Structural weight is mostly a function of the surface area and fuel capacity and payload are a function of the volume. If you make the rocket bigger, it's payload mass fraction increases.
Agree with this.
> If you make the rocket bigger, it's payload mass fraction increases.
Don't agree with this. The way I see it, as a rocket gets bigger, and stays in one piece, its payload mass fraction decreases. The inability to jettison heavy engines and structural components means those things become part of the 'mass fraction' that ends up in orbit. And the bigger you make those things, more and more of your mass fraction is being committed to carrying stuff and less is available for non-rocket payload. Hence its a decreasing mass fraction in terms of amount of payload.
Its fun to play around with this in Kerbal but its pretty much a hard limit.
Things that can affect the mass fraction in a positive way are things like more ISP in the engines. When you look at the evolution of the Falcon 9, the increase in mass to LEO was a result of two things, one upgrading the efficiency of the Merlin 1D engine and two developing a way to put more propellant and oxidizer in the same volume by super chilling it.
I really love the out-in-the-open development process. It doesn't cost SpaceX anything, yet they attract lots of internet media where people set up streams, discuss progress etc. The next year should be pretty exciting as they develop things further. Starship has a number of big innovations, which are: - the raptor engine. This was developed behind closed doors and is sort of finished. We won't see much of it, but it…
> 31 raptor engines That'll be something to see haha N1
Does anyone else get super depressed by this? I did some great work today. I coded something pretty cool and useful. I built a little deck to explain it. My coworkers loved it. My job security went up. I enjoyed it. The journey is the reward. But these guys are making rockets in tents. Should I be rethinking life? Because that's how it feels. I love it. I admire them. But it feels unobtainable. I want to make that ki…
We're hiring for Starship and Starlink software teams: https://grnh.se/080f65d02us It sounds like you're passionate about your work and that's an important quality. As gorgoiler points out, "Making a difference in the world is what counts." If you'd like to help, consider applying! :)
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> 31 raptor engines That'll be something to see haha N1
The Falcon Heavy uses 27 engines and has a perfect track record ,so they've got some credibility here.
I really love the out-in-the-open development process. It doesn't cost SpaceX anything, yet they attract lots of internet media where people set up streams, discuss progress etc. The next year should be pretty exciting as they develop things further. Starship has a number of big innovations, which are: - the raptor engine. This was developed behind closed doors and is sort of finished. We won't see much of it, but it…
> 31 raptor engines That'll be something to see haha N1
[1]: https://en.wikipedia.org/wiki/N1_(rocket)#Block_A_first_stag...
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> 31 raptor engines That'll be something to see haha N1
Indeed, the N1 design [1] will finally be done right. [1]: https://en.wikipedia.org/wiki/N1_(rocket)#Block_A_first_stag...
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Also, since its mostly made from steel, it will be fairly simple (as far as rockets go) to conduct repairs, you just need a welding rod or two. This is important for early stage bases where you don't have the equipment/materials to make carbon fiber or exotic aluminum alloy replacement parts.
Given how much difficulty they've had with welds and materials to date, is it really feasible to conduct in-situ repairs without a ton of advanced equipment?
That is, something you can have a fair chance of fixing while in orbit or on Moon or Mars.
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SpaceX as a company is trying to solve the "transportation problem" of becoming a spacefaring civilization. Specifically, how do you reduce the cost of access by multiple orders of magnitude? There are three big targets they need to hit: 1. Make Low Earth Orbit (LEO) cheap with a combination of launch cadence and reusability. 2. Reset the rocket equation in LEO by doing in-orbit fuel transfer. 3. Reset the rocket equ…
> 2. Reset the rocket equation in LEO by doing in-orbit fuel transfer. What do you mean by this? If you want to propel a mass M to delta-v V, you need a certain amount of initial mass. Dividing it into stages is already taken into account. If you split the lower stages into multiple trips, you might change the mass per trip, but you don't change any of the total early-stage mass required, right? Doesn't the rocket eq…
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Given how much difficulty they've had with welds and materials to date, is it really feasible to conduct in-situ repairs without a ton of advanced equipment?
I feel the same way. Likely not to start but over time I think they would build up capability. I wonder how lesser gravity on Mars would help/hurt their efforts. Easier to heft heavy gear up high? I'm also thinking on the flip side, say a Starship somehow gets irreparably damaged getting to Mars (but successfully gets there). With some basic gear they should be able to part it out and re-use the steel. Like for a new…
But you have to plan for another mission to pick up the crew, unless you're on the Moon where you could use an electromagnetic catapult to achieve orbit, and then slowly ascend to the rocket that would take you home.