SpaceX test flight of Starship SN-5 [video] • Hacker News Board

Re: SpaceX test flight of Starship SN-5 [video]

#141

Post by TomMarius » Wed, Aug 05, 2020, 9:25 AM UTC

zizee wrote: post #126

octaveguin wrote: post #121

Earlier quoted context omitted.

The Expanse also has UBI on earth. With it, most people still lack opportunity and live a rather destitute, powerless life. Seems like a pretty good perdition of our future, really. UBI recipients with no labor of value to offer won't have power to change their government for long. It's unfortunate that the authoritarian future of Star Trek probably wouldn't lead to paradise. Or at least, that's how our culture's vie…

In The Expanse, the main reason for complaint from earthers seems to be caused by overpopulation which leads to difficulty in obtaining realestate and the benefits that landownership brings. If UBI was implemented as in The Expanse (food, shelter, and meds are free), I would expect the population of the earth to plummet. The UBI would allow for more people to pursue learning and educating others. It has been shown th…

Was it really shown? Is there a single country that did not replace stress of violence and starvation with economic stress? Do we have at least one larger example of what would happen if the general population was rich?

Re: SpaceX test flight of Starship SN-5 [video]

#142

Post by Teever » Wed, Aug 05, 2020, 9:26 AM UTC

skissane wrote: post #92

rbanffy wrote: post #75

Earlier quoted context omitted.

Same here. Understand they need to somehow weed through their applications. Experienced engineers are costly to assess and having a cheap test to remove the obvious negatives helps them at the cost of a few false ones. :-( I'm also not a US citizen, so that's another cheap test I can't pass.

> I'm also not a US citizen, so that's another cheap test I can't pass. Unlike other "cheap tests", that one is imposed by US government regulations, not SpaceX's own decisions. I imagine SpaceX would be quite happy if ITAR was loosened, but I doubt that will happen. I honestly can't see why ITAR applies to citizens of friendly countries such as Canada or the UK. The point of ITAR is to stop unfriendly countries like…

The ulterior motive to ITAR is protectionism.

Re: SpaceX test flight of Starship SN-5 [video]

#143

Post by martindbp » Wed, Aug 05, 2020, 9:27 AM UTC

sfjailbird wrote: post #130

Thank God for that guy in the corner helping me to know how to feel. Seriously though, this has been an incredibly annoying trend for a few years, everything has to be tagged with some pre-packaged emotional reaction. Such a dumbing down of public discourse. Someone linked the official video and it's amazing: https://youtu.be/s1HA9LlFNM0

Re: SpaceX test flight of Starship SN-5 [video]

#144

Post by wongarsu » Wed, Aug 05, 2020, 9:29 AM UTC

joakleaf wrote: post #132

mpweiher wrote: post #128

Earlier quoted context omitted.

> game changer Absolutely, and the quantitative analysis is just stunning. In 2018 all of humanity launched a total of 111 payloads into space (out of 114 attempts). At around 5t per launch, that would be 555 tons. Starship is supposed to have a payload to LEO of > 100 tons. So 5-6 launches would handle all of that, by weight. But SpaceX says their goal is to fly these up to 3 times a day. So let's assume they can do…

Indeed these numbers are impressive, but can it even be done? Is it even possible both in terms of climate change/overall environmental impact, and in terms of how much methane (fuel) we actually have. Elon Musk's vision is getting 1 million people to Mars (if I remember correctly) within this century. 100 per starship will require 10000 launches. Distributed over 70 years, that's about 1300 Martian voyages per year.…

Methane can be synthesized from CO2 and hydrogen. Going this route could potentially make the rocket fuel carbon negative, since the rocket will carry some of the carbon outside the atmosphere. Supply is basically unlimited as long as we have CO2 and water.

Currently we postpone many launches due to an abundance of caution. As spaceflight gets more routine we will increase our risk tolerance and launch in worse weather.

Re: SpaceX test flight of Starship SN-5 [video]

#145

Post by nieksand » Wed, Aug 05, 2020, 9:32 AM UTC

nieksand wrote: post #139

fermienrico wrote: post #65

Can someone please explain the significance of this milestone for a space-ignorant person like myself? I thought SpaceX does these types of landings all the time. :)

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…

An addendum to the "progress" section....

SpaceX has been flying cargo to the International Space System for some time using their Dragon capsule. A few days ago they completed their first manned mission on the Crew Dragon.

Three big items from this:

1. They have a reusable cargo/crew capsule for LEO operations.

2. They have gained experience in building human life support systems and associated ground operations.

3. They implemented autonomous docking for both the cargo and crew variants of Dragon. This is one of the keys to achieving in-orbit propellent transfer. Item (2) in my original post.

Re: SpaceX test flight of Starship SN-5 [video]

#146

Post by dmurray » Wed, Aug 05, 2020, 9:38 AM UTC

adventured wrote: post #111

dodobirdlord wrote: post #107

Earlier quoted context omitted.

It seems you could buy a stake in a number of publicly traded companies and funds that themselves own a stake. Seems like Google and Fidelity each own about 4% of SpaceX, maybe Fidelity is offering it as a component of some fund? https://en.wikipedia.org/wiki/SpaceX#Ownership,_funding_and_...

Google at least is a bad option. You won't actually get any value representation, any exposure, due to their extreme market cap. Most likely close to 0% of the SpaceX ownership stake is represented in Google's stock. Let's assume though for the sake of argument that some large part is, say $1.3 billion of the stake is represented (3% of $44 billion). That's equal to about 1.3% of Google's market cap (~$1t). Whatever…

I don't get the Berkshire Hathaway analogy. If you buy that stock, in what way are you not getting "1-to-1 direct exposure to the Berkshire portfolio"? You're owning the same investments Warren Buffet owns, in the same proportions, to within a rounding error.

It would be a mistake to invest in BH because, say, you're really bullish on Dairy Queen, but that doesn't seem like the mistake you're describing.

Re: SpaceX test flight of Starship SN-5 [video]

#147

Post by kieranmaine » Wed, Aug 05, 2020, 9:39 AM UTC

nubero wrote: post #120

sabujp wrote: post #114

Earlier quoted context omitted.

Future of space as presented in shows like the Expanse. controlled by trillionaires and their companies and powerful people in governments all killing each other over space rocks. We're a long way from Star Trek, that's going to take a more fundamental advance not at all related to technology.

I’m glad that not everyone in human history has shared your bright outlook, otherwise we would still live in caves…

Could it be the case that a bright outlook leads people to overlook issues that need to be addressed. Maybe a more depressive (or realistic) disposition motivates people to enact change.

Re: SpaceX test flight of Starship SN-5 [video]

#148

Post by daniel_reetz » Wed, Aug 05, 2020, 9:42 AM UTC

grey-area wrote: post #94

paranoidrobot wrote: post #81

Earlier quoted context omitted.

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?

The difficulty is making it light and strong. If you're doing an emergency patch repair on a small area you could sacrifice some cargo and use much thicker material and more welds to be sure it will hold. It wouldn't be easy but is much easier than the initial build.

The difficulty is making a weld that doesn't weaken or anneal the parent metal through heat induced material changes.

Welding thick to thin is nontrivial because of the different heat input required in each substrate. You tend to burn through the thin part.

Patching may be possible but thick patches don't make things any easier.

Re: SpaceX test flight of Starship SN-5 [video]

#149

Post by jacquesm » Wed, Aug 05, 2020, 9:46 AM UTC

llboston wrote: post #43

zizee wrote: post #33

No one has seemed to have mentioned it yet, but the game changer of Starship will be full reusability of both the first and second stage of the rocket. Falcon 9's reusability of the first stage was a huge step towards making access to space a lot cheaper. If SpaceX can realize full reusability with Starship it will enable things like large scale moon bases, space hotels and mars colonization. They still have a lot of…

Another significant thing is that Starship is designed to be mass manufactured at a relatively low cost. SpaceX can crank out thousands of Starships, fly them to Mars and build a million people colony. Starship is truly a game changer!

You write that as if it is a done deal. Mars' atmosphere is roughly .5% of that of Earth and almost exclusively CO2. Temperature ranges are well out of what they are on Earth. It is hard for technology to survive there, it is impossible for people to survive there until there has been an unbelievable investment in infrastructure.

If you think there will be a million people colony on Mars in your lifetime than you are not in touch with the physics of this kind of endeavor. All of our GDP for the next 50 years pooled together would likely not be enough to pull off a feat like that. The scale we're talking about here is too large to even contemplate.

10 people in a shitty little dome, maybe. Right up to the moment they die because of some small mishap.

Re: SpaceX test flight of Starship SN-5 [video]

#150

Post by skissane » Wed, Aug 05, 2020, 9:49 AM UTC

rbanffy wrote: post #138

skissane wrote: post #104

Earlier quoted context omitted.

> A country is friendly until it isn’t If the US can trust the UK with information on nuclear weapon designs and delivery systems, surely it can handle a few UK citizens working for SpaceX? In the unlikely event that the UK and US had some falling out, the US government could always order SpaceX to lay off UK citizen employees.

And what will you do with their knowledge?

It seems rather silly to me to worry about the knowledge of a few UK citizen SpaceX engineers, in the event of a hypothetical US-UK breakup, considering how much information the US and the UK already share in the fields of nuclear weapons and SIGINT. Surely knowledge about the later two is a much bigger concern than the first? Yet, if they are willing to risk the later, why not risk the former as well?

Besides that, the risk of a US-UK breakup has always appeared to be low, and Brexit arguably makes it even less likely.