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The main difference is that this is built by a private corporation who can't afford to throw money away, while the Space Shuttle was build by the government, and moreover it had to fulfill a number of conflicting requirements, and commercial profit was not one of them.

But on a more technical level. I think the vertical landing is the main difference. Vertical landing was obviously known and done by NASA, this is how the lunar modules landed on the Moon. But doing it on Earth, with vehicles weighing hundreds of times more, I don't think the world had that technical readiness a few decades ago, when the space shuttle was designed.

And another major difference is the mass manufacturing idea. From the start SpaceX planned for getting to mass manufacture its rockets. The Falcon rockets are much cheaper than any other alternatives even if you remove the reusability.

Then it's the methane burning engines. This was pure old fashioned engineering progress. SpaceX's engines are miracles of rocket engineering. Aside from that, the fuel choice is extremely smart. Methane is better than all other fuels, except for hydrogen. Hydrogen was the fuel of the space shuttle, but it's very tricky to work with. It has very low volumetric density, so the tank of the space shuttle was absolutely humongous. Hydrogen needs to be stored at an absurdly low cryogenic temperature, so this adds to the complexity. And that tank was not reusable, so it adds to the cost.




In order to land as a glider, you'll need wings, landing gear, doors, rudder, stabilizer, flight controls, streamlining, all the structure needed to support it, and a heat shield for all of it. All that complexity has to work reliably, too.

All of that adds tremendous weight, complexity, and cost.


> Methane is better than all other fuels

There are better fuels in terms of Isp and density. They have some downsides such as being corrosive or having highly toxic exhaust.

https://x.com/ToughSf/status/1453391050681327622


Yeah, methane is kind of second best (or worse) in many parameters, but most importantly, it's cheap, abundant, and easily and safely storable and transportable, and it does the job.


Also chosen as it may be possible to synthesize on Mars.


And while not the reason, also on Venus! Venus seems like a very interesting colonization target - gravity almost like on Earth, and there is a place in Venus atmosphere where temperature is around 30 degrees Celsius and pressure is 1 atmosphere (Earth); and human air is a lifting gas in Venus atmosphere. As a bonus, interaction of Venus atmosphere with the Sun produces a magnetic shield.


> temperature is around 30 degrees Celsius and pressure is 1 atmosphere (Earth)

And unbreathable and full of sulphuric acid. You may as well just stay in orbit.


Staying in orbit means risk of catastrophic failure on puncture and doesn't provide access to the heat of lower layers of Venus atmosphere that can be used as energy source or carbon source. You also have to think about heat management - big colony means gigantic radiators. And most importantly no gravity and no magnetic shield - these make Venus imho better colonization target than Mars.

On Venus, a puncture doesn't immediately destroy anything - because of equal pressure on each sides of the balloon wall. You have more than enough time to put on a protective coat and fix it.

And building more living space is much easier + you could source the material (carbon) on site.


I'd be a bit boring in your balloon above Venus though. At least on Mars you could wander around and check out the rocks or something.


You are going to have hundreds of years of fun terraforming Venus... https://en.m.wikipedia.org/wiki/Terraforming_of_Venus#/media...


> and commercial profit was not one of them

But it's high cost was the end of it.


Its high cost would (should!) have killed it regardless, but its low reliability was going to be a huge problem too, and arguably it's the lack of reliability that finally killed it.

The high cost should have killed the project before it ever flew, but that's not how governments behave.


What is all this rocketry doing for climate change if they're burning methane? Hopefully it's methane from landfills etc?


I did the math, and the impact is not negligible. One single launch releases the equivalent of 5000 tons of CO2. Elon wants to get to the point where there are thousands of Starships, each doing a few trips to orbits per day. That would be more than one millions launches per year, or more than 5 GT of CO2-equivalent. That's about 10% of the worldwide emissions today.


One million launches per year seems to be adequate trade for 10% global emissions. This level of technology implies we are able to reduce emissions elsewhere.


I think it’s ludicrously optimistic to think that this would substitute for reductions elsewhere. What possible mechanism could reduce 10% of global co2 emissions when many of these launches will be tourists and starlinks?


1 million launches per year implies at least a decade or two of development. There is a lot that can change in that time - for example energy production can move towards renewable and nuclear. Few decades more and we might get fusion too.


I agree with you. I was just stating a fact, not criticizing.


If we actually get to that point, we'll eventually be doing a lot more activity and manufacturing off the Earth where the CO2 emissions don't matter.


Presumably co2 emissions in LEO would end up in the atmosphere though?


The limiting effect for Starship launches won't be CO2 (direct air capture could counter that), it's injection of water into the stratosphere. Ballpark I think the limit would hit at about 100,000 launches/year.


burning methane turns it into much less damaging CO2. They probably get it from Natural Gas that the US produces.


Spacex might be a private company, but this project is funded by NASA, meaning the American taxpayer. Approved by a person whose last act was this approval before leaving NASA and joining Spacex (effectively putting money in their own pocket).

It is also yet to be seen how Starship will ever be profitable (outside of spending government money), who is going to pay for those launches and for what purpose. Other than Starlink, of course.


> this project is funded by NASA

Partially. They have a fixed-price contract to land humans on the Moon, and notably got that contract because they severely undercut the other bids and were the only bid that actually fit within the available budget: they bid $2.94B, while Blue Origin bid $5.99B and Dynetics $9.08B.

That 3 billion is also much less than what they're spending on the project.


With a payload volume of 8m diameter by 22m height you could fit a James Webb size telescope inside with minimal folding. The sunshield (21.2 m by 14.2m) would only need to fold along one axis and the mirror (6.6 m) could be monolithic instead of having to fold, probably only requiring the mounting points for the primary and secondary to be hinged. This shouldn't be discounted because it makes telescope design much simpler and less expensive.

It also allows for launching individual space station modules that have almost the same volume as the entire ISS in one launch.

Their plans for refuelling on orbit with tanker versions of the starship open up the entire solar system to unmanned missions with much shorter timelines and much higher payload size and weight.

The fact the entire system is re-usable will make it both cheaper and faster to use than any other launch system.

All of this combined mean that it won't just be countries and space programs bidding for space on launches, it puts space within reach of many corporations and some private individuals. This isn't conjecture, it's already happening with the Falcon 9. Starship will make it even more accessible.


> With a payload volume of 8m diameter by 22m height you could fit a James Webb size telescope inside with minimal folding.

Of course, that means you could also fit a James Webb-folded telescope except make it a lot bigger :-)


Probably need on-orbit refueling to work for that to happen, but they're working on it.


Just park the starship as the sun shield. Or two starship, or an origami starship that unfolds for more surface area, your own personal sun umbrella made from a starship.


Yes! that too.


> It also allows for launching individual space station modules that have almost the same volume as the entire ISS in one launch.

My favorite related thing is that the Starship itself could serve as a large space or moon station.


> but this project is funded by NASA

About 10% funded by NASA. Starship is a >$10B program; SpaceX is getting $3B for Artemis of which >2/3 is for operational tasks and moon-specific stuff that SpaceX aren't relevant for SpaceX's goals of LEO and Mars.


The Artemis money could evaporate and Starship would still make commercial sense and likely be a successful product.


The federal government smartly invested in SpaceX after being sued by SpaceX to fix rigging (things what the system working looks like).

Now taxpayers have a 10x return on investment.


The problem is that launch costs went down fast but satellite costs haven't gone down as fast and still have long development timelines. The other problem is the market for satellite services hasn't developed as fast as anticipated, except for starlink.


Starlink for all intents and purposes is the market for satellites now. All the other launches are nice to have extras.

Now personally I’m looking forward to NASA, ESA and JAXA to launch outer solar system probes like new horizons but with tons of fuel left in the tank to safely make orbit around there.


Having enough lift capacity to take a shot at putting a pair of telescopes out far enough to exploit solar gravitational lensing to resolve exo-planet surfaces would be a hell of a thing. Orbital refueling would mean we could reasonably build something big enough to be able to boost out that far (would still take decades to arrive).


Isn't that 500 AU out?


Yes, but the trick with getting there is building the vehicle. Time takes care of the rest (you'd do it using ion thrusters).


The whole design process for them is based around launches being expensive and taking a long time to plan. It will be very interesting to see what happens when the whole process gets used to launches being relatively cheap and frequent. No need to spend years making sure the design is perfect and will definitely last a long time if you can launch a new one in a week if you make a mistake.


Starlink is predicted to have something like 6.6B in revenue. SpaceX isn't a rocket company they are an ISP that launches rockets.


Is that long term or this year? Because honestly 6.6B is not a lot for their scale of operations.


That is projections for this year only with a target closer to 10 billion revenue next year.


SpaceX is profitable from that income alone, even allowing for starship development costs.


Things can only be cheap if you mass produce them. That tends to require standardization of components, and inevitably standardized components are a compromise between requirements, where up until now, saving mass was a critical requirement. If you don't have to care nearly so much about mass and volume, then that opens up many avenues for much cheaper standard satellite components.


I'm disappointed that you still can't order ten cubesats from Shenzen Satellite Supply Co via AliExpress.


> Spacex might be a private company, but this project is funded by NASA, meaning the American taxpayer.

So was the space shuttle, so that's not a difference between the launch costs of the two vehicles.


The purpose of funding SpaceX with taxpayer money is to make competitors that can launch rockets to space so that it is cheaper.


Exactly. Private companies like space X would not exist if NASA didn't deliberately make the market for Private space companies. That's what governments do, make markets.


Elon founded SpaceX w/o an expectation of subsidies.


How do you know he didn't lobby for them?


And yet, without the funding for CRS from NASA Spacex would’ve gone broke or at least wouldn have built F9 much much later.




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