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Comment by IG_Semmelweiss | Hacker News Reader

The average user knows what SpaceX is about, likely has heard the falcon 1 rocket achieved a milestone with rocket reuse after multiple successful launches.

But, why this launch is so important? why so much is riding on this ?

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This will be the first ever launch of "Starship" SpaceX's next generation rocket.

Starship (and more specifically the Super Heavy booster that carries Starship) is the most powerful rocket in history and is designed for the purpose of carrying humans to Mars. SpaceX's new Starlink satellites are much bigger than the old ones and really require a larger rocket - this will be Starship.

This is also the first ever orbital flight test of a "Full Flow Staged Combustion Engine" [0], making the Raptor Engine the most advanced rocket engine in the world. Many people didn't think that full flow staged combustion would work so this is a great vindication of the concept.

Starship will also be the lunar lander for the upcoming NASA Artemis moon landings.

[0] https://everydayastronaut.com/rocket-engine-cycles/

Thank you for this

The key difference is that this is 100% reusable. With Falcon and Falcon heavy, the second stage is non-recoverable which is still quite expensive.

I'd argue not that much actually _riding_ on this, it might just blow up on the launchpad or it might go up in the air. Either way they will try again in a few months.

So the difference between success (defined by musk as getting far away enough from the launchpad not to damage it) and failure (rud on pad) is a few months on the development timeline and money to rebuild the (quite complicated) tower.

Will be fun to watch either way, unless its a scrub.

If they have, like, 3 consecutive launchpad explosions over the next few years, then maybe we'd start talking about the whole project being in trouble.

If it actually does the whole flightpath then that will be pretty amazing.

The other question, why is this important: Its the biggest, most re-usable most ambitious rocket ever made. The 33 engines, apart from being numerous, are of a design more ambitious/challenging than any other rocket engine we've ever seen.

(edit: engine adjectives)

>> Even each one of the 33 engines has more complicated design than any other rocket engine we've ever seen.

I was with you up to there. Spacex loves simple designs. The Raptor seems much simpler that the Space Shuttle main engines for example. Moat advanced design maybe, but not sure about "complicsted".

To be fair at least one of the intermediate raptors was quite complicated, gp's info might just be out of date

ok maybe complicated is the wrong word, but my understanding is that full-flow staged combustion was rated as very hard to develop verging on impossible a decade or two ago

https://everydayastronaut.com/raptor-engine/

https://hackaday.com/2019/02/13/the-impossible-tech-behind-s...

Complicated can be more than physical complication. I understand (though I could be wrong) that these engines have a much more finicky timing sequence for things like startup than other engine types. I think calling that sort of thing a complication fair.

Here's a video of Elon explaining the Raptor engine design, and comparing Raptor 1 and Raptor 2 (Raptor 2 is much simpler): https://www.youtube.com/watch?v=E7MQb9Y4FAE

The cheapest and most popular rocket today in terms of cost per kilogram sent to low-earth-orbit is the SpaceX Falcon 9, which is estimated to cost about $2700/kg. If the Starship meets its goals, it will cost $10/kg to LEO. It has a payload capacity and infrastructure which can economically deliver massive payloads to any solid surface in the solar system. It could send three full-sized bulldozers to Mars in a single trip. This is the largest scale space project ever conceived and portents a major shake-up to the space industry and a big step towards establishing a permanent human presence off Earth.

$10/kg to LEO is insane

That's the cost to SpaceX. There's no way they charge customers anywhere near that.

Even if they charged $100/kg it would change the world.

It is. The Falcon 9, of which there have been hundreds of launches already, costs $60 Million per launch. And somehow Musk thinks he can make a rocket that is 10 times bigger 30 times cheaper? Wishful thinking. Best case imho is that they take the launch cost down to about 200M-ish over the next 15 years. That's a cost of $1000/kg and sounds about right to me.

How much of a setback would disaster be? Would SpaceX keep going, or would failure leave room for competitors to take over? (If there are competitors? I don't even know tbqh.)

if the 2nd stage re entry turns out to be fundamentally unworkable, big setback. but if the rocket fails for any of 100 other reasons, no big deal

I haven't followed this specific launch in much detail, but part of why SpaceX has been so successful is they expect a certain amount of failure and don't pin the failure of the program on the failure of any one test. This allows them to iterate faster than other programs that might have less test launches and thus rely more on the success of the launches they do perform. I've heard for example that this rocket is already out-of-date and the next planned rockets already have a bunch of improvements.

It would range from unfortunate to a non-issue. The entire flight is not expected to be successful, the purpose is data gathering. The worst case scenario is that it fails on the pad and damages the launch infrastructure, which would be a huge setback to the project. If it fails anywhere else it's probably fine.

Not a big setback at all. They would have to analyze reasons for failure and make changes. There are no serious "reusability" competitors, especially at Starship size.

SpaceX is trying to iterate quickly on this rocket so they have several already assembled. Next two launches will also be fully expendable.

Disaster is complete demolition of the launch site, setting their schedule back many months and costing them a rumored hundreds of millions to rebuild. They've run enough tests to support reasonable confidence that won't happen. The directionality towards mass manufacturing the rockets, instrumenting to observability scale data collection to feed engineering course corrections, and resilience to setbacks is promising.

The hundreds of millions figure doesn’t sound implausible either way necessarily, but I wonder if it includes the R&D costs? I.e. building number 2 would be incrementally much less expensive than building number 1.

I wouldn't be surprised R&D numbers were included in the rumored figures, but considering their lessons learned today from the extensive concrete spalling incurred by the launch, there is even more R&D to perform with the next build-out. Especially when we take into account some observers are claiming SpaceX is installing a deluge system [1] for the next build.

I'd like to hear from some rocket nerds why launch pads don't sit on top of a giant, deep water body, as the deluge systems as I vaguely understand them seem primarily to manage the shock and secondarily the heat, and concrete is a difficult material to manage over a long period of frequent use as a shock absorber.

[1] https://fossbytes.com/nasas-water-jet-system-protect-rocket-...

>How much of a setback would disaster be?

SpaceX has followed a tech startup-like model of iterative development AKA "move fast, break things", in which many rockets go boom and (as saberdancer said) every boom is studied to reduce the odds of the next one go boom. Basically an edit-compile-debug loop writ large. This is why SpaceX's official countdown schedule states "excitement guaranteed" at T-0:00.

>Would SpaceX keep going, or would failure leave room for competitors to take over? (If there are competitors? I don't even know tbqh.)

As saberdancer said, there is no serious competitor. Rocket Lab has achieved ~~reusability~~ recovery of small rockets and has a good launch record, but a) has not yet figured out how to get them to land other than on the ocean and b) can't launch them weekly/daily like SpaceX. Bezos's Blue Origin actually landed rockets before SpaceX, but only suborbitally. ULA (US) and Arianespace (Europe), the two large commercial-payload providers pre-SpaceX, aren't at the point of test launches of any reusable rockets.

The above is all before Starship, which if it works will give SpaceX a) a fully reusable launch vehicle (existing SpaceX rockets' upper stages aren't reusable), and b) the ability to launch gigantic payloads. The combination of the two will further massively cut launch cost. I've read that even if Starship is fully expended, it will still be the same $2700/kg that existing SpaceX rockets cost, with that aforementioned gigantic payload capacity.

>The cheapest and most popular rocket today in terms of cost per kilogram sent to low-earth-orbit is the SpaceX Falcon 9, which is estimated to cost about $2700/kg. If the Starship meets its goals, it will cost $10/kg to LEO.

I've read that the cost will be $2700/kg even if Starship is completely expended; that is, no reuse. But far, far, far larger payloads, of course.

It is the largest rocket in history and it is planned to be fully reusable.

If SpaceX manage to make this work they will have a launch vehicle capable of launching much more mass to orbit which will open up space exploration.

It also provides us with a kind of access to space that we lost when the Space Shuttles were grounded. It's interesting that the Shuttle was considered a hugely wasteful boondoggle in its day and age, yet now a private profit-seeking enterprise is making something that's just as capable on a way bigger scale.

The shuttle ended up having a cost of $1.5B per launch. Starship is aiming for a cost of $2M per launch. They'll likely miss that goal, but even missing by an order of magnitude will be a huge game changer. And obviously price will be very different from cost.

We're looking at the cost of a tonne to orbit being similar to what a kg was during the shuttle era.

the problem with the space shuttle is that it's minimum payload was an airplane with room for 7 people. it's like if you wanted to mail someone a letter so you put the letter in a van, and called a towing company to send the van.

The shuttle was hamstrung by DoD and senate requirements.

Arguably the entire concept was flawed, fueled more by a sci-fi concept of "wouldn't it be cool if" rather than a sober cost-benefit analysis. It was a space station, built into a rocket, built into an airplane that is also a reentry vehicle - most of the motivation to reuse the vehicle in the first place goes away if you don't make it so damn complex!

It just makes so much more sense to launch big payloads on heavy lift rockets, humans separately on human rated craft, and leave the space station part (robot arm etc) in orbit.

(The one type of mission you can't do without something like an orbiter is satellite retrieval. This capability was used a total of 4 times. Not really worth it.)

I am 100% good with NASA pursuing "wouldn't it be cool if" and leaving sober ROI-gated developments to private industry.

https://en.wikipedia.org/wiki/Space_Transportation_System

The actual concept was actually pretty decent (even kerbals would say so!), except somehow it got cut down to the point of uselessness.

It is the same idea that they had for a Space Shuttle. Reusable vehicle that can be used many times and make space accessible. Unfortunately, Space Shuttle did not make that a reality as it was too complex and required a large multi month refurbishment after each mission.

Starship should be able to solve that issue and make space accessible. At least that is the idea. We will see how it ends up.

I would argue that the Space Shuttle was mostly wasteful because it really wasn't that reusable. You had to fully refurbish the SRBs, you lose the tank, The Shuttles required a ton of refurbishment themselves, all for a rather small amount of mass to orbit.

Falcon 9 can be partly reused. Falcon 1 was a predecessor, that only flew 4 times IIRC.

It has more engines than any rocketship, making it the most powerful rocket ever built. (33 total)

https://ibb.co/7SrTK7P

https://en.wikipedia.org/wiki/SpaceX_Starship

There's far less certainty around how viable a system it will be and the only way to fully know is through a semi-successful test flight.

TL;DR it’s the tallest and most powerful rocket, is reusable, designed to refuel in space, and intended to take cargo/humans to Mars, and thus its successful launch marks the beginning of us becoming a multi-planetary species, per Musk’s plan.

They currently send up Starlink satellites in batches of about 50 on the Falcon 9. On a more or less weekly cadence or 4 times/200 satellites a month.

When Starship gets going it might carry as many as 400+ per launch. In other words eventually they'll be able to throw more stuff into orbit in 1 month than they currently can in 1 year.

It literally means their bottle neck will be producing enough starlinks, and other payloads, per day. Incidentally, those things are also used by the military and in Ukraine.

Having this much payload capacity at this moment in time is very important. Without SpaceX people who want to put satellites into orbit would be somewhat at the mercy of Russia and China as capacity elsewhere is extremely limited.

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