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Re:Starship is still not understood by altcognito on Thursday October 28, 2021 @10:06AM (#29026283)
Blue Origin said it would be 16, Musk has claimed it won't be more than 8.

https://wccftech.com/musk-rejects-blue-origins-claim-of-16-s...

It ends up being ~100,000 launches over 10 launch windows. Elon has talked about building 1000 starships (presumably you would need less boosters)

https://www.tesmanian.com/blogs/tesmanian-blog/1000-starship...

Anyway, it's absolutely the case that transferring a million tons of cargo will require a new way of thinking about the scale of launches.I would also not assume that the refueling launches have to all take place within the window, that's a bad assumption to start with. You would start your refueling launches well ahead of the window.

added point - I do think the article overlooks that while Starship will change things, the timing is likely to be slow enough that NASA will be able to adapt. They do have ridiculous timelines on some of their projects, but just like everything else, they will just rewrite those timelines if new solutions present themselves.

Re:Starship is still not understood by qayxc on Thursday October 28, 2021 @10:17AM (#29026406)
Even 90,000 launches over 10 launch windows is 9,000 launches per window. Launch opportunities are about 30 days max per window (depending on the flight profile) so that'd be 300 launches per day or over 12 launches per hour .

I'm not saying this is bonkers, but this is completely ridiculous and it doesn't matter whether it's 90,000 or 180,000 or even "just" 45,000 launches - it's completely impractical.

Not to mention that proponents always act as if it's no biggie to just crank out thousands of metric tons of useful equipment for a permanent Mars settlement in just a couple of years.

You, know, including R&D and engineering and paying for all that.

Re:Starship is still not understood by altcognito on Thursday October 28, 2021 @10:25AM (#29026489)
Don't assume that launches for refueling operations happen during the launch window. The window is really as long as you want it to be for refueling. Yes, there are engineering challenges associated with having fuel in orbit over a longer period.

I'll agree there is a shortage of plans and an excess of hope in what you're going to ship to Mars in the near term. But I can also see where others are saying -- something this big requires a slow organization like NASA to start planning now.

Re:Starship is still not understood by SECProto on Thursday October 28, 2021 @12:12PM (#29027721)
> Don't assume that launches for refueling operations happen during the launch window. The window is really as long as you want it to be for refueling.

Indeed, the parent comment was making a bad assumption. If you look at it that way, refueling can happen anytime in the 2-years between windows. So say 10,000 launches over 730 days is 13 or 14 launches per day. Given multiple launch sites, seems feasible enough (in the same sense of feasible as producing 100,000 tonnes of goods destined for mars every 2 years).

Re:Starship is still not understood by skedaddle on Thursday October 28, 2021 @01:40PM (#29028789)
Launching isn't the whole mission though, even if you can achieve that rate. For every launch you also need hours of time for rendezvous, docking, and fuel transfer. And even if somehow there is a solution to this schedule, you're talking about doing it 10,000 times safely and without a hitch.
Re:Starship is still not understood by atq2119 on Thursday October 28, 2021 @11:59PM (#29035007)
Genuine question: how important is the launch window when you start thinking about bulk transport to Mars? If you build thousands of starships, how much does it matter if some of them are slower to arrive?

It's not like flying to Mars is impossible outside the launch window. It takes longer and probably needs more fuel, but by how much?

Re:Starship is still not understood by qayxc on Friday October 29, 2021 @05:23AM (#29036760)
> how important is the launch window when you start thinking about bulk transport to Mars?

Launch windows aren't just about time of travel. They are primarily about the energy required to get to your target.

You can in principle launch to anywhere at any given moment, but the required energy will be much higher. So high in fact, that a Starship-type spacecraft would be unable to make the trip due to lack of fuel.

Hyperbolic trajectories require higher energies and the exact amount involves solving partial differential equations that depend on the exact orbital configuration (i.e. date and location of launch), so I cannot provide a general answer as to how much more fuel would be required.

Suffices to say it would take more fuel than a Starship is able to carry and a hyperbolic trajectory would require en-route refuelling, which is basically impossible since the tankers/fuel depot would have to move at the same speed.

Re:Starship is still not understood by gremloni on Thursday October 28, 2021 @10:32AM (#29026564)
Based on what, your gut feel? 12 launches per hour does not seem insane at all.
Re:Starship is still not understood by qayxc on Thursday October 28, 2021 @11:56AM (#29027550)
> Based on what, your gut feel?

Based on the fact that every orbital launch requires airspace restrictions, local road closures, blocked patches of sea and launch permissions.

The regulatory framework alone is incapable of dealing with that (keep in mind that every orbital rocket is basically an ICBM), let alone the fact that you'd have to spread launches over multiple sites therefore rendering considerable patches of air- and waterways completely closed up for weeks on end.

And that's just the regulatory side of things. There's also the logistical side wherein you'd have to consider methane production and -storage as well as ground operations.

100t-class orbital rockets aren't aeroplanes and the procedures involved in checking, refuelling and launch are much more involved. Keep in mind that SpaceX of all companies was the first company who managed to lose a rocket during fuelling in over 5 decades.

Now scale that risk (of currently 1:129 - make that 1:1000 since I'm being generous here) to 9,000 launches and you'd be looking at about 9 major explosions (worst case) per launch campaign and that's without the added stress from an unprecedented launch cadence taken into account.

You'd be looking at this: https://youtu.be/AOFVuAmcoCA?t=43

two times a week and handwaving that away by quoting fantasy goals for the achievable reliability isn't going to change the fact that even one such incident would halt the entire program for a considerable amount of time.

Re:Starship is still not understood by Dylan16807 on Thursday October 28, 2021 @01:33PM (#29028696)
> Based on the fact that every orbital launch requires airspace restrictions, local road closures, blocked patches of sea and launch permissions.

So set up a [semi]-permanent airspace restriction somewhere inland, remote enough that there are no local roads to worry about, and don't block any patches of sea. And do the permission in bulk, obviously.

> major explosions (worst case) per launch campaign

Failure rate is something to consider in several ways but largely unrelated to the launches-per-hour metric.

Re:Starship is still not understood by garmaine on Friday October 29, 2021 @10:04PM (#29045378)
It can’t be inland, because there’d be a huge stretch of flyover restrictions. It’d be at sea on top of mobile floating platforms. Like the two oil rigs SpaceX bought last year…
Re:Starship is still not understood by vanattab on Thursday October 28, 2021 @10:50AM (#29026757)
In 2020 there was 114 orbital launches supporting all space missions around the world. That's 0.013 launches per hour. 12 launches per hour to support a single mission does not seem at least a little insane? I love SpaceX and am hopeful for their Mars plans but we are scientists and engineers let's think with our brains and not our hearts.
Re:Starship is still not understood by gremloni on Thursday October 28, 2021 @06:51PM (#29033060)
Think about what you’re saying, does 12 launches per hour sound all that crazy? Maybe having 1000s of planes up in the air at the same time would have sounded similarly crazy to someone on the 50s
Re:Starship is still not understood by brianwawok on Thursday October 28, 2021 @11:23AM (#29027172)
if computers taught me anything.. it's if you can do 1 thing really really well perfectly, it's not a ton of work to do it 10x or 100x in parallel.

We don't have enough data to know reliability of say Falcon long term. Is it 99% successful? 99.9%? 99.999999%? Doing a ton of launches, you really want to work on the 9s, so 0-1 of your launches blow up, not 100+. But once you do, you just copy paste it baby and go to town.

Re:Starship is still not understood by vanattab on Thursday October 28, 2021 @11:32AM (#29027282)
I am not convinced the scalability of cyberspace applies to actual space.
Re:Starship is still not understood by AnimalMuppet on Thursday October 28, 2021 @12:28PM (#29027909)
I don't think it's a good example either. But the scalability of mass production may apply, and that might be good enough...
Re:Starship is still not understood by snowwrestler on Thursday October 28, 2021 @12:15PM (#29027748)
There is a literally a book called “The Mythical Man Month” about the limits of parallelism in computer engineering. It’s arguably one of the fundamental texts of the discipline.
Re:Starship is still not understood by micropresident on Thursday October 28, 2021 @12:59PM (#29028283)
And that book has literally nothing to do with what is being discussed.
Re:Starship is still not understood by brianwawok on Friday October 29, 2021 @12:48PM (#29040715)
Right. I didn't say we hire 100 developers to code the project 100x faster.

I said let's build 100 parallel rocket pads with 100 parallel rockets.

It will indeed launch rockets 100x faster.

The term you are looking for is embarrassingly parallel.

Re:Starship is still not understood by snowwrestler on Friday October 29, 2021 @04:30PM (#29043218)
Only parts of the system are embarrassingly parallel. But you need the whole system to be available for every launch.

Poorly parallel parts of the system include regulatory clearance and accident investigations. There is only so much clear air space available each day. And if a rocket blows up (which they often do), they’ll all sit on the ground until there is understanding as to why. And then potentially sit even longer if they each require work to correct or mitigate flaws that are found.

Starships are still hand-built prototypes. And Musk has a history of underestimating the difficulty in scaling and automating physical manufacturing.

It’s way too early to be confident this can embarrassingly parallel. Parallelism is hard in general. It’s hard because often constraints aren’t obvious until you’re actually doing it.

Re:Starship is still not understood by meepmorp on Thursday October 28, 2021 @11:56AM (#29027551)
What's a few orders of magnitude among friends?
Re:Starship is still not understood by ClumsyPilot on Thursday October 28, 2021 @10:48AM (#29026728)
Based on the fact that it would be more flying mass than the domestic airline industry.
Re:Starship is still not understood by abledon on Thursday October 28, 2021 @10:52AM (#29026776)
> It ends up being ~100,000 launches over 10 launch windows. Elon has talked about building 1000 starships

managing that many launches...spaceships mid-journey, refueling in space ETC... would the 'head count' at spaceX have to increase greatly, or would they keep a relatively small crew and just 'scale out' having it mostly controlled by code/automation

Re:Starship is still not understood by brianwawok on Thursday October 28, 2021 @11:23AM (#29027182)
For sure both.