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.
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.
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.
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).
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?
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.
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.
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.
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.
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.
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.
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
Or they've been replaced with some big Aldrin cyclers built using Starships.
Before you had it, suggesting mining a asteroid was just pointless and insane. Now you can actually think about.
And that is what NASA should do. Now getting stuff to LEO is 'solved' what can you actually do.
Thank you for pointing that out - I just realized that with Starship, we even could start thinking about putting some smaller asteroids out of a potential collision course with it.
I think the idea that Starship will get us cities on mars is pure fantasyland. You could have a decent base on the moon, and maybe a visit to Mars, but if you want million tons to Mars, you have to go beyong chemical rockets, build a mars transit vehicle, etc.
It makes no sence to forgo those technologies if you are moving billions of tons.
There's just not enough raw materials and fuel for that amount of launches, and environmental objections will catch up with them long before that.
There's not enough oxygen? Hydrogen? We can make renewable methane just fine.
Even if we used oil a quick calculation says that 1000 tons * 10000 launches would barely break a tenth of a percent of our current semiannual oil use. I think that's an affordable impact for a truly massive mars campaign.
We could as first guess say that it's about 5000 tons of CO2 per launch. So 1000 launches would be 5 million tons.
US CO2 emissions per capita are about 16 tons per year, so it would be equivalent to the yearly emissions of 300,000 Americans or one thousandth of the country's yearly emissions.
10,000 launches would be 1% of US total emissions.
So that's 850M tons, about a 10% increase (on top of the 2nd most polluting country in the world), so yeah, not happening.
I would personally rally against the govt. (and everything that allowed that to happen) if Elon gets a free pass on that.
I think the premise of the article is wrong anyway.
I think no matter what the system is like, it still makes sense to optimize for mass in a reasonable way. That means, not sending dead weight to high delta vee. Leave big tanks or engines behind.
It's a bit like you don't transport your car with the airplane. It would be madness.
Exponentials are unintuitive. The total mass of all fuel in all stages is directly proportional to the mass that needs to be sent to the highest delta vee. So for example (to take a few shortcuts) if your moon ascent stage is 1% heavier, everything has to be 1% heavier, including the first stage of the launcher. So 1 kg in the ascent stage might not look like much but it grows the first stage at something like 1000 kg.
That's why I'm really skeptical of the architecture of landing atmospheric stages to the surface. They are just unnecessarily heavy. You have maybe quadrupled your total launch amount from the surface (haven't done an analysis).
Early Apollo planning had direct landing because docking in orbit had not been demonstrated. Gemini validated that. Orbital docking works fine and Apollo could continue with muchh more efficient architectures. Actually, docking has gotten a lot better, we did have Apollo, yes, and we have robotic tugs routinely flying to ISS.
Engines haven't made significant progress since the sixties, not enough to warrant really big architectural changes towards less mass efficiency.
If anything, the improved docking and automation that has already been demonstrated would swing the architectural plans for moon or Mars to have even more docking, berthing, refueling and staging!
Direct landing might only make sense with something like nuclear propulsion...
Lunar starship is not an atmospheric stage.
So yes the heat shield goes all the way down to the lunar surface and back.
https://caseyhandmer.files.wordpress.com/2021/03/artemisspac...
At least that can cause interesting discussion other than , BUT CO2 and WARMING.
We fly ~40M flights a year. It'd be a drop in the bucket.
Super Heavy Dry Mass: 350,000-440,000lbs Super Heavy Fuel Weight: 7,500,000lbs Starship Dry Mass: ~200,000lbs Starship Fuel Weight: 2,600,000lbs
Starship+Booster total: 10,695,000lbs
175,000lbs vs 10,965,000lbs!
There is no such thing as a similarly sized aircraft!
A single-digit percentage global increase in aviation emissions.
(I'm also very skeptical of that level of Starship launches. By the time you're getting anywhere near that, you're likely to have captured some comets and are processing fuel for interplanetary missions in an orbital refinery. Net zero emissions except for getting the people and Earth-only parts up to LEO.)
I think you’re underestimating both the mass of a comet and that the geopolitical implications of a private company being one industrial accident away from replicating something several orders of magnitude closer to Chicxulub than to Tsar Bomba would prevent them being allowed to even try it.
I did a napkin estimate a while back, and even optimistically 10,000 Starship launches is just where you start going “hmm, perhaps we should think about starting to seriously plan the basics of an orbital ring or a launch loop” — a 40Mm circumference steel loop with a cross section of 1m^2 is still about 30 times less massive than 67P/Churyumov–Gerasimenko.
Meh, you could regulate it fairly effectively. Changing the path of a comet is something that's gonna have to be done years out. Deviating from the planned course would be obvious long before it'd hit anything.
If it was a naïve straight-line path with no funky orbital mechanics to make things even harder to get right, the difference between hitting the Earth at 90° and missing by the orbit of the moon is a sideways delta-v of 13 m/s one year in advance. The sideways Δv between a 45° impact and LEO, 7 days in advance, is 3.5 m/s.
I’m curious: Even ignoring engine errors, given near-Earth solar orbital velocities, what’s the mass of the smallest asteroid which, if it impacted that comet 7 days before the comet reached Earth, could cause it to hit Earth? For whatever orbit you want to put it in, and whatever mass of comet you want to suggest using.
In other words, the larger the comet, the better.
You'd need a fairly obvious number of rockets to impart that sort of velocity change on a large one, right? And if you're doing it to a pebble, it doesn't matter too much?
I don’t think so? If you’re bringing in a big one you need more engines to push it into the right orbit to start with, so I think the risk is always things that scale up directly with the comet’s mass, e.g. “the engines are misaligned by $foo degrees”.
Also, a pebble in space terms is still a potential city-killer, and no nation in their right mind is going to want to let a private company — not one of their own, let alone a private company in another nation if they have even the slightest say in the matter — wield that kind of potential: https://en.wikipedia.org/wiki/Meteor_Crater
We watch asteroids zing by regularly. The ones we know about have their chances of hitting calculated years or decades out.
And the sort of rock that could shift 67P from a safe to a dangerous path (LEO to 45 degrees one year ahead) would be about 13 metres radius. The Wikipedia citation is 5 years old, so I don’t know what we know today, but in 2016 the estimate was we only knew somewhere around 1.3% of asteroids between 40m and 3.5m diameter (and 0.003% of smaller than that, because things get harder to spot as you get smaller).
Wiki: https://en.wikipedia.org/wiki/Near-Earth_object#Size_distrib...
ArXiv link because the citation in Wikipedia was giving me a server error: https://arxiv.org/pdf/1604.06328.pdf
So, honestly, please, stop.
A) Was attacked by the parent comment B) Needs defending here of all places C) Is the only person doing something inspiring in the world
Indicate that you might want to broaden your worldview.
Electric cars will not save us from climate change, nor will rockets send us into climate oblivion.
So, someone can do the math to work out how much CO2 is generated by burning that much of that mix. In any case, that is very small compared to the overall emissions of human society.
That being said, methane can be produced a number of ways, for instance digestion of food waste. Therefore, they could source methane in a way that would allow to claim (quite reasonably) that they are carbon-neutral.
Not sure why PR statements matter.
https://www.tandfonline.com/doi/full/10.1080/147776209027688...
So at 100tons per starship sent to Mars that's 10,000 trips or 1000 per launch window. But the current plans call for something like 16 starship launches just for refuelling the one starship for the lunar mission. Suppose we can do the Mars trip with the same number of flights that's 170,000 launches to transport that 100million tons? And this guy is mad that nasa is not assuming that this is achievable?