Do they describe somewhere how they achieved the apparently successful propellant transfer in microgravity in flight 3? Having pressure difference might not be enough if the fuel is a mix of liquid and gaseous phases.
Edit: aha, found - "Then, SpaceX will fine-tune tank pressures and fire propellant settling thrusters." And they are using free flow. Wonder how long the transfer will take and how much of a propellant settling acceleration is needed?.. Also :) the relative positions of ships become important if no pumps are used...
No, I'm confused between "free flow", "no pumps" and "pressure difference", which to me a sort of a pump - in some sense, active forces applied to propellants. So I was thinking about flowing from a point of higher potential energy to point of lower one, on Earth you put the empty glass below the full when you need to pour water from the full to the empty. If Starships actually use pressure difference, then it's not quite free flow, and geometrical positions aren't that important.
> If Starships actually use pressure difference, then it's not quite free flow, and geometrical positions aren't that important
That's how I'm reading it, analogous to a pressure-fed engine [1]. A separate, expendable gas supply pressurises the donor tank to force the propellant out and over.
Not sure if it's too similar to pressure-fed engine, that one works with a clear acceleration direction, which really helps to keep fuel at the local bottom.
> A separate, expendable gas supply pressurises the donor tank to force the propellant out and over.
But what if the fuel is a mix of liquid bubbles and the gas freely floating in the tank?
> that one works with a clear acceleration direction, which really helps to keep fuel at the local bottom
I believe the plan is to impart a gentle spin.
> some pumps applicable here could be really simple
The Venturi effect reduces pressure. It's definitely worth exploring. But you'd need to test it to explore where it causes volumetric effects, e.g. by exacerbating boil off.
Heating the donor by exposing it to sunlight while shading the receiver should provide some pressure differential for no added power. Gentle rotation would start with the center of gravity wihin the donor, but as the transfer goes on, it'd move to the middle of the two rockets and stop the transfer at that point.
It wasn't intended as a jab, spinning it up to settle the propellant for transfer sounds like a good idea to me. Of course, failing to exit the spin is still mission-ending but they'll figure it out.
Now we just need the Attenborough voiceover about the mating habits of starships as they spin through space.
I'd definitely prefer to decouple the carrying fuel to the orbital depot and the refueling at the said depot, when it already does have the fuel amount needed.
As for spinning two Starships of significantly different mass... that should be interesting to see. Doable, yes :) but interesting nevertheless.
I understand their desires to eliminate parts and reduce weight in the second stage (Starship), but I foresee them eventually adding in pumps to aide in transfer of propellants.
Maybe not in all variants, but definitely in the crew version, as having the ability to transfer propellant even if the pressure differences and settling cannot be achieved seems worth the lost performance.
I’m a fan of that channel. But he seemed to miss the point of Artemis. The criticisms were valid. But his KISS call on the framework seemed to ignore that the point isn’t getting to the Moon, it isn’t even getting to the Moon repeatedly; it’s developing a system for repeatedly getting to Mars.
And keeping it simple will inevitably drive costs up due to the additional brute force required, making it all uneconomical in the first place. Apollo was simple. It also cost 25% of the US's yearly GDP in total.
25% of GDP is closer to what World War II cost in its peak year. Perhaps 30%.
But it’s kinda hard to define, since it also grew GDP tremendously (in the US). It may have been a much higher percentage with 1945 costs measured against 1939 GDP, if that makes sense, but I’m not sure it’s appropriate to make that comparison.
So you want to use system that needs 14 launches to get to the moon to get to mars? Let that sink in... Falcon a much simpler rocket has a reuse window of over a month. How long would it take to re-certify starship for a launch?
You are going to need dozens of them launching everyday for months to prep one mission and hoping nothing will go bad.
Those kind of missions are complex tasks and complicating things make them more complex and error prone exponentially
So, on that recent presentation Musk talked about around 250,000 tons to Mars in one launch window - every 2 years - which's gonna take ~1000 Starship flights to Mars. So if every flight to Mars needs 10, nah, 15 refueling flights, that means 15,000 Starship flights in 2 years, which is 20 flights a day. Which is way, way less than the commercial aviation is doing today. And btw Starship is way simpler, at least in many places, than Boeing 747. So what's the problem?
Re-certify for flight? I can envision an automated procedure which would analyze the data obtained from the rocket in flight and after flight which makes a decision in a split second, just like some systems in cars routinely do.
Hoping nothing will go bad? You can get much more risks on unmanned missions. You'll also get numbers on your side, when if something goes wrong you fix it, systematically, for future attempts. That's not exactly just hoping, right?
There's seemingly no physical - or economical, for that matter - reason for this to be impossible, so why not? Starship definitely didn't complete testing at this point, many things are still ahead of us, but to talk about impossibilities - why? Yes, of course we didn't do that yet, but we're talking about possibilities in the future.
You’d expect at least some evidence that it can lift that much weight by this point with a dummy load in the hold. Especially considering that they should be long past that point according to their last updated roadmap.
> You’d expect at least some evidence that it can lift that much weight by this point
"By this point". Well, we have testing program here (which to me looks pretty successful so far), the capabilities of the system - demonstrated, that is - are increased with each flight. Load test - that is, bringing to orbit the full payload the Starship is designed for - has not happened yet, and, as far as I remember, Falcon also didn't have such a test for some record mass. I'm sure we'll see some reasonable payload flights at some point "soon". What's the problem here?
> Especially considering that they should be long past that point according to their last updated roadmap.
Ah :) maybe you're talking about the thing which SpaceX refers jokingly as "we transform impossible things to late". Yes, "Musk's time" is always very aggressive, and I even suspect to know why he's, as an engineer and a visioner, does that. And why Shotwell's estimates are more accurate - she excels at operations, after all.
But I don't see a principal problem here either. Yes, the - rather aggressive, by aerospace standards - schedule slips to the right, while still producing results, years in a row. Big deal.
I suspect this isn’t happening this year and this article is only a few years old. On traditional launches in the past, at least a 25% load is put in the hold, even on the first launch. You generally want to show off that you can at least lift off the ground, unless you can’t.
There is no evidence to backup your statement that it didn't have enough fuel to complete it's mission. It intentionally did not go to orbit because they didn't want to risk stranding such a huge vehicle that can withstand re-entry in orbit if its engines were unable to relight. And indeed they did have issues with relighting the engines so that was a very good decision in retrospect.
It was an intentional decision not to go into orbit.
Um. They showed how much fuel was remaining and it was empty. Just some back of the napkin math shows they used far less delta-v to get to their test flight, with no payload, and ran out of fuel. That doesn’t bode well.
> you want to use system that needs 14 launches to get to the moon to get to mars?
Again, the criticisms are valid. But it's unlikely we can get to Mars--repeatedly and sustainably--without mastering in-orbit re-fuelling. So while it isn't technically necessary for a Moon mission, nor even repeated Moon missions, it is for a Moon mission that's building to Mars. (Again, repeatedly--we can do without it [1]. But it's far more expensive in the long run.)
> How long would it take to re-certify starship for a launch?
Falcon 9 has been turned around in 3 weeks [2]. The bottleneck has thus far been launch pads. If you can cut that to 2 weeks, you need 5 to 7 refuelling Starships ready per launch. Once again, the bottleneck would be launch pads.
You and I are on the same page about that re-fuelling overhead being bonkers. It's mostly because SLS and Orion suck. But if the only thing we learn from Artemis is fuel depoting, that's a huge win.
> You are going to need dozens of them launching everyday for months to prep one mission and hoping nothing will go bad
The timeline for the first propellant-transfer test is three to four weeks. 14 launches over 30 days comes to a launch every other day. Ambitious, but only about twice as frequently as the Falcon family launched in 2023, and for a shorter interval.
> Not sure I understand your numbers here in relation to the quoted part
The unknown variable is in-orbit propellant boil-off. How much propellant will poof away for each day in orbit, and during the propellant transfer. The test next month will observe this for 3 to 4 weeks. So for the actual mission, we will presumably have 3 to 4 weeks to put all the fuel in orbit. Assuming it takes 14 launches to launch that fuel (we won't know the final number until we do the tests), that gives us a required average launch cadence of about 2 days.
Thanks. I'd assume the boil-off should be insignificant, in a sense, or - alternatively - some active cooling systems can be used, they don't need to be big or complex.
And, where, pray, does that liquid come from ... in space? It also seems like a terrible idea to leave little ice particles flying around at hundreds of km/h...
Falcon has a reuse window of less than a month, 21 days in fact. And that's why you use multiple vehicles. Falcon also uses multiple vehicles which is how it achieves flights on average every 3 days so far this year. Also Falcon is inherently harder to reuse because of its fuel choice causing substantial soot buildup on the vehicle that needs to be cleaned away whenever inspections are done both inside the engines and on the vehicle itself. Its fairings also get dunked into sea water every time they're reused which needs to be cleaned off.
I didn't yet watch the video, but my overall point is that Gateway and Moon HLS is not the thing which will help us get to Mars. Or least it is bad for innovation per dollar spent. The best place space station to construct for future Mars expedition should have been in the LEO and fully manned. Moon orbital station is a detour. Actually more of crutch for the Orion. And HLS will land in a different mode than future Mars lander.
I do agree that we need to do small steps before big steps. But overall this "lets save money with reusing Shuttle stack" has backfired spectacularly. And delayed both small step and bigger step for decade(s).
> best place space station to construct for future Mars expedition should have been in the LEO and fully manned. Moon orbital station is a detour
There are real questions about LEO versus deep space habitation, specifically in respect of solar radiation. Gateway will help settle those questions.
> this "lets save money with reusing Shuttle stack" has backfired spectacularly
100% agree. And I honestly don't see us using SLS and Orion to go to Mars. But Gateway will be proving real science and hardware. And SLS, Orion and even the Gateway are more easily deprecated from the Artemis framework than e.g. Starship.
Could we have a better system? Sure. Is there a better path forward if we want boots on Mars in the 2030s? No.
His critisim was that it wasnt clear how many launches it was, not that its many.
And having many launches if you actually get a lot out of it isn't really a problem.
His whole approch seem to be 'this more complex then apollo' and therefore bad.
He spent a lot of time going after SpaceX but spent almost non going after the real problem with the moon program. The incredible expensive lagecy technology forced by congrsss that is dragging the whole programs potential down.
So I think in totalility message is really just reinforcing the Johnson center ultra conservative 'money is irrelevant' approch to engineering.
I'm reluctant to criticise Destin as he is infinitely more knowledgeable about this than I am BUT that video did not convince me.
I see Artemis as an attempt to industrialise the process of getting humans and large volumes of materials to the Moon, ultimately as a stepping stone to Mars. This isn't a proof of concept self-contained "mission" like Apollo was. It felt a bit like saying the global aviation system is overengineered compared to the Wright Flyer. I don't see why it really matters if it needs 15, 20 or even 50 reusable vessels for orbital refuelling as long as that process is repeatable and safe.
That said, it's been a few months since I watched that video so I may not have done a good job here of remembering what my criticisms even were.
The 15 launches is a big deal, because it requires either a dozen or so Starship Tanker full stacks, or very-rapid reuse to be fully solved. But it's probably solvable, and otherwise SpaceX can "just" build a dozen Tankers, and reuse them slowly. It's solvable, but personally, I'm not all that optimistic on the timeline though.
The shocking thing for me from that video was learning how useless the Lunar Gateway is most of the time due to its near-rectilinear halo orbit. This leads it to be only within range for rescuing those on the moon, for a couple days a week.
Why does Gateway have this type of orbit? Because the Senate Launch System doesn't have the delta-v to get the capsule to circularized low-lunar orbit. We designed a moon rocket, which can't get to the moon.
> leads it to be only within range for rescuing those on the moon, for a couple days a week
I genuinely never heard about the Gateway being there for rescue until Destin's talk. (Not saying he invented it. Just that it wasn't what it was advertised for.) Compared to just landing a spare Earth ascent vehicle, it seems like a stupid way to solve for our lack of low-gravity trauma medicine experience.
> Why does Gateway have this type of orbit? Because the Senate Launch System doesn't have the delta-v to get the capsule to circularized low-lunar orbit
NRHO also minimises communication black-outs with Earth. With the Gateway in orbit, other craft in circular orbit can maintain continuous contact with the Earth.
Well, the argument in his video is that there are multi-day gaps in the ability to rescue astronauts off the moon. Balancing that out with a few very small relay satellites, I would pay for a couple Electron launches for the relay, and have a lifeboat capability 24/7.
> The Gateway is also, as I understand it, a staging ground for testing habitation for a vehicle to Mars.
I have heard that as well, but what I don't understand is how a higher orbit simulates a Mars trip much better. I mean, either way you are not inside a magnetosphere, right? I guess in low-lunar orbit you are more shaded from solar wind by the moon half the time?
> the argument in his video is that there are multi-day gaps in the ability to rescue astronauts off the moon
Right, which is where he loses me--this is not why we have a Gateway.
> Balancing that out with a few very small relay satellites, I would pay for a couple Electron launches for the relay, and have a lifeboat capability 24/7
Building a communications relay constellation isn't a simple task. It's on the roadmap for Artemis.
> what I don't understand is how a higher orbit simulates a Mars trip much better
The high orbit is irrelevant to this aim. You'd get the same deep-space habitation science from a low, circularised orbit. The high orbit is for creating a one-and-done communication relay.
> Right, which is where he loses me--this is not why we have a Gateway.
I am just an everyday armchair astronaut, so please correct me where I'm wrong, but I figured:
1) A lunar lander does not have the delta-v for direct return to earth, from the lunar surface. (or the heat shielding)
(2) Part of the Gateway's function is similar to Apollo's Command Module. A place for the lander to dock upon return, and facilitate return to earth.
I can see how Gateway differs from Apollo's Command Module, in that it does not return to Earth, but stays in lunar orbit. This does test Mars-like endurance, and is cool. Orion will detach from Gateway, and return independently, right? But why the near-rectilinear halo orbit, which puts the lifeboat capability out reach sometimes? If an astronaut needs something like an appendix removed (random example,) then a few days waiting for Gateway to swing by could make a difference.
edit: Oh, near-rectilinear halo orbit also makes it easier for Orion to return to Earth, right? So maybe he said that Orion lacks the delta-v, not SLS. Maybe that helps explain it.
> lunar lander does not have the delta-v for direct return to earth, from the lunar surface. (or the heat shielding)
Starship HLS is the lunar lander [1]. That said, it is not designed to survive Earth re-entry at lunar velocities.
> why the near-rectilinear halo orbit, which puts the lifeboat capability out reach
I guess I'm sceptical of any Gateway serving as a lifeboat in an emergency with a day-to-day sensitivity where aid can be provided on Earth but not on the Moon.
> The 15 launches is a big deal, because it requires either a dozen or so Starship Tanker full stacks,
It's more a logistics problem than anything else. If a Superheavy and Tanker takes 3 weeks to relaunch, you build 3 to launch weekly and 21 to launch daily. Now you need to have 21 processing facilities and 21 times more people to do that. Launch pads, landing pads, and Mechazillas don't need that long to recover, so you can build just a couple extra ones with each one serving a group of processing facilities.
SmarterEveryDay's proposal is both more expensive and less capable than using 14 Starship refueling flights. 14 flights seems insane, but since the system is fully reusable, the only consumables are <$2M of fuel each flight. Compared against the $4.3B cost of each SLS flight...
Criticize the parts of the system that are both expensive and prevent us from taking advantage of Starship's ability to land 100 tons on the moon. SLS.
> but since the system is fully reusable, the only consumables are <$2M of fuel each flight.
> prevent us from taking advantage of Starship's ability to land 100 tons on the moon.
the system is unable to get to the orbit, its not tested. Its all high-hopes and conjectures as it is now.
All of those plans are opinions, that's the problem.
Its like planning your infrastructure around hyperloop, but it doesnt exists. So all of the plans are founded on vaporware.
I would hope nobody bases their existing infra on vaporware, but planning a future endeavor around future tech is risky but not stupid. These are not actually critical missions - they are essentially technology demonstrations with some science whitewashing. And tech demos always adopt or assume new tech.
I don’t think it’s problematic. You don’t build a system then figure out how to use it. You make a goal and that figure out what it takes to meet it and build accordingly.
Starship does seem to make very reasonable progress, the last test flight was pretty successful. And NASA has much more visibility into the actual progress of SpaceX here than we outsiders have.
I don't think you can compare Hyperloop and Starship, Hyperloop is just a wild bullshit idea, Starship is a far more realistic project and there are some real resources behind its development.
I would view the claims about the cost of reuse with a huge question mark though. SpaceX has been much better than previous efforts in making reuse feasible, but I think only looking at the fuel is likely to be hugely misleading in terms of actual costs.
hindsight 2020, there have been bilion of $ thrown at it. Musk was promoting it as easy thing to do. And yet its "wild bullshit idea" how come reusable rockets is not a "wild bullshit idea"?
I dont understand how people can eat anything up Musk wildly claims and forget all BS the moment it turns out it was BS.
According to his claims, he will have people on the way to mars last year, for sure.
How come people who hired bunch of grannies to knit a nav computer memory got to moon without loosing a single rocket. And now loosing 3 rockets and still not orbiting is an amazing achievement?
> how come reusable rockets is not a "wild bullshit idea"?
I don't understand the question. Could it be the fact that a Falcon 9 just landed after its 20th trip to space? Seems pretty reusable to me.
> How come people who hired bunch of grannies to knit a nav computer memory got to moon without loosing a single rocket.
Apollo 1 wasn't the whole rocket, but I'd say the three astronauts who died were worth more than that.
How many astronauts has SpaceX lost? ETA: Not one of those first stages returned to earth intact, so in that sense, all the rockets that launched were lost. ETAA: Apollo 1 wasn't on a Saturn V, so my initial response doesn't really follow.
> I dont understand how people can eat anything up Musk wildly claims and forget all BS the moment it turns out it was BS.
All Musk weirdness aside - SpaceX revolutionized the launch business for the planet, and for quite some time already, so it makes sense to watch what they're doing. Results tend to follow, even though many are delayed - but delayed only in comparison to announcements, not to how it's done elsewhere.
> How come people who hired bunch of grannies to knit a nav computer memory got to moon without loosing a single rocket. And now loosing 3 rockets and still not orbiting is an amazing achievement?
Well :) Saturns were simpler, and more modest by performance. And also tested more on test stands, not like Russians used to do - with more emphasis on flight testing. Look how much more successful the Starship testing program is in comparison to Soviet N-1 flights - and remain assured, N-1 was made by serious professionals.
It's a fact Musk is neither as brilliant and infallible as his fans say, nor as clueless as his detractors would like him to be. He's smart and arrogant, a dangerous combination that SpaceX, it seems, grew defenses against.
Just like anyone else, Musk is right some times, wrong at others, and averages out as kind of OK. He's very good at attracting investment though, and SpaceX has been executing really well.
> How come people who hired bunch of grannies to knit a nav computer memory got to moon without loosing a single rocket.
NASA did lose a good couple rockets. They also lost the Apollo I and its crew even before it flew, as well as a number of near misses that were recovered by the brilliance of astronauts (Armstrong saved the day TWICE) and ground crews alike. They also lost two shuttles precisely because they couldn't afford bad news from propagating back to the senate.
> And now loosing 3 rockets and still not orbiting is an amazing achievement?
NASA-style development is very risk averse, which is natural, as it's primarily a government agency tasked with keeping the aerospace and rocket industry happy and healthy, and preventing talented engineers and scientists from moving to Europe, India, Russia, or China. Or North Korea.
NASA can't afford to lose three rockets, because each small piece is expensive and exhaustively simulated and tested before being assembled and launched. It does that to advance our theoretical understanding of how to build spacecraft.
SpaceX iterates quickly and cheaply, blows up engines, rockets, tanks, launch pads and anything else, because it makes them cheaply and use them to learn what NASA does by careful simulation and lab testing.
Last starship launch was orbit equivelent in terms of delta-v expended at each stage of the flight, it just went for a higher apogee and thus lower perigee to avoid the risk of not being able to relight.
That's more than SLS has managed.
The flight also did a fuel transfer test.
The larger question is whether it will be able to reenter. However 14 fully expendible starships are still cheaper than a single SLS launch.
I was under the impression that Artemis I was already a full unmanned mission to moon orbit two years ago, using SLS + Orion.
SLS did get to earth orbit with the Orion payload. While the latest Starship (IFT-3) barely reached "orbital speeds" and failed on re-entry. How is that "more than SLS has managed"?
You could argue that since SLS is not reusable, it kind of also failed on re-entry by design. But the Starship failure was an accident and it has never actually reached orbit, nor has it delivered a meaningful payload successfully. And Starship has ambitions do a lot more than SLS, acting as a full lunar lander and being reusable.
All in all, Starship is in a much earlier stage of development. SLS already fulfilled the purpose it was designed for back in 2022.
> I was under the impression that Artemis I was already a full unmanned mission to moon orbit, using SLS + Orion
You correct. Artemis 1 put the Orion capsule in a distant retrograde lunar orbit [1] before successfully splashing down, all unmanned. I believe this is the same orbit astronauts are going to fly in Artemis 2 in 2025.
SLS burned an absurd amount of money and spent over a decade making sure that the first launch went relatively well, because they can't afford to have visible failures, in part because people are stupid when it comes to testing, and in part because they can only build them fast enough to launch once every other year (unless they're given another ridiculous sum of money and another decade to build more infrastructure).
Starship is testing iteratively, so they spend less money up front to figure out everything before flying, and instead put in a reasonable effort ahead of time and then just fly to figure out what needs improvement. They can afford to do this, because they are designing for mass prduction and because as a private company, they don't have to answer to the ignorant public. Building a new Starship stack is a matter of months, and they're more limited by the rate at which they can test and get through paperwork to launch the things than the rate at which they can build them.
For reference, SLS launched in 2022 and next might launch in 2025, Starship had a close to orbital velocity launch in March (it effectively proved they can get to orbit, it was not actually orbital so as to avoid leaving debris stuck in orbit until they can prove the ability to deorbit) and is expected to launch again in late May/early June.
> SLS burned an absurd amount of money and spent over a decade making sure that the first launch went relatively well, because they can't afford to have visible failures
SLS burned a lot of money because it needed to have massive production in politically-needed districts.
I agree, I was only refuting the "more than SLS has managed". The statement surprised me and I had to look it up to check if I was missing something.
Indeed SLS is very inefficient, Starship certainly has more potential and its achievements are more impressive already in terms of innovation, speed of development and costs. But it's not nearly as capable yet, there are still many unknowns.
> the system is unable to get to the orbit, its not tested.
Yes. Just like every other rocket that is under development.
> Its all high-hopes and conjectures as it is now.
Engineering plans from the company that built the most reliable rocket in human history while pioneering first-stage reusability are "hopes" and "conjectures". They're just spitballing, you guys.
> All of those plans are opinions, that's the problem.
Totally agree. Engineering is more of an feeling than a science.
What kind of ground operations are expected for Starships? The rocket is reusable, the fueling is automated, the in-between flight checks are, what, how do they do that in practice? What are intermediate actions which need to happen in a sequence of launches?
> What kind of ground operations are expected for Starships? The rocket is reusable, the fueling is automated, the in-between flight checks are, what, how do they do that in practice?
Fuelling, systems checks, clearing the launch area, launching, fuel transfer, re-entry, recovery, diagnostics, repairs, recertification, snacks for the repair crew, lawyers, drinks for the lawyers, et cetera.
The goal is automating everything. But even the Falcon family is currently around 3 weeks' sustainable turnaround.
They pump tons of fuel per second, obviously automated. Connecting/disconnecting pipes are with that movable platform. Granted, today it's different, and some more operations might be needed, like, say, more careful stage positioning on the launch system after it landed previously, but they don't seem problematic to include, right?
> systems checks,
SpaceX vastly increased number of channels collecting data on rocket performance. They have much better understanding of the rocket state after landing because of that. Some checks could be done on earth, but we surely don't do system checks every time we sit in a car, and this comparison is only somewhat stretched, agree?
> clearing the launch area,
For Super Heavy the landing happens some minutes after launch; don't think there's going to be many people near the pod. The zone below the trajectory will probably be permanently closed, at least for period of intensive pad use, just like it's done for construction projects now.
> launching,
Of course.
> fuel transfer, re-entry, recovery,
All in-flight operations are automated, even today, because there's no crew around. Problems and misses today, but we're just testing.
> diagnostics,
What's the (crucial) difference with system checks? Seems like we're talking about the same goals.
> repairs,
No repairs for the nominally working system. If checks show repairs are needed, the system - rocket stage - goes to the factory for fixes, that's much longer than the time between flights, but we have spares to use while the repairs happen.
> recertification,
What do we need here to do that is costly or takes a long time? How long does recertification take for a commercial airliner between flights?
> snacks for the repair crew,
Well, repairs are supposed to be a relatively exceptional thing, so done in the factory, with full lunches if not dinners.
> lawyers, drinks for the lawyers, et cetera.
All that for customer's money and time, not on a launch pads.
> The goal is automating everything. But even the Falcon family is currently around 3 weeks' sustainable turnaround.
Don't you have a suspicion that Falcons aren't being improved that much now because it doesn't make sense for the current mass flow to orbit and given that Starship is planned to become available soon?
> pump tons of fuel per second, obviously automated
Sure. Easier said than done, particularly with rapid reuse and when all your equipment is being repeatedly thermal and pressure shocked.
> Some checks could be done on earth, but we surely don't do system checks every time we sit in a car, and this comparison is only somewhat stretched, agree?
We don't send cars to space and back again. (We've also had cars for a century.) Hopefully by the time we're sending humans to Mars, this will be automated. But not in time for Artemis.
> zone below the trajectory will probably be permanently closed
You're describing major shipping lanes in the ship-surveillance area. KSC and CC also tends to close off a few popular flight routes into Orlando.
> in-flight operations are automated, even today, because there's no crew around
Still need people monitoring, including--by law--people ready to abort or order redirect.
> What's the (crucial) difference with system checks?
You have to open the rocket up.
> No repairs for the nominally working system
This has never been demonstrated. (Repairs/refurbishment.)
> Don't you have a suspicion that Falcons aren't being improved that much now because it doesn't make sense for the current mass flow to orbit and given that Starship is planned to become available soon?
No. Falcon launches are currently pad limited.
Note: I think Starship is vastly superior to SLS. But that's in part because the ground operations, including infrastructure, are reused and thus amortised across many flights.
They're aiming for a turnaround time of eventually less than a day. I'm not sure how ships are going to be caught and stacked, but even if ground ops took hundreds of people it's still less than a man-year effort as far as cost when it's done in a day.
To an extent I concur that people are giving his opinion a weirdly large amount of attention relative to its value. They're all worn out arguments in rocketry circles, very reminiscent of all the dumb claims Blue Origin made when they lost the first HLS contract, only to settle on a very similar architecture for the second one.
However, IIRC he has an aerospace masters, is currently pursuing a PhD and used to work on testing missiles, so he's not a complete rando.
By 'giving his opinion a weirdly large amount of attention relative to its value' I'm not saying that his opinion has little value due to his lack of specific space credentials (else my opinion wouldn't matter either lol). I'm saying his opinion has little value because the issues he's pointing to have been discussed to death already by other rocketry enthusiasts and anyone interested would've found those discussions easily.
Sure, the debates aren't fully settled yet, but they're certainly comprehensive enough to make it obvious that the criticisms are kind of weak, such that even if Starship isn't the one to establish all the necessary tech for meeting Artemis' stated goals, it's by far the most promising attempt to do it, as the others weren't even trying.
My comment was more of an agreement, I do think that good points can come from various sides, not only "certified by the upper levels of government".
Starship is in testing, which was chosen to be done with test flights. Those test flights are of course something very different than assumed regular launches later on, after the system would be complete in design, development and testing. Right now Starship isn't even planned to immediately come back to Mechazilla. Starship is obviously incomplete now, but that doesn't mean it can't be completed and successfully used.
Comparing to that the existing plans and results with NASA's Artemis parts are more bleak. Expensive, slow, underperforming - and even dangerous. Smarter Every Day's video points to gaping problems, and he's even explaining why he chose to talk about it - there and then. It shouldn't matter much that he's an engineer - though he couldn't perhaps to talk about it without enough understanding. In his case, it was more important to articulate important points aloud.
> It's like asking, who, Miss Universe what her opinion on the US Space Program is.
I wonder what would happen if this Hollywood star - https://en.wikipedia.org/wiki/Hedy_Lamarr - would be asked about, say, spread spectrum communications. Or a certain patent bureau clerk - about the world-filling ether.
I'm not a rocket scientist but I am very experienced at project management and I can say fairly certainly that an iterative engineering approach to something and complex and full of hard dependencies as Starship will achieve rapid reusability sometime between much later than promised and never. This is a project with an unknowable worst-case completion date because there are way too many issues with too many unknowable times to resolve issues, many of which can only be worked on once previous issues are resolved, and way too many issues continue to be discovered. Converging on completion is not in sight.
Some indicators are that starship's payload capacity keeps getting revised down, and the launch system still needing weeks of repairs between launches, which means even pessimistic estimates of the number of tanker launches and their cadence are probably too optimistic.
> iterative engineering approach to something and complex and full of hard dependencies as Starship will achieve rapid reusability sometime between much later than promised and never
To the opposite, you can't have a complex system working without having first simpler system working, and then iterating from that. Let me know if you need the quote. For rockets in particular, the approach "build a little, test a little" is the current best practice. Starship complexity of course is splittable into engine complexity, set of engines, body, simple control and then other functions - actually, with the exception of Raptors, it's quite an iterateable system.
> This is a project with an unknowable worst-case completion date because there are way too many issues with too many unknowable times to resolve issues, many of which can only be worked on once previous issues are resolved, and way too many issues continue to be discovered.
No, this is totally wrong. And the current pace of existing testing shows just that.
"unknowable worst-case completion date" - strictly speaking, you can never be sure 100% about anything, and if you understand this statement "reasonably", then it's just wrong. Starship will be flying more or less successfully in 3 years, that's rather conservative, and in this decade, very conservatively. Otherwise it will probably be dropped, but chances for that are really low.
"there are way too many issues with too many unknowable times to resolve issues" - no, there are just several rather well-known areas - like, attitude control on the orbit (done with somewhat smaller orbiting bodies), thermal protection during return (done with similar materials, spaceplanes, so both materials and aerodynamics are not completely new), active bracking with engines (done extensively with Falcon-9 first stages), getting caught with Mechazilla (fine controls for Falcon-9 landings and even helicopter catches of payloads from space are relevant) and then quite a number of progressively smaller issues. Will work no problem in the end, high probability.
"many of which can only be worked on once previous issues are resolved" - not exactly. While you can't return with orbital speed unless you got that speed in the first place, other issues could be tested - and Starship flights to 10 km altitude a few years ago were just that, tests for the last 10 km of flight. Not exactly identical to how it's going to happen according to today's plans, but not irrelevant either.
"way too many issues continue to be discovered" - why do you think that? Rockets are something which was done with 50+ years old technology, which for this area is quite a bit; there's just not too much of complexity here. "Rocket science is not a rocket science", as they say in the industry.
"Converging on completion is not in sight." - again, where did you get this from? You're way off in your estimates.
It's not known about number of tankers needed to refuel one Starship. But this is not a particularly important question. Even with 30 tankers required the system still could be made to work. And likely there will be much less of tanker flights than that, so what's the problem?
I’m not sure why we wouldn’t focus on technology, which seems to be the only actually useful part of this mission. I know that some people really like sticking people on objects in space for fun, but at this point it seems like a strange and expensive hobby. Supposedly it’s supposed to get us closer to living in space. Leaving aside whether or not that’s the appropriate goal for the moment, and not, say, 400 years from now, it’s unclear that any of the missions over the past 60 years have actually brought us closer to that. We’ve seen countries that could send people into space in the 60’s lag behind, while others that couldn’t come anywhere close are jumping forward. All signs point to the manned missions themselves not conferring a lot of lasting value.
I want to remind here that, according to some professional space roboticists, humans in space can run certain missions cheaper than automata.
Maybe it's somewhat outdated point of view - it's about 10 years old. But, if you think in general, you might still agree that for complexities above certain point robots could become very, very expensive.
Also, we shouldn't forget that human flights became vastly cheaper than they used to be.
The problem is that “certain missions” are often make work, even for robots in space. Hence why there’s a lot of talk about “doing science” and “doing missions”, very little about what the actual goal is. Or you get certain claims like helium-3 mining that sound good if you’re not paying attention, but then make no sense when you look at the details.
A lot of the manned space stuff - even a lot of the unmanned space stuff - is someone deciding that we need to use a hammer to make something, and therefore making nails part of every plan they have. Even if the job is inflating a balloon.
I was probably too terse. Those missions are above some level of complexity. Robots - even today's ones - scale rather poorly with the complexity required, while for humans a lot of what's needed comes "for free". So, if you need a large expedition to the Moon, which explores places and various aspects, human crews can possibly return results faster and cheaper than similar results could be returned by space robots.
> A lot of the manned space stuff - even a lot of the unmanned space stuff - is someone deciding that we need to use a hammer to make something, and therefore making nails part of every plan they have.
Used to be more, now it's less and less, with decisions being less centralized. In USSR space science initially was discussed on the level of national academy, the highest existing. Now a small group of students can invent a mission to study a particular aspect and get to results.
Potentially more then one might assume. This is an area that needs more research, but initial estimates seem to indicate that an increase in launched very much warrants concern.
CBC made this nice interactive graph highlighting the issue.
I'm a huge proponent of space flight, but my main concern is how the drive towards commoditization, again, seems to gloss over potential hidden costs with a complex, global impact.
Starship doesn't emit most of the emissions listed in that article because it uses clean burning CH4 + O2. Of "soot (black carbon), nitrogen oxides, alumina particles, chlorine, hydrochloric acid and water vapour", only water vapour is a concern.
And it emits about the same amount of CO2 as a trans-pacific jet flight.
So the idea of refueling in space is interesting, but I am a bit confused by the practicality. if we could refuel from the Moon, yeah I 100% see the value of it due to less wasted fuel getting off the moon.
But unless I am mistaken, the biggest problem with fuel is that it obviously costs fuel to get fuel up. It has a weight so its not like you can just say, I want 100 lbs of extra fuel, you need that amount of fuel plus the amount of fuel to carry that amount (and then the amount to carry that amount, and so on and so forth).
So in reality what is the difference between say, 100lbs of fuel across 10 Starships vs 100 lbs of fuel on a single ship?
Yeah you would need a bigger ship to handle all of the fuel necessary, but something about this being necessary for the moon seems off? Mars I can understand more.
I just feel like I am missing something here, until reading this I did not realize that refuel in space was necessary for the Moon.
Also to be clear I am not discounting the work on doing this, but I was just always under the impression that this was a thing that was necessary for Mars where now it seems like we are talking 11 launches to get too the moon?
Maybe there is a typo in the article then that is why this seemed weird?
The first paragraph:
> ambitious refueling demonstration, a technical feat that will put the Moon within reach.
Again here:
> By the time NASA and SpaceX are ready for a lunar landing, multiple Starship tankers will take off from at least two launch pads to aggregate propellants at a depot to supply the Moon-bound Starship.
Then again here:
> On future Starship missions targeting destinations in deep space, like the Moon, this docking maneuver and refueling process will be repeated multiple times to give the vehicle enough gas to boost itself out of Earth orbit.
Another one:
> The results of this refueling demonstration will allow SpaceX and NASA engineers to calculate how many refueling tankers they will need to fill up a Starship heading for the Moon.
All of this makes it seem like this is necessary just to get to the moon with Starship which really makes me wonder about the practicality of this when later it mentions the possibility of 10 refueling missions.
> All of this makes it seem like this is necessary just to get to the moon with Starship
The Artemis architecture requires in-orbit refuelling to go anywhere interesting. (More due to the limitations of SLS and Orion than Starship, but I digress.) The Artemis architecure isn't necessary to go to the moon--Apollo had no in-orbit refuelling.
We've chosen an architecture that requires in-orbit refuelling to go anywhere because it better scales to going to Mars.
100lbs is obviously not a lot of mass for refueling to mean much. But, if Apollo needed to launch 3000t to land 16t on the Moon, a Starship with 100t of payload and say, 300t of propellant, would need a ~75000t rocket from Earth. Efficiency improvements reduce this a bit, but not meaningfully.
Hopefully you can see how that's kind of unrealistic and unscalable to do in one launch.
Orbital refueling is a core technology necessary for sending useful amounts of payload around the solar system because the rockets themselves can't really get much larger without becoming completely uneconomical. Congress understood that orbital refueling would make their obscenely expensive SLS program unnecessary, which is why they effectively banned NASA from using the word "depot" (until Senator Shelby retired) under threat of canceling the entire space technology program, and strongarmed ULA into not pursuing an upper stage capable of carrying Orion and performing orbital refueling (which again, would've replaced a $2B per launch rocket with a couple of launches of a ~$150M rocket).
The number of launches sounds like a lot, but consider that F9 is already launching 2-3 times each week, and Starship is being designed explicitly to not have the factors that are limiting F9 cadence from increasing further. The engines are better designed for reuse, the launch infrastructure is easier to build many copies of, the boosters always come back to land, the second stage integrates onto the booster at the launch pad etc.
Also, as a side note, they'll need roughly the same number of refueling flights for Mars. The fuel requirements for going to the Lunar surface and Martian surface are actually pretty similar, since on Mars you can save a lot on using the atmosphere to slow down, while you can't on the Moon.
The amount of fuel limits how far you can go in terms of delta-v and mass. So, if you have to have all the fuel on board when you launch from the ground, there's only so far you will go and so much you can take with you. The point of going back to the moon is not only just planting a few more flags but actually taking some meaningful amount of resources there to ultimately be able to build a moon base. Same with Mars. And we might want to take some more stuff back (rocks, minerals, whatever). So, that requires fuel as well.
The point of refueling is getting to orbit and then topping up all the fuel you lost getting there (i.e. most of the fuel because getting out of the atmosphere takes a lot of energy). Starship when it starts flying will be by far the largest amount of mass we can get to orbit. Like upto 150 tonnes or whatever the maximum payload is going to be. So, that amount of fuel would enable large amounts of mass to be accelerated to a path to the Moon, Mars, or wherever way beyond what would otherwise be feasible.
And with a reusable launch vehicle, it actually gets doable from a price point of view as well.
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[ 103 ms ] story [ 401 ms ] threadEdit: aha, found - "Then, SpaceX will fine-tune tank pressures and fire propellant settling thrusters." And they are using free flow. Wonder how long the transfer will take and how much of a propellant settling acceleration is needed?.. Also :) the relative positions of ships become important if no pumps are used...
It shouldn’t if they’re using pressure to feed propellant. Do you mean relative to the Sun in respect of boil off?
That's how I'm reading it, analogous to a pressure-fed engine [1]. A separate, expendable gas supply pressurises the donor tank to force the propellant out and over.
[1] https://en.wikipedia.org/wiki/Pressure-fed_engine
> A separate, expendable gas supply pressurises the donor tank to force the propellant out and over.
But what if the fuel is a mix of liquid bubbles and the gas freely floating in the tank?
(BTW, on the different point, some pumps applicable here could be really simple, like analogous to https://en.wikipedia.org/wiki/Vacuum_ejector#Water_aspirator)
I believe the plan is to impart a gentle spin.
> some pumps applicable here could be really simple
The Venturi effect reduces pressure. It's definitely worth exploring. But you'd need to test it to explore where it causes volumetric effects, e.g. by exacerbating boil off.
That would be something new. And for a partially refueled stage, that's a lot of mass to spin. How fast? the speed of spinning could be important too.
No clue! But I think they were targeting mili-g acceleration--could probably be achieved by the boil off alone.
Now we just need the Attenborough voiceover about the mating habits of starships as they spin through space.
That would send fluids to the back of the tanks.
At this stage it might be easier to build fueling station in the orbit with actual transfer pumps.
As for spinning two Starships of significantly different mass... that should be interesting to see. Doable, yes :) but interesting nevertheless.
Pushing the liquids is not the hard part. Settling the liquids in 0g is the hard part.
Maybe not in all variants, but definitely in the crew version, as having the ability to transfer propellant even if the pressure differences and settling cannot be achieved seems worth the lost performance.
Pumps are way more complicated than pressure feeding.
[1] Talking about the Artemis program to the American Astronautical Society https://www.youtube.com/watch?v=OoJsPvmFixU
Well, peak ~4% of US budget, not GDP, in 1966. A lot, but not that much.
But it’s kinda hard to define, since it also grew GDP tremendously (in the US). It may have been a much higher percentage with 1945 costs measured against 1939 GDP, if that makes sense, but I’m not sure it’s appropriate to make that comparison.
I think the average figure is 2.5% yearly for 10 years, so that would be as if it were 25% in one year for the entire programme.
Those kind of missions are complex tasks and complicating things make them more complex and error prone exponentially
Re-certify for flight? I can envision an automated procedure which would analyze the data obtained from the rocket in flight and after flight which makes a decision in a split second, just like some systems in cars routinely do.
Hoping nothing will go bad? You can get much more risks on unmanned missions. You'll also get numbers on your side, when if something goes wrong you fix it, systematically, for future attempts. That's not exactly just hoping, right?
Except there isn't any data to back that up. It took off empty this last time, and didn't have enough fuel to complete it's mission.
There's seemingly no physical - or economical, for that matter - reason for this to be impossible, so why not? Starship definitely didn't complete testing at this point, many things are still ahead of us, but to talk about impossibilities - why? Yes, of course we didn't do that yet, but we're talking about possibilities in the future.
"By this point". Well, we have testing program here (which to me looks pretty successful so far), the capabilities of the system - demonstrated, that is - are increased with each flight. Load test - that is, bringing to orbit the full payload the Starship is designed for - has not happened yet, and, as far as I remember, Falcon also didn't have such a test for some record mass. I'm sure we'll see some reasonable payload flights at some point "soon". What's the problem here?
> Especially considering that they should be long past that point according to their last updated roadmap.
Ah :) maybe you're talking about the thing which SpaceX refers jokingly as "we transform impossible things to late". Yes, "Musk's time" is always very aggressive, and I even suspect to know why he's, as an engineer and a visioner, does that. And why Shotwell's estimates are more accurate - she excels at operations, after all.
But I don't see a principal problem here either. Yes, the - rather aggressive, by aerospace standards - schedule slips to the right, while still producing results, years in a row. Big deal.
https://www.nasa.gov/news-release/nasa-publishes-artemis-pla...
I suspect this isn’t happening this year and this article is only a few years old. On traditional launches in the past, at least a 25% load is put in the hold, even on the first launch. You generally want to show off that you can at least lift off the ground, unless you can’t.
Would note that to date, Artemis has been solely delayed by Orion not being able to get its shit together.
Everything on Artemis is late; Starship is less late than pretty much everything else.
It was an intentional decision not to go into orbit.
Again, the criticisms are valid. But it's unlikely we can get to Mars--repeatedly and sustainably--without mastering in-orbit re-fuelling. So while it isn't technically necessary for a Moon mission, nor even repeated Moon missions, it is for a Moon mission that's building to Mars. (Again, repeatedly--we can do without it [1]. But it's far more expensive in the long run.)
> How long would it take to re-certify starship for a launch?
Falcon 9 has been turned around in 3 weeks [2]. The bottleneck has thus far been launch pads. If you can cut that to 2 weeks, you need 5 to 7 refuelling Starships ready per launch. Once again, the bottleneck would be launch pads.
You and I are on the same page about that re-fuelling overhead being bonkers. It's mostly because SLS and Orion suck. But if the only thing we learn from Artemis is fuel depoting, that's a huge win.
> You are going to need dozens of them launching everyday for months to prep one mission and hoping nothing will go bad
The timeline for the first propellant-transfer test is three to four weeks. 14 launches over 30 days comes to a launch every other day. Ambitious, but only about twice as frequently as the Falcon family launched in 2023, and for a shorter interval.
[1] https://en.wikipedia.org/wiki/Mars_Direct#Second_launch
[2] https://twitter.com/SpaceX/status/1520155013661659137?ref_sr...
Not sure I understand your numbers here in relation to the quoted part?
The unknown variable is in-orbit propellant boil-off. How much propellant will poof away for each day in orbit, and during the propellant transfer. The test next month will observe this for 3 to 4 weeks. So for the actual mission, we will presumably have 3 to 4 weeks to put all the fuel in orbit. Assuming it takes 14 launches to launch that fuel (we won't know the final number until we do the tests), that gives us a required average launch cadence of about 2 days.
It should be, but we haven't done it yet [1].
> active cooling systems can be used, they don't need to be big or complex
Cooling in space is always complicated given the only way to dump heat is radiating (or dumping into ejected mass, i.e. boil off).
[1] https://en.wikipedia.org/wiki/Orbital_propellant_depot#Heavy...
Yes, but there were some calculations for this - http://astronautix.com/n/n1blocksr.html - which hints on boiling off to be manageable for large stages.
I do agree that we need to do small steps before big steps. But overall this "lets save money with reusing Shuttle stack" has backfired spectacularly. And delayed both small step and bigger step for decade(s).
There are real questions about LEO versus deep space habitation, specifically in respect of solar radiation. Gateway will help settle those questions.
> this "lets save money with reusing Shuttle stack" has backfired spectacularly
100% agree. And I honestly don't see us using SLS and Orion to go to Mars. But Gateway will be proving real science and hardware. And SLS, Orion and even the Gateway are more easily deprecated from the Artemis framework than e.g. Starship.
Could we have a better system? Sure. Is there a better path forward if we want boots on Mars in the 2030s? No.
And having many launches if you actually get a lot out of it isn't really a problem.
His whole approch seem to be 'this more complex then apollo' and therefore bad.
He spent a lot of time going after SpaceX but spent almost non going after the real problem with the moon program. The incredible expensive lagecy technology forced by congrsss that is dragging the whole programs potential down.
So I think in totalility message is really just reinforcing the Johnson center ultra conservative 'money is irrelevant' approch to engineering.
I see Artemis as an attempt to industrialise the process of getting humans and large volumes of materials to the Moon, ultimately as a stepping stone to Mars. This isn't a proof of concept self-contained "mission" like Apollo was. It felt a bit like saying the global aviation system is overengineered compared to the Wright Flyer. I don't see why it really matters if it needs 15, 20 or even 50 reusable vessels for orbital refuelling as long as that process is repeatable and safe.
That said, it's been a few months since I watched that video so I may not have done a good job here of remembering what my criticisms even were.
The shocking thing for me from that video was learning how useless the Lunar Gateway is most of the time due to its near-rectilinear halo orbit. This leads it to be only within range for rescuing those on the moon, for a couple days a week.
Why does Gateway have this type of orbit? Because the Senate Launch System doesn't have the delta-v to get the capsule to circularized low-lunar orbit. We designed a moon rocket, which can't get to the moon.
I genuinely never heard about the Gateway being there for rescue until Destin's talk. (Not saying he invented it. Just that it wasn't what it was advertised for.) Compared to just landing a spare Earth ascent vehicle, it seems like a stupid way to solve for our lack of low-gravity trauma medicine experience.
> Why does Gateway have this type of orbit? Because the Senate Launch System doesn't have the delta-v to get the capsule to circularized low-lunar orbit
NRHO also minimises communication black-outs with Earth. With the Gateway in orbit, other craft in circular orbit can maintain continuous contact with the Earth.
But why would you set that as a pre-requisite?
The Gateway is also, as I understand it, a staging ground for testing habitation for a vehicle to Mars.
Well, the argument in his video is that there are multi-day gaps in the ability to rescue astronauts off the moon. Balancing that out with a few very small relay satellites, I would pay for a couple Electron launches for the relay, and have a lifeboat capability 24/7.
> The Gateway is also, as I understand it, a staging ground for testing habitation for a vehicle to Mars.
I have heard that as well, but what I don't understand is how a higher orbit simulates a Mars trip much better. I mean, either way you are not inside a magnetosphere, right? I guess in low-lunar orbit you are more shaded from solar wind by the moon half the time?
Right, which is where he loses me--this is not why we have a Gateway.
> Balancing that out with a few very small relay satellites, I would pay for a couple Electron launches for the relay, and have a lifeboat capability 24/7
Building a communications relay constellation isn't a simple task. It's on the roadmap for Artemis.
> what I don't understand is how a higher orbit simulates a Mars trip much better
The high orbit is irrelevant to this aim. You'd get the same deep-space habitation science from a low, circularised orbit. The high orbit is for creating a one-and-done communication relay.
I am just an everyday armchair astronaut, so please correct me where I'm wrong, but I figured:
1) A lunar lander does not have the delta-v for direct return to earth, from the lunar surface. (or the heat shielding)
(2) Part of the Gateway's function is similar to Apollo's Command Module. A place for the lander to dock upon return, and facilitate return to earth.
I can see how Gateway differs from Apollo's Command Module, in that it does not return to Earth, but stays in lunar orbit. This does test Mars-like endurance, and is cool. Orion will detach from Gateway, and return independently, right? But why the near-rectilinear halo orbit, which puts the lifeboat capability out reach sometimes? If an astronaut needs something like an appendix removed (random example,) then a few days waiting for Gateway to swing by could make a difference.
edit: Oh, near-rectilinear halo orbit also makes it easier for Orion to return to Earth, right? So maybe he said that Orion lacks the delta-v, not SLS. Maybe that helps explain it.
Starship HLS is the lunar lander [1]. That said, it is not designed to survive Earth re-entry at lunar velocities.
> why the near-rectilinear halo orbit, which puts the lifeboat capability out reach
I guess I'm sceptical of any Gateway serving as a lifeboat in an emergency with a day-to-day sensitivity where aid can be provided on Earth but not on the Moon.
> Orion lacks the delta-v, not SLS
Correct. SLS is expensive, Orion underpowered.
[1] https://en.wikipedia.org/wiki/Starship_HLS
Or any velocity. It doesn't have thermal tiles.
It's more a logistics problem than anything else. If a Superheavy and Tanker takes 3 weeks to relaunch, you build 3 to launch weekly and 21 to launch daily. Now you need to have 21 processing facilities and 21 times more people to do that. Launch pads, landing pads, and Mechazillas don't need that long to recover, so you can build just a couple extra ones with each one serving a group of processing facilities.
Criticize the parts of the system that are both expensive and prevent us from taking advantage of Starship's ability to land 100 tons on the moon. SLS.
the system is unable to get to the orbit, its not tested. Its all high-hopes and conjectures as it is now.
All of those plans are opinions, that's the problem.
Its like planning your infrastructure around hyperloop, but it doesnt exists. So all of the plans are founded on vaporware.
That is highly problematic thinking.
I don't think you can compare Hyperloop and Starship, Hyperloop is just a wild bullshit idea, Starship is a far more realistic project and there are some real resources behind its development.
I would view the claims about the cost of reuse with a huge question mark though. SpaceX has been much better than previous efforts in making reuse feasible, but I think only looking at the fuel is likely to be hugely misleading in terms of actual costs.
hindsight 2020, there have been bilion of $ thrown at it. Musk was promoting it as easy thing to do. And yet its "wild bullshit idea" how come reusable rockets is not a "wild bullshit idea"?
I dont understand how people can eat anything up Musk wildly claims and forget all BS the moment it turns out it was BS.
According to his claims, he will have people on the way to mars last year, for sure.
How come people who hired bunch of grannies to knit a nav computer memory got to moon without loosing a single rocket. And now loosing 3 rockets and still not orbiting is an amazing achievement?
I don't understand the question. Could it be the fact that a Falcon 9 just landed after its 20th trip to space? Seems pretty reusable to me.
> How come people who hired bunch of grannies to knit a nav computer memory got to moon without loosing a single rocket.
Apollo 1 wasn't the whole rocket, but I'd say the three astronauts who died were worth more than that. How many astronauts has SpaceX lost? ETA: Not one of those first stages returned to earth intact, so in that sense, all the rockets that launched were lost. ETAA: Apollo 1 wasn't on a Saturn V, so my initial response doesn't really follow.
All Musk weirdness aside - SpaceX revolutionized the launch business for the planet, and for quite some time already, so it makes sense to watch what they're doing. Results tend to follow, even though many are delayed - but delayed only in comparison to announcements, not to how it's done elsewhere.
Well :) Saturns were simpler, and more modest by performance. And also tested more on test stands, not like Russians used to do - with more emphasis on flight testing. Look how much more successful the Starship testing program is in comparison to Soviet N-1 flights - and remain assured, N-1 was made by serious professionals.
Is that, I have no arguments so I call people names reply? There are so many of the posts using it like a 'I win ticket'
Its just a stupid Ad hominem attack.
The stuff i can make up and call it probable future that never materializes but then nobody remembers it as I move on to another grift, facts wink
> How come people who hired bunch of grannies to knit a nav computer memory got to moon without loosing a single rocket.
NASA did lose a good couple rockets. They also lost the Apollo I and its crew even before it flew, as well as a number of near misses that were recovered by the brilliance of astronauts (Armstrong saved the day TWICE) and ground crews alike. They also lost two shuttles precisely because they couldn't afford bad news from propagating back to the senate.
> And now loosing 3 rockets and still not orbiting is an amazing achievement?
NASA-style development is very risk averse, which is natural, as it's primarily a government agency tasked with keeping the aerospace and rocket industry happy and healthy, and preventing talented engineers and scientists from moving to Europe, India, Russia, or China. Or North Korea.
NASA can't afford to lose three rockets, because each small piece is expensive and exhaustively simulated and tested before being assembled and launched. It does that to advance our theoretical understanding of how to build spacecraft.
SpaceX iterates quickly and cheaply, blows up engines, rockets, tanks, launch pads and anything else, because it makes them cheaply and use them to learn what NASA does by careful simulation and lab testing.
It couldn’t even get its attitude right for rentry.
That's more than SLS has managed.
The flight also did a fuel transfer test.
The larger question is whether it will be able to reenter. However 14 fully expendible starships are still cheaper than a single SLS launch.
SLS did get to earth orbit with the Orion payload. While the latest Starship (IFT-3) barely reached "orbital speeds" and failed on re-entry. How is that "more than SLS has managed"?
You could argue that since SLS is not reusable, it kind of also failed on re-entry by design. But the Starship failure was an accident and it has never actually reached orbit, nor has it delivered a meaningful payload successfully. And Starship has ambitions do a lot more than SLS, acting as a full lunar lander and being reusable.
All in all, Starship is in a much earlier stage of development. SLS already fulfilled the purpose it was designed for back in 2022.
You correct. Artemis 1 put the Orion capsule in a distant retrograde lunar orbit [1] before successfully splashing down, all unmanned. I believe this is the same orbit astronauts are going to fly in Artemis 2 in 2025.
[1] https://en.wikipedia.org/wiki/Distant_retrograde_orbit
SLS burned an absurd amount of money and spent over a decade making sure that the first launch went relatively well, because they can't afford to have visible failures, in part because people are stupid when it comes to testing, and in part because they can only build them fast enough to launch once every other year (unless they're given another ridiculous sum of money and another decade to build more infrastructure).
Starship is testing iteratively, so they spend less money up front to figure out everything before flying, and instead put in a reasonable effort ahead of time and then just fly to figure out what needs improvement. They can afford to do this, because they are designing for mass prduction and because as a private company, they don't have to answer to the ignorant public. Building a new Starship stack is a matter of months, and they're more limited by the rate at which they can test and get through paperwork to launch the things than the rate at which they can build them.
For reference, SLS launched in 2022 and next might launch in 2025, Starship had a close to orbital velocity launch in March (it effectively proved they can get to orbit, it was not actually orbital so as to avoid leaving debris stuck in orbit until they can prove the ability to deorbit) and is expected to launch again in late May/early June.
SLS burned a lot of money because it needed to have massive production in politically-needed districts.
It had orbital velocity, but it wasn't on an orbital trajectory. At least based on the numbers provided and Scott Manley's description of events.
I think the NASA award for pumping tonnes of oxidizer required them to be at or above orbital velocity.
Indeed SLS is very inefficient, Starship certainly has more potential and its achievements are more impressive already in terms of innovation, speed of development and costs. But it's not nearly as capable yet, there are still many unknowns.
What's the problem here which is going to stop the progress on the Starship program?
> the system is unable to get to the orbit, its not tested.
Yes. Just like every other rocket that is under development.
> Its all high-hopes and conjectures as it is now.
Engineering plans from the company that built the most reliable rocket in human history while pioneering first-stage reusability are "hopes" and "conjectures". They're just spitballing, you guys.
> All of those plans are opinions, that's the problem.
Totally agree. Engineering is more of an feeling than a science.
Fuelling, systems checks, clearing the launch area, launching, fuel transfer, re-entry, recovery, diagnostics, repairs, recertification, snacks for the repair crew, lawyers, drinks for the lawyers, et cetera.
The goal is automating everything. But even the Falcon family is currently around 3 weeks' sustainable turnaround.
They pump tons of fuel per second, obviously automated. Connecting/disconnecting pipes are with that movable platform. Granted, today it's different, and some more operations might be needed, like, say, more careful stage positioning on the launch system after it landed previously, but they don't seem problematic to include, right?
> systems checks,
SpaceX vastly increased number of channels collecting data on rocket performance. They have much better understanding of the rocket state after landing because of that. Some checks could be done on earth, but we surely don't do system checks every time we sit in a car, and this comparison is only somewhat stretched, agree?
> clearing the launch area,
For Super Heavy the landing happens some minutes after launch; don't think there's going to be many people near the pod. The zone below the trajectory will probably be permanently closed, at least for period of intensive pad use, just like it's done for construction projects now.
> launching,
Of course.
> fuel transfer, re-entry, recovery,
All in-flight operations are automated, even today, because there's no crew around. Problems and misses today, but we're just testing.
> diagnostics,
What's the (crucial) difference with system checks? Seems like we're talking about the same goals.
> repairs,
No repairs for the nominally working system. If checks show repairs are needed, the system - rocket stage - goes to the factory for fixes, that's much longer than the time between flights, but we have spares to use while the repairs happen.
> recertification,
What do we need here to do that is costly or takes a long time? How long does recertification take for a commercial airliner between flights?
> snacks for the repair crew,
Well, repairs are supposed to be a relatively exceptional thing, so done in the factory, with full lunches if not dinners.
> lawyers, drinks for the lawyers, et cetera.
All that for customer's money and time, not on a launch pads.
> The goal is automating everything. But even the Falcon family is currently around 3 weeks' sustainable turnaround.
Don't you have a suspicion that Falcons aren't being improved that much now because it doesn't make sense for the current mass flow to orbit and given that Starship is planned to become available soon?
Sure. Easier said than done, particularly with rapid reuse and when all your equipment is being repeatedly thermal and pressure shocked.
> Some checks could be done on earth, but we surely don't do system checks every time we sit in a car, and this comparison is only somewhat stretched, agree?
We don't send cars to space and back again. (We've also had cars for a century.) Hopefully by the time we're sending humans to Mars, this will be automated. But not in time for Artemis.
> zone below the trajectory will probably be permanently closed
You're describing major shipping lanes in the ship-surveillance area. KSC and CC also tends to close off a few popular flight routes into Orlando.
> in-flight operations are automated, even today, because there's no crew around
Still need people monitoring, including--by law--people ready to abort or order redirect.
> What's the (crucial) difference with system checks?
You have to open the rocket up.
> No repairs for the nominally working system
This has never been demonstrated. (Repairs/refurbishment.)
> Don't you have a suspicion that Falcons aren't being improved that much now because it doesn't make sense for the current mass flow to orbit and given that Starship is planned to become available soon?
No. Falcon launches are currently pad limited.
Note: I think Starship is vastly superior to SLS. But that's in part because the ground operations, including infrastructure, are reused and thus amortised across many flights.
They're aiming for a turnaround time of eventually less than a day. I'm not sure how ships are going to be caught and stacked, but even if ground ops took hundreds of people it's still less than a man-year effort as far as cost when it's done in a day.
It's like asking, who, Miss Universe what her opinion on the US Space Program is.
However, IIRC he has an aerospace masters, is currently pursuing a PhD and used to work on testing missiles, so he's not a complete rando.
Sure, the debates aren't fully settled yet, but they're certainly comprehensive enough to make it obvious that the criticisms are kind of weak, such that even if Starship isn't the one to establish all the necessary tech for meeting Artemis' stated goals, it's by far the most promising attempt to do it, as the others weren't even trying.
Starship is in testing, which was chosen to be done with test flights. Those test flights are of course something very different than assumed regular launches later on, after the system would be complete in design, development and testing. Right now Starship isn't even planned to immediately come back to Mechazilla. Starship is obviously incomplete now, but that doesn't mean it can't be completed and successfully used.
Comparing to that the existing plans and results with NASA's Artemis parts are more bleak. Expensive, slow, underperforming - and even dangerous. Smarter Every Day's video points to gaping problems, and he's even explaining why he chose to talk about it - there and then. It shouldn't matter much that he's an engineer - though he couldn't perhaps to talk about it without enough understanding. In his case, it was more important to articulate important points aloud.
I wonder what would happen if this Hollywood star - https://en.wikipedia.org/wiki/Hedy_Lamarr - would be asked about, say, spread spectrum communications. Or a certain patent bureau clerk - about the world-filling ether.
Some indicators are that starship's payload capacity keeps getting revised down, and the launch system still needing weeks of repairs between launches, which means even pessimistic estimates of the number of tanker launches and their cadence are probably too optimistic.
> iterative engineering approach to something and complex and full of hard dependencies as Starship will achieve rapid reusability sometime between much later than promised and never
To the opposite, you can't have a complex system working without having first simpler system working, and then iterating from that. Let me know if you need the quote. For rockets in particular, the approach "build a little, test a little" is the current best practice. Starship complexity of course is splittable into engine complexity, set of engines, body, simple control and then other functions - actually, with the exception of Raptors, it's quite an iterateable system.
> This is a project with an unknowable worst-case completion date because there are way too many issues with too many unknowable times to resolve issues, many of which can only be worked on once previous issues are resolved, and way too many issues continue to be discovered.
No, this is totally wrong. And the current pace of existing testing shows just that.
"unknowable worst-case completion date" - strictly speaking, you can never be sure 100% about anything, and if you understand this statement "reasonably", then it's just wrong. Starship will be flying more or less successfully in 3 years, that's rather conservative, and in this decade, very conservatively. Otherwise it will probably be dropped, but chances for that are really low.
"there are way too many issues with too many unknowable times to resolve issues" - no, there are just several rather well-known areas - like, attitude control on the orbit (done with somewhat smaller orbiting bodies), thermal protection during return (done with similar materials, spaceplanes, so both materials and aerodynamics are not completely new), active bracking with engines (done extensively with Falcon-9 first stages), getting caught with Mechazilla (fine controls for Falcon-9 landings and even helicopter catches of payloads from space are relevant) and then quite a number of progressively smaller issues. Will work no problem in the end, high probability.
"many of which can only be worked on once previous issues are resolved" - not exactly. While you can't return with orbital speed unless you got that speed in the first place, other issues could be tested - and Starship flights to 10 km altitude a few years ago were just that, tests for the last 10 km of flight. Not exactly identical to how it's going to happen according to today's plans, but not irrelevant either.
"way too many issues continue to be discovered" - why do you think that? Rockets are something which was done with 50+ years old technology, which for this area is quite a bit; there's just not too much of complexity here. "Rocket science is not a rocket science", as they say in the industry.
"Converging on completion is not in sight." - again, where did you get this from? You're way off in your estimates.
It's not known about number of tankers needed to refuel one Starship. But this is not a particularly important question. Even with 30 tankers required the system still could be made to work. And likely there will be much less of tanker flights than that, so what's the problem?
Maybe it's somewhat outdated point of view - it's about 10 years old. But, if you think in general, you might still agree that for complexities above certain point robots could become very, very expensive.
Also, we shouldn't forget that human flights became vastly cheaper than they used to be.
A lot of the manned space stuff - even a lot of the unmanned space stuff - is someone deciding that we need to use a hammer to make something, and therefore making nails part of every plan they have. Even if the job is inflating a balloon.
> A lot of the manned space stuff - even a lot of the unmanned space stuff - is someone deciding that we need to use a hammer to make something, and therefore making nails part of every plan they have.
Used to be more, now it's less and less, with decisions being less centralized. In USSR space science initially was discussed on the level of national academy, the highest existing. Now a small group of students can invent a mission to study a particular aspect and get to results.
And how much is that going to pollute our atmosphere?
But then it's much less of passenger * mile with the given definition.
CBC made this nice interactive graph highlighting the issue.
https://newsinteractives.cbc.ca/features/2023/rocket-polluti...
I'm a huge proponent of space flight, but my main concern is how the drive towards commoditization, again, seems to gloss over potential hidden costs with a complex, global impact.
And it emits about the same amount of CO2 as a trans-pacific jet flight.
But unless I am mistaken, the biggest problem with fuel is that it obviously costs fuel to get fuel up. It has a weight so its not like you can just say, I want 100 lbs of extra fuel, you need that amount of fuel plus the amount of fuel to carry that amount (and then the amount to carry that amount, and so on and so forth).
So in reality what is the difference between say, 100lbs of fuel across 10 Starships vs 100 lbs of fuel on a single ship?
Yeah you would need a bigger ship to handle all of the fuel necessary, but something about this being necessary for the moon seems off? Mars I can understand more.
I just feel like I am missing something here, until reading this I did not realize that refuel in space was necessary for the Moon.
Also to be clear I am not discounting the work on doing this, but I was just always under the impression that this was a thing that was necessary for Mars where now it seems like we are talking 11 launches to get too the moon?
Exponential.
> something about this being necessary for the moon seems off? Mars I can understand more
It's not necessary for the Moon. The reason we're doing it is so once Artemis is done on the Moon, we have a system ready to send astronauts to Mars.
[1] https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation#Ex...
The first paragraph:
> ambitious refueling demonstration, a technical feat that will put the Moon within reach.
Again here:
> By the time NASA and SpaceX are ready for a lunar landing, multiple Starship tankers will take off from at least two launch pads to aggregate propellants at a depot to supply the Moon-bound Starship.
Then again here:
> On future Starship missions targeting destinations in deep space, like the Moon, this docking maneuver and refueling process will be repeated multiple times to give the vehicle enough gas to boost itself out of Earth orbit.
Another one:
> The results of this refueling demonstration will allow SpaceX and NASA engineers to calculate how many refueling tankers they will need to fill up a Starship heading for the Moon.
All of this makes it seem like this is necessary just to get to the moon with Starship which really makes me wonder about the practicality of this when later it mentions the possibility of 10 refueling missions.
Or am I misreading what this is saying?
The Artemis architecture requires in-orbit refuelling to go anywhere interesting. (More due to the limitations of SLS and Orion than Starship, but I digress.) The Artemis architecure isn't necessary to go to the moon--Apollo had no in-orbit refuelling.
We've chosen an architecture that requires in-orbit refuelling to go anywhere because it better scales to going to Mars.
This is the same goal with SpaceX. To drive the price of ton to orbit down a lot. That is the only way a city on Mars happens.
Hopefully you can see how that's kind of unrealistic and unscalable to do in one launch.
Orbital refueling is a core technology necessary for sending useful amounts of payload around the solar system because the rockets themselves can't really get much larger without becoming completely uneconomical. Congress understood that orbital refueling would make their obscenely expensive SLS program unnecessary, which is why they effectively banned NASA from using the word "depot" (until Senator Shelby retired) under threat of canceling the entire space technology program, and strongarmed ULA into not pursuing an upper stage capable of carrying Orion and performing orbital refueling (which again, would've replaced a $2B per launch rocket with a couple of launches of a ~$150M rocket).
The number of launches sounds like a lot, but consider that F9 is already launching 2-3 times each week, and Starship is being designed explicitly to not have the factors that are limiting F9 cadence from increasing further. The engines are better designed for reuse, the launch infrastructure is easier to build many copies of, the boosters always come back to land, the second stage integrates onto the booster at the launch pad etc.
Also, as a side note, they'll need roughly the same number of refueling flights for Mars. The fuel requirements for going to the Lunar surface and Martian surface are actually pretty similar, since on Mars you can save a lot on using the atmosphere to slow down, while you can't on the Moon.
The point of refueling is getting to orbit and then topping up all the fuel you lost getting there (i.e. most of the fuel because getting out of the atmosphere takes a lot of energy). Starship when it starts flying will be by far the largest amount of mass we can get to orbit. Like upto 150 tonnes or whatever the maximum payload is going to be. So, that amount of fuel would enable large amounts of mass to be accelerated to a path to the Moon, Mars, or wherever way beyond what would otherwise be feasible.
And with a reusable launch vehicle, it actually gets doable from a price point of view as well.