Aren’t rockets to the moon vs LEO and GEO on completely different levels of requirements?

To send starship to the moon takes 5-10 more starships to refuel it first. Of course, comparing orion to starship is like comparing a dragon to the space shuttle. Starship is enormous and that's why it needs so much fuel lol.

I'm not saying there's room for improvement, but I think people neg Artemis way too hard for what it is. And people give Starship too much credit for what it is (so far). (And I DO like the idea of Starship and hope it succeeds). If it succeeds things will be awesome!

Starship hasn’t made orbit yet. I’m hopefully it will, even factoring in Elon time (wasn’t he talking about reaching Mars unmanned in 2024?) it’s slow going.

I’m hopeful it will meat here falcons success, but until then compare what’s actually possible today.

That is a very unfair comparison. You are giving numbers for Starship going to NRHO, then landing the whole upper stage on the moon, then returning it to NRHO. That is a completely different ballpark to SLS's ‘dump a capsule in a lunar flyby which itself can't even get to LLO’.

And if the SLS/Orion architecture wasn't so underperforming, Starship could waste less energy making up for it.

Not really. If you have enough payload to LEO you can also throw something to TLI, just less. All commercial rockets like Falcon 9 or Atlas 5 can throw lots of payload to the moon as well. Even tiny rockets like Rocket Lab Electron have launched moon missions.

Now what is true that the further out you go, a hydrogen RL-10 based upper stage will win out better then a Falcon 9 based kerlox upper stage.

So while the payload to LEO between rockets can be pretty close, the payload to a moon orbit can be quite different.

2nd LEO should be something else.

Correct, I originally wanted to write LLO but that wasn't correct either as that requries a space craft to fly insertion and many rockets couldn't do that. But TLI is what all rockets should be capable of doing.

I've seen a lot of people claim that, but it's misleading. Falcon Heavy is the most powerful rocket to LEO, GEO, TLI (trans lunar injection), and higher energy orbits like the ones you use for Jupiter and beyond.

When SLS finishes development, it will also hold the record for all 3.

I’m curious about this too. Are any of the private companies anywhere near ready to send a ship to the moon and back?

Falcon Heavy (existing SpaceX rocket, not human rated) can get a ship to above the moon and back today, but probably not within enough margin to land on the moon in one launch. Making a lander which launches on top of it would require substantial development work anyways, so not really close (and not planned).

Starship is a SpaceX rocket reasonably late in the development cycle, and is planned to land on the moon in an uncrewed demonstration flight no earlier than 2024, and with people during NASA's Artemis 3 mission no earlier than 2025. According to the plan this will be the first mission to land people on the moon since Apollo.

SLS at this point is not planning on launching a vehicle that lands on the moon, instead just a very very expensive taxi to a starship in lunar orbit which could have easily carried the astronauts there itself...

That said, it seems unlikely that a vehicle will go from "has never reached orbit and has a novel refueling model" to "is rated for human spaceflight" in a year or two. I think the Starship is cool as hell, but realistically we're probably looking at 2027+ before we see substantial missions on it.

No earlier than dates are optimistic by nature. I could believe the dates if everything (from launches to environmental approvals) goes well, that is unlikely though.

Regardless of the dates, Artemis using starship as a lander seems practically guaranteed at this point, so SLS really is relegated to the role of unnecessary taxi...

On-orbit refueling is neither very complex nor untried.

Really? We've loaded that much cryogenic fuel before on a manned mission?

Pretty sure it's untried. Theoretically easy, just like launching starship is theoretically easy.

Fuel transfer is mechanically the same whether there are people around or not, and whether you are talking 1 ton of propellant or 100 tons.

It does matter if people aboard, there are more rules and procedures. You need a vessel with safeties that can allow them to eject safely if there's an anomaly.

Of course it's more challenging.

And it does matter if there's more fuel, you have to have valves and pipes that won't freeze after lengthy contact with cryogenic fuel. And you need larger pressure vessels, which scale in volume differently from surface area. It's not at all the same whether you move one ton or a hundred.

The fueling is done without people onboard.

But you still have to build additional safeties into the craft if it's rated for humans. A refueling craft is more complex than a non refueling craft. A crewed craft is more complex than an uncrewed craft (even if no one is aboard). A crewed, refueling craft is more complex still.

SpaceX is closest, but no. Not until Starship flies.

If history is any guide and they haven't missed any big blockers though, then they'll get there - but I think a 10 year horizon is probably a reasonable expectation.

Yes. If you send stuff to orbit you can probably also send stuff to the Moon, it's just a payload penalty.

Several Moon missions were launched on commercial rockets. Even tiny RocketLab launched one: https://en.wikipedia.org/wiki/CAPSTONE

Eh, once you get to orbit you are more than halfway there. Once you get to the moon you need only very little deltaV to make it back.

But yeah, they’re on completely different levels.

No. Falcon 9 can launch objects to the moon as well.

Not to and from the moon. It has a Delta v budget a little low for a full round trip that includes a landing and ascent, iirc. It could hurl something at the moon though.

SLS can't do that either ...

The Artemis 3 will launch on SLS and land humans on the moon?

It's worth mentioning the "single-use engine" you refer to is, in fact, the Space Shuttle Main Engine. Yes, those reusable engines used on the Space Shuttle.

But Artemis does not, in fact, reuse them.

Indeed, my point exactly.

Nothing SpaceX currently has can bring Humans to the moon. Yes, SLS is expensive and inefficient, but it is ready to fly.

Falcon Heavy could send Crew Dragon to the Moon. They’d just have to rate it for human space flight.

Which means they don't have anything that can take Humans to the Moon. That certification requires the technology to be much more proven. Also Falcon Heavy only carries 26t into LEO so I actually doubt it would be enough (don't know for sure). At the very least you need a transfer stage of course.

Next problem would be Crew Dragon itself. It's probably not able to return from the moon, the speed and thus the temperature is higher so you need a capsule designed for this. Which Orion is and Dragon isn't.

> Which means they don't have anything that can take Humans to the Moon.

Neither does the SLS/Orion stack. What are you even comparing here?

A lander is required anyway.

> Also Falcon Heavy only carries 26t into LEO

I assume you don't mean LEO.

> Next problem would be Crew Dragon itself. It's probably not able to return from the moon, the speed and thus the temperature is higher so you need a capsule designed for this. Which Orion is and Dragon isn't.

Actually, the Crew Dragon Heat Shield is designed for moon reentry. There might be a few updates for avionics but nothing to big.

SLS/Orion/Orion SM and Falcon Heavy/Dragon stack are both underpowered. There are solution to this is you were willing to invest the smallest amount of money.

Dragon could be extend by adding a extra fuel tank into the trunk. That would be a reasonably cheap solution. Alternatively a separately launched Service Module. That would likely cost a few 100M, but that is jump change compared to SLS/Orion.

Or even better, don't launch the capsule to moon orbit at all, switch to the moon lander in LEO. Then you can simply use commercial crew to get the astronauts up and down and the lander to go to the moon and back.

All of these idea would save 10s of billions.

"To the Moon" doesn't mean surface, but in any case, lunar orbit is the first step in any practical mission.

No, you don't scale up the 26t by the factor of 4 in a heartbeat.

Yes, you need to take the capsule to lunar orbit because the lander wouldn't survive reentry and you don't want to take the transfer stage down to the lunar surface and back again.

SLS is ready to fly. There are no alternatives which can do the same thing which are ready to fly. This is a fact.

> That certification requires the technology to be much more proven.

Human rating certification is more about paperwork, not technology demonstration.

And getting that rating is the hard part.

Not really. Falcon Heavy and Crew Dragon were already designed for those rating, they just didn't go threw the certification process.

Its not like Orion has actually flown, Crew Dragon and Falcon Heavy are more proven then SLS/Orion and would be easier to certify.

>> they just didn't go threw the certification process.

You don't have much aerospace and certification experience, do you?

Instead of making smart as comments, why not actually make an argument.

Nobody denies its hard and would take singificant work.

But the fact is, all the individual subsystems are certified. The Falcon 9, a closely derived rocket is fully certified. The Dragon is fully crew certified for LEO. And both Falcon Heavy and Dragon are engineered from the ground up to be able to be certified if required.

If this was an argument about if it cost 5 million of 50 million then we could have a discussion.

BUT ITS LITERALLY ABOUT 10+ billion $. So unless you can make an argument that it somehow cost more to human certify Falcon Heavy and Crew Dragon for moon then the complete Falcon 9 and Dragon program cost in the first place then you don't have an argument. Only smart-ass comments.

So please tell me, what do I not understand. Why would it cost 10 billion to do the things I suggest. In reality, we know that it wouldn't even cost 1 billion $.

Costs will come down - while yes, it'll still be more expensive because its a heavy lift vehicle - comparing it to SpaceX is comparing Apples and Wednesday.

The way SpaceX does programatic accounting, and the way NASA does programatic accounting are I suspect, wildly different.

NASA itself estimates costs of about 800m+ each (depending how you account for program overhead). Also, if SLS is used to launch stuff to LEO, its a cosmic waste of money. None of the Falcon rockets can really meet the program goals of SLS.

A whole number of things wrong here.

First of all, that 800m number is mostly a very optimistic estimate that might come true sometime around 2030 or later.

And even then its only true if you completely ignore amortization of development cost, something SpaceX can't really do.

Some of the items that are getting ordered now are for rockets in the late 2020s and if you look at those unit prices its not close to 800m yet.

1b will also need a new upper stage, the price of that is as of yet pure speculation and anybody that has watched the SLS program knows that will happen before its done. And the unit price will also not be there.

SLS will almost certainty be canceled before they reach anywhere close to 800m a launch.

> None of the Falcon rockets can really meet the program goals of SLS.

That is simply not true, or rather, its only true as so far as the whole Artemis program was designed to use SLS. When the NASA administrator suggest that Falcon Heavies could be used some in congress threatened him and seriously suggested he should resign. He shut up quite fast after that.

Many at NASA in the early 2010s didn't want SLS, simple because such a rocket is not required. And even today with a few changes and tweaks it wouldn't be required. But of course if you spend 45 billion into a specific solution it will be better then the solution you spend 0$ on.

But even so, its still not to late, even now canceling SLS and redesigning Artemis would be worth it. Artemis assumes that Starship will exist anyway, and human transport to LEO is fixed already. Starship is the lander already. So really, only thing you need is somehow to get humans from LEO to the moon. And guess what, Starship already has to fly that anyway.

> SLS will almost certainty be canceled before they reach anywhere close to 800m a launch.

Thats, speculation, one covered in the source article, that notes, because of the spread of the project - virtually every state makes something for it, its proven itself more or less immune to budget cuts because of this.

Beyond that, there is a dearth of heavy lift rockets out there, the idea of a single source from SpaceX is.. one, contrary to normal federal procurement rules, and two, not a sane idea - if for no there reason than it doesnt match the mission profile for a lunar mission.

I'll note, that even a Block I SLS launches 30t more into LEO than Falcon Heavy does, the numbers go up even higher for later blocks, presumably this advantage is even high for lunar missions.

Why compare a fantasy rocket that doesn’t exist yet to one that has already flown? If you’re comparing future rockets at least put future SLS versions up against future Starship and Starship Heavy for that matter… not against Falcon Heavy.

> Thats, speculation

Its speculation but informed speculation.

> more or less immune to budget cuts because of this

That is true so far but not a law of nature. There are many in congress who don't like it. It touches every state, but some state far more then others. And an alternative solution would also spend money.

SpaceX is in California, Texas, Florida and Washington. And other commercial providers like BlueOrigin are in Alabama and Florida.

Originally it was a Alabama and Florida Senator who pushed SLS. A Florida senator didn't want commercial space, he wanted SLS launching from Florida. However since then every Florida senator will understand that SpaceX aud Commercial launch is 1000x more important for Florida then a SLS launch every year.

So a state like Florida was incredibly pro SLS, now this is no longer true. Alabama and Utah will continue to be pro SLS. However Texas and California (slightly relevant stats) will certainty not be.

There are forces in congress that don't like the waste and Alabama/Utah dominance and when Starship fly's regularly before Artemis 2 even launches you will see some series attacks on SLS castle. And if SLS has any series issues it will be easy to topple. Even just delaying funding for the new upper stage can kill it.

Its a very long time from now until late 2020s. Consider the difference in the industry over the last 7 years. 7 years ago there were still influential voices who thought reusable rockets would never be real, now reusable rockets are so boring that even hard core space nerds don't watch all the launches anymore.

SLS already looks like a flying antique in a few years it will just be comical.

> one, contrary to normal federal procurement rules

Federal procurement rules don't really apply to large NASA missions. As SLS is single sourced right now.

> two, not a sane idea

So then by your own logic SLS is not a sane idea. I guess we agree.

> I'll note, that even a Block I SLS launches 30t more into LEO than Falcon Heavy does, the numbers go up even higher for later blocks, presumably this advantage is even high for lunar missions.

We are not talking about Apollo. This is not a single all-in-one launch architecture. Artemis already relies on multiple launches for all its missions. Anything but single launch payload comparison will come out much better using commercial rocket.

Falcon 9 heavy can launch literally 5-20 times as often while you can launch 20 of them for the price of single SLS launch. 20 Falcon Heavy rockets costing 140M a pop (likely would be less) cost would literally be cheaper then Artemis 1 launch cost alone.

You can also do the numbers for New Glenn, Vulcan, Terran R, Neutron and all the other commercial rockets. Going to a multi launch architecture designed for launch vehicles of current size is sensible, far more so then single source multi-billion SLS.

You could literally pay for 10 years of all launches required with the price of just the Artemis 1/Artemis 2. Its financial idiocy beyond rime or reason and nobody who seriously looks at the numbers can defend it.

There are so many other architecture that could make sense. Even dumb things like launching the Service Module and Orion separately would work and if you did, Falcon Heavy would be totally doable and far, far cheaper then the current architecture. But of course current Orion isn't designed to do that, no-no, we couldn't do sensible architectures like that.

If you actually gave space mission architects freedom from the the political milestones, not a single one of them would ever come up with the current Artemis program.

All of this is before we even consider the existence of Starship. SLS/Orion are terrible ideas BEFORE you even consider Starship. If you consider Starship (and Artemis already has a hard dependency on it) SLS/Orion go from terrible ideas to borderline insanity.

> None of the Falcon rockets can really meet the program goals of SLS.

This is not accurate even according to the NASA administrators in the past. Falcon Heavy should be able to meet the vast majority of the goals if not all; many of which were arbitrarily defined to only fit SLS anyway.

Falcon Heavy is not rated for carrying humans. That's only because SpaceX chose not to bother because 1) low demand and 2) starship will do it anyway.

Falcon Heavy is not rated to carry humans because NASA has no need for it, had they designed Artemis around it, SpaceX would have been happy to do so.

Its literally just paper work, Falcon Heavy is already DESIGNED AND BUILT TO MEET human rating standards. They just didn't to the paper work.

Falcon Heavy is fully certified for the most difficult level of uncrewed launches by NASA and the Space Force -- including reusing side boosters.

NASA's crewed rating is one step farther, but not a huge step farther.