The Most Powerful Rocket – Ever
Starship on the launch pad
Keith’s note: This is not a CGI image. It is an actual SpaceX aerial photo of a Starship and its booster on the launch pad. In a month or so NASA PAO will need to delete the “most powerful rocket in the world” phrase from their sound bite collection since this rocket will utterly eclipse whatever it is that SLS weighs, thrusts, or throws – and it will certainly chop a few zeroes off of what it costs to launch – to say nothing of the whole re-launch thing. Ad Astra y’all.
10 responses to “The Most Powerful Rocket – Ever”
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They might amend their comment by saying that it is the most powerful rocket to be able to send a spacecraft directly to the Moon. Something that Starship can’t do.
SLS can’t even put Orion into LLO. Even if you posit a hypothetical lander launched in place of the Orion stack, Starship could launch a bigger one, *in a single launch*.
Directly to the Moon, or directly to lunar orbit? SLS/Orion can make it to a high lunar orbit, but it can’t land on the Moon directly–or even, as CJH said below, get to an Apollo-style low lunar orbit.
That said, if you’re willing to expend both the SuperHeavy booster and a stripped-down Starship, it’ll put roughly the same payload into TLI as SLS Block 1: somewhere between 25t and 35t. There’s obviously some guesswork in that number, but Starship pays a huge price for having a recoverable SuperHeavy booster. If you’re willing to forgo that recovery, things get pretty interesting. And it’s likely less than a quarter of the cost of using an SLS.
And then SLS gets the title back with Block 1B.
How does that work?
Even in the Block 2 configuration, SLS liftoff thrust will be 9,200,000 lbf, as compared to Starship Superheavy’s 17,100,000 lbf projected liftoff thrust, so I don’t see where SLS could claim “most powerful” once Starship reaches orbit. I agree that SLS should hold the title for “largest cargo mass to LEO or TLI in a single launch” for some time. That is understandable since Starship is designed for complete reusability and needs fuel reserve, additional structure, aerodynamic surfaces, and heat shield mass. Once the tanker fleet is viable, the Mass to TLI title gets vague, as SLS Block 2 can only send 46 t to the Moon, while a refueled Starship can take its entire 100 t payload, so you need to tack on the caveat “in a single launch”. I will concede there are some “once[s]” above, as these Starship launches have yet to occur, but there don’t seem to be any engineering / technical hurdles that are insurmountable.
I would be curious what mass could be launched to LEO or TLI, if SpaceX were to configure an expended launch trajectory for Starship & Superheavy and optimized them for an expendable launch (delete the heat shield, wings, grid fins, etc.). Given the mass-production techniques that are being applied at SpaceX, an expendable Starship / Superheavy stack could still end up being significantly cheaper than SLS, but that wasn’t the design goal.
The SLS “payload to LEO” isn’t just cargo, it includes the upper stage and propellant for TLI. Measuring Starship’s “payload” the same way, it puts nearly twice as much mass in LEO as SLS Block 2.
And remember, SLS isn’t actually “operational” yet, the results of its test launch will be extensively reviewed and much work done before it can start regular launches, even with Block 1. It won’t be doing its second flight for at least a couple years, while Starship is planned to be *landing on the moon* around the same time.
SLS’s “LEO” payloads are essentially fiction, it’s designed to launch lighter payloads to higher orbits, and its “LEO” payload includes the upper stage and propellant needed to do that. And taking TLI as representative of that (all planned SLS launches being to TLI), Block 1B only increases TLI payload from 38 t to 42 t. Block 2 only pushes that up to 46 t. They’re going to need to do more than bump up capacity by a few tons to catch up with Starship.
Probably not. By the time Block 1B is ready to launch, the Raptor engines will likely be operating at high enough chamber pressures that an expendable SuperHeavy and stripped-down Starship will be able to put 45t of payload into TLI. Best estimates for Block 1B are 42t.
Just like SpaceX has designed the F9 and FH cores to be reusable, SuperHeavy and Starship are designed to be reusable. But they don’t **have** to be reusable. And they can throw a lot more payload to TLI if they’re expended. And they’ll **still** cost a fraction of what SLS will.
The important specs are annual payload mass to orbit and the cost of those launches. SLS, since it will be behind Starship by orders of magnitude, belongs in a museum next to the steam locomotive.
SLS still outperforms Starship in terms of payload capcity to TLI per launch and by quite a large margin too, considering Starship can sent 0 tons to TLI if they want to reuse it and about ~20 tons to TLI if they fly with an expendable second stage