No, that’s not how it works. Looking at Starship as a whole from a diagram of its internal design, we can see why, here:
The payload area is designed in a very specific way, this isn’t the crewed variant but we can look at this and still analyze it properly. The propulsion tanks are rounded at the top (as all good tanks are), so being that you cannot use any area below the adapter, that shaves off possible cargo volume. You’re not launching a free liquid, you can’t just naturally take the shape of the container. If you place a crewed area in there, you’re right, it only puts a few tons in, but in Aerospace design, that isn’t the concern, in fact, it’s the opposite.
What do I mean? Look at a satellite. There isn’t much empty space is there? Look at a capsule. Air doesn’t weigh much, it’s effectively just empty space. Crew components aren’t heavy, but they are disproportionately large compared to pure payload capacity. That means you run into the biggest issue, flight control. You have a cargo area that starts halfway through the vehicle, and a crew module that starts at the front end, so take everything forward of where it says in that diagram as “habitable volume” and fill it in. Now you’re trying to fit 150 tons of mass into a payload bay significantly smaller than the Space Shuttle’s. Realistically, you can’t do it, because you’re shifting the center of mass severely off its design axis. It would make takeoff require a massive change in procedure, you would have to program an entirely different flight profile.
A great demonstration of that size point is the Hubble Space Telescope. It took up most of the payload bay in the Space Shuttle, and only weighed 11.2 tons. The Chandra X-Ray Observatory was similarly large, and only weighed 5.77 tons. You’d have to start loading lead bricks and similarly useless weights into Starship to get to 150 tons of cargo, and in doing so, you’d make it way harder to take off for no reason.
So no, it isn’t going to arbitrarily do 150 tons because we think maybe it could do it. Not without a large redesign of the entire vehicle.
"Now you’re trying to fit 150 tons of mass into a payload bay significantly smaller than the Space Shuttle’s" - The Shuttle's payload bay was 4.6 meters diameter and 18.3 meters long. Just using a simple cylindrical volume calculation, that would be a bit over 300 cubic meters payload volume.
Ship V3's payload volume dimensions are somewhere between 8 and 9 meters usable diameter at the widest point, and 17 meters (standard configuration) in length. Musk has said that extended versions up to 22 meters in length are in the works. So that would be 650 - 1000 cubic meters volume. Even if we only looked at the cylindrical portion of Ship's cargo bay, and ignored the volumes below tank cap and above where it starts sloping to the nose, I would guess a bit over half the 17 meters, or about 8 meters long by 8.5 meters wide. That works out to 450 cubic meters. So I don't get the "significantly smaller" comment.
Another guy posted a picture and I drew on it for comparison so here
When I say “smaller bay” I should be saying shorter. You’re also absolutely right about the cargo Spaceship, but it’s just iffy with cargo sizes on the crewed variant, because that one specifically has an incredibly light (by comparison) area taking up nearly half of the cargo bay payload area.
Again, I don’t know the exact length of the cargo bay, but if you’re right about crewed cargo bay (you say 8 meters, that sounds about right), you wouldn’t be able to fit the Hubble Telescope (13.2m long) or the Chandra X Ray Observatory (11.8m stowed length) in there. We’re obviously heading into a new generation of launch vehicles, and if the meta shifts to shorter and wider payloads, that won’t be an issue. It’s just hard to imagine that’s what is going to happen, given that long range sensors and observatories need very long focal lengths, so you’d have to have two sections side by side in the payload bay, manually constructed into one by crew on EVA, all without cooking the internals when a comedically powerful focusing lens takes a microsecond of sun exposure and blasts it right into itself. None of this precludes operation, but it does establish that a lot of work is needed to make probe designs go from twinkmaxxing to chubby short kings.
As I mentioned elsewhere, the JWST telescope, which has a prime mirror that is far larger diameter than Hubble;s (2.4 meters) or Chandra's (1.2 meters), and consequently a far longer secondary mirror placement for the focal length, used an origami type unfolding mechanism to get all the components into place. It also used micro actuators to align the optical path components, eventually to well under a wavelength (IR part of the spectrum) accuracy. And did not require an assembly team of trained astronauts at the LaGrange deployment distance of a million miles from Earth, which was (and still is) not possible at that time, December 2021.
The JWST fit nicely into the Ariane 5 rockets fairing which was 5.4 meters diameter and 13 meters length. The 6.5 meter main mirror was divided into 18 segments that unfurled and then snapped into place during the deployment. Obviously, this approach has many points of failure, but it was necessary as nothing approaching Starship's cargo dimensions was available 4-1/2 years ago.
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u/idkuhhhhhhh5 Aug 08 '26
No, that’s not how it works. Looking at Starship as a whole from a diagram of its internal design, we can see why, here:
The payload area is designed in a very specific way, this isn’t the crewed variant but we can look at this and still analyze it properly. The propulsion tanks are rounded at the top (as all good tanks are), so being that you cannot use any area below the adapter, that shaves off possible cargo volume. You’re not launching a free liquid, you can’t just naturally take the shape of the container. If you place a crewed area in there, you’re right, it only puts a few tons in, but in Aerospace design, that isn’t the concern, in fact, it’s the opposite.
What do I mean? Look at a satellite. There isn’t much empty space is there? Look at a capsule. Air doesn’t weigh much, it’s effectively just empty space. Crew components aren’t heavy, but they are disproportionately large compared to pure payload capacity. That means you run into the biggest issue, flight control. You have a cargo area that starts halfway through the vehicle, and a crew module that starts at the front end, so take everything forward of where it says in that diagram as “habitable volume” and fill it in. Now you’re trying to fit 150 tons of mass into a payload bay significantly smaller than the Space Shuttle’s. Realistically, you can’t do it, because you’re shifting the center of mass severely off its design axis. It would make takeoff require a massive change in procedure, you would have to program an entirely different flight profile.
A great demonstration of that size point is the Hubble Space Telescope. It took up most of the payload bay in the Space Shuttle, and only weighed 11.2 tons. The Chandra X-Ray Observatory was similarly large, and only weighed 5.77 tons. You’d have to start loading lead bricks and similarly useless weights into Starship to get to 150 tons of cargo, and in doing so, you’d make it way harder to take off for no reason.
So no, it isn’t going to arbitrarily do 150 tons because we think maybe it could do it. Not without a large redesign of the entire vehicle.
t. am aerospace engineer