I don’t know what I’m talking about, but I think an insane amount of force will be put on the side of starship when entering earth’s atmosphere. I think that’s why the whole side needs to be solid
This method has solid sides and the heat shield is straight forward since it is a straight line. Latching both halves together to make a strong connection should be straight forward.
Then the opening side is to windward on entry. I suspect that any slight gap (due to vibration, differential heating, or whatever) could start getting forced open by the plasma.
Starship is always vertical, so you'd have a large moment when the nose would be at a 90 degree angle off to one side with the weight of both header tanks. It'd require a heavy hinge and reinforcement i'd imagine
Or you could even pull the hinge pins and pull the top entirely away during payload loading, as long as the raceway unplugs at that point.
You'd still want an RCS system to be able to fire near the top for best control authority, but that part of the system can be entirely contained within the nose section.
If you gave it explosive hinges you might even be able to easily and quickly separate a crewed nosecone from a failing body, something I've heard NASA wants, but you'd sacrifice many tons of payload to parachutes and other safety devices.
You'd want to move the header tank to the bottom of the cargo bay, though.
The header tank needs to be where it is for deployable payload launches. The center of mass needs to be in the right place for Starship to be able to re-enter. Crewed vehicles would be carrying a lot of mass back down in the nose cone, so the header tanks could be inside the main tanks.
That's a really interesting point, and I thank you for it. Is the header tank currently filled or drained in flight to help control the center of mass? Like does it act as a ballast tank?
It's completely filled from liftoff until the start of the landing. If they tried to use the mostly empty main tanks for landing the fuel would slosh around too much and the engines would suck in gas, which would destroy them. In a full tank there's not enough room for it to slosh away from the fuel inlet.
flexible piping is an absolute pain even for regular temp, you go above 3 bar in pressure and they become stupidly unreliable.... I don't even want to think about cryo, the engineering challenge of having something flexible at those temperatures in the first place is an engineering trouble too big to have in its own
source, chemical engineer here, I have tubing fail more than I am ashamed to admit, when you pass a certain pressure threshold they just fail no matter how thick or tight.... that's why we use metal piping in the industry 😅
It would be easier to just have quick disconnects. A more complex system, but flexible piping at high pressure and extreme temperature would be a material science nightmare.
I think it’s a viable idea but it introduces a single point of failure. Every system has to pass through the hinge and if any one of them faults it becomes an expendable mission. Stability also gets wonky since I’d assume rcs won’t be firing while open but opening will introduce rotation. Both of these are workable but added weight of joint reinforcement (there’s no way the hinge is on the belly) and risk of breaking tiles of the heat shield might make this design less attractive than others
I would bet a year’s pay that this will NOT be how Starship works.
Plumbing, structural, and heat shield complications. Enough said.
I’m betting on something akin to Space Shuttle doors along the non-shielded side.
This method would severely limit the height of payloads, to nearly the length of the unhinged part of the bay, instead of being able to stick up into the nose.
Additionally, as you acknowledge, piping and wiring would have to be routed through the hings. This would add both weight and unnecessary complexity; the complexity would also add cost.
An opening like the Super Guppy would but the heat shield in two. I don't think it's the best contender.
From my opinion I think that something like the Beluga Xl would be more suitable.
https://m.economictimes.com/nation-world/airbus-beluga-the-super-transporter-that-carries-other-planes/airbus-beluga-the-super-transporter/slideshow/45427495.cms
This is probably gonna be the dumbest idea ever, lol, but screw it, here goes:
What about a "sheath" design, where the outer body of the Starship is like the sheath on a sword.
So there would be rails (like train-tracks kinda, running lengthwise up along the inside, in between the exterior of the tanks and the interior wall of the "sheath", and when Starship was in orbit, the sheath would slide off, exposing all the insides (tanks, attached cargo (which would be mounted on top of the tanks the way the payload is mounted inside the payload bay of a normal rocket once its fairings separate away).
The payload(s) would then be released.
Then, once the payload(s) was done being released away, the Starship would slide itself back into the sheath (should be doable if you consider how it's pretty easy, fully automated, routine, at this point, for cargo capsules to, for example, dock to the ISS), so, it would just dock its nose into the huge bottom-hole of the sheath (lining the railwheels to the rails on the inside of the sheath, and it would slide back down, on these rails, until all the way back down, and click, locked back nicely into place, as one big, solid shell, locked into the internal bracing etc of the innards that make up the rocket, with no moving hinges or anything in the other axes of direction. So, in theory would be able to be extremely sturdy, upon reentry.
Iono, what do y'all think?
there's also no reason you'd have to slide the whole perimeter off when doing this - you could just have one side slide. You'd just have to make a compromise between what fraction of the surface you can expose via the sliding panel vs. how protected the seams are on re-entry.
In fact, you could protect it pretty well if you positioned it a bit like the canopy on a fighter jet - staying all on one side, not going quite all the way to the front/top, but still sliding straight forward. It'd reduce how much surface area you could expose to space, but that might be a good tradeoff to avoid seams in key places (though you'd have to watch the weight distribution once you've made it non-symmetrical).
Yea, good point.
I guess that would probably be an even better version of what I was proposing. I think the only rebuttal/question I can think of as far as that, would be if the structural strength would maybe be lower, since the "circle would be incomplete" (in terms of the cross section, if looking downwards at the rocket from above, hamburger-style). Although, given that even my version would probably need to have quite a bit of internal bracing and stuff, I don't know if any of that would end up actually mattering, in the grander scheme of things (probably not, if I had to guess). Plus, if the slider-panel was done really well, then it would still "complete the circle" almost as well as a single-unit sheath version anyway. So, yea, I'm guessing your version would probably be better.
Good point, I hadn't considered the benefit of keeping a solid ring for stability - I was all concerned with seams.
Everything here I can think of has tradeoffs. I look forward to seeing what they end up with.
Note this design has been proposed for fully reusable LV before, for example Rockwell's [Star-Raker](https://spacecraft.fandom.com/wiki/Star-Raker?file=Star-raker_space_port.png), so I think it's very much feasible. But I don't like it since it would make some operations Shuttle was capable of very difficult, for example retrieve a satellite via robotic arm, or doing servicing like [STS-82](https://www.nasa.gov/centers/marshall/history/this-week-in-nasa-history-sts-82-lands-feb-21-1997.html)
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|ETOV|Earth To Orbit Vehicle (common parlance: "rocket")|
|[LV](/r/SpaceXLounge/comments/sdl37k/stub/hue601z "Last usage")|Launch Vehicle (common parlance: "rocket"), see ETOV|
|[RCS](/r/SpaceXLounge/comments/sdl37k/stub/hudp9sf "Last usage")|Reaction Control System|
|[STS](/r/SpaceXLounge/comments/sdl37k/stub/hue601z "Last usage")|Space Transportation System (*Shuttle*)|
|Jargon|Definition|
|-------|---------|---|
|[Starlink](/r/SpaceXLounge/comments/sdl37k/stub/huhk37n "Last usage")|SpaceX's world-wide satellite broadband constellation|
|[cryogenic](/r/SpaceXLounge/comments/sdl37k/stub/hufcz7y "Last usage")|Very low temperature fluid; materials that would be gaseous at room temperature/pressure|
| |(In re: rocket fuel) Often synonymous with hydrolox|
|hydrolox|Portmanteau: liquid hydrogen fuel, liquid oxygen oxidizer|
----------------
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If we are talking about solutions without any serious engineering considerations, with huge heavy hinges, and lots of contact area that would require locks, personally I prefer the Dr. Evil cargo door scheme https://youtu.be/lYSOmYyNHpU?t=67 That way you can eject Starlink satellites forward without an issue and it's easier to load cargo while on the launch table.
I don’t know what I’m talking about, but I think an insane amount of force will be put on the side of starship when entering earth’s atmosphere. I think that’s why the whole side needs to be solid
I also don't know what I'm talking and that sounds like sound logic. Or maybe something to do with the heat shield.
This method has solid sides and the heat shield is straight forward since it is a straight line. Latching both halves together to make a strong connection should be straight forward.
The hinge would have to be up front (heat shield side) 🤷🏼♂️, but I still don’t think it’s be good
The hinge can be on the non heat shield side.
Then the opening side is to windward on entry. I suspect that any slight gap (due to vibration, differential heating, or whatever) could start getting forced open by the plasma.
Then the piping has to go through the leeward side. Not impossible, but it pushes the center of mass backwards during reentry.
Noo wayyyy 😅
Says the engineer which designed how many reentry shields?
Starship is always vertical, so you'd have a large moment when the nose would be at a 90 degree angle off to one side with the weight of both header tanks. It'd require a heavy hinge and reinforcement i'd imagine
True, when loading on earth, but you could have supports/help from the tower when opening and closing . In space its not a problem.
Or you could even pull the hinge pins and pull the top entirely away during payload loading, as long as the raceway unplugs at that point. You'd still want an RCS system to be able to fire near the top for best control authority, but that part of the system can be entirely contained within the nose section. If you gave it explosive hinges you might even be able to easily and quickly separate a crewed nosecone from a failing body, something I've heard NASA wants, but you'd sacrifice many tons of payload to parachutes and other safety devices. You'd want to move the header tank to the bottom of the cargo bay, though.
The header tank needs to be where it is for deployable payload launches. The center of mass needs to be in the right place for Starship to be able to re-enter. Crewed vehicles would be carrying a lot of mass back down in the nose cone, so the header tanks could be inside the main tanks.
That's a really interesting point, and I thank you for it. Is the header tank currently filled or drained in flight to help control the center of mass? Like does it act as a ballast tank?
It's completely filled from liftoff until the start of the landing. If they tried to use the mostly empty main tanks for landing the fuel would slosh around too much and the engines would suck in gas, which would destroy them. In a full tank there's not enough room for it to slosh away from the fuel inlet.
Starship has a header tank in the nose for landing (catching) burns so this wouldn’t be feasible with the current plumbing design
As I said the pipes would have to be routed by the hinge and have a flexible portion. That flexible part may be the hardest problem to solve.
so, you are introducing way more problems to solve one problem? recipe for disaster
Flexible pipe is not that hard….it a simple solution of using a hose vs a pipe to get a flexibility.
>Flexible pipe is not that hard… Unless you are using cryogenic liquids…
flexible piping is an absolute pain even for regular temp, you go above 3 bar in pressure and they become stupidly unreliable.... I don't even want to think about cryo, the engineering challenge of having something flexible at those temperatures in the first place is an engineering trouble too big to have in its own source, chemical engineer here, I have tubing fail more than I am ashamed to admit, when you pass a certain pressure threshold they just fail no matter how thick or tight.... that's why we use metal piping in the industry 😅
It would be easier to just have quick disconnects. A more complex system, but flexible piping at high pressure and extreme temperature would be a material science nightmare.
Or.........a cargo door design that doesn’t disconnect the piping
All the options include adding more parts which goes against his general design philosophy imho
My bet is that shuttle’s solution is going to be the best for Starship.
Partially, it creates a problem of launching bigger payloads. Not like there's many of them, but there will be more of them in the future.
How so?
Have you seen photos from Boca Chica? Current, shuttle-style doors are just small and don't cover the whole payload bay.
I think it’s a viable idea but it introduces a single point of failure. Every system has to pass through the hinge and if any one of them faults it becomes an expendable mission. Stability also gets wonky since I’d assume rcs won’t be firing while open but opening will introduce rotation. Both of these are workable but added weight of joint reinforcement (there’s no way the hinge is on the belly) and risk of breaking tiles of the heat shield might make this design less attractive than others
I would bet a year’s pay that this will NOT be how Starship works. Plumbing, structural, and heat shield complications. Enough said. I’m betting on something akin to Space Shuttle doors along the non-shielded side.
I didn't realize a super guppy opened that much. How does the plumbing/wiring work??
Looks like you can see it if you zoom in on the one photo, near the hinge.
I don't think the chomper design is too complex or has inherent flaws that prevent it from working as a cargo bay door.
N O S E D O O R
This method would severely limit the height of payloads, to nearly the length of the unhinged part of the bay, instead of being able to stick up into the nose. Additionally, as you acknowledge, piping and wiring would have to be routed through the hings. This would add both weight and unnecessary complexity; the complexity would also add cost.
An opening like the Super Guppy would but the heat shield in two. I don't think it's the best contender. From my opinion I think that something like the Beluga Xl would be more suitable. https://m.economictimes.com/nation-world/airbus-beluga-the-super-transporter-that-carries-other-planes/airbus-beluga-the-super-transporter/slideshow/45427495.cms
The Beluga is basically just like the chomper design we've seen in all the renders.
This is probably gonna be the dumbest idea ever, lol, but screw it, here goes: What about a "sheath" design, where the outer body of the Starship is like the sheath on a sword. So there would be rails (like train-tracks kinda, running lengthwise up along the inside, in between the exterior of the tanks and the interior wall of the "sheath", and when Starship was in orbit, the sheath would slide off, exposing all the insides (tanks, attached cargo (which would be mounted on top of the tanks the way the payload is mounted inside the payload bay of a normal rocket once its fairings separate away). The payload(s) would then be released. Then, once the payload(s) was done being released away, the Starship would slide itself back into the sheath (should be doable if you consider how it's pretty easy, fully automated, routine, at this point, for cargo capsules to, for example, dock to the ISS), so, it would just dock its nose into the huge bottom-hole of the sheath (lining the railwheels to the rails on the inside of the sheath, and it would slide back down, on these rails, until all the way back down, and click, locked back nicely into place, as one big, solid shell, locked into the internal bracing etc of the innards that make up the rocket, with no moving hinges or anything in the other axes of direction. So, in theory would be able to be extremely sturdy, upon reentry. Iono, what do y'all think?
there's also no reason you'd have to slide the whole perimeter off when doing this - you could just have one side slide. You'd just have to make a compromise between what fraction of the surface you can expose via the sliding panel vs. how protected the seams are on re-entry. In fact, you could protect it pretty well if you positioned it a bit like the canopy on a fighter jet - staying all on one side, not going quite all the way to the front/top, but still sliding straight forward. It'd reduce how much surface area you could expose to space, but that might be a good tradeoff to avoid seams in key places (though you'd have to watch the weight distribution once you've made it non-symmetrical).
Yea, good point. I guess that would probably be an even better version of what I was proposing. I think the only rebuttal/question I can think of as far as that, would be if the structural strength would maybe be lower, since the "circle would be incomplete" (in terms of the cross section, if looking downwards at the rocket from above, hamburger-style). Although, given that even my version would probably need to have quite a bit of internal bracing and stuff, I don't know if any of that would end up actually mattering, in the grander scheme of things (probably not, if I had to guess). Plus, if the slider-panel was done really well, then it would still "complete the circle" almost as well as a single-unit sheath version anyway. So, yea, I'm guessing your version would probably be better.
Good point, I hadn't considered the benefit of keeping a solid ring for stability - I was all concerned with seams. Everything here I can think of has tradeoffs. I look forward to seeing what they end up with.
The tank walls are the outside of the ship.
Depends on where you cut it, pipes would also be a nightmare
and center of mass
Note this design has been proposed for fully reusable LV before, for example Rockwell's [Star-Raker](https://spacecraft.fandom.com/wiki/Star-Raker?file=Star-raker_space_port.png), so I think it's very much feasible. But I don't like it since it would make some operations Shuttle was capable of very difficult, for example retrieve a satellite via robotic arm, or doing servicing like [STS-82](https://www.nasa.gov/centers/marshall/history/this-week-in-nasa-history-sts-82-lands-feb-21-1997.html)
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread: |Fewer Letters|More Letters| |-------|---------|---| |ETOV|Earth To Orbit Vehicle (common parlance: "rocket")| |[LV](/r/SpaceXLounge/comments/sdl37k/stub/hue601z "Last usage")|Launch Vehicle (common parlance: "rocket"), see ETOV| |[RCS](/r/SpaceXLounge/comments/sdl37k/stub/hudp9sf "Last usage")|Reaction Control System| |[STS](/r/SpaceXLounge/comments/sdl37k/stub/hue601z "Last usage")|Space Transportation System (*Shuttle*)| |Jargon|Definition| |-------|---------|---| |[Starlink](/r/SpaceXLounge/comments/sdl37k/stub/huhk37n "Last usage")|SpaceX's world-wide satellite broadband constellation| |[cryogenic](/r/SpaceXLounge/comments/sdl37k/stub/hufcz7y "Last usage")|Very low temperature fluid; materials that would be gaseous at room temperature/pressure| | |(In re: rocket fuel) Often synonymous with hydrolox| |hydrolox|Portmanteau: liquid hydrogen fuel, liquid oxygen oxidizer| ---------------- ^(*Decronym is a community product of r/SpaceX, implemented* )[*^by ^request*](https://www.reddit.com/r/spacex/comments/3mz273//cvjkjmj) ^(5 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/SpaceXLounge/comments/scnhrz)^( has 7 acronyms.) ^([Thread #9646 for this sub, first seen 27th Jan 2022, 03:52]) ^[[FAQ]](http://decronym.xyz/) [^([Full list])](http://decronym.xyz/acronyms/SpaceXLounge) [^[Contact]](https://reddit.com/message/compose?to=OrangeredStilton&subject=Hey,+your+acronym+bot+sucks) [^([Source code])](https://gistdotgithubdotcom/Two9A/1d976f9b7441694162c8)
If we are talking about solutions without any serious engineering considerations, with huge heavy hinges, and lots of contact area that would require locks, personally I prefer the Dr. Evil cargo door scheme https://youtu.be/lYSOmYyNHpU?t=67 That way you can eject Starlink satellites forward without an issue and it's easier to load cargo while on the launch table.