Quote from: Norm38 on 01/20/2025 03:08 pmDecided to dredge up this thread as a better place to continue this discussion.Quote from: RoboGoofers on 01/17/2025 05:35 pmThe only operational payload I expect from starship in the next 2 years is starlink. Part of the reason is that nobody knows what the final dimensions of the payload bay are or how a payload will be deployed. Chomper starships, if still in the pipeline, feel like they won't be tested this year. Companies and governments will start designing for NG assuming that if it'll fit in NG it'll fit in starship when it's done.the big starlink sats have been held up by starship development, so a disposable upperstage, no wings, just tanks and raptors with a fairing (stainless, even) could have filled that gap and attracted attention from the industry (someone is going to want a simple disposable upper stage sooner or later to put up something massive). They could have been improving their ground operations and working on booster reuse all while launching payloads and the occasional starship for testing. While they want to ramp up this year to 25, the mishap investigation(s) are going to eat into their time, so these failures hurt.Hindsignt and all, but i feel there was a better way.Is there a true customer need for an expendable upper stage for very large payloads? Where the Starship structure won't allow a payload to be deployed? Something like a single launch space station, or huge station modules for a fuel depot or starship service dock. A big space tug or space debris catcher or asteroid miner?Would it be cost effective if it enabled truly massive infrastructure?There's a small gap between "small enough to fit in the cargo bay" and "large enough to require orbital assembly" that might benefit from it in the short term. But if Starship meets its launch cost goals I suspect most customers will quickly move on to the larger structures constructed in orbit.
Decided to dredge up this thread as a better place to continue this discussion.Quote from: RoboGoofers on 01/17/2025 05:35 pmThe only operational payload I expect from starship in the next 2 years is starlink. Part of the reason is that nobody knows what the final dimensions of the payload bay are or how a payload will be deployed. Chomper starships, if still in the pipeline, feel like they won't be tested this year. Companies and governments will start designing for NG assuming that if it'll fit in NG it'll fit in starship when it's done.the big starlink sats have been held up by starship development, so a disposable upperstage, no wings, just tanks and raptors with a fairing (stainless, even) could have filled that gap and attracted attention from the industry (someone is going to want a simple disposable upper stage sooner or later to put up something massive). They could have been improving their ground operations and working on booster reuse all while launching payloads and the occasional starship for testing. While they want to ramp up this year to 25, the mishap investigation(s) are going to eat into their time, so these failures hurt.Hindsignt and all, but i feel there was a better way.Is there a true customer need for an expendable upper stage for very large payloads? Where the Starship structure won't allow a payload to be deployed? Something like a single launch space station, or huge station modules for a fuel depot or starship service dock. A big space tug or space debris catcher or asteroid miner?Would it be cost effective if it enabled truly massive infrastructure?
The only operational payload I expect from starship in the next 2 years is starlink. Part of the reason is that nobody knows what the final dimensions of the payload bay are or how a payload will be deployed. Chomper starships, if still in the pipeline, feel like they won't be tested this year. Companies and governments will start designing for NG assuming that if it'll fit in NG it'll fit in starship when it's done.the big starlink sats have been held up by starship development, so a disposable upperstage, no wings, just tanks and raptors with a fairing (stainless, even) could have filled that gap and attracted attention from the industry (someone is going to want a simple disposable upper stage sooner or later to put up something massive). They could have been improving their ground operations and working on booster reuse all while launching payloads and the occasional starship for testing. While they want to ramp up this year to 25, the mishap investigation(s) are going to eat into their time, so these failures hurt.Hindsignt and all, but i feel there was a better way.
I expect it will be the opposite, actually. Anything you can fit in Starship will be cheap, but anything requiring risky and training-intensive EVAs for assembly (or some sort of custom R&D assembly robot) will be a lot more expensive.
Quote from: steveleach on 01/20/2025 03:20 pmThere's a small gap between "small enough to fit in the cargo bay" and "large enough to require orbital assembly" that might benefit from it in the short term. But if Starship meets its launch cost goals I suspect most customers will quickly move on to the larger structures constructed in orbit.I expect it will be the opposite, actually. Anything you can fit in Starship will be cheap, but anything requiring risky and training-intensive EVAs for assembly (or some sort of custom R&D assembly robot) will be a lot more expensive.
There's a small gap between "small enough to fit in the cargo bay" and "large enough to require orbital assembly" that might benefit from it in the short term. But if Starship meets its launch cost goals I suspect most customers will quickly move on to the larger structures constructed in orbit.
Quote from: Twark_Main on 01/25/2025 01:30 amI expect it will be the opposite, actually. Anything you can fit in Starship will be cheap, but anything requiring risky and training-intensive EVAs for assembly (or some sort of custom R&D assembly robot) will be a lot more expensive.Yet another reason to want that "orbital drydock." Especially if we can get NASA to pay for it!
Quote from: Twark_Main on 01/25/2025 01:30 amQuote from: steveleach on 01/20/2025 03:20 pmThere's a small gap between "small enough to fit in the cargo bay" and "large enough to require orbital assembly" that might benefit from it in the short term. But if Starship meets its launch cost goals I suspect most customers will quickly move on to the larger structures constructed in orbit.I expect it will be the opposite, actually. Anything you can fit in Starship will be cheap, but anything requiring risky and training-intensive EVAs for assembly (or some sort of custom R&D assembly robot) will be a lot more expensive.Yes, clearly small things that can transported in a single reusable vehicle will be cheaper.But when you go larger than that you have to choose between...
I don't expect risky and training-intensive EVAs to be a thing for very long, once Starship brings launch costs down to where SpaceX want them to be. Starship's refuelling model, when implemented at scale, will make rendezvous and docking fast and trivial.
We know there are companies developing robotic orbital assembly technologies, but they aren't currently financially viable because current launch costs...
Quote from: steveleach on 01/25/2025 09:16 amQuote from: Twark_Main on 01/25/2025 01:30 amQuote from: steveleach on 01/20/2025 03:20 pmThere's a small gap between "small enough to fit in the cargo bay" and "large enough to require orbital assembly" that might benefit from it in the short term. But if Starship meets its launch cost goals I suspect most customers will quickly move on to the larger structures constructed in orbit.I expect it will be the opposite, actually. Anything you can fit in Starship will be cheap, but anything requiring risky and training-intensive EVAs for assembly (or some sort of custom R&D assembly robot) will be a lot more expensive.Yes, clearly small things that can transported in a single reusable vehicle will be cheaper.But when you go larger than that you have to choose between... Let me stop you right there.If. If you go larger than that. There's no inevitable progression where things have to necessarily get bigger, such that this is somehow an unavoidable problem that must be solved.If bigger things are dramatically more expensive, then the far more obvious answer is that you just won't make things bigger. "Doctor, it hurts when I do this!" Quote from: steveleach on 01/25/2025 09:16 amI don't expect risky and training-intensive EVAs to be a thing for very long, once Starship brings launch costs down to where SpaceX want them to be. Starship's refuelling model, when implemented at scale, will make rendezvous and docking fast and trivial.We've had rendezvous and docking long before the ISS, and yet we still used many many "risky and training-intensive EVAs" for that. So clearly this analysis is missing something.Quote from: steveleach on 01/25/2025 09:16 amWe know there are companies developing robotic orbital assembly technologies, but they aren't currently financially viable because current launch costs...That's just one hypothesis to explain why they aren't financially viable.Looking at the actual technology, a more likely hypothesis is that they haven't actually solved the right problem. Most of the "robotic assembly" I see is just creating empty shells, but the vast majority of the cost isn't in the shell, it's in outfitting the interior equipment.
...There's no inevitable progression where things have to necessarily get bigger, such that this is somehow an unavoidable problem that must be solved.
If bigger things are dramatically more expensive, then the far more obvious answer is that you just won't make things bigger.
Most of the "robotic assembly" I see is just creating empty shells, but the vast majority of the cost isn't in the shell, it's in outfitting the interior equipment.
Quote from: Twark_Main on 01/27/2025 07:35 pmQuote from: steveleach on 01/25/2025 09:16 amQuote from: Twark_Main on 01/25/2025 01:30 amQuote from: steveleach on 01/20/2025 03:20 pmThere's a small gap between "small enough to fit in the cargo bay" and "large enough to require orbital assembly" that might benefit from it in the short term. But if Starship meets its launch cost goals I suspect most customers will quickly move on to the larger structures constructed in orbit.I expect it will be the opposite, actually. Anything you can fit in Starship will be cheap, but anything requiring risky and training-intensive EVAs for assembly (or some sort of custom R&D assembly robot) will be a lot more expensive.Yes, clearly small things that can transported in a single reusable vehicle will be cheaper.But when you go larger than that you have to choose between... Let me stop you right there.If. If you go larger than that. There's no inevitable progression where things have to necessarily get bigger, such that this is somehow an unavoidable problem that must be solved.If bigger things are dramatically more expensive, then the far more obvious answer is that you just won't make things bigger. "Doctor, it hurts when I do this!" Quote from: steveleach on 01/25/2025 09:16 amI don't expect risky and training-intensive EVAs to be a thing for very long, once Starship brings launch costs down to where SpaceX want them to be. Starship's refuelling model, when implemented at scale, will make rendezvous and docking fast and trivial.We've had rendezvous and docking long before the ISS, and yet we still used many many "risky and training-intensive EVAs" for that. So clearly this analysis is missing something.Quote from: steveleach on 01/25/2025 09:16 amWe know there are companies developing robotic orbital assembly technologies, but they aren't currently financially viable because current launch costs...That's just one hypothesis to explain why they aren't financially viable.Looking at the actual technology, a more likely hypothesis is that they haven't actually solved the right problem. Most of the "robotic assembly" I see is just creating empty shells, but the vast majority of the cost isn't in the shell, it's in outfitting the interior equipment.I know you like a good argument, but I think you're maybe trying a little too hard here.
Quote from: Twark_Main on 01/27/2025 07:35 pm...There's no inevitable progression where things have to necessarily get bigger, such that this is somehow an unavoidable problem that must be solved.Inevitable? Maybe not, but human history shows that humans do like to make things bigger, whether that is transportation systems, buildings, machines, etc. And the reason for that is economic in a lot of cases, in that making whatever it is bigger results in being able to do more of something.
Quote from: Twark_Main on 01/27/2025 07:35 pmIf bigger things are dramatically more expensive, then the far more obvious answer is that you just won't make things bigger.This is really a question for the people and companies that want to solve problems in space by building something here on Earth and launching it into space. THEY will be the ones to decide how big or small something should be.
Me personally, though the cost of a Starship Cargo launch will be economical even if you don't fill up the payload bay, I think everyone will be trying to maximize each launch opportunity, since time is money too.
Quote from: Twark_Main on 01/27/2025 07:35 pmMost of the "robotic assembly" I see is just creating empty shells, but the vast majority of the cost isn't in the shell, it's in outfitting the interior equipment.The ISS was the last major assembly project in LEO, and it used humans to do all of the detailed assembly work, though sometimes with the help of robotic arms. Even the Chinese are still using humans for their much smaller space station.But humans cost a LOT to get to and keep in space, so for commercial activity in space that requires some degree of assembly I think the hardware designers will focus on how to use remote and robotic assembly techniques to assemble large (and small) components in space.
Since it seems SpaceX has the Superheavy booster down pat. However, why can't they just build a stripped down Starship upper stage, expendable for now, to launch Starlink satellites? Then work on the Reusable Starship. They could probably do both at the same time. It would at least see how much refurbishment the booster will take before relaunching. If they can do 200-250 tons expendable, that could get a lot of Starlinks up on one launch. Sure, it would probably be in line with what it is costing using F9 expending the upper stage, but Starlink would work faster and get more customers. Also, with an expendable upper stage, they could do an entire moon launch with lander and Orion ala Apollo with Saturn V in one launch. Starship is to me, going to be the hard part, making it work reusable.
Expendable would be best utilized for an unusually large deep space probe, which would be a rare mission. Enceladus and Europa have oceans with a frozen surface. A mission might have:1) A lander2) A stationary communications relay that stays with the lander3) A nuclear powered mini submarine which melts its way through the ice, unspools a communication cable as it does so, then leaves a signal relay station at the bottom of the ice. The sub then goes off to explore the submerged world.Again, this would be rare and it would be high mass. If done in an architecture with non-distributed mass, a disposable US makes sense. A fairing is jettisoned upon reaching vacuum, and the US is re-propped in LEO, possibly again in cis-lunar space. The second stage in essence is reused as both a third stage, and possibly even a fourth stage, simply by taking on additional prop at specified waypoints.
If going to worlds with no atmosphere (Mercury, moons of gas or ice giants, unless you’re willing to aerocapture in the GG itself - very risky potentially, we’ve never done that), the fairing is dead weight
No TPS (~25t)No Elonerons (~10t including actuators & stuff?)
Quote from: TomH on 01/30/2025 05:00 amExpendable would be best utilized for an unusually large deep space probe, which would be a rare mission. Enceladus and Europa have oceans with a frozen surface. A mission might have:1) A lander2) A stationary communications relay that stays with the lander3) A nuclear powered mini submarine which melts its way through the ice, unspools a communication cable as it does so, then leaves a signal relay station at the bottom of the ice. The sub then goes off to explore the submerged world.Again, this would be rare and it would be high mass. If done in an architecture with non-distributed mass, a disposable US makes sense. A fairing is jettisoned upon reaching vacuum, and the US is re-propped in LEO, possibly again in cis-lunar space. The second stage in essence is reused as both a third stage, and possibly even a fourth stage, simply by taking on additional prop at specified waypoints.Why would you jettison a fairing? You waste up to 10km/sec of aerocapture potential
The radiation environment of Europa is so extreme that it probably wouldn't have the same con-ops as an Enceladus lander-drill mission.For eg, you might not want to leave most of your hardware on the surface, but instead leave just a passive comms relay, while everything else is melted into the ice.