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SpaceX Launches, Landings and News

BaseDeltaZero said:
Honest question, this seems like a good a place as any to ask: What's the point of catching the booster? It's impressive but what does it give compared to just landing on a pad? It can't be for faster refresh time, right?
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While there are a variety of advantages to catching the big one that justifies this, with the others mostly being side benefits, is the mass reduction. The Falcon 9's landing legs are actually pretty heavy as landings are hard and they need to be strong enough to handle that, we recently saw how close that threshold is with the failed landing due to one of the legs collapsing. Superheavy is, as the name implies, far heavier then the Falcon 9's first stage and thus would require even beefier legs to handle landing*.

*Yes they could probably land softer due Superheavy's ability to hover whereas Falcon 9's booster has >1 TWR when empty even on one engine. However just look at the issues the earlier 10km hop tests had with the (admittedly temporary) legs giving way.


By using the catching tower SpaceX can shift pretty much all the catching/landing hardware onto the tower with the only part of Superheavy necessary being the pins it lands on which are already required for lifting and thus add no unnecessary mass to the booster. This cuts down on Superheavy's dry mass which in turn improves the system's total payload capacity.
 
Another issue... well.

BaseDeltaZero said:
Honest question, this seems like a good a place as any to ask: What's the point of catching the booster? It's impressive but what does it give compared to just landing on a pad? It can't be for faster refresh time, right?
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Even aside from "this saves weight on the landing legs," something else occurs to me.

For Starship, the first stage is over 200 feet tall. It is built to the same general scale as a good-sized office building. But unlike a typical 20-story building, on landing it is a hollow cylinder, mostly empty (the rocket fuel's been burned up) with relatively thin walls (to save mass and be more efficient).

Starship's first stage, per Wikipedia, only weighs 275 tons empty. Meanwhile, it has a cross-sectional area of 30 times 233 is about 7000 square feet. It seems to me that the thing just plain tipping over in a strong wind is not an unreasonable concern, especially on a platform at sea. So you would very much want to make sure it's firmly secured at multiple points along its height.
 
Another thing to note is that with the capture mechanism, the Superheavy never touches the ground. Neither during launch, nor during landing.

If the capture mechanism is replicated offshore, it means not worrying about whether the hot plumes from the engines will damage your landing ship. Because the Superheavy's engines will be several storeys above the ship's deck.
 
Elbrasch said:
So, launch today is at 23 o'clock CET, not sure I will be catching that one.
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The launch should be tomorrow in your time zone, I believe. SpaceX pushed the date back from November 18 to 19 a couple days ago.

Starship IFT-6 is currently scheduled for: NET (or 2024-11-19 2200 UTC)
Article:
The sixth flight test of Starship is targeted to launch Tuesday, November 19. The 30-minute launch window will open at 4:00 p.m. CT

[ . . . ]

The next Starship flight test aims to expand the envelope on ship and booster capabilities and get closer to bringing reuse of the entire system online. Objectives include the booster once again returning to the launch site for catch, reigniting a ship Raptor engine while in space, and testing a suite of heatshield experiments and maneuvering changes for ship reentry and descent over the Indian Ocean.

[ . . . ]

Several thermal protection experiments and operational changes will test the limits of Starship's capabilities and generate flight data to inform plans for ship catch and reuse. The flight test will assess new secondary thermal protection materials and will have entire sections of heat shield tiles removed on either side of the ship in locations being studied for catch-enabling hardware on future vehicles. The ship also will intentionally fly at a higher angle of attack in the final phase of descent, purposefully stressing the limits of flap control to gain data on future landing profiles. Finally, adjusting the flight's launch window to the late afternoon at Starbase will enable the ship to reenter over the Indian Ocean in daylight, providing better conditions for visual observations.

Video links:


EDIT: highlights from the previous test flight, IFT-5, for anyone that needs a recap:


View: https://www.youtube.com/watch?v=hI9HQfCAw64
 
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apnews.com

SpaceX launches giant Starship rocket, but aborts attempt to catch booster with mechanical arms

SpaceX has launched another Starship rocket, but passed up catching it with giant mechanical arms. The world's biggest and most powerful rocket blasted off from Texas on Tuesday.
apnews.com apnews.com
Unlike last month's success, the booster was directed to a splashdown in the Gulf of Mexico. The catch was called off just four minutes into the test flight from Texas for unspecified reasons, and the booster hit the water three minutes later.

Not all of the criteria for a booster catch was met and so the flight director did not command the booster to return to the launch site, said SpaceX spokesman Dan Huot. He did not specifying what went wrong.

At the same time, the empty spacecraft launched from Texas atop Starship soared across the Gulf of Mexico on a near loop around the world similar to October's test flight. Skimming space, the shiny retro-looking craft targeted the Indian Ocean for a controlled but destructive end to the hourlong demo.

... Flight 6 carried the first-ever Starship payload — a plush banana onboard [Starship's upper stage — a 165-foot-tall (50 m) spacecraft called Starship, or simply "Ship"] which served as a zero-gravity indicator. (It was not deployed into space.) In addition, Ship briefly re-lit one of its six Raptor engines about 38 minutes into the flight.

This burn helped show that Ship can perform the maneuvers needed to come back to Earth safely during orbital missions. Indeed, Ship is designed to be fully and rapidly reusable, just like Super Heavy; SpaceX eventually intends to catch it with the chopstick arms as well, and will likely try to do so on a test flight in the near future.
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... that seems like a notable amount of heat discoloration on the outside of the upper stage during that landing sequence.

I've seen that color before personally, and that is on things intended to be disposable use because of the heat involved in their use case. Things much less critical than the hull of a supposedly reusable spacecraft, and intended to be replaced after they look like that.
 
E.I.G. said:
... that seems like a notable amount of heat discoloration on the outside of the upper stage during that landing sequence.

I've seen that color before personally, and that is on things intended to be disposable use because of the heat involved in their use case. Things much less critical than the hull of a supposedly reusable spacecraft, and intended to be replaced after they look like that.
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Did you watch the previous landings? It actually looked much better than IFT-4 or even IFT-5.

As the SpaceX engineers on the livestream noted, they pushed the envelope for this test by removing a lot of the heat tiles to see how much they could get away with. It's also using an older version of the heat shield material and ship design. On future flights, the flaps will be moved so they're less exposed during reentry.
 
mistakenot said:
Did you watch the previous landings? It actually looked much better than IFT-4 or even IFT-5.

As the SpaceX engineers on the livestream noted, they pushed the envelope for this test by removing a lot of the heat tiles to see how much they could get away with. It's also using an older version of the heat shield material and ship design. On future flights, the flaps will be moved so they're less exposed during reentry.
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... "looked much better" than 4's "total writeoff" and 5's "still notably burned the thing" is not the gotcha you seem to think it is.
All three of these Starships are scrap metal and I am not impressed by stainless steel that has been heated to the point of discoloration on the side entirely opposite from the heat shield.

I'm not even talking about the flaps this time, I mean the overall structure of the vessel is discolored in a way I know happens to stainless steel in the face of notable heating.
As a comparison, the Space Shuttle had a full coating of various heat protections:
en.wikipedia.org

Space Shuttle thermal protection system - Wikipedia

en.wikipedia.org en.wikipedia.org
Not just bare stainless steel that is notably discolored at a point as far from the heat shielding as it is possible to get.
 
Moving the upper flaps is probably for the best, the top inner corner looked rather glowy red and some what burnt. They could probably find a solution for it in time, but just pulling the hinges out of the immediate airstream is probably just easier and still gives them the control authority they need.


And with the stainless steel the question would be if the discoloration would actually lead to any major weakening of the material, if it doesn't and it's most cosmetic it doesn't really matter for practical use, and if it does... well then it's a problem. Still I haven't heard of anyone being particularly concerned about that level of discoloration of the steel before, so I kind of figured this was with in expected margins still.
 
E.I.G. said:
... "looked much better" than 4's "total writeoff" and 5's "still notably burned the thing" is not the gotcha you seem to think it is.
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Didn't mean it like that, just that it was a surprising comment given the ship performed better this time. I didn't recall if you'd followed the previous test flights, so I was wondering if you were unaware of the context.

These test articles are not the final design and aren't meant to be reused. They'll learn from the results and continue to improve.
 
Quickshot0 said:
And with the stainless steel the question would be if the discoloration would actually lead to any major weakening of the material, if it doesn't and it's most cosmetic it doesn't really matter for practical use, and if it does... well then it's a problem. Still I haven't heard of anyone being particularly concerned about that level of discoloration of the steel before, so I kind of figured this was with in expected margins still.
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Previous flights have been in the dark, I think this might be the first time they have appeared.
I will admit, I do not know for sure that this represents outright damage, but we are talking about rocketry. Any notable change in that sort of thing could mean problems, and I for one would want a lot of reassurance before I put a payload on a reused rocket with those splotches.
Hopefully someone will detail the meaning of the color change somewhere, but I'm unimpressed with their size and locations.
mistakenot said:
Didn't mean it like that, just that it was a surprising comment given the ship performed better this time. I didn't recall if you'd followed the previous test flights, so I was wondering if you were unaware of the context.

These test articles are not the final design and aren't meant to be reused. They'll learn from the results and continue to improve.
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It did "better", but my longtime issue with what I've seen of these launches is that they don't seem anywhere close to reusability, and they are putting a whole lot of effort into that goal.

... as far as I know this entire project is currently funded as part of the US moon mission plans. This is taxpayer money being used to try for reusable systems that are currently struggling to be worth reusing, and I don't think the contract cares about that part.
I'm kind of upset that Musk might end up in charge of a government office instead of explaining his rocket company's spending to Congress.
 
E.I.G. said:
It did "better", but my longtime issue with what I've seen of these launches is that they don't seem anywhere close to reusability, and they are putting a whole lot of effort into that goal.
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Glass half-full or half-empty, I guess. They're making progress, and they have a lot of experience with Falcon 9 to draw upon.

... as far as I know this entire project is currently funded as part of the US moon mission plans. This is taxpayer money being used to try for reusable systems that are currently struggling to be worth reusing, and I don't think the contract cares about that part.
I'm kind of upset that Musk might end up in charge of a government office instead of explaining his rocket company's spending to Congress.
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The HLS contract with NASA is just for the lunar lander variant. It doesn't come close to funding the entire Starship program.
 
E.I.G. said:
Previous flights have been in the dark, I think this might be the first time they have appeared.
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The color changes have been spotted in previous reentries as well, so it's nothing new in that sense and so far they don't seem to have particularly cared. Also I have heard steel will change colors when exposed to higher temperatures, I haven't heard anything so far over this leading to some kind of permanent damage though so I suspect that isn't actually the case.

Now if one were to guess, heating a material to very high temperatures and then cooling it down to room temperatures many times over... well there is probably a limit to how many times one can cycle a component like that. Though if one asked me to guess I'd kind of expect that cycle endurance would be more then a few dozen times, and could easily be in the thousands range or far beyond. But I lack material engineering knowledge to really say for sure.
E.I.G. said:
... as far as I know this entire project is currently funded as part of the US moon mission plans.
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As some one else noted, it's for the moon landing system, yeah. And the contract itself is fixed price and was by far the lowest bid for the entire thing, NASA literally not even being able to afford trying any other option with the funds given.

So basically the amount of money NASA can lose on this is fixed and very much on the very low side for what manned lunar landers of any size cost.

The reusability testing is as such entirely on SpaceX, though their way of testing involves just trying it out in test articles and seeing in which ways they fail. There is some debate in engineering circles on the best ways of testing, but this is apparently not all that expensive relative to alternatives for items like this and is one of the fastest ways to progress such a project. It however obviously doesn't play the best optics wise though, as for most people an exploded rocket no matter how intentional very much looks like a failure.

Still that's why they seem not that disturbed by various failures, so long as it doesn't fall short of their actual minimum goals they basically consider it as successfully getting data on more things. And if they get much better then expected, well then they can more quickly move on to later parts of the project.
Simon_Jester said:
One wonders if by the time they add enough heat shielding to make the rocket safely reusable, they'll have any payload capacity left.
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Considering that with this rocket they apparently decided to start reducing the amount of heatshield protection they had, gives the impression they thought the last rocket might have demonstrated being over protected in most areas. So it wouldn't actually be strange if the heatshield mass might go down in future designs. Though we'll have to see what conclusions they draw from the current designs results.
 
Quickshot0 said:
Considering that with this rocket they apparently decided to start reducing the amount of heatshield protection they had, gives the impression they thought the last rocket might have demonstrated being over protected in most areas.
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Didn't someone just say that the last rocket looked heat-damaged too?

I'm worried that we may be looking at a scaled-up version of the Titan minisub debacle, where overconfident people radically underestimate how much it takes to produce a rocket that is reliably safe to use twice. Just because you can land it the first time doesn't mean it won't blow up if you try to fly it again, and you can't really run a space industry on "we've made launch so cheap that it's okay if 10% of our payloads blow up because the reused first stages are unreliable."
 
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Simon_Jester said:
I'm worried that we may be looking at a scaled-up version of the Titan minisub debacle, where overconfident people radically underestimate how much it takes to produce a rocket that is reliably safe to use twice. Just because you can land it the first time doesn't mean it won't blow up if you try to fly it again, and you can't really run a space industry on "we've made launch so cheap that it's okay if 10% of our payloads blow up because the reused first stages are unreliable."
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On the other hand, Falcon 9 has proven to be very reliable even when reused. Its too soon to judge if SpaceX's priorities are flawed. They haven't even started trying to recover the starship yet, which they would need to do to be able to judge if the discoloration is purely cosmetic or not.
 
E.I.G. said:
... as far as I know this entire project is currently funded as part of the US moon mission plans. This is taxpayer money being used to try for reusable systems that are currently struggling to be worth reusing, and I don't think the contract cares about that part.
I'm kind of upset that Musk might end up in charge of a government office instead of explaining his rocket company's spending to Congress.
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The entire HLS contract is about $2.9 billion? We have evidence that taxpayers have saved $40 billion due to SpaceX. Here is NASA administrator at the time Bill Nelson testifying at a congressional hearing about the number. Compared to launching on non-SpaceX services. I believe it's all the cost savings from launching GPS and NROL spy satellites for the military.


View: https://old.reddit.com/r/SpaceXLounge/comments/1guyjhb/starship_flight_6_objectives/
The objectives for Starship Flight 6 are:
  1. Restart of Raptor engines in vaccuim.
  2. Daylight landing of the ship.
  3. Higher peak heating (steeper reentry).
  4. Faster/harder booster catch.
There are thousands of small design changes also being tested.

If it looks like flight 6 hasn't improved on flight 5, that's by design. These flight tests are currently validating models by testing the limits of entire stack. During the livestream, it was noted that the upper stage had been reducing the amount of heatshield tiles and also purposefully left a section of the nose cone unshielded.
Simon_Jester said:
Didn't someone just say that the last rocket looked heat-damaged too?

I'm worried that we may be looking at a scaled-up version of the Titan minisub debacle, where overconfident people radically underestimate how much it takes to produce a rocket that is reliably safe to use twice. Just because you can land it the first time doesn't mean it won't blow up if you try to fly it again, and you can't really run a space industry on "we've made launch so cheap that it's okay if 10% of our payloads blow up because the reused first stages are unreliable."
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Despite Elon being off his rocker, I don't think the Titan debacle can occur. For one thing, the entire Artemis program never has humans on board during liftoff or landing on Earth. The program needs anywhere between 10-20 Starship launches for refueling before NASA astronauts get anywhere near the HLS for the moon landing. And if literally anything goes wrong during these 10-20 launches you bet your ass that NASA won't even launch the astronauts up to space in Orion for the rendezvous.

It won't be up to Elon, that's for sure.

Captainwolf said:
On the other hand, Falcon 9 has proven to be very reliable even when reused. Its too soon to judge if SpaceX's priorities are flawed. They haven't even started trying to recover the starship yet, which they would need to do to be able to judge if the discoloration is purely cosmetic or not.
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As for discolouration, SpaceX only needs to recover samples of the metal from the ocean. Metalurgical analysis of heat damage can be done with recovered debris. I actually think they have recovered some from IFT 5?
 
Simon_Jester said:
Didn't someone just say that the last rocket looked heat-damaged too?
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They said it had changed color, something that so far I know steel can do when it gets hot and this has happened for every reentry for Starship and so far no one has commented on it as being a particular matter of concern. As such, I don't think it is really enough to say there is anything like damage there, it could be a cause of concern of course, but these things are still many launches away from anyone ever getting onboard. So lots of time to properly test everything for better reliability.


I did actually notice one spot of actual for sure heat damage though, which I also commented on some posts ago. One of the top flaps upper corners at the hinge area seemed like it might have burned through a bit. It threw off some level of red sparks, was still glowing red hot during final descent and the structure seemed like it wasn't entirely in original state anymore. So the flaps clearly need more work still, though this was the last Block 1 launch, I believe from now on it will be Block 2 designs where the forward flaps are put more leewards, hopefully putting the hinges in the reentry shadow of the overall Starship bulk. So that may fix it already, we'll have to see.

But as such clearly the forward flap hinges are being the most challenging part so far during reentry.
 
Simon_Jester said:
and you can't really run a space industry on "we've made launch so cheap that it's okay if 10% of our payloads blow up because the reused first stages are unreliable."
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From the data I can quickly find (till 2013), we are at 6% failure rate for unmanned over the last 20 years in the data and 8% overall, so yes one can indeed run a successful space industry on 10% blowup rate ;)
 
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AntiSanity said:
The entire HLS contract is about $2.9 billion? We have evidence that taxpayers have saved $40 billion due to SpaceX. Here is NASA administrator at the time Bill Nelson testifying at a congressional hearing about the number. Compared to launching on non-SpaceX services. I believe it's all the cost savings from launching GPS and NROL spy satellites for the military.
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Not 40 billion due to launching on SpaceX in comparison to non-spaceX. It's 40 billion savings because of the existence of competition, so those non-SpaceX services had to lower their launch prices instead of vastly overcharging the miliary.
There used to be a de facto monopoly in the US launch market.

Arguably, overcharging the military still happens. The US military pays SpaceX a hundred million dollars whereas commercial launches pay 65 million, and SpaceX's own internal cost is estimated to be somewhere between 20 and 30 million.
 
10ebbor10 said:
Not 40 billion due to launching on SpaceX in comparison to non-spaceX. It's 40 billion savings because of the existence of competition, so those non-SpaceX services had to lower their launch prices instead of vastly overcharging the miliary.
There used to be a de facto monopoly in the US launch market.

Arguably, overcharging the military still happens. The US military pays SpaceX a hundred million dollars whereas commercial launches pay 65 million, and SpaceX's own internal cost is estimated to be somewhere between 20 and 30 million.
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Agreed on competition lowering prices. Delta IV Heavy used to cost the NRO $400 million per launch, after Falcon Heavy's existence the launches kept reducing in price until it dropped to around $150 million per launch. ULA made bank when it had no competition. Not after the Boeing and Lockheed Martin had their whole corporate espionage debacle and were forced by the courts to combine their launch divisions into ULA.

Government launches have always been more expensive because they have additional requirements and service requests that commercial launches don't have. For comparison, Falcon 9 commercial launches are $65 million and gov't launches $100 million. While a similar weight class rocket Delta IV medium has an estimated $160 million commercial charge and had a $200 million gov't charge.
 
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