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Starship Flight 5: Launch and booster catch [video]

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Re: Starship Flight 5: Launch and booster catch [video]

#871

Post by TMWNN »

asadotzler wrote: post #659
lquist wrote: post #200

What does Starship reusability mean for $/kg to LEO? I know there are longer term targets of $10/kg but that supposes efficiencies that aren’t here yet. Would be helpful to understand before Starship reusability where the state of the art was in terms of $/kg to LEO and where we would be with impending Starship reusability.

Everyone gets this wrong, cost is not price. SpaceX themselves launch Starlinks at about $1,200/kg but they charge customers closer to $12,000/kg. Do the math. Costs coming down are increases in SpaceX profits, not decreases in customer prices.

Besides what 55555 said, in the near term SpaceX has indeed passed at least some of the cost savings onto customers. NASA administrator Bill Nelson quoted a member of the Joint Chiefs as telling him that SpaceX had saved the US government $40 billion for just launching military payloads. https://www.fool.com/investing/2022/06/05/did-spacex-really-...>

On the civilian side, SpaceX saved NASA $2 billion for just one payload, Europa Clipper https://arstechnica.com/space/2023/10/a-year-from-launch-the...>, so who knows how many billions more from other launches.

Re: Starship Flight 5: Launch and booster catch [video]

#872

Post by inglor_cz »

Tepix wrote: post #864
inglor_cz wrote: post #113

Earlier quoted context omitted.

Massive. The designers of Starship studiously avoided all the problems that made Space Shuttle expensive to refurbish: a. Cheaper, more durable material (stainless steel). b. Cheaper, easier to manufacture engines. c. Easier to use fuel (methane is much "tamer" than hydrogen). d. Standardized heat shield with much smaller requirements for manual work.

> d. Standardized heat shield with much smaller requirements for manual work. We'll have to see how it works out.

It is a very daunting problem no doubt, maybe the hardest one, but I also don't doubt that the end form of Starship will require way, way less than 20 000 man-hours per turnaround (as the Space Shuttle required) to refurbish the heat shield. They simply cannot afford that.

Re: Starship Flight 5: Launch and booster catch [video]

#873

Post by adastra22 »

kqr2 wrote: post #753
davedx wrote: post #624

Earlier quoted context omitted.

The Mars Direct book is worth reading not only for things like transport and mission design but also a wealth of other good ideas about how to “live off the land” when we get there too. Truly worth reading for anyone remotely interested in space exploration

How does this differ from his other book The Case For Kats ?

Typo?

Re: Starship Flight 5: Launch and booster catch [video]

#874

Post by TMWNN »

slimebot80 wrote: post #694

The SpaceX engineers did a great job, as did NASA. The media needs to stop blindly attributing this to "Elon Musk". He did well taking the risks NASA was not allowed to take at the start. But these days he is toxic to the media and toxic to reporting, so for that reason alone the media could smarted up a little. Well done SpaceX and NASA engineers.

>The media needs to stop blindly attributing this to "Elon Musk".

Musk's biographer tweeted the pages from his book https://x.com/WalterIsaacson/status/1844870018351169942> discussing how in late 2020 Musk suggested, then insisted against considerable opposition from his engineers, that Superheavy be caught with chopsticks instead of landing on legs like Falcon 9.

(If this sounds familiar, also according to the book, Musk is the person who suggested and, against considerable opposition from his engineers, insisted on Starship switching to stainless steel instead of carbon fiber.

Hint: Musk was right and his engineers were wrong. Both times.)

Re: Starship Flight 5: Launch and booster catch [video]

#875

Post by jillesvangurp »

zaroth wrote: post #205
jillesvangurp wrote: post #75

Earlier quoted context omitted.

Methane is about 900-1500$ / ton. About 1000 tons is used for the launch in addition to 3600 tons of lox. That should be a bit cheaper than methane per ton. Ballpark, the propellant might cost around 2M$. A modern airliner on a long flight might burn around 80 tons of kerosene. It's slightly cheaper than methane. Call it 75-80K$.

Is the $1000/ton a law a physics, or could that ever possibly scale up and come down an order of magnitude?

Just the current market price for fossil methane, which of course goes up and down. But I'm assuming SpaceX gets their methane on the open market.

It's quite possible that SpaceX has access to some cheaper methane source. Texas produces a lot of it.

And SpaceX has speculated about eventually switching to some renewable source by e.g. synthesizing methane. In which case that would boil down to cost of electricity and carbon. I don't see that becoming cheaper short term but that could happen long term.

Re: Starship Flight 5: Launch and booster catch [video]

#876

Post by jonplackett »

flaburgan wrote: post #76
treespace8 wrote: post #14

I'm just so happy to see this level of progress. This another big step for opening up space. To think that one day this will be considered normal. 150 Metric tons sent on a fully reusable rocket. Thats like a 747 to space.

So, reusable is supposed to reduce the cost. But the space shuttle was reusable and it has been shutdown because it was too expensive. What is the differences between the two?

The main thing is... Space shuttle wasn't all that reusable. It had to be launched with a massive rocket and two massive boosters that just fall into the ocean.

Re: Starship Flight 5: Launch and booster catch [video]

#877

Post by mhandley »

ChuckMcM wrote: post #516

Pretty impressive. The engineering team at SpaceX is really something. Some thoughts; The 'chopsticks catch' was amazing to watch. Seems like it adds a lot of risk and clearly the booster needs additional fire suppression systems :-) perhaps the tower could mount something that sprays the booster like the barges have for the F9 boosters. The heatshield held out for a much longer time, the asymmetric heating on the fl…

As to whether catching the booster adds risk - I'm not sure it does.

First, to the extent the booster is out of position in the x (sideways) direction, the chopsticks can move to accomodate error. But actually I think this dimension is the easiest of the three, as the booster has plenty to time to null any error in this dimension.

In the y direction (direction of travel towards the tower), the rails on the chopsticks can cope with the booster touching down along quite a long distance. But importantly, they appear to be smooth, so the pins can initially skid along them and then the booster can swing if it has not fully nulled any horizontal movement. In contrast, if the booster used legs and has not yet fully nulled any horizontal motion at touchdown, there is a greater risk of breaking a leg or simply tipping over.

And in the z direction, it should be possible for the chopsticks can absorb more vertical motion than legs can absorb, because you can easily build in huge springs/dampers/etc into the ground equipment without concern about mass.

Catching also puts the booster in tension rather than compression - it's easier to be rigid in tension than compression.

Finally, if legs were used, the engines would have to get close to the ground during landing, so reflected shock from the ground could cause damage. I know Falcon 9 does this, but the area of the base of Starship is much greater, so there's effectively less room for the reflected energy to escape. Catching completely removes this risk.

On balance, I think they would have better chance of success for each mission by catching. The main downside would be if you fail to catch, you may need to build a new tower, whereas a flat pad would be cheaper and easier to repair.

Re: Starship Flight 5: Launch and booster catch [video]

#878

Post by pfdietz »

rtkwe wrote: post #794
teractiveodular wrote: post #19

It's difficult to overstate how important the milestone of catching the booster is. Now we have a reusable rocket an order of magnitude larger than anything we've had before, and the cost of kg to orbit just nosedived.

They're still having some significant burn through problems on the upper stage fins during reentry it looks like. Way better than last time but the top part of the fin was glowing far a while after the main reentry finished.

Even with a disposable upper stage, I believe Starship would be cheaper per kg than F9 or FH.

Re: Starship Flight 5: Launch and booster catch [video]

#879

Post by pfdietz »

sharlos201068 wrote: post #862
joejohnson wrote: post #842

Earlier quoted context omitted.

Amen! If it turns out we can’t make humans a multiplanetary species in any reasonable timeframe, at least we can make the last few decades of livable earth climate a friendly atmosphere for US business interests.

Even the worst expected impacts of climate change will leave earth tremendously more habitable than anywhere else in the solar system.

Even a nuclear war would have that outcome. Even a KT boundary scale asteroid impact would have that outcome. The rest of the solar system is just hell.

Re: Starship Flight 5: Launch and booster catch [video]

#880

Post by Dr4kn »

k4rli wrote: post #840
treespace8 wrote: post #14

I'm just so happy to see this level of progress. This another big step for opening up space. To think that one day this will be considered normal. 150 Metric tons sent on a fully reusable rocket. Thats like a 747 to space.

Where is the progress if they're 2 years behind their schedule? In Q1 2025 they should already be launching the HLS according to the timeline.

Falcon 9 is still the most advanced rocket flying real missions to date. The only thing close to it is Blue Origin, which didn't even have their maiden flight yet.

Is their timeline too optimistic? Yeah, but if the industry still catches up with F9 and they are close to having something a lot more advanced it really doesn't matter.

Even without reusability nothing comes close to Starship's cargo capacity. If you don't have to put a lot of engineering into getting things as small and light as possible you can put things in space a lot faster.

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