RCgothic

As someone who used to design wind turbines and is now designing a commercial fission plant for the upcoming nuclear renaissance, hard disagree. If you think wind and solar are cheap now, just keep giving them a bigger share of the grid and see what happens. As their share goes up, productivity drops due to oversupply and the price per kWh goes up massively. Nuclear is as cheap to build as anything else when you commit to having a lot and a lot cheaper than trying to transition entirely to wind and solar, or even worse continuing to burn carbon. Nuclear also has an enormously longer lifespan, is vastly more reliable, and uses far fewer resources and land. PWR nuclear plants are easy to decommission and spent nuclear fuel is such a valuable resource that it should be a crime to waste by burying it. Nobody has *ever* been seriously harmed by spent nuclear fuel from a commercial power plant, and if we absolutely must bury it it'd be no more dangerous to future generations than anything else we routinely put in industrial landfills, like mercury.

Requires reuse, definitely. A reused stage costs basically nothing per flight compared to a new one and F9 still expends S2 each flight, so if SS SH can manage full reuse it wins. Expendable vs expendable certainly there's no way Superheavy can come in under F9. It's over 4x the engines even if the structure breaks even for welded steel vs machined aluminium isogrid.

Not just lower per flight, single digit millions per flight. An order of magnitude less per flight and two orders of magnitude per kg.

Maybe, but that's doesn't appear to be what Scott's tweet says. The source of the apparent leak is speculation at this stage. Official update: https://www.spacex.com/launches/mission/?missionId=starship-flight-2 Booster was a RUD, ship was confirmed FTS triggered after loss of telemetry.

Interesting trajectory for a first launch. I'm presuming a smallsat payload isn't something NASA cares about too deeply.

And even if it did achieve passive heat-shield-first stability, that wouldn't last for long because aero forces would shred the open base of the fairing.

Theoretically pieces of a ship on a near-orbital trajectory could be converted onto an orbital trajectory by an energetic explosion event, but as Jonathan said it wasn't close enough.

Thinking more about the debris path there I think.

The Starship plume anomalies prior to FTS suggested a loss of attitude to me.

Musk's descent down the rabbit hole of public behaviour that would get any of us promptly banned from this site makes it a lot harder to enjoy SpaceX's successes and I certainly don't want him in charge of any off-world colonies. I am looking forward to IFT2 today though, and hope it goes as planned. I'm going to take "high teens" as the number of flights required for Artemis III with a pinch of salt. It's so at odds with what we've been hearing about payload capacity, the amount of fuel lunar starship would be able to hold, and the amount of fuel calculated as necessary for the mission.

If you look closely you'll see that of the two flat portions with the pins through, the left hand pin mount doesn't extend all the way down and the right hand pin mount doesn't extend all the way up. Two axis freedom. I'm 99% certain that's the gimbal mount.

Europe determines to source their next-gen launchers through a NASA-style competitive commercial procurement process: https://arstechnica.com/space/2023/11/after-the-sting-of-ariane-6-europe-finally-embraces-commercial-rockets/amp/

Apparently we don't have a dedicated thread for the European Space Agency (ESA). Some news that I'm sure has been covered in the Arianespace thread is a brewing rift among European Partners over the future of Europe's Launch Capability and the woes of Ariane 6 and Vega C: https://arstechnica.com/space/2023/11/ariane-6-cost-and-delays-bring-european-launch-industry-to-a-breaking-point/amp/ There's also news about a new programme to source a European capsule for which ESA will be the anchor customer to debut in 2028. https://www.bbc.com/news/science-environment-67339057.amp One of the competing concepts is Exploration Company's Nyx capsule: And the Argo concept from Rocket Factory Ausberg: The Seville meeting also opened up the Zero Debris Charter for signatories. "This encourages everyone operating in space to leave behind no hardware that might collide with operational missions. The UK, one of the big four nations in Esa, will be introducing a new regulatory framework early next year that aims to promote good behaviour and foster a market for services that remove trash from orbit. "We want to reward compliant operators," said UK science minister George Freeman. "If you're bringing back what you put up, if you're doing in-flight servicing and not contributing to space debris - we're going to give you faster licensing, better insurance and quicker access to finance," he told BBC News."

Note to self - Super Heavy is two words not one.

Actually "we won't sign fixed price contracts" isn't what they said. They said they won't do any development work on fixed price contracts. Maybe not as absolute an outcome as my first reading.

Death knell for Starliner beyond its already contacted missions I fear. Not a great prospect for SLS either as NASA desperately tries to reign in its budget.

I'd be very interested to know more about the hydrogen-fuelled Prometheus. Until now everything we know about it says methane.

That's certainly cutting a 2023 launch date fine.

This is so the crew aren't short a lifeboat if the capsule can't redock, not because the capsule can't do the docking itself. If it absolutely came to it, I reckon a cargo dragon could serve as a lifeboat if it had to with an immediate deorbit burn and the crew strapped down to the floor. Last resort.

4 crew every other year isn't one tenth as ambitious as either HLS option could reasonably support. And once again the problem is SLS/Orion.

With or without the upgrade the deluge system probably could withstand a launch-realistic test firing because it will have to in a launch. A full flight duration firing is of course quite different and any system to withstand that would need a tank capacity far larger than is reasonable. But they still won't do a full power launch simulation of the system because the launch clamps can't hold down a partially-fuelled stack at full thrust, and there's no good reason to take the small but potentially severely consequential risk of fully fuelling a stack and lighting the engines except for conducting an actual launch.

Agreed with most of what he said up until 17mins or so. I like ALPACA, but not more than either of the other two HLS solutions and I'm willing to wait. In my opinion getting back to the moon fast is not as important as getting back in a cost effective and scalable fashion, so I'm not especially upset ALPACA wasn't picked looking at the potential of the ones that were. Secondly, Starship doesn't need to be fully crew-rated for Earth entry descent and landing to perform creed lunar missions, and that wouldn't hold things up particularly in the absence of SLS. The crew can meet Starship in LEO via Dragon/Starliner, or even putting Orion atop an expendable Superheavy is something that looks comparatively quick and cheap. With Orion's oversized LAS and Superheavy's potentially high flight rate (even expendably), getting Superheavy crew-rated for launch really wouldn't that big a deal. Thirdly, even ALPACA would have needed orbital refuelling. This is just something we need to master, and he doesn't even doubt we will. So once again my disagreement is on schedule not feasibility, and so each to their own.

Saturn V could manage upwards of 140t to LEO and did not have a reasonably sized lander.

The capability options were interesting but additional complexity for greater performance isn't going to help with the cost, cadence, comanifest volume or schedule issues.

There just isn't any way to modify any part of SLS/Orion without making the cost and schedule problem worse, not better. All the low-cost/high-cadence architectures that we could reasonably achieve within 10 years are Earth Orbit Rendezvous using some combination of Falcon/Superheavy/Vulcan/New Glenn and Dragon/Starship HLS/BO HLS and probably Starliner once they finally get that flying. The biggest modifications to those basic elements we could get completed in a reasonable timescale and budget would be an expendable upper stage for Superheavy, and maybe one new service/propulsion module.