AckSed

Necessary for the US as a competitive edge over those dreadful, too-far-ahead Asians.

I'm still boggling at the 2nd stage tank being that lightweight. Remember, that almost has to have a common dome inside it for the methane tank, and then bonded to the wall securely enough that it isn't affected by the oxygen.

Aww yiss. Go on my son!

Third part: First stage to splashdown was there for an hour; they found barnacles on the engine. Once you gift it to the sea, the ocean "instantly starts consuming it". Marine assets still suck because they dissolve in front of your eyes, but they're a necessary evil. RE: Electron recovery on the manifest: Performance is always maximised over recovery Launch manifest a giant game of whack-a-mole; always changing, so recovery may end up added or taken away to missions Tank reuse relatively low-risk, but it's a small part of the rocket compared to the engines. Have been reusing previously-flown pressurisation and vent-relief systems. Priority is getting customers to orbit on time. Venus probe A "nights and weekends project" for them and the other teams working on it. NASA provided heatshield for reentry probe. Biggest question: "Are we the only life in the universe?" Descent probe passing through the semi-habitable zone 50km up will essentially have a "go/no-go gauge for life". It will have 120 seconds before it is crushed and melted. If yes, chances are life is all around the universe, if no it means we have to be a bit more careful with ourselves. Either way, a super-important and exciting thing to do. They've reached the point on Photon and Electron they can do this for a tiny amount of money. Wary of scope creep, but with Photon they can go anywhere in the near Earth regime, notably the Escapade missions for NASA. Is something about small satellites harder, given the amount of launch services struggling? What makes RL different? Incredible efficiency and automation; for e.g. flight-safety team, they can't afford to hire 30 people on a $7.5 million sticker-price, they have to do it with 3. With regard to small launch vehicles: not everything scales. E.g. a pressure transducer only goes so small. If you can pull that off, engineering a large launch vehicle is a piece of cake. Large vehicles take capital. A launch site for small launch doesn't take that much concrete or steel. The trouble with Neutron is the quanta of capital and the quanta of infrastructure required. It's why nearly all rocket companies start off with a small launcher to gain credibility and thus attract the capital for a large launcher. Neutron Tank test bigger milestone than people realise. Second stage has to be the lightest, highest-performing and also cost the least, because it's disposable. Economics, materials science, manufacturing all have to pass the test. Second-stage tank is 5 metres across and weighs the same as a Harley-Davidson - 300-something kilograms. Made comparison to Centaur [Note: dry mass of Centaur 2247 kg]. In comparison, the first stage tank has much more margin - thicker walls, made to be reused. In the honeymoon period where they are figuring out the margins and what works, what doesn't. It's a hung stage, but the payload load path is spread out over the launch cone to intersect with the sides - "super clean". Designed that first. Holding the fairings is a parasitic load, so you have to find other ways to save mass. Talks about the spiral of doom. You know you've done your job right when every engineer is unhappy with the compromises. Image listing achievements this year: 2nd stage tank testing, critical engine components manufactured, combustion device testing, stage lock and pusher, actuator motor controller, power management module, engine/stage controller functional testing, avionics I/O controller testing, TPS testing, canard test rig built. Still to do: fairing and upper module testing, Archimedes engine build and first hardware-in-the-loop flight to orbit Next year is a big year. Archimedes development going well, but it remains the long pole in the tent. Chose oxidiser-rich staged combustion because if you dial it back a bit from squeezing out every last bit of performance, you end up in really benign operation at the same level of performance as a gas-generator cycle, but "kind of bulletproof". Compared it to an airplane engine. Ox-rich combustor couldn't be dialed back too much or it would extinguish; had to solve that in the process of building the most boring, unboring engine. How many launches per year do you hope to get out of Neutron? Can't put a number on it, because you'll turn out to be wrong. Generally following the Electron beginning cadence. Customers they're talking to looking to use it as a mega-constellation deployer. Designed for high flight rate. Would you ever use drone ships for more intensive launches? Kind of resigned to it. Return to launch site is 8 tons, while downrange is 13 tons. You just trade out too much payload. Any hop tests? No, just try to bring it home, they learned from Electron's recovery. Fairing design now just two halves. Render not updated because they've been working on the rocket. No chance right now of reusable second stage, because payload suffers so horrendously if you have the reusable fairing on that. Also have to direct that to where you care. 70% of the cost of the vehicle is in the first stage. Cleared land to build LC3 for Neutron at Wallops. It's a big pad. Can't launch from NZ, there isn't the industrial base. All the LOX produced in NZ would fill half a Neutron - once. USA can supply multiple tanker-trucks. Wallops gives a good SSO dog-leg corridor, better than the Cape. Also supportive thanks to existing relationships built with Electron. Designing it to be human-rate*able*, not human-rated out of the gate. No market as of now, as the one customer for it is well-served. Needs more space stations, more destinations before they would try. Would jump on it if it made sense. Personal First launch he saw was the last Space Shuttle night launch. Favourite launch is every successful one. Most memorable was the NASA launch "This One's For Pickering" [NZ founder of JPL], as they had Pickering's family in the launch and growing up he always wanted to work for NASA. No allegiance to NASA 'meatball' or 'worm'. Capstone mission had the 'worm' - "craziest flight ever" - and there was a three hour debate over whether they could afford the mass of the sticker on the side of the vehicle or not. The worm was probably slightly lighter. Two/thirds of their business is building spacecraft. Escapade, Varda, MDA Global Star... whole goal of Rocket Lab is to be an end-to-end space company. Launch gives you the keys to space but is just one element. If you can put infrastructure into space, it's incredibly hard to compete. Methodically stepping their way through to that ultimate endpoint. How do you ensure RL survives the next two years? Small launch suffered from a lot of aspiration and not a lot of execution. RL not immune to that. Rigid on "did you do what you said you would do?" Prefer to execute and then tell rather than pump up. Trying to build a multigenerational, enduring space company; everyone's got a use-by date, so it can't be the Peter Beck show. Going public means you have to be profitable, to deliver - called it a forcing function. Without investment in Neutron, RL's profitable, but they're investing in the future.

Takeaway the second: Production is a pain but they're scaling just have to hold the rate; 1 Electron rocket every 15-17 days; Have 3 cleanrooms for integration; Why electric motor on 2nd stage? Propellant residuals on small stage can be 30kg; You risk cavitation on other methods of powering the engine; 1st stage can be completely sucked dry, and so can 2nd stage; Constantly monitoring mixture ratio which is easy with electric motors; Electron's a relatively tiny vehicle for the payload it can lift. Little launch vehicles more sensitive to added mass - 100 grammes on Electron is significant. Wallops a "key site". Certified for automated FTS at Wallops. Rapid-response good capability to have, but it's just how they roll anyway. Launch sites are "money hoovers"; they'll build a site if they feel there's a market opportunity, but not until then. Ocean recovery of Electron 1st stage: discovered not that much they need to do to make them waterproof and marinised. Cost of refurbishment vs. cost of helicopter pretty well neutral. Able to bring it down on last recovery within 400m of predicted landing, which is pretty good for a passive recovery. They don't do a braking burn. Now focusing on recovering in different weather conditions without damaging it. Not just about recovering and reusing, but doing so economically. Next step recovering and reflying all 9 first stage engines, then whole vehicle. Reuse on Electron a 'nice to have' not a must-have, as they're focusing on production.

This is where decreases and increases in the mass of the booster trickle down - the lighter it is, the more it can reserve and the longer it can hover.

This is a white-paper that's just come out. Preprint, so pinch of salt, but still! Highly relevant: Semiconductor Manufacturing in Low-Earth Orbit for Terrestrial Use It asserts that gaining the ability to manufacture semiconductors and other crystalline materials (CMs) in LEO will remove barriers to "quick, high-yield semiconductor production." They're talking about researching ways to take part of or all the whole production chain up there.

Takeaways, part the first: RE: the second stage failure in the last launch: it was caused by the very specific circumstances of that flight. The low-pressure mix of helium and nitrogen, the 500V DC, the pressure at that specific height, the AC 'ripple' of the DC synchronous motor when it starts up, all increased the ability of an arc to extend through a pinhole for a few centimetres to a metre or more. They had to stick a second stage in the vacuum chamber to find this out, as it's buried deep in the literature. They show a graph titled "1.6 seconds of anomaly data" where they recorded the fault and the loss of power 1.6 seconds later. Their solution was simple: pressurise the battery pack underneath a flexible 'boot'. 22 Electron launches planned for 2024, 9 of them slated for 12st stage recovery. 2 slated for HASTE.

That is a highly unusual combustion chamber, with seemingly no space for a powerhead. Other oddities: That 'frilled' flange with all the bolts - injector face? The top part with the exaggerated buttresses, brackets (for swivel joints?) and the pointy parts (hose connections, maybe). The second picture, where its being mated to a nozzle? I spot two cutouts on opposite edges of the lower combustion chamber, exposing fin-like protrusions. Film cooling? Speculation: it would be very cool if they managed to 3D-print some/all the hoses that normally stick out of a rocket engine into that top part.

Little rocks have smaller rocks, and smaller rocks besides them...

Oh yeah, if we're looking for an alternative foaming agent for heatshield silica, I just found out silicon carbide is used commercially to make foamed glass insulation. They get that from recycled and recovered solar panels. The SiC reacts with and reduces the molten silicon dioxide to make gas bubbles. Wait. There's also a paper that says silicon carbide foams are possible if you change the proportions ("Fabrication of pure SiC ceramic foams using SiO2 as a foaming agent via high-temperature recrystallization", 2011). Instead of a little carbide, add up to 25% in weight of dioxide to the molten carbide. Result: lightweight ceramic foam with concrete-like compressive strength. Silicon carbide can also be used to make telescope mirrors and is the basis of a lot of semiconductor technology. I know that silicon carbide inverters for solar panels are more efficient than previously. The moon might be the high-tech foundry of electronics in the future.

I like the thought of it accumulating ESA, NASA and other mission markings like one of those old suitcases. It's a world-traveller!

We can do Lunar-refined, Earth-landed titanium a little smarter, but still simply. Aluminium/oxygen rockets have disadvantages - the exhaust tends to clog up the combustion chamber and the temperature is really high - but it works well enough if you only plan to use them once, maybe twice. If it's too hot, feeding a little helium into the chamber both cools it and increases the specific impulse. (That last part may have to be gleaned as a byproduct from any fusion reactor or from helium-3 mining.) Combine that with the news that NASA has been 3D-printing and firing aluminium nozzles, and we have a way to decelerate payloads. I know it's usually the hydrogen or methane that cools the nozzle, but oxygen cooling has been fired in a real engine (I can't recall the name, but it was a kerelox engine from a startup with a Russian engineer). If that doesn't work, a carbon graphite ablative liner is cheap and easily machinable. The heatshield could be monolithic, foamed silica blocks or rings (foamed with what, you ask? Carbon dioxide) sawn out of a big block like polystyrene and sputtered with carbon if needed. In the dry, airless near-vacuum of Luna, this could be done in the open. The backing could be foamed, compressed titanium, which is strong and light and counts as part of the payload. In fact, make the entire inner surface out of foamed titanium, and have dual heatshields (one base, one cap) with a weight bias to sidestep the pesky problem of inverting in a supersonic airflow. Deceleration? Lithobraking at terminal velocity should suffice, but if you want to recover them slightly easier aim into an artificial lagoon, with robotic barges to bring them in. The payload might also have to be titanium sponge to keep the density below water's. It goes without saying that these will be monsters. They'll make StarShip's little skydive act seem quaint. I can't even imagine what a stream of hundreds of 150-ton Titanium Truckers (TM) will look like, and anything larger will make people very nervous.

When you have a couple of tons to spare, you too could look like a space-propellor.

https://www.nasa.gov/centers-and-facilities/marshall/nasas-innovative-rocket-nozzle-paves-way-for-deep-space-missions/ A new aluminium alloy was used to 3D-print rocket nozzles with integral cooling channels. Exciting, because aluminium is pretty abundant and lightweight; the alloy itself seems to be a tweak of 6061, which is ~98% aluminium with magnesium, silicon and some trace elements, none of them cripplingly rare on the Moon. It's interesting because I remember seeing aluminium rocket engines proposed for the miniaturised 'Mockingbird' SSTO, as well as the departed XCOR Aerospace trying much the same 3D-printed thing a decade earlier. They're clearly getting some good results, as running it on methalox and hydrolox, for 10 minutes, with 22 restarts and at chamber pressures of 56 bar (the RL10-C runs at 102bar) makes for a convincing expression of confidence; good for lunar lander engine, boost stage or clustered for medium-lift rocket. I don't know what the powerhead would be, though. They're even printing aerospikes with integral cooling channels, which has possibilities when you run it alongside expander cycle.

Well, some few universities have pretty deep pockets. And the ability to send a probe to other planets for achievable amounts of funding is a niche Rocket Lab would be happy to advertise.

https://arstechnica.com/space/2023/11/after-decades-of-dreams-a-commercial-spaceplane-is-almost-ready-to-fly/ Key takeaways: Supply-chain issues due to the pandemic caused them to take production of a majority of the components in-house. The biggest headache was creating the non-toxic thrusters to allow them to walk up to it on the runway. They run on kerosene and peroxide. Apparently, they're now the experts in working with both peroxide and zirconium, which doesn't decompose peroxide. Building the second one will take about two years but cost half as much. Seeing if they can recover the cargo module is also on their minds. They're still in the design phase of the human-scale DC-200. The lack of fairing and the need for an abort system means they're trying to be creative.

Side question: how many strings to their bow do Blue Origin have now? We've got the engines, New Shepard sub-orbital tourism, New Glenn reusable heavy-lift booster, Jarvis reusable upper stage, Blue Alchemist lunar ISRU, and now the Blue Moon lunar lander. I want to say Kuiper, but I think Amazon is building those in-house. The former Orbital Reef was also another ambition. I ask because if each one is a separate facility with its own staff and sub-management, I think BO has recreated the same problem as NASA of rival facilities: Ames, JPL, Goddard, Langley etc. have all gotten into each other's ways over the years as they championed things in relatively genteel science-fights (reusable spaceplanes! With Maglev! No, ramps up a mountain! No, composite tanks and SSTO!), all with an under-current of, "I don't want this to die when the funding is cut." Which is a shame, as this soup-to-nuts approach is bearing fruit. I'm an especial fan of Blue Alchemist, because that's a great way to make acres of solar-power, even on Earth.

Pilot power plant utilising supercritical CO2 turbine completed. This is very cool stuff. Supercritical CO2 not only makes the turbines 10% more efficient, it allows them to be smaller. Much smaller. Like, ten times smaller. If a normal 10MW steam turbine is the size of two tyres off one of those giant mining trucks stuck together, this is able to fit into its passenger seat. The US is very interested in these for making concentrating solar power more efficient. It also makes the whole plant much smaller and uses less water, whatever you use for heat.

Here's something that might be facilitated by cheap in-orbit manufacturing: waterless, high-efficiency recycling of lead-refining waste via vacuum distillation of metals. It also works to recover bismuth, tantalum from tantalum capacitors and germanium from coal fly ash. So those second stages could be loaded with (s)crap, unloaded into the factory, vented to low pressure and then heated. Zone-refining metal and semiconductor ingots of all types would also work, and might even work better in freefall. One thing that really should be worked out, though, is bulk material handling. The lack of gravity would be a boon in some ways (only moderately powerful cranes needed to transport large items), a curse in others (how do you get powders out of a hopper when even a small static/magnetic charge makes it stick to the sides? What about conveyor belts?)

I had a little brainworm of a notion that asked, "What would it take for manufacturing in orbit to have the same impact of the export of heavy industry to modern-day China coupled with the global shipping network?" Because when launch and downmass are really, stupidly cheap, with air-freight-like reusability... you might start to get the same absurdities that make buying, say, a pack of blue plastic beads off eBay, or a mobile phone battery from Aliexpress, and waiting for it to be shipped from almost halfway across the globe, an actually viable proposition. I'm not talking about asteroid mining, I'm talking about something stranger: sending raw materials from Earth, into an orbiting factory, converted into the things you want built, and returned back to Earth. The asteroids could come later, but we'll stick to Earth-mined for now. We'll also abstract the launcher and return vessel. *ahem* "...our patented SuperCheap booster and SuperLift reusable second stage can lift and return 50 metric tons to SpaceMade's orbiting tele-operated factory complex in LEO for $50 per kilogram return. Lower rates available for 'bundling'. Our engineers assure us that we can bring the costs down even lower, perhaps by a factor of five. We deliver to most spaceports. Import fees listed on request." The question I have to then ask: at this cost, what would make sense for this hypothetical factory to make? What about lower costs of launch? $25/kilogram? $10/kilogram? I'll assume its manufacturing has cost parity with a normal factory, but it has the advantages of cheap high-vacuum, abundant solar power and micro-gravity to make... whatever unique product that's an advantage for. It also has the disadvantages of radiation and needing to shed heat, but we'll assume the plant designer thought of that. I think the scale looks like this: $10,000,000/kg - This is where we are now. Commercial spaceflight has already dipped their toe in this, with Varda Space manufacturing rare pharmaceuticals such as ritonavir. (But they've run afoul of the FAA and gone to ask if Australia would be amenable. Something else that has to be worked out before the taps are opened.) $100,000/kg - Aerospace parts, exotic semiconductors; this is *waggles hand* national defence-level money. Could also produce therapeutic radio-nuclides without worrying about the neighbours; I think I saw a proposal for producing radioactive Rhenium from proton bombardment of a tungsten oxide target... and one of the Van Allen belts just happens to be full of energetic protons. $1000/kg - University projects, printing human organs in zero-G, specialised electronics, in-orbit production of satellites and probes. $100/kg - Starting to edge into luxury novelty goods: metallic glass for golf clubs, perhaps space-grown crops - Space-Cacao, anyone? $50/kg - Drawing a blank. At this price you have a good shot at going sub-orbital and delivering to anywhere in the world in less than an hour, and damn the manufacturing. What do people think?

They cared, but not enough to spend the staggering amounts of money needed. Elon Musk was weird enough and committed enough to plough money and time into a private rocket company when it was seen as a sure-fire way to lose your shirt. Given the previous track record of the 7 or 8 companies that went bankrupt, they were not wrong, and Musk did almost lose his shirt. My most likely (but still not that likely) bet for a brighter aerospace 2000s: Kistler Aerospace finding an angel investor to pull their behind out of the fire when Iridium went under, and hitching their wagon to NASA, enough to make the K-1 as promised. There would be trouble ahead with the use of the NK-33, but given they planned for full reuse it might have worked.

Oh, the poor dears.

When your booster is so powerful the water deluge sounds like a rocket itself.

As long as we're throwing out ideas for a liquid-fuelled booster, how about we go really Kerbal and slap two Super Heavy boosters to the side of SLS? I think I read somewhere that its performance was approaching SRB. As a bonus, you now have partial reusability.