AckSed

Seats adjustable from 4 feet 11 inches to 6 feet 4. Pilots requested more padding Suni in the capsule now - ahead of schedule

Suni made a call to engineer of the life-support system. Apparently the man came over to Boeing from Mc-Donnell Douglas and worked on Skylab. Also going to test with ISS astronauts how Starliner can serve as a lifeboat. Rocket is "fuelled and ready to go"

ULA literally heard a funny sound and is investigating what caused it Final Boeing white room huddle before boarding Another IVA detail: Can't confirm that the IVA suit helmet is fully zipped by yourself without a mirror on your wrist. Butch and Suni are going to test the manual controls once in orbit. Have to say, this is pretty good live coverage of all the steps

Little segment about Artemis testing: vacuum chamber, underway sea recovery and the escape slide baskets

Side-effect of the zips on the IVA suit: if you have some pooch on your chin, you have to wear sticking plasters on your chin and Adam's Apple Astro-van driving to the pad

That's a lot of mission patches in the ISS control room. Reminds me of a pub that stuck beer mats for all the beers they ever served on the wall. And since there's downtime in their schedule after the suit pressure test, the astronauts're playing a card game. Why? Tradition!

3 hours and 55 minutes to launch. Heh, I note Suni Williams' winged suit patch in her livestream bio portrait is "Sunita" but the actual suit is "Suni". Got it this time. 100th flight of the Atlas V

Here's the NASA livestream:

It's interesting to compare this to the pathfinder posted last year. (I still don't know what's up with the set of what looks to be ratchet set sockets at or near the injector head.) This looks like a fully-fitted out test engine. I'm seeing temperature and pressure probes all over. Also seeing a turbopump down by the nozzle that taps the feed before the main oxidiser and fuel turbopumps, then seemingly flows directly into it. Eager for more details.

Maybe so. However, these materials allow other wavelengths of light through, being transparent to translucent to visible light, so you could grow shade-tolerant plants underneath, or have solar panels. The paper describes a metamaterial that was consistently capable of 5 deg. C of cooling below ambient in Shanghai when it was ~28-30 deg. C and 40% humidity. It was also able to be treated to be hyperhydrophobic, and tough enough to be deemed weather-resistant. Now, if we wanted to get into active cooling using the IR window, we have to get weirder. Quantum. (I'm climbing out on a brittle limb, so all this is less about, "Why?" and more, "Why not?") Fortunately, it uses things we can already make: LEDs. Through physics I don't quite understand, LEDs at higher efficiency take in heat to produce light: So my thinking is, somehow further optimise the ultra-efficient LED to emit in the 8–13 μm atmospheric window, focus it so that the majority of the IR is directed upwards and you can in fact take the heat, and push it somewhere else. The authors of the paper proper state that at ambient temperature, with the light emitted captured by a PV cell, it has a coefficent of performance of 1.7, better than a thermoelectric cooler. At lower, cryogenic temperatures it's even better.

Do you mean Stirling engines? Anyway, this would need a lot more work to realise. For one, how tall are these? Cooling the Earth by radiating heat into the atmosphere is the equivalent of tidying up by rearranging junk in your house from one room to the next - you still have the same amount of junk. My analogy breaks down because some would be radiated up and out into space, but much more would be convected into the gas of the atmosphere and we're right back where we started. If you wanted to use massed Stirling heat-pumps to cool the world, you'd need to make sure it couldn't come back, and my first instinct is to make them either very tall so they're outside most of the atmosphere, or tune all the radiators so that the specific wavelength of IR they emit isn't absorbed by the atmosphere. You were on the right track when you mentioned shading. I'm going to presume that you're not talking about high-atmosphere or orbital infrastructure. You want cheap, simple and ground-based. There is indeed a wavelength of IR in which most of it simply escapes into space, and there are several metamaterials that, when silvered, reflect the majority back into space at that wavelength. The nuance is that that 'window' mostly works in hot, arid environments. In hot, tropical environments, that window changes because of the increased humidity. It's still useful in that case, mind: passive cooling by definition does not use any power, and in general the less power the world uses, the less heat and greenhouse gasses our civilisation creates. Here's an overview of these Passive Radiative Daytime Cooling materials and one that is supposed to work in all environments: https://www.nature.com/articles/s41467-020-20646-7

https://www.nasaspaceflight.com/2024/04/ift-4-prepares-starships-future-focus/ https://ringwatchers.com/article/s29-b11-updates Since those articles, the most that's happened is that Booster 4 has been taken into the hangar and scrapped, and Booster 13 has gone for cryo-testing to Massey's and back. Presumably, S29 and B11 will be ready for OFT-4 when it's ready.

German company HyImpulse launched a hybrid paraffin wax/LOX sounding rocket from Australia:

There are incremental grid upgrades that can be done to increase capacity: Temperature sensors for lines, so operators have a better idea how much the grid is being affected and where is being under-utilised; Re-conductoring powerlines with composite-core, trapezoidal annealed aluminium lines.

Here's interesting. Orbital Index alerted me to this part of SpaceX/NASA collaboration: Coupler for Propellant Transfer (CPT-TP) The really interesting part is what it's leading on to (notwithstanding a forest of other associated projects for setting up prop transfer in space), and the assumed timeline for TRL7 and testing ("End: 2028"): Cryogenic Fluid Management (CFM) Portfolio Project Most of all, I note: Does that sound like zero-boiloff propellant handling? Hope so.

The dream would be to find an actual commercial induction hob/stovetop that operates like this, no matter what premium I have to pay. (While I'm at it, a microwave too.) Wiring one up myself would be beyond me. Regardless, thanks for enlightening me.

Could someone chase down some scientific papers on how induction hobs work? Specifically, how the power circuitry works? I want to see if it's possible to change over from using the cheap, microwave-style on-off temperature control to something more gradiated.

RE: Kerelox ISP: Launcher/Vast's E-2 engine has reached 365s, 9.9 metric tons of thrust, and over three minutes of burntime on the test stand (and has a blue flame). Given the relative size and thrust, this seems like a replacement for the similar RD-58. If they needed an Orbital Manoeuvring Engine to shape up an orbit after their high-thrust engines cut out, that'd be a safe buy.

Would you feel happier if they built a Starhopper and practiced chopstick-catching?

Someone's looking to build a high-delta-V solar-thermal space-tug: https://arstechnica.com/space/2024/04/new-space-company-seeks-to-solve-orbital-mobility-with-high-delta-v-spacecraft/ Honestly, best wishes and good luck to them. The solar moth was always one of my favourite concepts.

I'm going to say something contentious. Now that manned flights are growing closer, we have to address a fact that isn't being spoken: space travel is dangerous. The Artemis program, or something connected to it, may have the first death in space in over a decade. Maybe not in the first launch, not in the second, hopefully never. But for all the talk about commercialisation, this is space exploration and it is not safe. This isn't pronouncing doom. As Chris Hadfield says in his TED talk on fear versus danger, NASA has considered risk, reduced it where possible. He also said that the Space Shuttle was a complex flying machine and the chances of a catastrophic event was, when he flew, 1 in 38. He still went. SLS and Orion is less complex, we have far better robotics than Apollo ever did, and an honest-to-Oberth partially-reusable 'space truck' in Falcon 9. However... we cannot fully design out the chance of death, nor pretend that we are not putting people in harm's way. SpaceX makes it look easy. SpaceX also has "Stay Paranoid" emblazoned on the desks of Mission Control. Even the Apollo 9-like mission proposed in tandem with SpaceX could result in deaths. What brought this on? A blog post by Wayne Hale on the laser-focus on monetary cost as the be-all, end-all of space exploration: https://waynehale.wordpress.com/2019/06/19/blood-and-money/ If in the future something does go wrong, I have a polite request for the few people reading this: don't go mad. Do not argue yourself into the hole that all exploration should be done robotically. That you knew this would happen and humans should never have left the ground, never mind Earth. Do not let your fear control you. If you see someone else who likes space falling into the same trap, I request - because I can't make you do a damn thing - that you pull them out. Wayne Hale thinks the risk is worth the reward, that it is brave to take on this risk, and so do I.

Glad to see that the prop-transfer test was a success- *double-take* *searches* Ah! I see hot-gas thrusters are still/back on the menu. I'd hoped for this, if only for the coolness factor. Edit: You know, if this is pulled off first time, we essentially have a functional launch system. Sure, it's far, far too heavy for reusable mode, but expendable would be well within reach.

I can't speak to the first, but yes, concrete will cure in a vacuum: https://space.nss.org/wp-content/uploads/Lunar-Bases-conference-2-518-Lunar-Concrete-For-Construction.pdf In fact, the concrete ended up being stronger, and did not lose as much water as thought. The real challenge is that concrete's compressive strength is not as much of an advantage in lower gravity. If making a pressure vessel out of it, the tensile strength is needed more - and that has historically been lower. Reinforcing it with glass fibres spun out of melted regolith may be needed. Last year, concrete was flown on the outside of the ISS, and made inside: https://www.concrete.org/publications/getarticle.aspx?m=icap&pubID=51738695 Extracting sulphur from troilite (an iron sulphur ore found on the Moon), melting it and mixing in ground-up regolith simulant has been tested, as the same technique's used to make acid-resistant sulphur concrete on Earth. The strength was lower but still fine. However, there are concerns that the sulphur would sublimate away in vacuum, and you do have to pre-heat the mould or you will have voids in the centre. Its advantage is that it's easily recyclable: heat it up and recast it. I've seen one video of railway sleepers made of the stuff being recycled this way. Amusingly, astronaut pee has been considered, as urea acts like a plasticiser in "geopolymer" concrete (regolith plus sodium silicate and sodium hydroxide), allowing the use of less water: https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Astronaut_urine_for_building_a_Moon_base Using it as mortar for sintered regolith blocks is also an option.

https://arstechnica.com/science/2024/04/metafluid-gives-robotic-gripper-a-soft-touch/ tl;dr adding hollow rubber spheres to a liquid allows you to make a colloid that decreases in volume but doesn't increase in pressure when exerting an external force. Thus, if you overpressurise a 'soft' gripper, the force it exerts does not exceed a certain threshold. This lets you engineer behaviours without using any control algorithms or electronics. It can be tuned by varying the size of the spheres, and stepped by adding different sizes of sphere. By reducing the size of the spheres to micrometre sizes and using the right materials, they found that they could also tune the rheology (thickness) and opacity with pressure, as the clear spheres collapsing turned themselves into something like lenses. I love simple things like this that have emergent behaviours. I don't love the resistance the researchers faced because "this was not an interesting idea".

Do I smell the sour pickle-juice whiff of sarcasm about your comment, sir? It would be cool to see, 'tis all.