AckSed

Side question: what are the Thousand Talents?

Eric Berger gives the overview of BO right now, and their hopes for the future (spoiler: ISRU): https://arstechnica.com/features/2025/01/after-the-success-of-new-glenn-blue-origin-to-focus-on-launching-frequently/ Surprising is the photo of Musk and Bezos talking at the recent inauguration, but Bezos says, "[In the space race]There are going to be multiple winners." Edit: Someone downthread put up a list of things BO is known to be working on:

I mentioned upthread that there is a magma swell underneath Cerberus Fossae, like Yellowstone National Park but as big as the United States. Some involved site selection, and you could utilise areothermal heat with less drilling. However, if you're digging for victory water, you might as well do both.

It's partially about the delta-V for orbits, too. Ballistic capture is slow, but more efficient and does not require a second burn to stabilise. Not sure where I saw it, but there is a way to fire ahead of the Moon with enough precision that it travels slowly for months, then is captured at just the correct time to fall into LLO. Also: https://en.wikipedia.org/wiki/Interplanetary_Transport_Network

SpaceX has a new, lighter Starlink satellite with upgraded hardware: https://spaceflightnow.com/2025/01/18/live-coverage-spacex-to-launch-27-starlink-satellites-on-falcon-9-rocket-from-california/

How an engineering camera on Mars Express became a capable science instrument: https://arxiv.org/abs/2410.02999 tl;dr slap a cheap camera on your probes with the software to send images back, you may just learn something.

'Modular blocks' was tried and bits started popping off when Orion reentered in its skip trajectory. You'd need to go back to the drawing board. A large inflatable heat-shield might be better, though I am not sure about the TRL after LOFTID. Hang on. *checks* With a successful demonstration from orbit... Hovering around TRL 6 or 7. Doable, but further back in development than the modular blocks as far as I know.

Funny story about fuel-cells: the NaFion polymer used as the substrate for the semi-permeable membrane in a lot of experimental fuel-cells (and the nitrogen-extracting cell I posted about a few weeks back) is the most expensive part. It's due to having to use elemental fluorine gas to make the polymer.

There's no perfect solution available now, only maybes. Wikipedia tells me that Block 1b has the capability of 105t to LEO and 46t to TLI. New Glenn might be the closest architecture with its hydrolox GS-2, yet it's optimised for thrust over specific impulse, and its TLI is a tiny 7t. Not insurmountable - a tank-stretch and/or deliberate under-running of the engines could give the endurance it needs - but we're choosing an untried rocket over what is seen by the Senate and the contractors as proven technology. Plonking ULA's Vulcan Centaur upper stage on SLS and skipping the EUS is a better deal and more palatable to the military side of the Senate, as it's closer to the EUS in performance. If you only wanted to launch Orion a single VC could probably do it, with 12t to TLI. Expending a Falcon Heavy is probably the best option. Even that will require adaptation. Then there's the monster truck in the room, Starship. If all the 'ifs' work out - docking & refuelling in orbit with a depot, reuse - then it's tempting to say that Orion can be docked with either the lander in LEO after refuelling and shuttled to the lunar orbit, or a dedicated transfer shuttle could take it and the LL would take them down.

Speaking of commercial space (should we have a general thread?), K2, they of the cheap and cheerful flat-pack sats, have done the vertical-integration thing and propose a 20kW satellite bus for defence and science for $15 million. Lockheed Martin's equivalent costs approx. $100 million and up: https://arstechnica.com/space/2025/01/company-aims-to-build-larger-satellites-for-new-era-of-launch-abundance/

Scott Manley telling us how rocket companies file NOTAMs and TFRs which always kick in... and DRAs (Debris Response Areas) that may kick in. The relevant shot for this thread is at 8:30, showing 4 pre-approved DRAs for Flight 7: Problem is, these aren't shared as publicly as the more common NOTAM.

Greek artist and scientist fell in love with silica aerogel, calling it "sky in a bottle". He became so good at working with the material he literally wrote the textbook. ARPA-E invited him to give a talk: The money shot is at the end, where he shows off the woman's handbag he made out of aerogel. People complained that it couldn't hold much, barely a lipstick or some keys...

It's said you should never generalise from fiction, but I think the Inner Sphere of the BattleTech universe is a pessimistic yet grounded take on space resources vs. space ownership. In short, once you settle it, it's yours... until either the people with bigger guns come to take over/raze it, or you're too inconsequential/too much of a faff to be taken over. (Side note: it's definitely on the harder end of the SF scale, with no anti-grav. Further, finding out their form of fusion was impossibly efficient led to (slow) FTL jump drives and Heinlein-level fusion torch drives. Then everything else followed.)

Per the Outer Space Treaty, outer space and its resources are "res communis": they do not belong to anyone, but can be used by everyone, like the air and water on Earth. So we can assume that the countries and organisations in those countries to have a presence in space and using the resources - be it orbital space, Lunar materials or Lagrange points - that the mines and satellites belong to them and that country's economy, and can be assumed to have a claim on that orbit or asteroid, but claiming anything else is (supposed to be) not kosher.

Raw space resources have quantity, but finished goods or intermediate building blocks like microgravity-cast steel beams and semiconductor boules will have a quality advantage.

It's the low quality footage and the overlay that really gives it that Kerbal feel.

ES frequently says, "I don't know", which is something a lot of aerospace and science YTers should do more often.

Dammit, text is tone-deaf. I had a longer argument leading into how to engage with someone continually stating a position past the point of reason, and provided a link, but it would have been too personal, might have been seen as an attack and closed off chances of dialogue. I was not expressing my distrust. Now, personal stance on SpaceX: I am worried that Musk seems to be dealing with several personal problems not that well, yet relieved he can still focus when talking about rocket science and SpaceX. Gwynne Shotwell and Kathy Lueders are treasures and I trust them to make Starship work. I believe their workplace culture and ethic and supporting project-management software is second-to-none. I think the iterative, hardware-rich approach is showing results.

In the end, this is a very human issue: trust. How much do we trust the major shareholder of SpaceX? How much do we trust the COO, the project manager, the engineers, the welders, the ground-support staff that they are all doing their jobs behind the scenes?

Well, yes, a rocket holding a denser fuel with the same structural mass, tank mass, the same amount of thrust and the same volume of fuel would have a worse TWR because it'd have a higher wet mass, but denser fuel = approx. more energy per kg, which leads to smaller tanks and lighter weight. I also remember the optimisation of burning denser fuel and oxidiser faster, leading to speedier lightening of the 1st stage and greater acceleration, leading to about a 7-8% decrease in delta-V to orbit (for a SSTO anyway). Further, for lower ISP it apparently optimises at a lower TWR (second post down). (Reference: "Evaluation of innovative rocket engines for single-stage earth-to-orbit vehicles" by Detlef Manski and James A. Martin, Journal of Propulsion and Power, Nov-Dec 1991. I can't access it, though. :-/) My copy of Bruce Dunn's post on SSTO propellants states, though: Now I realise all these references are for SSTO vehicles. However, reusable rocket boosters have to worry about many of the features inherent to reusable SSTOs, if to a much lesser degree: overcoming gravity loss, breaking atmosphere and approaching orbital velocities (far, far less, can be handed off to second stage), landing hardware and its mass (roughly the same), heat-shielding for reentry (much less but still needed), and reserving propellant for boostback, reentry and landing (the hypersonic reentry burn is new and compensates for shielding). Where does this leave NG 1st stage? I don't know. Maybe we'll just have a majestic Saturn V or Delta IV Heavy again, in semi-reusable form. And I'll look forward to it.

Might be right there. Perhaps the lower combustion chamber pressure (lower than Raptor, but 138 bar is still pretty high compared to other cryogenic engines like the RS68A [102.6 bar] or Landspace's TQ-12 [101 bar]) and lower-density propellant and landing hardware combine to make Delta IV Heavy levels of performance:

It hinges on whether they were babying the rocket in order to launch with a small payload and then land close-by, or it is actually underpowered and needs upgrades. Or a penalty-weight diet. I think I stand in the former camp.

Current Exo vibe:

NG GS1 staged very low in the atmosphere and the landing barge was relatively close-by to land. I think this is splitting the difference between Starship/Super Heavy's RTLS, 'near-SSTO with just enough booster to get out of the atmosphere' approach, and a F9 far-out landing barge. The closer the landing barge, the less time GS1 takes to reach port and be processed, improving cadence. Other possibilities are that this was a test of booster re-entry, and they were making this as gentle as possible. 'Proper ' payloads might necessitate a further-out landing barge.

I had hopes of another scorching Ship return through the atmosphere. Alas, I was complacent.