AckSed

There's always the Issac Arthur, 'landbound Project Orion' approach: Make a massive water/molten salt-filled containment vessel; stick a high-flow turbine on the outside; drop small fission-fusion bombs inside, and reap the power. No idea how effective or practical it would be, but he always brings it up in his videos on energy and fusion as things we could do now. Slightly closer to the topic are nuclear gas-core 'lightbulbs'. These eye-opening devices are supposed to start off at 22,000 deg. C, contained in an actively-cooled quartz tube so that the nuclear plasma can be both contained and radiate in the UV spectrum, both heating the flow of hydrogen and illuminating UV-tuned photovoltaic elements. The Soviet Union at the very least devoted a paper or two to making this into a viable reactor, and slightly saner gas-core fission reactors that used MHD generators and helium doping.

I don't know if it's cryo, ISRO seems to still be using hypergolics. Still, agree.

A (partial) history of the small spy satellites that detected Soviet radar and thus ships: https://spectrum.ieee.org/reconnaissance-satellite

ESA aiming to launch a cubesat in 2027 to Earth-Luna L2, to track the flashes of micrometeorites impacting the dark side of the Moon's surface: https://www.eoportal.org/satellite-missions/lumio This is a really clever idea, and should give a measurement of the frequency of MM impacts.

Nuclear-thermal fans, we're taking a step closer: https://www.ga.com/ga-successfully-tests-nuclear-thermal-propulsion-reactor-fuel-at-nasa-marshall-space-flight-center tl;dr Successfully tested hydrogen flowing over fuel pellets at operational temperatures of 2600K (2327 deg. C) at NASA's CFEET facility, with non-hydrogen propellant tested at 3000K.

Working off old, third-hand info from USENET, the answer is yes, for the reason you're thinking. Anything with an ablative nozzle or liner, or pyrotechnic starter is truly fire-once, but you don't scrap an engine after test-stand and hold-down firings.

End-of-2024 sum-up of Chinese space from CSM: https://chinaspacemonitor.substack.com/p/a-year-of-successes-ends-with-setbacks

Io continues to show off its volcanic activity, with a large eruption near its south pole that was picked up by Juno's JIRAM infrared imager: https://www.universetoday.com/170655/juno-sees-a-massive-hotspot-of-volcanic-activity-on-io/

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.