Once again, the UK is copying our nuclear homework! Now with more pictures because we all like to look at space stuff.

https://www.nasa.gov/sites/default/files/styles/side_image/public/thumbnails/image/kilopower_moon_render_1_1.jpg?itok=-uHzGRQf

Nuclear reactors in space are not a new concept. Power's pretty scarce up there, especially with some of the really shit solar panels we used to have, and a nuclear reactor is a lot of power for designers who are used to working with figures in hundreds of Watts. In most orbits (there are some weird polar orbits at specific times of the year when this doesn't apply) you don't have access to the Sun, because it's behind whatever you're orbiting. If it's a high orbit this doesn't matter so much, but it becomes a problem during low orbits, and you need enough battery capacity to power the whole thing while you're in the dark, and enough power generation capacity to recharge it while it's in the sun before it goes out again. This is going to be a huge problem on the Artemis program, because these astronauts are gonna be on the Moon for like a month at a time, and half of that is gonna be in total darkness. You need a lot of power to keep people alive (mostly warm, O2 is less of an issue than you'd expect).

https://www.ga.com/images/BlogFeaturedImages/DRACO-Milestone.jpg

This is not to be confused with nuclear rocket engines, which are really cool and also making a comeback. Rockets basically work by throwing stuff (mass) out the back of a vehicle and driving it forward. Like a standing on a skateboard and throwing a basketball. The more energy you can add to the stuff, the faster you can throw it, and the farther you'll go per unit of stuff you throw. The measure of how efficiently that works is called specific impulse (I_sp), and is tied to exhaust velocity, but it's kind of a pain in the butt to explain so just trust me on this. Usually you add energy by combusting a fuel (thing you burn) and an oxidizer (oxygen to burn thing with) into very hot gas, and then shooting out a nozzle. If you can add more energy with other methods, that also increases specific impulse. A nuclear thermal rocket takes that combusted gas, then runs a heat exchanger attached to a nuclear reactor through it, adding a shitload of energy. They're stupidly efficient. They'll be great for interplanetary transit, because they'll cut the travel time down by a lot.

That program used to be called NERVA (Nuclear Engine for Rocket Vehicle Application), and ran for twenty years but never launched because even the government who were nuke testing every week like it was going out of style thought it was too dangerous to fly on those old shitty rockets. And given how many of those rockets exploded constantly back then I'm not surprised. It was cancelled in the 70s by Nixon, who was a huge kitty. It's now being revived as a DARPA program called DRACO, which is sick. It's the second picture in this post, the artist mockup by GD.

https://solarsystem.nasa.gov/rails/active_storage/blobs/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBBa283IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--1ef594bebfa079a8d07c62bd354d538bad775ada/55_7513_97pc1536.jpg?disposition=attachment

Anyway for like the last decade, a very small team of NASA engineers have been trying to convince NASA to go back to using fission reactors on spacecraft so they can have real power budgets. There's a few programs that use plutonium radioisotope thermoelectric generators (see Perseverance, Curiosity, Cassini, Voyager 1+2), which have no moving parts and generate voltage off of the heat and radiation, but these new ones are different and way more powerful. They use uranium instead of plutonium (much more available than plutonium, more convenient reactor fuel), and run off of an actual thermodynamic cycle instead of metal bonding bullshit effects. They named it KRUSTY, which is kind of funny.

Plutonium is a huge pain to come by because there isn't a whole lot of it, and you basically have to run your weapons enrichment program to get more. Uranium is just kind of around. Plus radiation isn't an issue, because there's no birds to irradiate (@TED_SIMP will be happy), and a small nuclear reactor is peanuts compared to all of the other radiation floating around up there.

Anyhow, nuclear reactors for tons of spacecraft applications are incredibly convenient, and are going to mean huge leaps forward in space tech because we no longer have to run everything off of fricking solar panels. This concept is the UK's attempt at replicating the KRUSTY reactor. They don't give any real information, like size or power output, just that they're gonna try and copy our homework.

It's amazing that NASA today is still practically behind where they were in the late 60's/early 70's, and most space programs are behind even that. SpaceX is making huge advancements, but they're a commercial enterprise and it's gonna take some time before that tech gets moved over to the space exploration side of things. Soviet space tech was so ludicrously far ahead of everyone else, it's embarrassing.

Also thinking of changing my username, any recs?