Linux gamer, retired aviator, profanity enthusiast

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Joined 3 years ago
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Cake day: June 20th, 2023

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  • Humans have flown a total of ten manned missions that involved a Hohmann transfer: Apollo 8, Apollo 10-17, and Artemis 2. All ten flew to the Moon. On a typical Apollo mission, the outward bound coast leg is about 72 hours, between TLI and LOI, during which time they had to do the release-turn around-dock-extract maneuver with the lunar module and do at least one course correction.

    We’ve been wasting tax payer dollars for more than half a century now designing and redesigning manned Mars missions that aren’t ever going to fly. Some of the various “artist’s conceptions” over the decades have included various centrifugal gravity solutions, be it the wagon wheel type or the bolas type or whatever. I don’t believe any actual hardware has even begun construction. Before you start worrying about that, you’ve got to 1. have a society healthy enough to fly manned deep space missions, and 2. figure out how to shield the crew from radiation first. Neither of which we have figured out at the moment.


  • Because the constant rotation complicates things a lot.

    Specifically talking about the International Space Station, its main mission is a microgravity laboratory. We put it up there so we can learn about microgravity. Why go through all the expense of putting it up there and then spinning it to make gravity when we get it for free down here on the surface?

    As for other craft? We have yet to develop manned spacecraft that can do the duration where it would be worth doing. Even the longer Apollo missions were in space for a whopping two weeks and 2/3 of the crew still landed, got out and stretched their legs. It hasn’t been worth the engineering hassle to do it.

    And it is an engineering hassle, because…

    1. The ship has to be designed to handle it. It’s under additional stresses, so it’s got to be built tougher to handle it. That’s added weight, and just typing that sentence made at least three rocket scientists cringe to death.

    2. Humans actually aren’t great at living in a spin gravity environment. The smaller the radius of the spin, the worse it gets. For one thing, in a centrifuge, there’s a pretty steep gradient in centrifugal/centripetal/pedantic force, the farther toward the rim you are the greater the gravity. For very small distances that can be significant enough to cause problems on its own. But also, spinning humans isn’t good for their vestibular systems. Each of your inner ears has three semi-circular canals filled with fluid, and little hairs that can detect the movement of that fluid. This allows you to sense rotation around three axes, kind of like a gyroscope sensor. This evolved in an environment that rotates a 1 rotation per day, functionally stationary. Spin a human at several RPM and that constant rotation is enough to start throwing off balance, causing nausea etc. So the bigger the radius of the spin, and the slower, the better. That takes more weight, and there go three more rocket scientists.

    3. It makes the spacecraft a pain to handle. You need to be able to orient spacecraft in space to point engines, windows, instruments, docking adapters etc. in various stable directions. A constant roll complicates that. “point in this direction and fire the engines” becomes a pain because, say you’re constantly rolling, and you need to change the direction your long axis points. What thrusters do you fire in what combination to steer the ship? Or do you stop the roll, maneuver/use your telescope/dock/whatever, then start rolling again? So now you’ve got to deal with gravity starting and stopping variously throughout the journey. Or, do you design the ship to have sections that do roll and sections that don’t? First, look up “gyroscopic precession” on Wikipedia. Second, wiring, plumbing etc. is a pain in the ass to handle via slip ring, let alone crew access. Third, that adds weight, which…I should probably stop saying that, rocket scientists aren’t cheap to train and that’s nine we’ve killed just in this list.

    In conclusion, look what you made me do.













  • Because that kit would cost around what a new Civic would cost, and you’re going to get a 16 year old car made worse.

    EV components don’t really swap into the spots that ICE components do. An engine is relatively large, a motor is relatively small. A gas tank is relatively small, a battery is relatively large. Most ICEs designed from the ground up use a “skateboard”-like chassis with the battery taking up basically all the volume below the floor. The motor can be tucked away somewhere, and then the body built on top. You don’t need the volume in the nose for the engine so you get a frunk. a 15 year old ICE car didn’t portion out the room for the batteries, so you’ve got some of the area under the trunk occupied by the gas tank. That’s about the volume that the batteries in a golf cart take up.

    Anyone who’s capable of designing and manufacturing that kit might as well go into production of new cars.




  • That’s the Agena Target Vehicle. Generally speaking the Agena was a rocket upper stage that was used for satellites and such, during Project Gemini it was launched on an Atlas rocket to practice rendezvous and docking with manned Gemini capsules.

    Gemini 8 first docked with an Agena Target Vehicle, flown by a couple of rookie astronauts named David Scott and Neil Armstrong. Shortly after the docking, as in, a minute or two later, the mated pair of ships began to inexplicably roll to the right. Thinking it was a malfunction of the Agena, they shut it down, but the roll kept increasing. It was caused by a stuck control thruster on the Gemini capsule. The roll got so violent the astronauts vision started narrowing. Armstrong flew the ship back into stable flight by hand looking at the attitude indicator. They called an abort and landed safely in the Pacific ocean. They’d planned to land in the Atlantic, making this to this day the farthest a manned NASA mission has missed its intended landing target.

    David Scott flew as Command Module Pilot of Apollo 9, the LEO test flight of a lunar module, becoming one of three men to perform the first docking of two manned spacecraft. And became the seventh human to set foot on the moon as commander of Apollo 15. 15 was the first mission to carry a lunar rover; which Scott set the extraterrestrial land speed record that still stands today: 12 miles per hour. It was Scott that collected the sample of lunar anorthosite dubbed the Genesis Rock. He spent over 22 days in space, He is currently 93 years old.

    Neil Armstrong had a much shorter space career than Scott, spending a mere 8 days in space. Armstrong would fly only one other mission, commanding a little milk run called Apollo 11, during which he became the first human to set foot on a celestial body other than the Earth. If you’re a big enough space nut you might have even seen the footage. Niel Armstrong passed away in 2012 at the age of 82.

    It’s odd to think, for longer than my entire life, only 24 men had seen the far side of the moon with their own eyes, including Armstrong and Scott. This morning that number increased to 27 men, 1 woman.