• PugJesus@piefed.socialOP
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      8 hours ago

      For most of the shuttle, yes, but the removal of the paint from the tank specifically was because the tank had a foam coating that was not actually meaningfully protected by the paint.

  • Digit@lemmy.wtf
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    1 day ago

    “Lower the inertial mass.” – Miles O’Brien, Star Trek Deep Space Nine, Season 1, Episode 1.

    • Bytemeister@lemmy.world
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      1 day ago

      That’s why American Airlines had the “cheat line” livery. Bare hulls saved them enough weight to carry like an extra 2 passengers.

      Plus, polished metal on airframes looks sweet IMHO. Real “DC3 golden era of aviation” vibes.

  • Digit@lemmy.wtf
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    1 day ago

    Though isn’t that decreasing the aerodynamics and increasing the friction?

    • Kate-ay@lemmy.world
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      11 hours ago

      No the purpose of the white pant was to help keep the external tank cool to reduce fuel boil off. The foam insulation was incredibly rough, not something a thin layer of paint could smooth over.

    • Atropos@lemmy.world
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      1 day ago

      Probably, but the slowest part of the trip is in the most dense air. Probably still a net benefit!

    • PugJesus@piefed.socialOP
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      2 days ago

      Back when NASA was flinging things into space for the first time, the tolerances that were even possible were extremely tight. Every pound mattered (every pound still matters, but because we have other things to do once we get to space nowadays, plus every pound is expensive).

      600 pounds of white paint for the fuel tank was considered unnecessary, once the engineering team figured that it didn’t actually protect the special foam covering of the fuel tank anyway. Thus the distinctive orange color!

    • excral@feddit.org
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      2 days ago

      It’s always hillarious to me to see boomers on expensive bikes that aim to save every gram while they could save 20kg on themselves.

      • infinitesunrise@slrpnk.net
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        1 day ago

        In the cycling community we call those guys Freds.

        And it’s more of a light ribbing than a condemnation, since at least they’ve got themselves on a bike.

        • RaisinCrazyFool@kopitalk.net
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          1 day ago

          If the point is to burn calories, then shaving weight off your equipment is counterproductive.

          But if it makes you want to ride more, then great!

      • HugeNerd@lemmy.ca
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        2 days ago

        Or skinny dudes with enormous ballsacks wearing tight Spandex on 15 pound carbon fiber bikes, but a 20 pound motorcycle lock.

        • SpongyAneurysm@feddit.org
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          2 days ago

          Well, not if you still want to have some fun while doing so.

          But I agree, that a regular bike should suffice and you don’t need to worry about optimizing gear weight if you’re not competing for anything and just ride it for your own well-being.

        • infinitesunrise@slrpnk.net
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          1 day ago

          There’s a bell curve. If you burn out too quick you’re not gonna get nearly as much cardio, and the torque required to move a real clunker is extra stress on your joints. Plus it’s just not as much fun, cycling is a sustainable exercise largely because it’s fun. But it’s very true that a decent workout bike can be had for $100 if you look. My two workout bikes were both built in the 90s.

        • wolfpack86@lemmy.world
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          2 days ago

          Well, not necessarily. A bike that’s got a full carbon frame also absorbs shock and vibration from the road better. This means you can ride longer distances without getting fatigued in places like your wrists or ass. Longer rides = more exercise.

          But once you have a carbon frame, chasing grams on other components gets to be a bit silly.

          • autriyo@feddit.org
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            1 day ago

            I’ve yet to ride a carbon frame for any amount of real distance, so idk how good they actually are.

            But having a less harsh ride can also be archived by not using the thinnest pizza cutter tires at 10 bar. Especially if we care about time ridden and not avg. speed.

            And it’s going to be slightly harder to get the same speed out of comfy tires, so that’s also more exercise.

            • infinitesunrise@slrpnk.net
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              1 day ago

              It was really funny about a decade back watching the entire bike industry all at once acknowledge friction coefficients, and suddenly the tires all went from 24mm/90psi to 38mm/40psi. All because the roadies started riding on gravel.

              You could argue that TPI tubes / tubeless made larger road tires practical. But we all secretly know it was because people at the time just thought thin tires looked cooler and “more aero”.

          • infinitesunrise@slrpnk.net
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            1 day ago

            Steel is real. The road feel difference between carbon and steel is negligible, steel is usually way cheaper, survives a whole lot longer, is more often built to widely compatible standards, is fully recyclable, and in my humble opinion just straight up feels better under you on a ride. As for weight, unless one is a pro race cyclist there is never any reason to chase gram shavings, you will almost always lose more weight and go faster by working out your own body. But FWIW my default steel rig is 19 pounds and competes on weight with most carbon builds.

            • BradleyUffner@lemmy.world
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              1 day ago

              That’s less efficient time-wise though, since it takes significantly longer to walk the same distance compared to riding.

              Ie, riding 2 hours burns FAR more calories than walking for 2 hours.

              • jeffep@lemmy.world
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                1 day ago

                I enjoy walking and don’t mind walking even for 40 minutes in the morning. Not every day, but if it fits in the schedule it gives me more movement in practice than a bike (also due to some local circumstances).

                The point was more generally that walking is a great alternative. Everyone hypes bicycles, walking has no lobby and is one of the healthiest things to add to your day.

                Also, if the goal is to lose weight, cardio is fine but only supportive at best. It’s way more effective to eat less calorie dense food than trying to run/bike it off. The difference between an hour walking and biking is negligible for most people compared to dietary changes.

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        2 days ago

        Well, it’s also fun to go places you know. If a shitty bike can only get you 20mi / 30km but a on a good one you feel confident doing a 30mi / 45km ride then the purchase makes sense.

    • Owl@mander.xyz
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      2 days ago

      But, why ? You drink a bit more water that day and it’s void.

      • Annoyed_🦀 @lemmy.zip
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        2 days ago

        It’s a competition between brand. They’re at the point where decrease a single gram is incredible task and are all racing to become the lightest weight and aero-est bicycle and get to claim that.

        • megopie@beehaw.org
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          2 days ago

          And then you have E bike companies producing lead bricks that are non-functional without the motor doing 90% of the work. Or with the massive motorcycle seats that make pedaling actually impossible.

  • TankovayaDiviziya@lemmy.world
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    2 days ago

    I’m too dumb for maths because I have dyscalculia, but i am always amazed by the engineering crowd on how they could improve efficiency by finding and tweaking just the little things.

    • tetris11@feddit.uk
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      1 day ago
      • Artemis tanks were 10m wide and 30m tall.
      • Cylinder surface Area = (2.pi.r2) * (2.pi.r.h) [1]
        • 2 * pi * 5 * 30 ~ 1100m2 to paint
      • Paint paints about 10m2 per Litre paint
      • Need 1100 / 10 = 110 Litres of paint
      • 1L of paint weighs about 2kg
      • 110 Litres of paint weighs about 220kg

      1. curved area plus top and bottom circles ↩︎

    • neuromorph@lemmy.world
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      2 days ago

      Its simple rocket math. Every lb of weight must consume fuel.

      Si.pky. 1 lb of weight needs 1 lb of fuel to escape orbit. But the fuel has weight also. So the effective fuel you need to lift the rocket and payload is exponential.

      The harder stuff is orbital mechanics. Getting things into orbit is easy. Having thwm go where you want is the hard part.

  • atomicbocks@sh.itjust.works
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    2 days ago

    Fun fact: Columbia, pictured with the white tank, was the heaviest shuttle and was not modified to have the airlock necessary to dock with the ISS because the performance losses compared to the other shuttles made it difficult to use for ISS operations.

      • atomicbocks@sh.itjust.works
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        1 day ago

        IIRC the original Shuttle design called for an ejection mechanism around the entire cockpit. During STS-1 and I believe STS-2, which was also Colombia, there were extra emergency mechanisms present, but I don’t think the seats themselves ejected through the roof like a fighter pilot’s would. For the most part though these were useless as they could not be used above 30,000 feet or something like that so it could only be used during the first minute or two of the flight.

        Several of the safety mechanisms and other things that were going to be part of the original design that had not already been scrapped for weight (like jet engines for powered decent) were scrapped for weight when the DOD stepped in and offered NASA extra money for the Shuttle if the Shuttle could hit very specific, higher and less fuel efficient, orbits. This came from an offhand comment that Jimmy Carter made, and then had to make good on the threats and implications of.