Why are people impressed with SpaceX?
  • marsokod marsokod 7d ago 98%

    There are a few things that are different from what NASA has done in the past:

    1. SpaceX Rocket is the most powerful rocket ever, surpassing everything that NASA or anyone else has ever done.

    2. they are landing the rockets, with the aim of being able to recover them. If you skip the technicality that SpaceX first stage is suborbital but is part of an orbital launcher, that makes SpaceX the only entity who has achieved that, with some comparison to the Space Shuttle and Buran, though both were losing significant sections of the initial launcher, with very difficult repairs once on the ground.

    3. the cost of the launcher. In terms of capabilities, NASA's SLS is probably close to Starship. However, it costs around $2B/launch, and nothing is recoverable. Starship is meant for low cost. It is estimated that the current hardware + propellant for a single launch is under $100M. With reusability, a cost per launch under $10M is achievable in the mid term (10 years I would say) once the R&D has been paid ($1.4B/year at the moment, I would guess the whole development for Starship will be $10-20B, so same if not less than SLS).

    4. the aim for high speed reusability - SpaceX aim is to launch as much as possible, as fast as possible, with the same hardware. While it is a bit early to understand how successful they will be (Elon was saying a launch every 1hr, which seem to be very optimistic, I would bet 6-12hrs to be more achievable). That was NASA's original goal for the Space Shuttle, and they failed that.

    5. finally, orbital refueling means you have a single vehicle that can basically go anywhere in the inner solar system without much issues, and minimal cost.

    Also, what gets people excited are the prospects of what this enables. A 10-100x decrease in the access to orbit changes completely the space economics and opens a lot of possibilities. This means going to the Moon is a lot simpler because now you don't need to reduce the mass of everything. This makes engineering way easier as you do not need to optimise everything to death, which tends to increase costs exponentially. And as for Mars, Starship is what makes having a meaningful colony there possible. Doing an Apollo like mission on Mars would have been possible for decades, but at a significant price for not much to show for. With cheap launch, you can just keep sending hardware there.

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  • There Are Now More Fully Electric Cars On Norwegian Roads Than Gas Cars
  • marsokod marsokod 1mo ago 100%

    That's electric Vs pure gasoline only. Technically true, and it shows BEV are progressing in terms of share of cars on the road, but this is a very specific milestone that is only useful for click-baiting.

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  • Pris de panique, les constructeurs automobiles demandent à l’Europe de différer le durcissement des normes CO₂
  • marsokod marsokod 1mo ago 100%

    Solution numéro 4: intégrer le prix de l'amende aux voitures polluantes ? Ça fera passer une partie des ventes vers de l'électrique et donc évitera l'amende ?

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  • Ukraine war latest: Ukraine blows hole in another Russian bridge; Kursk offensive puts 'new constraints' on Putin's war plans
  • marsokod marsokod 2mo ago 100%

    The more it goes, the more there will be pressure on the Russian forces to divert their resources there. It seems to be a relatively cheap way for Ukraine to alter the whole battlefield, fighting where they are stronger.

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  • Arm announces an open-source graphics upscaler for mobile phones
  • marsokod marsokod 3mo ago 100%

    Around 20-25% power consumption reduction against native resolution, that's neat.

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  • World first UK prototype could pave the way for constant energy all the time - from space | Science & Tech News
  • marsokod marsokod 7mo ago 100%

    To complete that good answer, satellites in GEO will experience eclipses 2x21 days per year (around March and September). The eclipse duration during these periods will vary from 0 to 70minutes and then down to 0 again, with one eclipse per day, around midnight.

    So your solar plant in space will work 100% of the time 320+ days a year, and will have a small down time that can be up to an hour in the middle of the night otherwise. Not perfect but actually very manageable with a little bit of storage on the ground.

    Overall, the main concern with these systems is the total cost, including launch cost. It is hard to tell if it will be competitive with solar + battery on the ground.

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  • Do bike tires increase pressure in summer?
  • marsokod marsokod 7mo ago 83%

    To do the math, an assuming constant volume, a 30C increase corresponds to around 10% increase in pressure. That's well within the margins of the tyre even if you go to the max rated.

    If you then consider deformation and most importantly leakage over several weeks, this is a non-issue.

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  • Recommendations for lightweight wiki servers?
  • marsokod marsokod 7mo ago 100%

    I have been using Bookstack, I like it though it is missing a few features I would love:

    • you cannot insert a video in it
    • there is no possibility to comment on a particular text
    • the permissions management is only done with roles. That's fine generally but I wanted to be able to share a specific page with a specific user, and for that I had to basically create a dedicated role for this use.
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  • British nuclear sub missile launch fails as Trident dramatically misfires and ‘plops’ into ocean just yards away
  • marsokod marsokod 8mo ago 100%

    You cannot really hide it. The launch has to be public to warn airplanes and ships so they can avoid the area. And once the launch is public, such a failure is quite evident to anyone who was interested in following it, so you might has well publish the news instead of trying to hide the unhidable.

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  • Why do people wear shoes inside the house?
  • marsokod marsokod 8mo ago 100%

    I wear slippers inside mostly to protect agains cold floor, coffee tables, and most important of all, Lego bricks on the loose.

    Also another reason to wear shoes inside is when you are constantly going inside and outside. Which means then your floor is dirty.... which means you want to protect your feet from the dirt. That's a vicious cycle but can be one of the reasons.

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  • space
    Space 8mo ago
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    Chickpeas grown in lunar regolith are stressed but reach maturity, shows study
  • marsokod marsokod 8mo ago 100%

    I am not familiar with what is required for hydropony, but I would guess it requires more equipment. Plus growing them on Lunar soil means eventually you get some elements from the Lunar soil itself and do not need to have full recycling otherwise, which means you don't have to have a fully closed cycle for this.

    There is still the issue of the closed cycle for air though (which is where Mars is easier than the Moon for medium term colonies).

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  • space
    Space 8mo ago
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    Chickpeas grown in lunar regolith are stressed but reach maturity, shows study
  • marsokod marsokod 8mo ago 100%

    It is on the Moon, it knows it can die due to decompression at any moment and we completely screw up it's circadian cycle with 30+ days. Of course it will be anxious, no need to prove it.

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  • space
    Space 9mo ago
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    Stricken Japanese Moon mission landed on its nose
  • marsokod marsokod 9mo ago 100%

    Let's see if it wakes up once the sun hits the solar panels. Hopefully the thermal conditions do not kill it by then.

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  • Meet Helios, a new class of space tug with some real muscle
  • marsokod marsokod 9mo ago 100%

    The main difficulty for this kind of tug is finding the market. There is currently only a very limited market for such missions:

    1. If the customer is big enough, then the rocket itself can do the injection. Otherwise, you can try to find another customer on the same orbit
    2. If it is a geo satellite, then it will have electric propulsion and adding a separate stage is hard to justify just by shortened transfer time
    3. If you are planning on reusing the same tug for multiple missions, you are fighting the rocket equation. This thruster here makes it really hard, you need more efficiency.

    The market fit is quite difficult, and this requires high investment. So very hard problem until we have an actual space economy with people on the moon.

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  • Une batterie pleine est-elle plus lourde qu'une batterie vide ?
  • marsokod marsokod 9mo ago 100%

    Pour une voiture, cet effet est de l'ordre de microgrammes, donc somme toute négligeable par rapport à tout ce qui peut se passer autrement.

    A noter qu'il y a aussi des types de batteries qui ont leur masse qui varie en fonction du taux de charge, car fonctionnant en système ouvert. Typiquement les batteries métal-air sont comme ça : tu fait rouiller pu dérouiller un métal avec l'oxygène de l'air.

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  • ukraine
    Ukraine 9mo ago
    NSFW
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    WWIII will be fought with sticks and drones.
  • marsokod marsokod 9mo ago 100%

    He should have used a 2000 y.o. equipment. Romans knew how to defeat drones: https://en.wikipedia.org/wiki/Retiarius

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  • france
    France 10mo ago
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    Un homme qui "rend fière la France" - Contre Attaque
  • marsokod marsokod 10mo ago 100%

    En même temps, maintenant tu parles de ça au lieu de parler de la loi. Il a réussi son coup.

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  • United States weighs hike in tariffs on Chinese EVs
  • marsokod marsokod 10mo ago 100%

    It means that U.S. automakers find it cheaper to have their vehicles made in China and then import them in the U.S., rather than make them directly in the U.S. in the first place.

    This means that manufacturing in China is so cheap that even with the tariffs, it is more cost effective to go there. If your goal with the tariffs is to level the game, then this should not happen (no one would relocate like that unless there is a massive gain).

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  • This haircut
  • marsokod marsokod 11mo ago 100%

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