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Joined 1 year ago
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Cake day: June 14th, 2023

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  • 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.










  • 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.





  • 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).





  • Can we? Yes. Should we do it right now? That’s debatable.

    The question is how much this would cost vs getting a two weeks offline every 26 months?

    These two weeks do not create any additional requirements (you already have to make sure the probes can survive for a few weeks without comms), science does not fully stops during these two weeks. And it gives an opportunity to do long duration maintenance on the ground segment.

    Frankly, there is little need to spend >$100M for such relays satellites until we actually have a permanent human presence on Mars.