Weird, I didn't find the term "delta-V" anywhere in the article. Most on HN probably know this but delta-V is the change in velocity required to reach some goal.
Fun fact: it requires more delta-V to hit the Sun than it does to leave the Solar System. For giggles, here's a delta-V map of the Solar System [1].
Of course there's the issue of getting things off Earth to begin with but even if you take that as (economically) solvable the detla-V problem remains.
Site note: there are lots of proposals for cheaper LEO solutions (in $/kg terms). Probably the most famous is the space elevator but that's actually a bad solution for many reasons and possibly not even feasible since we'd have to invent a material strong enough.
What could well reduce that from $thousands/kg to <$10/kg is an orbital ring [2] (and check out the rest of his Uplift series if you're interested at the other options). The beauty of this is it doesn't require any magical material (cough graphene cough) and requires no new physics. It's largely just an engineering problem. Granted it's a massive engineering problem.
To be fair, the article does mention how much energy you'd have to lose but it strikes me as just being so much easier to explain in delta-V terms.
[1]: https://external-preview.redd.it/U5iH7huE5qKth7ZFvipXt8vzaFO...
[2]: https://www.youtube.com/watch?v=LMbI6sk-62E
Fun fact: it requires more delta-V to hit the Sun than it does to leave the Solar System. For giggles, here's a delta-V map of the Solar System [1].
Of course there's the issue of getting things off Earth to begin with but even if you take that as (economically) solvable the detla-V problem remains.
Site note: there are lots of proposals for cheaper LEO solutions (in $/kg terms). Probably the most famous is the space elevator but that's actually a bad solution for many reasons and possibly not even feasible since we'd have to invent a material strong enough.
What could well reduce that from $thousands/kg to <$10/kg is an orbital ring [2] (and check out the rest of his Uplift series if you're interested at the other options). The beauty of this is it doesn't require any magical material (cough graphene cough) and requires no new physics. It's largely just an engineering problem. Granted it's a massive engineering problem.
To be fair, the article does mention how much energy you'd have to lose but it strikes me as just being so much easier to explain in delta-V terms.
[1]: https://external-preview.redd.it/U5iH7huE5qKth7ZFvipXt8vzaFO...
[2]: https://www.youtube.com/watch?v=LMbI6sk-62E