Why We Don't Shoot Earth's Garbage into the Sun (2019)

This is like asking why we don't use the Large Hadron Collider to make toast, and then answering by going into detail about how tricky it would be to coax the LHC into making toast of acceptable quality.

We don't do it because you don't use hyper-expensive mega-engineering to solve mundane problems with easy solutions, like "where do I put my banana peel".

How can this really be a question? It's obvious that it's expensive to launch things in rockets: that has very little to do with the orbital mechanics nerding out of "actually you can't just fall into the sun, you need a surprising amount of delta-v" and everything to do with the cost of building skyscraper-sized shiny single-use machines that are 90 parts fuel, 9 parts expensively machined metal, and 1 part "garbage" payload.

In other words, launching garbage in any kind of rocket is incredibly inefficient compared to dumping it on the ground or into the ocean, so the consideration of "would it be cheaper to send it to the Sun or Jupiter" doesn't really come into question.

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

There might be a slightly modified version of this question which might actually make sense: "Why we don't shoot nuclear waste into the Sun".

Surely, the cost of storing that type of waste here (on Earth) is very expensive, both from economical perspective and from risk management perspective. It could be very interesting to compare the costs of sending 1kg of nuclear waste into the sun (or out of our solar system, if that makes it cheaper) compared to storing 1kg of nuclear waste anywhere here on Earth, + adding the cost of the infrastructure that is required to actually store and preserve that waste, + adding the cost of people that are required to protect that infrastructure (a facility of some sort), etc...

Even if we had a cheap, reliable way of sending garbage to the sun I am skeptical of the idea that the garbage would just magically disappear. It would probably accumulate into another problem later down the road.

Even if it would be cheap to launch junk into space, we'd still have to solve some of the same issues we'd have to solve now as well: collection. To put it on a rocket, you'd have to collect the junk first, which we currently don't do well (except in a couple of countries). Nuclear waste is well collected though, I'd say.

Breaking that down to it's constituent protons and neutrons would make it harmless right? Though I have no idea how much energy that would cost, only that the lower bound is probably well above what is reasonable.

If it ever gets that far, I'd rather see it launched in an orbit around the sun than into the sun, the material could still be useful later

One alternative could be instead of shooting surface based garbage into the Sun can we not not just sequester the thousands of dead/decommissioned/dangerous human launched objects orbiting around our planet and launch them towards Sun?

Cheaper in energy to burn it or bury it, than to put it into orbit, and then accelerate it enough to fall into the sun. Yes, accelerate.

Simple. The goal is to get rid of trash. This accomplishes the goal but others ways accomplish the same goal at much lower expense.

why don't we build a chimney up to space and release all that co2 into space?

Humanity in a nutshell: "Why change our polluting ways when we could just blast our junk into space?"

Why do we think we have the right to blast our junk into space?

Who does the cleanup when a rocket explodes after launch and covers Florida/Guyana/Khazakstan in used diapers and hypodermic needles?

If only we could shoot all those rocket exhaust fumes into the Sun.

TLDR: It takes a ton of fuel to slow down enough to get a payload to fall into the sun.

Because 1 kg to orbit costs 5000 USD.