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Comment by excalibur | Hacker News Reader

I hate to burst their bubble, but it's unclear how they intend to keep their bubbles from bursting prematurely. They could easily be popped by space debris, or solar flares, or projectiles launched by a rogue state, or just because that's what bubbles do.

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They are proposing putting the bubbles out at the Earth-Sun L1 point which is far outside where most of our current satellites are. Space debris is not really a concern there and I wouldn't put projectiles launched by a rogue state up there (there's plenty of closer things they would want to hit first).

There are plenty of inflatable space-based structures that have been proposed and some number of them tested (large inflatable antennas, inflatable elements to increase drag and bring space debris in, inflatable space habitats).

Granted, nothing is even within a few orders of magnitude of what they are proposing building so there are certainly still technical challenges.

Edit: Another technical challenge is the L1 lagrange point is not a stable point, so the bubbles will require some sort of control system (i.e. thrusters) to perform small orbit adjustments and remain in that spot.

I agree that space debris isn't too much of a concern if they have a very large grid of these bubbles. A percentage popping over a decade will be calculated in.

But L1 doesn't mean it won't get hit. James Webb has already been hit at its point in space.

Build a bubble machine that constantly replaces popped bubbles

I wonder if they could use a material that would "dry" or "freeze" in the shape of the bubble. Maybe harden from the UV.

If the James Webb telescope gives a reasonable indication for the amount of stuff floating around these Lagrange points, it would be popped around once per month [1]!

1. Four hits after 5 months: https://www.theatlantic.com/science/archive/2022/06/james-we...

Space debris, solar flares, and rogue states are issues that would impact other solar-shield type solutions (unlike popping).

What the bubbles do address immediately is the manufacture of something in space with a high planar surface area compared to the volume and density (for getting it into space).

Looks like they are optimizing for having the ability to easily destroy the solar shield if, for example, the cooling effect is greater than intended. I think that’s a wise precaution. If the bubbles can also be produced easily, which seems plausible, then perhaps losing some of them to harsh conditions won’t be such a big deal. With reusable rockets becoming a thing, replacing them could become more cost effective and simpler as time goes on.

Perhaps it's as simple as "blow another one" - since they propose constructing them in space one might keep the construction mechanism nearby to replace any that are prematurely popped

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