World Solve — A living repository of problems worth solving.

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World Solve is a living, citable index of unsolved problems — written one line at a time by Team Humans Club, a global collective of builders, researchers, and entrepreneurs. We do not solve the problems here. We Democratize Innovation.

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In-orbit propellant transfer between moving spacecraft in microgravity is unstable.

open Global / Unspecified, Global

Without gravity, liquid fuels float randomly inside tanks, causing air bubbles to enter fuel pumps during orbital refilling. Scalable fluid-settling systems and bladderless zero-g fuel transfer ports must be built.

transfer orbit propellant between moving science-space

WS02146 · Logged by Ian Patel on 2026-07-22T08:00:00Z · Horizon: 2027 · Working on: 0

Citation ID: WS02146 Title: In-orbit propellant transfer between moving spacecraft in microgravity is unstable. URL: https://worldsolve.org/index.php?api=problem&id=2146

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2165 public problems
2165 open challenges
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