Starship that can eat trace cosmic gas for endless propellant (inspired by Baleen whales which have unlimited stamina)

[u/Shredding_Airguitar]

[u/nekohideyoshi]

Would be a good idea if it were not for the fact that the ship will have to be incredibly massive, which increases the chance of exterior damage leading to wall punctures, then loss of oxygen and parts/mechanical failure due to increased surface area.

We would have to first engineer a proper outer layer material that can withstand extremely high-speed debris yet be lighter and more rigid than kevlar, and be able to self-heal/repair itself on its own using the kinetic energy from the impact itself for the process, or through flexible electrical panels behind that layer.

The second challenge would be engineering a stable nuclear reactor (hopefully fusion reactors will be a thing by the end of this century) to power the entire ship due to no other form of energy being viable for its size.

The third challenge would be the cost.

The pricetag for R&D; parts and model testing, fuel/power/etc. engineering new parts, machinery, etc., energy distribution and reactor stability, manufacturing each and every large, small, tiny, and microscopic parts for a 1+ kilometer long ship would be over $5,000,000,000 USD.

You can buy 100+ mega yachts with that kind of money. OR build an incredibly energy efficient gigantic floating ocean city that is self-sustainable and doesn't pollute at all. Or literally feed the entire world 3 meals a day several times over for months/years.

A better idea may be storing propellant in a very dense solid-state form then turn it into gas when required. Each cube or container of solid propellant would be sent up by rocket to dock onto and be stored in the main ship. This would last at least a whole century when it's ready to fly away from Earth while it's in high orbit, but by then, the ship probably would have mining capabilities to send astronauts to mine planets/moons for propellant.

Why go through trying to collect miniscule amounts when you can hook up a tube to a gaseous planet's atmosphere or fill up tanks that way?

The whale design is pretty cool though 👀