[Crazy] Venus and Planetary-scale engines?

[Hivemind_Chan]

Well. Even if you want to capture some of it for Mars - 90-odd percent of it will still be waste CO2. 

In truth, you don't even have to accelerate the planet to make it tolereable. Just flare the gas off and siphon enough off to stabilise the flare tower against the planet's spin, while supporting the solar arrays necessary to power the flares. Build them at the poles so they're always in sun, maybe?  That's probably that *bit* less energy intensive. Along with the control comet-parking that seems to be happening on Mars to add the hydrogen.

It's a bit of a drunken idea.

I never really got how the broadleaf process on the wiki was supposed to work.

Well, first of all you can filter gas out of the atmosphere and fire it in a higher concentration or in a barrage of essentially pressurized cans. Also, Mars has less than 1% of Earth atmospheric pressure so it would still want to get lots of CO2 along with nitrogen. However, once again the main issue there is the energy. You need ridiculous quantity of solar panels, likely comparable to plating a large part of the planet in photovoltaics. It might make more sense to use huge fusion plants per every mass driver. We literally need billions of times the output of entire Earth from a population that numbers several million across entire fenspace. By the way, the reason for such high exhaust velocity is to have more or less decent ISP and thus efficiency per expelled mass of gas. If you go less you end up needing to expel more gas to reach same goal and if you go slower than Sol escape velocity you end up running into your own expelled gas eventually.

It would actually be easier with a gas giant since there is a concept of Fusion Candle which is essentially two fusion engines floating in the atmosphere, one pointing up and one pointing down. When you built hundreds of millions of them you can fly Jupiter like a spaceship, even if with terrible acceleration. It can't be used on Venus because its atmosphere doesn't consist out of fusion fuels.