# Time taken to spin venus with mass drivers

So, returning (once more) to the prospect of the terraformation of Venus, I have finally come up with a method of spinning this rock to something approaching 24 hours which (cross fingers) might work for a sub-kardashev civilisation.

A huge mass driver is built along venus’ equator. At base of this driver are engines that extract carbon from the atmosphere (forget about where the oxygen goes for now). The carbon is compacted and shot from mass driver into space. Each launch has a “knock-back” effect which slightly increases venus’ rotation. All this is being powered by solar farms placed between venus and mercury.

Some fact figures:

• One payload is launched every second
• The mass driver is 6,000 miles long
• The payloads are launched at about 23,200 mph, or 10.37 km/s

How long would it take for this method to speed up venus’ rotation to 24 hours?

• Are you sure than slingshotting a one-tonne projectile at cosmic speed inside the atmosphere of Venus will result in something other than a big explosion? Feb 7 at 12:29
• @AlexP if the mass driver is made like a proposed "space tram" device, it can well be above the atmosphere. Feb 7 at 12:36
• Why do you want to spin the place up? Place a big starshade at L1, use it to freeze out the atmosphere, export, pave over or process the ice. The starshade can double as a solar power plant beaming power home. After the surface is ready, set up L4 and L5 mirrors as well as orbital ones. This lets you set the daylength. Move an asteroid into orbit and create a plasma ring from it, then run a current through it. Out of the box magnetosphere. Feb 7 at 13:18
• I think you overestimate the mass of the atmosphere relative to Venus. Also, if your goal is terraforming, you kind of need that carbon for biomass... Feb 7 at 15:18
• @TheDyingOfLight It won't, unless the starshade is charged in some way. Anyway the worst it can do is to very slowly remove the atmosphere by heating up the outermost parts of it. Solar particles are far too low in energy to reach the ground through an atmosphere of 1 bar.
– Karl
Feb 8 at 20:51