[dvdkhlng]

Whether liquid or not, running the formula for kinetic energy of the counterweight, I'm getting something around 1 GJ (gigajoule) for a weight of 1 ton at 1500 m/s [1].

According to this site [2] that's equivalent to around 200 kg of TNT. Even with the counterweight being mostly water, that's quite a lot of energy to disperse. How does one evenly spread out the water to a surface the size of a football field? Would that even be enough area to prevent a shock wave being reflected back at the launch equipment?

[1] https://calculator.academy/joule-calculator/#f1p1|f2p0

[2] https://www.convert-me.com/en/convert/energy/tntkg.html?u=tn...

[aww_dang]

Perhaps it would be possible to use liquid carbon dioxide. The change from liquid to gas inside the vacuum chamber might help disperse the energy.

[mgsouth]

There's a slide in Manley's video that says gross vehicle weight is 11,000 kg. And 450 RPM @ 100 m diameter, so 2 km/s. Kinetic energy for vehicle is 22 GJ. Equivalents:

* 5 metric tons TNT

* 1/3000 Little Boy atomic bomb

* 4 barrels of crude oil (!)

* Boil 2,300 gallons of water

* 0.25 mg of matter converted to energy

* Enough energy to melt two 11,000 kg iron counterweights, with 2 GJ left over

* A magnitude 3.7 earthquake [1]

[1] https://www.volcanodiscovery.com/earthquakes/energy.html