Sigh, the challenge of magnetic rail launchers and this slingatron thing is the atmosphere. Sure if you could pull a vacuum around the launch facility you might get close, but consider that the typical rocket launch gets maximum dynamic pressure as it goes supersonic on its way out of the atmosphere. This thing is going to hit that and live in that space while its going around the loop. Now compute the effect of a supersonic shockwave that is curling in on itself. The standing wave you generate it going to generate some amount of overpressure, back of the envelope, looking at four to six wavefronts collapsing on themselves as you go around the final loop of maybe 6 atmospheres?
There is a reason fish don't swim in a circle to build up speed to jump out of the water, because their own wake would stop them cold.
I wonder if someone could do a quick CFD of a payload travelling in a 7.6km/s at sea level is in the 'high hypersonic' regime (> MACH 10 closer to MACH 25) The energy you are dumping into the air at that point is going to create a pretty impressive flame front by itself. This is perhaps the coolest things about the really high speed videos of the Navy railgun project.
There is a reason fish don't swim in a circle to build up speed to jump out of the water, because their own wake would stop them cold.
I wonder if someone could do a quick CFD of a payload travelling in a 7.6km/s at sea level is in the 'high hypersonic' regime (> MACH 10 closer to MACH 25) The energy you are dumping into the air at that point is going to create a pretty impressive flame front by itself. This is perhaps the coolest things about the really high speed videos of the Navy railgun project.