Ignoring air resistance (which you really shouldn’t, especially not when you’re talking in the thousands of meters per second), you need to launch something at around 1400m/s get it to 100km high “suborbital”. You need to launch it over 8000m/s to get it into orbit. In 2022, Spinlaunch were getting to ~450m/s, but that was two years ago and maybe they’ve improved.

Now, 1400m/s is in the neighborhood of a tank cannon, which is doable. But 8000m/s on the surface, or about 29.000 kph, is about mach 23. That’s like running smack into a brick wall of air, every millisecond. And in reality, you need MUCH more speed, because you’re shooting at a much shallower angle, so there’s a lot more air to get through.

If you really believe that this will work anytime in the next decade, and that it doesn’t need a rocket to circularize the projectile’s orbit, I have a bridge to sell you.

So the article says they’ve done ten successful launches.

What does that actually mean? It’s real short on details.

They’ve successfully put ten payloads in orbit? Or what?

Iraq nearly constructed the world’s largest gun this way.

The US spent a few decades pursuing enormous cannons as a space launch platform. As in, rocket equation be damned, give something high speed and high altitude by sticking it in a tube atop a dump truck’s worth of gun powder. The main guy was really just into cannons. So when that project ended, he went into private industry as the Space Research Corporation, which unsurprisingly wound up making guns for normal gun-related activities. Ironically those too were slowly made obsolete by rockets. Unable to give up on big guns, he sold arms to apartheid South Africa, and when he got out of jail for that, he sold arms to Saddam Hussein.

And when I say arms I mean 150m long cannons permanently pointed at Israel. You would say he died under mysterious circumstances, if you are the sort of person who thinks Columbo is a whodunnit.

Anyway, the gun segments were manufactured in Yorkshire by a respectable major forge provided with final blueprints. British authorities became suspicious of the “plumbing equipment” because it was rifled.

SpinLaunch’s approach seems closer to a sling than to a catapult or trebuchet.

They have been trying to find somewhere to build their next scale up for a few years now.

Either way, it’s good that the article spends some space on the possible uses of satellites. Otherwise people could get the impression it’s all for fun, or something like that.