Kinetic orbital launchers

Rockets are one way to get things into orbit – but there's a growing number of alternatives in development that aim to do things significantly cheaper, by accelerating launch vehicles to hypersonic speeds on the ground, and either flinging or shooting them skyward, replacing first-stage launch rockets with a variety of interesting high-energy alternatives.

Astronomy

Longshot targets $10/kg launch costs with Nazi uber-cannon on steroids

Rockets are expensive, so a number of kinetic launch startups are working on ways to simply yeet payloads into orbit and bring costs down. This one's very fun – a six-mile-long concrete cannon that'll squeeze launch vehicles to Mach 30 in one second.