Nukes.[1]
Lasers. [2] (Doesn't work, yet.)
Balloons.[3] (Floating megastructures in the upper atmosphere is hard.)
Giant cannon. [4] (Downside - huge g-forces on payload.)
Extra fun with angular momentum.[5] (Even higher g-forces.)
Exotic materials[6], with novel failure modes.[7]
Humanity has not been idle when it comes to imagining alternate ways to get to orbit. But so far, the only one that works in practice is rockets.
Humanity has not been idle when it comes to imagining alternate ways to get to orbit. But so far, the only one that works in practice is rockets.
1. https://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propu...
2. https://en.wikipedia.org/wiki/Laser_propulsion
3. https://en.wikipedia.org/wiki/JP_Aerospace#Airship_to_Orbit_...
4. https://en.wikipedia.org/wiki/Space_gun
5. https://en.wikipedia.org/wiki/SpinLaunch
6. https://en.wikipedia.org/wiki/Space_elevator
7. https://www.gassend.net/publications/FateOfABrokenSpaceEleva...