[Spaceships] getting into orbit without superscience?

[Rupert]

Originally Posted by fdsa1234567890

Orion drives would also work, but they also involve deliberately setting off nuclear weapons within the atmosphere, which make them extremely impractical as a common launch system. NTRs have a similar radiation flaw and are also no better than metallic hydrogen in terms of delta-v with even less thrust.

NTRs need not leak radioactive materials.

As for the overall question - yes, getting off Earth (and similar planets) with realistic rockets is a pain. Non-super science fusion is a no-go. Antimatter Thermal using high-thrust and/or water versions is workable at very high TLs, but isnt really any better than HEDM chemical rockets. On top of that, unless antimatter production is extremely cheap any antimatter rocket is going to cost an enormous amount to run. On the plus-side, antimatter-catalysed hydrogen (or water) fuel doesn't count as a volatile system.

There is another option from Spaceships 7 - the laser rocket. It gives the same performance as an HEDM rocket, but is cheaper and doesn't involve volatile fuel. The catch is that it depends on powerful laser systems at the launch facility, so it's not a low-infrastructure option. Also, the propellant is really cheap.