The earth is basically made of nuclear waste from a star.

Disposing of radioactive waste from nuclear reactors is expensive, but burying it deep underground is cheaper than sending it into space. Sending rockets into space uses vast amounts of fuel, so would do far more environmental damage than the methods currently used.

I agree with Angela that space disposal of waste in any form is totally unpractical; too expensive, too cumbersome, too dangerous, unless you have a crash-proof launching system.

I agree with her that burial underground is cheaper and safer.

I would just like to remark that still cheaper and safer would be storage above ground or in shallow repositories that permit us to recover valuable materials as required.

The best disposal for radioactive isotopes is using them up.