Just like a spacecraft entering the Earth’s atmosphere, friction with air molecules would slow, and catastrophically heat up any object without a heat shield, that was launched at orbital velocity from a rail gun. The incredible acceleration (“G forces”) from the launch would also crush any passengers. There have been studies to launch canisters of fuel or water (that don’t care about G forces) from a rail gun located on tall mountains near the equator. Mt. Kilimanjaro, at an altitude of 19,000 feet, would be a excellent site due to the much thinner atmosphere at the summit. Launch speeds would still have to be limited to Mach 6 or 7, so a solid rocket motor would have to be attached to the payload container to get it up to orbital velocity.