>2. mass driver, which needs to be in a vacuum Project HARP[0] disagrees. Launched a payload 110 miles (177km) into space using a 120 foot (36m) long cannon. T

>2. mass driver, which needs to be in a vacuum Project HARP[0] disagrees. Launched a payload 110 miles (177km) into space using a 120 foot (36m) long cannon. This was in the 1960s. [0] https://en.wikipedia.org/wiki/Project_HARP https://en.wikipedia.org/wiki/Project_HARP