Hyperloop is a proposed mode of passenger and freight transportation that would propel capsule-like vehicles at over 700 miles per hour through low-pressure tubes. It was conceptualized by Elon Musk as a faster, safer, lower-cost alternative to existing surface transportation options like trains, buses and cars. The key components are tubes made of steel to form a low-pressure environment, capsules containing passengers and linear electric motors for propulsion, and air compressors to create air bearings for levitation. Several companies are currently developing Hyperloop systems, with the first successful test of passengers aboard a capsule achieved by Virgin Hyperloop.