The Boring Company plans to begin full-scale testing of hyperloop, a still theoretical transportation system that sends passengers through a tube at speeds in excess of 600 miles per hour.

Less than a week after The Boring Company raised $675 million at a $5.7 billion valuation, Musk announced on Monday that the company would attempt to build a working hyperloop.

The idea of hyperloop was first floated by Musk in a white paper. Musk encouraged others to take on the challenge by sharing the basic engineering plans and not personally pursuing the project. The hyperloop competition was hosted by Musk's company, SpaceX, between 2015 and 2019. A prototype hyperloop test track was built in October of 2016 There are no commercial operating versions of the proposed transport systems deployed by other companies.

Until the past few days, Musk's public commentary and activity around hyperloop had seemed to fade, with the exception of the annual contest. From the hyperloop Pod to the tunnel. The Not-a-Boring Competition was hosted by The Boring Company. Tum won the overall competition. Tum has won before.

Teams are invited to design, build and race their own tunneling machines at a factory in Texas when the Boring competition returns in 2022. Teams will compete in four categories, including the fastest to complete the tunnel, design, accuracy and tightest turn.

The idea of hyperloop has attracted many people. Despite years of effort and some progress, there is not a working example of the system in the world.