SpaceX apparently isn't discouraged by an explosion last week during an engine test at the company's facility in McGregor, Texas. A test of a device called the Raptor engine resulted in a fire followed by an enormous fireball around 4 p.m. Thursday. SpaceX describes the Raptor as a reusable methane-oxygen engine that powers the Starship system. The company announced the next day that Starship's fourth test may happen on June 5th if they get regulatory approval.