Watch our interview with two International Space Station astronauts

A prototype for SpaceX’s Starship vehicle imploded during a pressurization test at the company’s facility in South Texas Friday night, an event captured on video by local residents.

Space station commander Peggy Whitson and astronaut Jack Fischer are set for a two-and-a-half hour spacewalk Tuesday, a quickly-planned excursion to replace a recently installed external computer that failed Saturday.

Four European navigation satellites fastened on top of an Ariane 5 rocket lifted off from Kourou, French Guiana, at 1836:07 GMT (1:36:07 p.m. EST) Tuesday to propel the Galileo navigation network closer to global service. The Ariane 5’s upper stage delivered the spacecraft to a circular orbit more than 14,000 miles above Earth around four hours after launch.