Photos: Delta 4-Heavy launch as seen from press site

An engine failure that cut short the first test flight of Virgin Orbit’s air-dropped LauncherOne rocket in May was caused by a faulty propellant feed line, the company’s CEO said this week.

A Soyuz rocket arrived at a historic launch pad in Kazakhstan on Tuesday, where ground crews lifted the booster vertical to begin final preparations for liftoff Thursday with two Americans and one Russian heading for the International Space Station.

SpaceX launched a classified payload for the National Reconnaissance Office on Monday after a first stage sensor problem halted a countdown Sunday. Liftoff from launch pad 39A at NASA’s Kennedy Space Center in Florida occurred at 7:15 a.m. EDT (1115 GMT), and the first stage landed at nearby Cape Canaveral around nine minutes later. The upper stage’s flight entered a pre-planned news blackout a few minutes after launch.