Q&A with Elon Musk, founder and CEO of SpaceX (members only)

A European-built Ariane 5 rocket rolled out to a launch pad in the South American jungle Wednesday with a pair of commercial television broadcast satellites for AT&T and Eutelsat, setting the stage for liftoff Thursday evening.

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.

Assuming SpaceX’s plans come to fruition, a Falcon 9 flight from Cape Canaveral on Sunday will end with a vertical rocket-assisted landing at an abandoned Cold War-era launch facility a few miles away.