Live coverage: Kennedy Space Center to reopen Friday

A hydrogen-fueled rocket engine ignited with a bone-rattling sonic wave Thursday at NASA’s test facility in Southern Mississippi, throttling up to more than a half-million pounds of thrust to verify upgrades to the space shuttle’s main engines can power a humongous new launcher off the planet.

Gearing up for a predawn blastoff July 31, launch crews have positioned a Delta 4-Heavy rocket in the starting blocks on a seaside launch complex at Cape Canaveral as engineers inside a tightly-controlled clean room a few miles away put the final touches on a NASA probe that will travel closer to the sun than any mission before.

Fans of classical mythology and the fictional Star Trek universe can vote for two new candidates as the name of United Launch Alliance’s next generation rocket, with Vulcan and Zeus joining three other options in an online poll revealed earlier this week.