Photos: Predawn launch of Atlas 5

Scientists eager for answers to long-standing questions about the geology of Mars will get a lift Saturday with the blastoff from California of an Atlas 5 rocket with NASA’s InSight mission, a robotic landing craft that will take the pulse and temperature of the red planet.

Towering more than 30 stories tall, the mobile gantry structure at the Delta 4-Heavy rocket’s launch pad at Cape Canaveral was wheeled into position for liftoff of the triple-core launcher Thursday with a classified payload for the National Reconnaissance Office.

A collection chamber that could contain more than 2 pounds of samples gathered from an asteroid in deep space last week has been sealed inside of a return capsule on NASA’s OSIRIS-REx spacecraft to bring the extraterrestrial specimens back to Earth in 2023, officials announced Thursday.