Live coverage: Atlas 5 countdown and launch journal

A United Launch Alliance Delta 4-Heavy rocket, crowned by a solid-fueled upper stage kick motor, will send NASA’s Parker Solar Probe on a speedy voyage through the inner solar system following liftoff from Cape Canaveral.

Building on a mission canceled last year, NASA is developing a mobile robot named VIPER for launch in 2022 to scout for water ice at the moon’s south pole, the same region where the agency aims to land astronauts by 2024.

A new image captured minutes before NASA’s New Horizons probe zipped by a rocky object in the Kuiper Belt on New Year’s Day shows the dual-lobed world — nicknamed Ultima Thule — is covered with intriguing fractures and a large crater-like depression that could provide clues about the early history of the solar system.