Snapshots from Atlas 5 launch

NASA managers Thursday cleared the $1.5 billion Parker Solar Probe for launch early Saturday on a daring mission to “touch the sun,” repeatedly flying through its outer atmosphere to find out why the blazing corona is millions of degrees hotter than our star’s visible surface.

Boeing has reshuffled a sequence of test flights planned for the company’s CST-100 Starliner capsule after stuck valves inside a test version of the ship’s service module caused a fuel spill in June, delaying the commercial spacecraft’s first unpiloted orbital demo mission until late this year or early 2019, and moving back the first crew launch to mid-2019, a company official said Wednesday.

An ultra-sensitive camera on NASA’s Parker Solar Probe caught an ethereal glimpse of the night side of Venus during a flyby last year, revealing terrain seen through the thick haze of the planet’s atmosphere.