Live coverage: Space station crew back on Earth

NASA has declared assembly complete on the core stage for the first Space Launch System heavy-lift rocket in New Orleans, signaling a long-awaited transition from manufacturing to testing as the core stage is set to move to the nearby Stennis Space Center in Mississippi for a hold-down firing next year of its four shuttle-era main engines.

Blue Origin has partnered with Lockheed Martin and Northrop Grumman to build elements of the company’s human-rated lunar lander, and Draper will lead development of the lander’s avionics and guidance systems, with an aim to be ready to land a crew on the moon by 2024, company founder Jeff Bezos announced Tuesday.

Scientists working on a new lightning detection instrument mounted outside the International Space Station said Tuesday they expect little effect on the sensor’s performance from possible contamination from the upper stage of a SpaceX Falcon 9 rocket that launched it into orbit April 2.