Q&A with Keith Gendreau, principal investigator of the first X-ray space communications experiment (members only)

Russian officials have delayed until Saturday the launch of a Proton rocket from Kazakhstan with the Spektr-RG X-ray astronomy observatory, an ambitious mission jointly developed with Germany to probe dark energy.

Watch a 4K video replay of Thursday’s Falcon 9 launch from NASA’s Kennedy Space Center in Florida.

Along with plans for a moon base, senior NASA managers also outlined work to develop nuclear power systems for use on the moon and Mars to keep astronauts, habitats and other equipment warm while providing the electricity needed for research, construction and daily operations.